domestic water end use study: an investigation of the

Domestic Water End Use Study: An Investigation of the WaterSavings Attributed to Demand Management Strategies andDual Reticulated Recycled Water Systems

Author

Willis, Rachelle M

Published

2011

Thesis Type

Thesis (PhD Doctorate)

School

Griffith School of Engineering

DOI

https://doi.org/10.25904/1912/916

Copyright Statement

The author owns the copyright in this thesis, unless stated otherwise.

Downloaded from

http://hdl.handle.net/10072/367759

Griffith Research Online

https://research-repository.griffith.edu.au

DOMESTIC WATER END USE STUDY: AN

INVESTIGATION OF THE WATER SAVINGS ATTRIBUTED TO DEMAND MANAGEMENT STRATEGIES AND DUAL RETICULATED

RECYCLED WATER SYSTEMS

RACHELLE M. WILLIS B.Eng (Hons 1)., Grad Cert. Research Mgmt.

GRIFFITH SCHOOL OF ENGINEERING

SCIENCE, ENVIRONMENT, ENGINEERING AND TECHNOLOGY GRIFFITH UNIVERSITY

SUBMITTED IN FULFILMENT OF THE REQUIREMENTS OF THE DEGREE OF DOCTOR OF PHILOSOPHY

AUGUST 2010

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Acknowledgements

It has been quite a pleasure undertaking this PhD due to the positive and supportive people who

have been involved. First and foremost, I would like to sincerely thank my Griffith University

supervisors, Dr Rodney Stewart and Dr Philip Williams, and my Gold Coast Water manager,

Bill Capati, for their encouragement and support. Dr Stewart’s unrelenting time, guidance,

mentoring and energy significantly enabled such an extensive body of work to be undertaken. I

am very grateful to have had such an excellent supervisor. Bill Capati’s drive, support and

enthusiasm significantly facilitated my progress and ensured the wide distribution and

promotion of this body of work. Without Bill’s support, this work could not have occurred nor

would it have been so applicable for practical industrial application. Dr Williams has also

provided invaluable guidance throughout my course of study.

I would especially like to thank the Australia Research Council (ARC) for funding my APAI

scholarship and also the industry partners involved in the ARC Linkage Grant, being Gold

Coast Water, the Institute for Sustainable Futures, Wide Bay Water and the Queensland Water

Directorate. Sincere thanks to the Griffith University Centre for Infrastructure Engineering and

Management for my placement, and Gold Coast Water for situating me within the organisation

for the entirety of my industry-based PhD. Thanks also to all the kind Gold Coast residents that

participated in this research, it would not have been possible without you all kindly offering

your valuable time.

I am also indebted to many Griffith University and Gold Coast Water colleagues and friends. To

Dr Kriengsak Panuwatwanich for all his assistance, input and expertise with paper publications,

especially with statistical analysis. Thanks to Lisa Rutherford, Sarah Jones and Scott Emmonds

(GCW - Demand Management) who have all significantly contributed to the development and

success of the Gold Coast Watersaver End Use Project through project management, day-to-

day support and encouragement. To the GCW ‘Shed Crew’ who brighten up every work day at

GCW through excellence conversion, friendship, coffee run’s and general camaraderie. To

fellow PhD candidate, Tracy Britton and all the Griffith University masters and undergraduates

that assisted me through their thesis and IAP projects, thank you. It has been a pleasure working

with you all.

I also wish to thank all my dear friends who make up our beautiful ‘Brissy Family’. Each and

every one of you has provided me with amazing support, superb friendship and very welcome

distractions throughout this journey. To the wonderful girlfriends who have always been there

walking alongside me, providing friendship and an understanding that never fails and will

Domestic End Use Investigation: WDM and Dual Reticulation, R.M. Willis (2010)

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always remain strong. Such excellent friends are rare indeed, and while you are now distributed

far and wide across this beautiful planet, you remain in my thoughts daily. I look forward to

future adventures with all of you.

To my dearest Mum, Dad and brother, who have supported me from the start and remain the

most amazing family one could wish for. Thank you for your unrelenting love, friendship and

encouragement throughout my life and for the rest of it. I could not imagine a better family. Last

but by no means least, to my wonderful partner Ryan. You have been my backbone for so many

years providing unconditional love, friendship, patience, laughter and encouragement when I

have needed it most and you have seen me through the entirety of this exhausting journey.

Thank you for making everyday a better one, I could not have completed this without you.

As a final note, I would like to dedicate this work to Annette Atwood, a beautiful friend who is

dearly missed. Your aspirations, dreams and memories are carried with me. Water is

fundamental for life. Misuse and over consumption of this precious resource will only result in

ruin. One can only hope that this research adds some of the much needed empirical support and

inspires further sustainable management and consumption of our most precious resource.

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List of Publications

The following papers were produced to disseminate concepts and results from the work

undertaken by the author during the course of this Ph.D. research study.

Journal Publications

1. Willis, R.M., Stewart, R.A., Williams, P.R., Hacker, C.H., Emmonds, S.C. & Capati, G.

(2011) Residential potable and recycled water end uses in a dual reticulated supply system.

Journal of Desalination. Vol 273:1-3, May 2011, pp. 201-211. DOI:

10.1016/j.desal.2011.01.022 (In-press, accepted January 2011). [Chapter 10]

2. Willis, R.M., Stewart, R.A., Panuwatwanich, K., Williams, P. & Hollingsworth, A. (2011)

Quantifying the influence of environmental and water conservation attitudes on household

end use water consumption. Journal of Environmental Management (In press, accepted

March 2011). [Chapter 7]

3. Stewart, R.A., Willis, R.M., Giurco, D., Panuwatwanich, K. & Capati, G. (2010) Web-

based knowledge management system: linking smart metering to the future of urban water

planning. Australian Planning, Vol. 47:2, June 2010, pp. 67-74. DOI:

10.1080/07293681003767769 (In-press, accepted April 2010).

4. Willis, R1., Stewart, R.A., Panuwatwanich, K., Jones, S. & Kyrakides, A. (2010) Alarming

visual display monitors affecting shower end use water and energy conservation in

Australian residential households. Journal of Resources, Conservation and Recycling, Vol.

54:12, October 2010, pp. 1117-1127, DOI: 10.1016/j.resconrec.2010.03.004 (In-press,

accepted March 2010). [Chapter 8]

5. Willis, R.M., Stewart, R.A, Giurco, D., Talebpour, M. R., Mousavinejad, A. (2011) End

use water consumption in households: impact of socio-demographic factors and efficient

devices. Journal of Cleaner Production (under review, submitted October 2010). [Chapter

6]

1 Awarded IWA Grand Award for Research Excellence: Sustainable Urban Water Management


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6. Willis, R.M., Stewart, R.A. & Emmonds, S. (2010) Pimpama-Coomera dual reticulation

end use study: pre-commission baseline, context and post-commission end use prediction.

IWA Water, Science and Technology: Water Supply, Vol 10:3, pp. 302-314, DOI:

10.2166/ws.2010.104 (In-press, accepted January 2010). [Chapter 9]

7. Willis, R., Stewart. R.A., Panuwatwanich, K., Capati, B. & Giurco, D. (2009) Gold Coast

Domestic Water End Use Study. Water Journal of Australian Water Association, Vol 36:6,

pp. 79-85(In-press, accepted August 2009). [Chapter 5]

Conference Papers

1. Willis, R., Stewart, R., Chen, L. & Rutherford, L. (2009) Water end use consumption

analysis into Gold Coast dual reticulated households: Pilot. Australia’s National Water

Conference and Exhibition: OzWater'09, Melbourne Convention & Exhibition Centre,

Melbourne, 16-18 March 2009. Melbourne.

2. Willis, R., Stewart, R., Capati, B. (2009) Closing the loop on water planning: an integrated

smart metering and web-based knowledge management system approach. 10th IWA

Conference on Instrumentation Control and Automation, 15-17 June 2009. Cairns,

Australia2.

3. Willis, R., Stewart, R., Panuwatwanich, K. & Williams, P. (2009) Influence of household

socioeconomic region and resident type on end use water consumption levels. 2nd

International Conference on Water Economics, Statistics, and Finance, International Water

Association, 3-5 July 2009. Alexandroupolis, Greece.

4. Willis, R., Stewart, R. & Emmonds, S. (2009) Pimpama-Coomera Dual Reticulation End

Use Study: Baseline Situational Context and Post-Commission End Use Prediction. 7th

IWA World Congress on Water Reclamation and Reuse, 21-24 September 2009. Brisbane,

Australia3.

5. Willis, R., Stewart, R., Talebpour, M. R., Mousavinejad, A. & Jones, S. (2009) Influence of

Demographics and Behaviour on the Water Saving Potential of Efficient Fixtures. 5th IWA

Specialist Conference on Efficient Use and Management of Urban Water. 25-28 October

2009. Sydney, Australia.

2 Awarded ‘Best Poster’ International Water Association 3 Awarded ‘Best Paper Presented by a Young Water Professional’ International Water Association

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Abstract

Rainfall patterns in Australia have altered in recent decades, with trends of lower rainfall across

densely populated southern areas recorded. Such drastic changes in climatic conditions have

triggered a re-evaluation of traditional techniques and methods to manage urban water demand

and supply. Throughout the nation, movement towards sustainable urban water resource

management is becoming the norm. This water security method involves the planning and

implementation of a range of water supply, demand management and source substitution

initiatives to meet short term demand and provide long term supply security to urban

populations. Examples of these initiatives include: desalinated potable water, water restrictions,

water efficient fixtures, awareness campaigns, dual reticulated recycled water supply and on-lot

rainwater tanks. In the urban water planning and management industry, these initiatives are

relied upon to provide alternative potable supply types and reduce average daily water demand.

Predictions and estimations of the potable water savings attributed to water demand

management and source substitution measures are often assumed and included in city-wide

planning and forecasting documentation. These water demand management and source

substitution measures play a significant part in meeting projected city future demand however,

these initiatives are all too often planned and implemented without validation of actual potable

water savings. Some examples of measuring potential savings through bulk demand reductions

are documented although this often involves further application of estimations for other

influencing factors such as climate, household makeup and leakage. Understanding the actual

potable water savings attributed to water demand management and source substitution

initiatives requires the application of end use water consumption monitoring due to the need to

establish the point of source savings related to these measures.

Significant residential end use water consumption studies have been carried out in Perth and

Melbourne in Australia and, in the United States of America. These investigations have

ascertained the unique consumption behaviours of residents in the monitored location and

presented some examples of measuring water savings attributed to water efficient devices. The

variation in end use consumption between the studies and the useful application of results from

these investigations has prompted the encouragement of further research in this field. To date,

no statistically significant end use water consumption study has occurred in the state of

Queensland, Australia. In response to the current gaps in the body of knowledge, this research

focused on determining end use water consumption and investigating the end use savings

attributed to water efficient fixtures, resource consumption awareness devices, and dual

reticulated recycled water supply regions in the Gold Coast, Australia. This study also


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investigated the relationship between attitudes towards the environment and water conservation

and the impact that this had on end use water consumption. The research also developed end use

diurnal patterns of consumption for both single and dual reticulated regions on the Gold Coast.

A mixed methods approach was adopted to achieve the above mentioned research objectives.

This explanatory mixed methodology included: the development and application of natural

science research, quantitative survey questionnaires, numerous statistical analysis techniques,

experimental analysis, qualitative behavioural methods and software development. These

methods resulted in the experimental measurement of end use water consumption via high

resolution smart metering technology, at various times over a two year period, which included

before and after the introduction of resource consumption awareness shower monitors and, pre-

and post-commissioning of recycled water to the Pimpama Coomera dual reticulated region.

Water stock surveys and behavioural interviews assisted in developing end use water

consumption patterns and behaviours within homes. Questionnaire surveys determined socio-

demographic characteristics of the research sample and allowed for the development of

constructs to measure environmental and water conservation attitudes.

Due to the array of objectives, methods, data types and results, this thesis has been structured

around significant refereed journal publications produced during the course of the PhD study.

This allowed for unique elements and objectives to be explored and presented through peer-

reviewed journal papers. Two themes emerged from the research being: (1) influence of demand

management on water end uses; (2) and end uses of dual reticulated recycled water supply

schemes. The first theme covered: domestic end use water consumption in the Gold Coast; an

investigation into the impact of socio-demographic and water efficient devices on end use water

consumption; analysis of the effect of environmental and water conservation attitudes on end

use water consumption; and, an experiment to determine the effective water savings attributed

to a resource consumption awareness shower monitor device.

Showering was found to be the highest indoor end use consumer in single detached residential

households. Clothes washing was the next highest followed by tap and toilet use. Leak, bathtub

and dishwasher categories all had relatively small consumption volumes. When irrigation was

included in total end use consumption breakdowns, it was situated fourth after showering,

clothes washing and tap use. The effectiveness of water efficient shower heads and clothes

washing devices was empirically explored with payback periods of less than half a year and 6.5

years determined respectively. Irrigation was halved in properties with rainwater tanks. The

effect of attitudes on total and discretionary end use water consumption was very apparent.

Residents with very high concern for the environment and water conservation and awareness

consumed significantly less total (128.2 L/p/d) and discretionary end use water than those with

Abstract

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moderate concern (169.0 L/p/d). This demonstrated the importance of instilling positive

environmental and water conservation awareness to consumers due to the significant water

savings apparent from such attitudes. The experimental study exploring the effectiveness of a

resource consumption awareness shower monitor revealed significant reductions in shower

volumes, durations and flow rates.

The second phase of research was the dual reticulated recycled water study in the Pimpama

Coomera Waterfuture Master Plan region. This involved the measurement of end use water

consumption pre-commissioning of recycled water, the prediction of consumption post-

commissioning and the monitoring of actual post-commissioning water end use, along with the

development of diurnal patterns of demand. Pre-commissioning recycled water end use was low

due to irrigation volumes being minimal. A predictive uptake model was developed based on

influencing factors reported in the literature including water restriction levels, climatic

influences, price and the uptake of recycled water in other dual reticulated schemes. The

predicted most likely uptake post-commissioning of recycled water to the Pimpama Coomera

region was determined to be 53 L/p/d or 30.5% of total end use. End use water consumption

was monitored post-commissioning in both a low and high consumption period, which allowed

for the formulation of average recycled water end use. Average recycled water uptake in the

Pimpama Coomera region was recorded as 59.1 L/p/d or 32.2% of total end use water

consumption. Of this recycled water use, the end uses of irrigation, toilet and leakage were 28.9,

27.5 and 2.7 L/p/d respectively. Potable water consumption in the dual reticulated region was

124.5 L/p/d or 67.8%. The end use post-commissioning recycled water consumption was almost

the same as that predicted pre-commissioning, irrigation consumption being particularly close.

End use diurnal patterns of consumption varied significantly between the single and dual

reticulated regions with the potable peak hour demand being almost twice as high in the single

reticulated region when compared to the dual reticulated region. This finding demonstrates the

need to undertake validation research to determine the effectiveness of unique source

substitution supply schemes.

The data and results from this extensive investigation into end use water consumption for single

and dual reticulated households in the Gold Coast, along with the measurement of end use water

consumption savings related to water efficient devices, educational prompt devices,

environmental and water conservation attitudes and the application of dual reticulation for

residential use, are highly applicable for industry and academia. This research significantly

contributes to the urban water resource planning and management field through the

determination of empirical data on a range of end use, water demand management and source

substitution initiatives. The results from the study can be readily applied to improve urban water

planning and management and the application of sustainable urban water resource management.

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Table of Contents DECLARATION OF ORIGINALITY.......................................................................................I

ACKNOWLEDGEMENTS......................................................................................................III

LIST OF PUBLICATIONS....................................................................................................... V

ABSTRACT ............................................................................................................................. VII

TABLE OF CONTENTS..........................................................................................................XI

LIST OF TABLES .................................................................................................................. XX

LIST OF FIGURES ............................................................................................................. XXII

LIST OF ACRONYMS.........................................................................................................XXV

CHAPTER 1 ................................................................................................................................ 1

INTRODUCTION....................................................................................................................... 1

1.1 Research Background.................................................................................................................... 1

1.2 Research Objectives and Scope .................................................................................................... 3

1.3 Research Method Overview .......................................................................................................... 4

1.3.1 Knowledge acquisition ......................................................................................................... 6

1.3.2 End use baseline and water demand management ................................................................ 6

1.3.3 Dual reticulated recycled water ............................................................................................ 6

1.4 Thesis Layout ................................................................................................................................. 7

1.5 References..................................................................................................................................... 10

CHAPTER 2 .............................................................................................................................. 13

LITERATURE REVIEW......................................................................................................... 13

2.1 The Water Conditions in Australia ............................................................................................ 14


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2.2 Water Consumption and Demand Forecasting in Urban Australia........................................ 15

2.3 Gold Coast City’s Solution to the Water Crisis......................................................................... 17

2.4 Integrated Urban Water Resource Management...................................................................... 19

2.4.1 Supply sources.................................................................................................................... 20

2.4.2 Demand management ......................................................................................................... 22

2.4.3 Source substitution.............................................................................................................. 23

2.5 Water Demand Management ...................................................................................................... 23

2.5.1 Water metering ................................................................................................................... 24

2.5.2 Enforcement........................................................................................................................ 25

2.5.3 Water pricing ...................................................................................................................... 26

2.5.4 Engineered water efficient devices ..................................................................................... 27

2.5.5 Education and awareness .................................................................................................... 30

2.6 Source Substitution with Recycled Water ................................................................................. 31

2.6.1 Dual reticulation ................................................................................................................. 32

2.6.2 The Pimpama Coomera Waterfuture Master Plan .............................................................. 32

2.6.3 Overview of dual reticulated schemes in Australia............................................................. 34

2.7 Advanced Water Consumption Monitoring Technologies ....................................................... 36

2.7.1 Smart metering ................................................................................................................... 36

2.7.2 End use studies ................................................................................................................... 38

2.8 Research Justification.................................................................................................................. 42

2.8.1 Water end use and demographics ....................................................................................... 43

2.8.2 Engineered efficient devices, consumer attitudes and water end use.................................. 44

2.8.3 Recycled water end use ...................................................................................................... 45

2.9 Chapter Summary ....................................................................................................................... 45

2.10 References..................................................................................................................................... 46

CHAPTER 3 .............................................................................................................................. 55

RESEARCH METHOD AND DESIGN ................................................................................. 55

3.1 Overview of Research Method and Design ................................................................................ 55

3.1.1 Explanatory mixed method design...................................................................................... 56

3.1.2 Quantitative research .......................................................................................................... 58

3.1.3 Qualitative research ............................................................................................................ 58

3.1.4 Explanatory mixed methods: follow-up explanations model design .................................. 59

3.2 Phase 1: Knowledge Acquisition................................................................................................. 61

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3.3 Phase 2: Water End Use and Demand Management ................................................................ 62

3.3.1 Stage 2a: End use water consumption design ..................................................................... 64

3.3.2 Stage 2b: Obtain consenting sample ................................................................................... 66

3.3.3 Stage 2c: Potable end use water consumption data............................................................. 70

3.3.4 Stage 2d: Stock survey and water use behaviour audit ....................................................... 72

3.3.5 Stage 2e: Potable end use water consumption .................................................................... 73

3.3.6 Stage 2f: Questionnaire development, distribution and analysis ........................................ 74

3.3.7 Stage 2g: Educational shower monitor device.................................................................... 77

3.4 Phase 3: Dual Reticulated Recycled Water................................................................................ 78

3.4.1 Stage 3a: Predictive dual reticulated recycled water uptake model .................................... 78

3.4.2 Stage 3b: Dual reticulated recycled end use data collection and analysis........................... 80

3.4.3 Stage 3c: Dual reticulated recycled water end use consumption ........................................ 81

3.5 Chapter Summary ....................................................................................................................... 82

3.6 References..................................................................................................................................... 82

CHAPTER 4 .............................................................................................................................. 85

SITUATIONAL CONTEXT AND DESCRIPTIVE DATA ANALYSIS............................. 85

4.1 Research Sample Group.............................................................................................................. 85

4.2 Research Sample Characteristics ............................................................................................... 88

4.2.1 Socioeconomic status of areas ............................................................................................ 89

4.2.2 Descriptive statistic characteristics of the total research sample ........................................ 90

4.2.3 Descriptive statistic characteristics of individual research areas ........................................ 92

4.2.4 Comparing single and dual reticulated regions................................................................... 93

4.3 Situational Context of Study ....................................................................................................... 94

4.3.1 Water restriction regimes over the data collection period .................................................. 94

4.3.2 Temperature and rainfall patterns on the Gold Coast ......................................................... 96

4.3.3 Climate, bulk recorded supply and end use data throughout the study period.................... 98

4.4 End Use Water Consumption Data .......................................................................................... 102

4.4.1 Winter 2008 ...................................................................................................................... 102

4.4.2 Summer 2008.................................................................................................................... 105

4.4.3 December 2009................................................................................................................. 108

4.4.4 March 2010....................................................................................................................... 112

4.4.5 Summary of all end use water consumption data ............................................................. 115

4.5 Chapter Summary ..................................................................................................................... 117

4.6 References................................................................................................................................... 117


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CHAPTER 5 ............................................................................................................................ 118

GOLD COAST DOMESTIC END USE STUDY................................................................. 118

5.1 Abstract....................................................................................................................................... 118

5.2 Introduction................................................................................................................................ 118

5.3 The Gold Coast Watersaver End Use Study............................................................................ 119

5.4 Research Method ....................................................................................................................... 119

5.4.1 End use analysis process in brief ...................................................................................... 121

5.5 Results and Discussion............................................................................................................... 122

5.5.1 Water end use on the Gold Coast...................................................................................... 122

5.5.2 End use comparison with previous studies ....................................................................... 122

5.5.3 End use comparison: percentage or volume?.................................................................... 124

5.5.4 End use comparison for individual households ................................................................ 124

5.6 Conclusion .................................................................................................................................. 128

5.7 Future Work............................................................................................................................... 128

5.8 References................................................................................................................................... 129

CHAPTER 6 ............................................................................................................................ 131

END USE WATER CONSUMPTION IN HOUSEHOLDS: IMPACT OF SOCIO-

DEMOGRAPHIC FACTORS AND EFFICIENT DEVICES ............................................ 131

6.1 Abstract....................................................................................................................................... 131

6.2 Introduction................................................................................................................................ 131

6.2.1 Improving urban water security ........................................................................................ 131

6.2.2 Domestic water consumption and conservation................................................................ 132

6.2.3 Advent of smart water metering ....................................................................................... 132

6.2.4 Overview of Gold Coast End Use Study .......................................................................... 132

6.2.5 Engineered water efficiency ............................................................................................. 133

6.2.6 Influences of socio-demographic factors .......................................................................... 133

6.2.7 Research objectives .......................................................................................................... 133

6.3 Method ........................................................................................................................................ 134

6.3.1 Mixed method study design.............................................................................................. 134

6.3.2 Sample .............................................................................................................................. 134

6.3.3 Water consumption end use study .................................................................................... 134

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6.3.4 Questionnaire survey ........................................................................................................ 135

6.3.5 Household appliance stock survey and water behaviour investigation............................. 136

6.3.6 Water end use analysis and comparison ........................................................................... 136

6.4 Results ......................................................................................................................................... 137

6.4.1 Influence of socio-demographic factors............................................................................ 137

6.4.2 Stock efficiency versus end use consumption................................................................... 140

6.5 Conclusion .................................................................................................................................. 145

6.6 Acknowledgements .................................................................................................................... 145

6.7 References................................................................................................................................... 145

CHAPTER 7 ............................................................................................................................ 148

QUANTIFYING THE INFLUENCE OF ENVIRONMENTAL AND WATER

CONSERVATION ATTITUDES ON HOUSEHOLD END USE WATER

CONSUMPTION .................................................................................................................... 148

7.1 Abstract....................................................................................................................................... 148

7.2 Introduction................................................................................................................................ 148

7.3 Theoretical Background............................................................................................................ 151

7.3.1 Water consumption attitudes and behaviour..................................................................... 151

7.3.2 Water end use monitoring................................................................................................. 154

7.3.3 Research propositions....................................................................................................... 157

7.4 Research Method ....................................................................................................................... 158

7.4.1 Situational context ............................................................................................................ 158

7.4.2 Research sample ............................................................................................................... 159

7.4.3 End use smart metering approach ..................................................................................... 159

7.4.4 Questionnaire development and survey ............................................................................ 160

7.5 Data Analysis and Results ......................................................................................................... 160

7.5.1 Descriptive statistics ......................................................................................................... 160

7.5.2 Measurement model assessment ....................................................................................... 161

7.5.3 Exploration of clusters ...................................................................................................... 164

7.5.4 Water consumption end use analysis ................................................................................ 166

7.6 Discussion ................................................................................................................................... 170

7.6.1 Overview on water consumption and attitudes ................................................................. 170

7.6.2 Linking socio-demographic variables with attitudes ........................................................ 172


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7.7 Conclusions and Implications ................................................................................................... 173

7.8 Acknowledgements .................................................................................................................... 174

7.9 References................................................................................................................................... 174

CHAPTER 8 ............................................................................................................................ 178

ALARMING VISUAL DISPLAY MONITORS AFFECTING SHOWER END USE

WATER AND ENERGY CONSERVATION IN AUSTRALIAN RESIDENTIAL

HOUSEHOLDS....................................................................................................................... 178

8.1 Abstract....................................................................................................................................... 178

8.2 Background ................................................................................................................................ 179

8.2.1 Climate change and improving urban water security........................................................ 179

8.2.2 Domestic water consumption and conservation................................................................ 180

8.2.3 Advent of smart water metering and end use analysis...................................................... 180

8.2.4 Engineered water conservation appliances and fixtures ................................................... 181

8.2.5 Visual display technologies and alarming devices influencing resource conservation

behaviour ..................................................................................................................................... 182

8.2.6 Overview of Gold Coast Watersaver End Use study ........................................................ 184

8.3 Research Objectives................................................................................................................... 185

8.4 Research Method ....................................................................................................................... 186

8.5 Baseline Water Consumption End Use Analysis ..................................................................... 189

8.6 Visual Display Monitors Influencing Shower End Use Events .............................................. 191

8.6.1 Influence on shower duration ........................................................................................... 192

8.6.2 Influence on shower volumes ........................................................................................... 193

8.6.3 Influence on shower flow rates ......................................................................................... 195

8.7 Resource Conservation and Financial Modelling.................................................................... 196

8.7.1 Water and energy conservation......................................................................................... 196

8.7.2 Monetary savings and capital pay-back............................................................................ 197

8.7.3 Wider non-monetary benefits ........................................................................................... 199

8.8 Conclusions and Futures Directions......................................................................................... 200

8.9 References................................................................................................................................... 201

CHAPTER 9 ............................................................................................................................ 204

Table of Contents

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PIMPAMA-COOMERA DUAL RETICULATION END USE STUDY: PRE-

COMMISSION BASELINE, CONTEXT AND POST-COMMISSION END USE

PREDICTION ......................................................................................................................... 204

9.1 Abstract....................................................................................................................................... 204

9.2 Australian Dual Reticulated Communities .............................................................................. 205

9.3 Pimpama-Coomera Dual Reticulation Scheme ....................................................................... 207

9.4 Pimpama-Coomera Dual Reticulation End Use Study ........................................................... 208

9.5 Baseline Situation: Recycled Water Pre-Commissioning End Uses ...................................... 209

9.6 Predicting Recycled Water Post-commissioning End Uses .................................................... 211

9.6.1 Predictive analysis approach and input factors ................................................................. 211

9.6.2 Establishing baseline end use situational context ............................................................. 211

9.6.3 Influence of irrigation end use measurements conducted elsewhere ................................ 212

9.6.4 Influence of water restriction levels and changes ............................................................. 213

9.6.5 Influence of customer water source preferences............................................................... 214

9.6.6 Influence of recycled water pricing .................................................................................. 215

9.6.7 Influence of climate .......................................................................................................... 216

9.6.8 Influence of lot size .......................................................................................................... 216

9.6.9 Influence of recycled water awareness campaign............................................................. 216

9.7 Predicting Post-commissioning Dual Reticulation End Uses ................................................. 217

9.7.1 Possibility theory underpinning prediction model ............................................................ 217

9.7.2 Prediction model application ............................................................................................ 217

9.8 Future Research: Post-commissioning Comparative Analysis .............................................. 219

9.9 Conclusion .................................................................................................................................. 219

9.10 References................................................................................................................................... 220

CHAPTER 10 .......................................................................................................................... 223

RESIDENTIAL POTABLE AND RECYCLED WATER END USES IN A DUAL

RETICULATED SUPPLY SYSTEM.................................................................................... 223

10.1 Abstract....................................................................................................................................... 223

10.2 Integrated Urban Water Resources Management .................................................................. 223

10.2.1 Water services planning.................................................................................................... 224

10.2.2 Water end use and diurnal patterns................................................................................... 225


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10.2.3 Gold Coast’s Pimpama Coomera dual reticulation scheme.............................................. 227

10.3 Objectives and Scope of the Paper ........................................................................................... 229

10.4 Pimpama Coomera End Use Water Consumption Study ...................................................... 231

10.4.1 Pre-Commissioning of recycled water to Pimpama Coomera region ............................... 231

10.4.2 Post-Commissioning of recycled water to Pimpama Coomera region ............................. 233

10.4.3 Comparison of Phase 1 prediction with Phase 2 data ....................................................... 235

10.5 Compilation of end use average hourly diurnal patterns ....................................................... 236

10.5.1 Developed end use diurnal pattern software tool.............................................................. 236

10.5.2 Diurnal patterns of consumption....................................................................................... 236

10.5.3 End use diurnal patterns of consumption.......................................................................... 238

10.5.4 Variation in peaks between single and dual reticulated supply schemes .......................... 240

10.6 Conclusions, Implications and Future Directions ................................................................... 240

10.7 References................................................................................................................................... 242

CHAPTER 11 .......................................................................................................................... 245

CONCLUSIONS, CONTRIBUTIONS AND IMPLICATIONS......................................... 245

11.1 Research Objectives and Outcomes ......................................................................................... 245

11.1.1 Knowledge acquisition ..................................................................................................... 247

11.1.2 Water end use and demand management.......................................................................... 247

11.1.3 Dual reticulated recycled water ........................................................................................ 250

11.2 Study Contributions................................................................................................................... 251

11.2.1 Contributions to existing body of knowledge ................................................................... 251

11.2.2 Implications for water planning and management ............................................................ 253

11.3 Study Limitations and Future Research Directions................................................................ 254

11.4 Closure ........................................................................................................................................ 255

11.5 References................................................................................................................................... 256

REFERENCES........................................................................................................................ 257

APPENDIX A .......................................................................................................................... 271

APPENDIX B .......................................................................................................................... 282

Table of Contents

- xix -

APPENDIX C .......................................................................................................................... 284

APPENDIX D .......................................................................................................................... 288

APPENDIX E .......................................................................................................................... 290

APPENDIX F........................................................................................................................... 296

APPENDIX G.......................................................................................................................... 307

- xx -

List of Tables

Table 2-1 Australia’s water consumption by sector 2004-05 (ABS, 2007) ................................ 15

Table 2-2 Gold Coast Waterfuture Water Balance (GCW & GCCC, 2007)............................... 18

Table 2-3 Savings from various WDM measures (Sarac et al., 2002, pp. 7).............................. 28

Table 2-4 Class A+ recycled water uses (GCW, 2009b) ............................................................ 33

Table 2-5 Water use in Pimpama Coomera versus existing communities (Gold Coast Water,

2004) ................................................................................................................................... 34

Table 2-6 Summary of dual reticulated schemes in Australia..................................................... 35

Table 2-7 Summary of findings from other water end use studies.............................................. 41

Table 2-8 Comparison of Asia-Pacific end use water consumption studies ............................... 42

Table 3-1 Strengths and weaknesses of Explanatory Mixed Methods (Creswell, 2008) ............ 57

Table 4-1 Overview of research area and recruited participants................................................. 88

Table 4-2 Overview of research area and socioeconomic status indicators ................................ 89

Table 4-3 Descriptive statistics of research regions.................................................................... 91

Table 4-4 Gold Coast water restriction overview and timeframe ............................................... 95

Table 4-5 Climatic, bulk supply and end use water consumption data from Gold Coast City ... 99

Table 4-6 Winter 2008 end use data for research regions ......................................................... 105

Table 4-7 Summer 2008/09 end use data for research regions ................................................. 107

Table 4-8 Summer December 2009 end use data for research regions ..................................... 111

Table 4-9 March 2010 End use data for research regions ......................................................... 115

Table 5-1 Comparison between national and pacific water end use consumption studies........ 123

Table 6-1 Comparison between national end use water consumption studies (Willis et al.,

2009b) ............................................................................................................................... 137

Table 6-2 Showerhead efficiency cluster comparisons ............................................................. 141

Table 6-3 Clothes washer efficiency comparisons.................................................................... 142

Table 6-4 Rainwater tank cluster comparisons ......................................................................... 143

Table 7-1 Measurement items for concern for environment factor........................................... 153

Table 7-2 Measurement items for water conservation awareness and practice factor............. 155

Table 7-3 Results from domestic end use studies ..................................................................... 156

Table 7-4 Socioeconomic descriptive statistics for sampled regions ........................................ 161

Table 7-5 Measurement items mean value and standard deviation........................................... 162

Table 7-6 Measurement model analysis results ........................................................................ 163

Table 7-7 Clustered comparative analysis results. .................................................................... 170

Table 8-1 Independent sample t-test for equality of means ...................................................... 194

Table 9-1 Summary of dual reticulated schemes in Australia................................................... 206

Table 9-2 PC baseline end use situational context .................................................................... 212


- xxi -

Table 9-3 Influence of water restriction levels on billed water meter consumption in the Gold

Coast (ML/d) ..................................................................................................................... 213

Table 9-4 PC respondent perceptions on preferred source for outdoor activities (n=70) ......... 214

Table 9-5 Recycled water for irrigation purposes influencing factors and weighted possibility

distribution ........................................................................................................................ 218

Table 9-6 PC recycled water post-commissioning end use prediction...................................... 219

Table 10-1 Summary of findings from other water end use studies.......................................... 226

- xxii -

List of Figures

Figure 1-1 Overarching mixed methods research design.............................................................. 5

Figure 2-1 Overview of reviewed literature topics ..................................................................... 13

Figure 2-2 Factors that influence demand (White and Turner, 2003; WSAA, 2008) ................. 16

Figure 2-3 Gold Coast Waterfuture Master Plan water balance 2007 (GCW & GCCC, 2007).. 18

Figure 2-4 Australian IUWRM framework (Turner and White, 2006)....................................... 21

Figure 2-5 WELS water rating label (Commonwealth of Australia, 2009) ................................ 26

Figure 2-6 Pimpama Coomera Master Plan – household water uses (Gold Coast Water, 2008b)

............................................................................................................................................. 33

Figure 2-7 Typical smart meter set up in residential household (Stewart et al., 2009)............... 37

Figure 2-8 Potential for demand reduction and alternative supply options across scales (Stewart

et al., 2009) ......................................................................................................................... 37

Figure 2-9 Matching technologies to objectives (Giurco et al., 2008a) ...................................... 38

Figure 2-10 Household end uses of water ................................................................................... 39

Figure 3-1 The explanatory mixed methods design (Creswell and Plano Clark, 2007).............. 56

Figure 3-2 Explanatory design: follow-up explanations model (QUAN emphasised) (Creswell

and Plano Clark, 2007)........................................................................................................ 56

Figure 3-3 Overarching mixed methods research design............................................................ 60

Figure 3-4 Phase 1 research activities and output ....................................................................... 61

Figure 3-5 End use measurement study design cycle (Giurco et al., 2008a) .............................. 62

Figure 3-6 Phase 2 research activities and output ....................................................................... 63

Figure 3-7 Stage 2a: End use water consumption design............................................................ 64

Figure 3-8 Stage 2b: Obtain consenting sample.......................................................................... 66

Figure 3-9 Stage 2c: Potable end use water consumption data acquisition testing ..................... 70

Figure 3-10 End use data downloading procedure...................................................................... 71

Figure 3-11 Stage 2d: Stock survey and water use behaviour audit............................................ 72

Figure 3-12 Stage 2e: Potable end use water consumption......................................................... 73

Figure 3-13 Stage 2f: Questionnaire development, distribution and analysis............................. 75

Figure 3-14 Diagram of relationships between dependent and independent questionnaire survey

variables .............................................................................................................................. 76

Figure 3-15 Stage 2g: Shower monitor investigation.................................................................. 78

Figure 3-16 Phase 3: Detailed overview of research activities and output ................................. 79

Figure 3-17 Stage 3a: Predictive dual reticulated recycled water uptake model......................... 80

Figure 3-18 Stage 3b: Dual reticulated recycled end use water consumption data collection and

analysis................................................................................................................................ 80

Figure 3-19 Stage 3c: End use model for dual reticulated recycled water consumption ............ 81


- xxiii -

Figure 4-1 Research areas for the Gold Coast Watersaver End Use study ................................. 86

Figure 4-2 Research areas and participating households ............................................................ 87

Figure 4-3 Yearly temperature and rainfall patterns for the Gold Coast, Queensland................ 97

Figure 4-4 Average daily per capita consumption for total sample in winter 2008 (n=151) .... 103

Figure 4-5 Average daily per capita consumption for single reticulated region in winter 2008

(n=38)................................................................................................................................ 104

Figure 4-6 Average daily per capita consumption for dual reticulated region in winter 2008

(n=113).............................................................................................................................. 104

Figure 4-7 Average daily per capita consumption for total sample in summer 2008/09 (n=127)

........................................................................................................................................... 106

Figure 4-8 Average daily per capita consumption for single reticulated region in summer

2008/09 (n=29).................................................................................................................. 107

Figure 4-9 Average daily per capita consumption for dual reticulated region in summer 2008/09

(n=98)................................................................................................................................ 107

Figure 4-10 Average daily per capita consumption total sample December 2009 (n=33)........ 109

Figure 4-11 Average daily per capita consumption single reticulated region in December 2009

(n=7).................................................................................................................................. 110

Figure 4-12 Average daily per capita consumption dual reticulated region in December 2009

(n=26)................................................................................................................................ 111

Figure 4-13 Average daily per capita consumption total sample March 2010 (n=100)............ 113

Figure 4-14 Average daily per capita consumption single reticulated region in March 2010

(n=27)................................................................................................................................ 113

Figure 4-15 Average daily per capita consumption dual reticulated region in March 2010 (n=73)

........................................................................................................................................... 114

Figure 4-16 Gold Coast indoor water consumption for entire study period (n=412)................ 116

Figure 4-17 Gold Coast total (indoor and outdoor) water consumption for entire study period

(n=411).............................................................................................................................. 116

Figure 5-1 Gold Coast Watersaver End Use study project schedule......................................... 120

Figure 5-2 Data loggers and collection technique..................................................................... 122

Figure 5-3 Average daily per person consumption (L/p/d): combined sample (n=151) ........... 123

Figure 5-4 Household daily per capita consumption: activity break down............................... 125

Figure 5-5 Household daily per capita consumption: shower only........................................... 126

Figure 5-6 Household daily per capita consumption: irrigation only........................................ 126

Figure 5-7 Average daily per capita water consumption: socioeconomic regions.................... 127

Figure 6-1 Schematic illustrating water end use analysis process ............................................ 135

Figure 6-2 Average daily per capita consumption (L/p/d): combined sample (n=151) ............ 137

Figure 6-3 Impact of socio-demographic area on end use water consumption ......................... 138

Figure 6-4 Impact of lot size and RWT installation on irrigation end use ................................ 139

List of Figures

- xxiv -

Figure 6-5 Impact of family income on water consumption ..................................................... 140

Figure 6-6 Relationships between household resident typologies and water end use consumption

........................................................................................................................................... 140

Figure 7-1 CFA model .............................................................................................................. 164

Figure 7-2 Profiles of clusters’ final centroids.......................................................................... 165

Figure 7-3 Average daily per capita consumption per end use: total sample (n=132).............. 166

Figure 7-4 Household daily per capita consumption distribution with water end use breakdown:

total sample (n=132) ......................................................................................................... 167

Figure 7-5 Average daily per capita consumption: VHC cluster (n=54) .................................. 168

Figure 7-6 Household daily per capita consumption distribution profile: VHC cluster (n=54) 168

Figure 7-7 Average daily per capita consumption: MHC cluster (n=78).................................. 169

Figure 7-8 Household daily per capita consumption distribution profile: MHC cluster (n=78)169

Figure 8-1 Alarming visual display device ............................................................................... 184

Figure 8-2 Sample end use break down: winter pre-retrofit (n=151)........................................ 189

Figure 8-3 Sample household end use distribution: winter pre-retrofit (n=151)....................... 190

Figure 8-4 Sample shower end use distribution: winter pre-retrofit (n=151) ........................... 191

Figure 8-5 Sample pre- and post- monitor retrofit shower event duration frequency distribution

........................................................................................................................................... 193

Figure 8-6 Sample pre- and post- monitor retrofit shower event volume frequency distribution

........................................................................................................................................... 195

Figure 8-7 Sample pre- and post- monitor retrofit shower event flow rate frequency distribution

........................................................................................................................................... 196

Figure 10-1 Factors that influence demand (White and Turner (2003) & WSAA (2008))....... 225

Figure 10-2 Rainfall and maximum temperature with bulk recorded supply for Gold Coast City

over the duration of the Gold Coast Watersaver End Use study July 2008 – June 2010 .. 231

Figure 10-3 Pre-commissioning end use water consumption data (summer 08/09) ................. 232

Figure 10-4 Post-commissioning end use water consumption data (summer 09/10)................ 234

Figure 10-5 Average hourly diurnal pattern profile: single and dual reticulated regions ......... 237

Figure 10-6 End use hourly diurnal pattern profile: single and dual reticulated regions .......... 240

Figure 11-1 Overarching mixed methods research design ........................................................ 246

- xxv -

List of Acronyms

ABC Australian Broadcasting Corporation

ABS Australian Bureau of Statistics

COAG Council of Australia Governments

CSIRO Commonwealth Scientific and Industrial Research Organisation (Australia)

DNRM Department of Natural Resources and Mines (Queensland, Australia)

EPBC Environmental Protection and Biodiversity Conservation Act (Australia)

GC Gold Coast

GCCC Gold Coast City Council

GCW Gold Coast Water

GCWF Gold Coast Waterfuture

GCWSEU Gold Coast Watersaver End Use (Project)

IPCC Intergovernmental Panel on Climate Change

IUWRM Integrated urban water resource management

PC Pimpama Coomera

PCWF Pimpama Coomera Waterfuture

Pot Potable water supply

PRW Purified recycled water

QWC Queensland Water Commission

Rec Recycled water supply

RWTs Rainwater tanks

RWTP Recycled water treatment plant

SD Standard deviation

SEQ South East Queensland

UKWIR United Kingdom Water Industry Research

UN United Nations

USA United States of America

USEPA United States Environmental Protection Agency

WDM Water demand management

WELS Water Efficiency Labelling and Standards

WSAA Water Services Association Australia

WWTP Waste water treatment plant

Measurements

L litres

L/h/p/d litres per hour per person per day


- xxvi -

L/H/d litres per household per day

L/p/d litres per person per day

kL kilolitre

kL/a kilolitres per annum (year)

$/kL dollars per kilolitre

ML megalitres

ML/d megalitres per day

GL gigalitres

GL/y gigalitres per year

- 1 -

Chapter 1

Introduction This thesis disseminates an extensive investigation into end use water consumption and the

effective water savings attributed to water demand management and source substitution

initiatives in the case study area of the Gold Coast, Queensland, Australia. The Gold Coast is a

major urban growth area of South East Queensland, located at the most south eastern corner of

the state, bordering New South Wales. The Gold Coast is projected to grow from the current 0.5

to 2.5 million people by 2056 (Po et al., 2003). The primary purpose of this research is the

establishment of end use water consumption data for single detached households in both

traditional single reticulated and non-traditional dual reticulated regions on the Gold Coast.

Other key purposes include: the quantification of actual end use potable water savings attributed

to dual reticulated recycled water supply schemes, determining the influence of water demand

management initiatives including educational messages and water efficient devices, and

evaluating the influence of socio-demographics and attitudes on residential end use water

consumption behaviours. This chapter provides an introduction to the research through a brief

description of the research background, the objectives of the study, the scope of the research and

an overview of the research method and design. The chapter concludes by providing detail on

the layout and structure of the thesis. Introductory background information pertinent to the

research is described in the following section.

1.1 Research Background

Water, like energy, is neither created nor destroyed but simply converted from one form to

another (Bouwer, 2000). Of the earth’s water, 97% is stored as salt water in the oceans, with

only 1% of the worlds global water occurring as liquid freshwater with the other two-thirds

captured as snow and ice (Bouwer, 2003). Of this available 1% liquid freshwater, 2% is

accessible in lakes and streams with the remaining 98% stored as ground water. Liquid

freshwater is thus an extremely finite and limited resource which needs to be managed

appropriately (Bouwer, 2000). Securing a reliable supply of fresh water for the world’s ever

increasing population is one of the biggest challenges facing society today. The United Nations

(UN) estimates that by 2025, two-thirds of the world’s population will face water shortages

(Barlow, 2009; UN, 2009).

The Intergovernmental Panel on Climate Change (IPCC) state that ‘observational records and

climate projections provide abundant evidence that freshwater resources are vulnerable and

have the potential to be strongly impacted by climate change, with wide-ranging consequences


- 2 -

for human societies and ecosystems’ (Bates et al., 2008, pp. 3). The Water Services Association

of Australia (WSAA, 2009a) states that relying on rainfall is a high risk strategy in an era of

climate change and that Australia’s frequent water scarcity occurrences has prompted residents

to see climate change as a ‘here and now’ issue rather than one of the future (WSAA, 2009a).

With such limited worldwide liquid freshwater, increasing urban water source pollution and a

growing populations steadily increasing demand on finite water sources, sustainable integrated

water planning and management has become pertinent to ensure the secure supply of freshwater

for the world’s future inhabitants. The described pressures on water supplies have instigated a

shift in urban planning towards integrated urban water resource management (IUWRM), which

sees the planning and application of a range of supply, demand and source substitution

initiatives to meet the urban water demands of the future.

The application of IUWRM initiatives has taken place readily throughout Australia with

detailed planning and implementation occurring in the research region of the Gold Coast. More

than a quarter of Gold Coast’s 2056 forecasted water demand will be supplemented by source

substitution or water demand management (WDM) initiatives. With the residential population

projected to increase from the current 0.5 million people to 2.5 million people in this time

frame, the water demand predicted to be reduced through water conservation, pressure and

leakage management, rainwater tanks and recycled water equates to 130 mega litres per day

(ML/d) (GCW & GCCC, 2007). To ensure volumetric savings are feasible, knowledge and data

on the effective potable water savings attributed to the individual WDM initiatives and source

substitution measures is necessary. Thus, an understanding of local residential consumption

behaviours and attitudes is essential. It is well documented that the monitoring and evaluation of

the effectiveness of IUWRM initiatives have been limited (White and Turner, 2003). Some

effort has been made to determine the saving attributed to WDM initiatives but this is generally

based on bulk recorded data, estimations or modelling. Only one Australian example of end use

monitoring of water efficient devices was reported in 2005, but the continued technological

developments in efficiencies of water use devices call for further research on this topic.

The relationship between attitudes and actual end use water consumption behaviour is another

area which requires significantly more investigation. Loh and Coghlan (2003) and the CSIRO

(2002) detailed how environmental attitudes affected outdoor water consumption but there is

currently no literature reporting the relationship between environmental and water conservation

attitudes on internal end use water consumption. Less precise bulk recorded water consumption

data has been linked with attitudes but researchers were not able to stipulate which water use

activities are actually influenced by attitudes (Nancarrow et al., 1996; Hassell and Cary, 2007).

The need to undertake monitoring, evaluation and review of WDM initiatives at an end use level

was stated by Giurco (2008a), Turner et al. (2005) and WSAA (2003). The need to undertake

Chapter 1: Introduction

- 3 -

location specific end use studies is also strongly encouraged to provide an understanding of

local consumption behaviours (Mayer and DeOreo, 1999; White and Fane, 2001; Turner et al.,

2005). To date, no statistically significant end use study has been carried out within Queensland.

Measurement of WDM and source substitution at an end use level requires the application of

advanced water monitoring technologies such as high resolution water meters, data loggers and

analysis programs. Monitoring end use water consumption involves recording individual usage

within households, which includes showers, clothes washing, taps, toilets, irrigation,

dishwashing and leaks. Understanding where, when and how water is being consumed assists in

the refinement and justification of WDM and source substitution initiatives.

The application of WDM initiatives is imperative in order to reduce demand and instil

sustainable water consumption behaviours in growing populations but, this is not a stand-alone

solution for the management of urban water. Additional and alternative sources are required to

augment and offset current supply sources like dams and desalination. The introduction of

recycled water to urban areas through dual reticulation is encouraged and is stated to be an

effective method of source substitution (COAG, 2009). To date, six dual reticulated urban

developments have been planned with several currently supplying residents throughout

Australia with recycled water. On the Gold Coast, residents and businesses in the Pimpama

Coomera region are now supplied recycled water through a centralised distribution dual

reticulation scheme. Measurement of potable water savings and recycled water consumption has

been calculated at the bulk supply level for many of the operating dual reticulation schemes. In

both Australian and worldwide literature, there is no evidence of an investigation on the end use

water consumption occurring within a dual reticulated recycled water region hence, the need to

undertake this study. Beyond this lack of a dual reticulation end use study, there exists a range

of significant gaps in the current body of knowledge addressing urban water resource

management. These include: a statistically significant end use water consumption investigation

for Queensland, description on the effective end use savings attributed to household stock

efficiency and educational devices and the relationship between water conservation and

environmental attitudes on end use consumption. Further discussions on current gaps in the

body of knowledge are presented in Chapter 2 and within Chapters 5 to 10. The following short

summary highlighting research gaps sets the scene for the research objectives and scope of this

study.

1.2 Research Objectives and Scope

The herein described research was conducted to provide data and knowledge to address the

above mentioned research gaps. The principle objectives of this research were: (1) to investigate

end use water consumption breakdowns and diurnal consumption patterns in detached


- 4 -

residential households; (2) to determine the potable water savings attributed to water demand

management initiatives and dual reticulated recycled water schemes and; (3) to assess the

relationship between consumer attitudes and end use consumption. More specifically, it aimed

to establish residential water end uses in both traditional single reticulated households and non-

traditional dual reticulated households and to ascertain diurnal patterns for both of these supply

types in the context of the northern growth corridor of the Gold Coast, Australia.

The research was conducted within the following scope:

The study was limited to the context of the Gold Coast, Queensland, Australia;

The research was restricted to the end use analysis of the residential sector only (i.e. does

not include the commercial or industrial sector); and

The research focused on household water consumption in only single detached residences

(i.e. no multi-unit developments, cluster housing or attached housing, etc.).

1.3 Research Method Overview

This interdisciplinary study required a research design adapting methods from the experimental,

social science and natural science fields. An explanatory mixed methods research approach was

adopted due to the extensive range of research objectives and required data sources. The mixed

methods design integrates both quantitative and qualitative research methods, which strengthens

the research design to satisfy the defined objectives (Creswell and Plano Clark, 2007; Creswell,

2008). The explanatory mixed methods approach places emphasis on the quantitative data and

results with qualitative data used to help build or explain the initial quantitative results (Morse,

1991; Creswell and Plano Clark, 2007). There were three main phases to the research method,

which included a knowledge acquisition phase, a water end use and demand management phase

and a dual reticulated recycled water phase. Each of these phases includes numerous research

stages that contained unique methods and design. Each key phase and associated stages of the

research method are presented in Figure 1-1.


- 5 -

Phase 1: Knowledge Acquisition

Phase 2: Water End Use & Demand Management

Phase 3: Dual Reticulated Recycled Water

Stage 1a: Literature Review

Stage 1b: Set Research Objectives

Stage 1c: Research Method

Stage 2b: Obtain consenting sample

Stage 2c: Potable end use water consumption data

Stage 2d: Stock survey and water use behaviour audit

Stage 2e: Potable end use water consumption

Stage 2f: Questionnaire development, distribution and analysis

Stage 2g: Shower monitor investigation

Stage 3a: Predictive dual reticulated recycled water uptake model

Stage 3b: Dual reticulated recycled end use water consumption data collection and analysis

Stage 3c: Dual reticulated recycled water end use consumption

Stage 2a: End use water consumption design

PHASE STAGEOUTPUT/REFEREED

PUBLICATION


Chapter 2: Literature Review

Chapter 3: Research Method and Design

Chapter 5: Gold Coast Domestic Water End Use Study

Chapter 6: Revealing the impact of socio-demographics factors and efficient devices

on end use water consumption: case of Gold Coast, Australia

Chapter 7: Quantifying the influence of environmental and water conservation attitudes on household end use water

consumption

Chapter 8: Alarming visual display monitors affecting shower end use water

and energy conservation in Australian residential households

Chapter 9: Pimpama-Coomera dual reticulation end use study: pre-commission

baseline, context and post-commission end use prediction

Chapter 10: Domestic Dual Reticulated End Use Pimpama Coomera, Gold Coast,

Australia

Chapter 11: Conclusions, Contributions and Implication

Chapter 4:Situational Context and Descriptive Data Analysis

Pub

Pub

Pub

Pub

Pub

Pub

Pub = Referred Publication

Figure 1-1 Overarching mixed methods research design

The vast array of research methods and some of the key data collection phases required to meet

the objectives of this research are demonstrated by Figure 1-1. Some of the predominant

methods include end use analysis techniques, participant recruitment, stock surveys,

questionnaire surveys, experimental designs and the prediction of recycled water end use. The

overarching method and design for the research is presented in Chapter 3, while additional

details on specific research methods are discussed in relevant chapters, which represent re-


- 6 -

formatted peer reviewed journal papers. A summary description for the key research phases are

presented below.

1.3.1 Knowledge acquisition

Published literature addressing all topics relevant to water consumption, IUWRM, demand

management, source substitution, end use studies and dual reticulated precincts was critically

reviewed to develop the required background knowledge and to formulate research objectives.

The result was the development of a subsequent two phased investigation to evaluate the

primary topics; namely, evaluating the influence of demand management initiatives on end use

water consumption and revealing the end use water consumption in a dual reticulation scheme

(i.e. end uses of potable and recycled water supplies). Details of the methods undertaken in each

phase are presented.

1.3.2 End use baseline and water demand management

The purpose of Phase 2 of the research method and design was to develop the measurement

techniques to obtain end use water consumption data and to undertake statistical and

experimental analyses to determine the water savings attributed to various water demand

management initiatives. Primarily, this phase included: establishing an understanding of

residential end use study design; determining appropriate technology for end use data collection;

verifying the sample size, research region and recruitment approach; determining the end use

consumption monitoring process and acquisition of data; developing water stock audits and

interview questions and undertaking these with each participant in the study to validate stock

and end use water consumption behaviour in households; undertaking analysis of end use water

consumption data; development, application and analysis of a questionnaire survey to establish

socio-demographics and attitudinal perceptions surrounding water related issues; and, the

recruitment, delivery and analysis of an experimental water demand management educational

shower monitor for a sub-sample of the research participants. This phase also involved the

establishment of the link between environmental and water conservation attitudes on end use

water consumption. The application of these methods resulted in the development of four

journal papers, which have been published or are currently under peer review (Chapters 5 to 8).

1.3.3 Dual reticulated recycled water

Phase 3 involved the adoption of methods and analysis techniques to investigate the potable end

use water consumption savings attributed to the supply of recycled water to dual reticulated

residential households in the Pimpama Coomera (PC) region. This phase of the research method

was implemented to develop a predictive uptake model and to subsequently measure the end use

water consumption occurring in a dual reticulated recycled water region. Primarily, this phase


- 7 -

included: the development, application and verification of a predictive recycled water uptake

model, pre-commissioning of recycled water to the PC region; measuring end use water

consumption in the PC region post-commissioning of recycled water; validating end use water

consumption in the PC region for both recycled and potable water; and developing a tool to

ascertain diurnal consumption patterns for dual and single reticulated regions. The application

of these methods resulted in the development of two journal papers either published or

submitted for peer review (i.e. Chapters 9 to 10).

1.4 Thesis Layout

This research is presented through a refined layout that includes both traditional thesis chapters

and reformatted peer reviewed publication chapters. This has resulted in a strengthened ‘thesis

by publication’ approach due to the distinctive academic and practical elements of the thesis.

The ‘thesis by publication’ layout differs from a traditional thesis by the inclusion of published

peer reviewed papers in place of traditional data analysis, results and discussion chapters.

However, traditional introductory chapters are included in order to outline the research

approach, methods and context of the study. Such chapters include the herein described

introduction, literature review, research method and design, and situational context and

descriptive data analysis. Published, accepted or submitted peer reviewed journal publications

make up the remainder of the chapters. The chapters that contain reformatted peer reviewed

papers each include a literature review, methodology, results and discussion specific to stated

research objectives and topic. The final chapter summarises overall research conclusions,

recommendations, contributions, implications, limitations and future research directions.

Readers should note that the literature review, research method and design, and situational

context and descriptive data analysis chapters all present overarching details of the entire

research project. However, each results chapter, represented by peer reviewed journal

manuscripts, also includes background information, a targeted literature review, and detailed

descriptions of methodologies and data analysis techniques applied.

There are two distinct components or phases of peer reviewed publications within this thesis

being:

1. The establishment of baseline end use water consumption in the Gold Coast and

investigations into the effect of water demand management initiatives including

efficient and consumption awareness prompt devices as well as establishing the

relationship between attitudes and end use water consumption behaviours; and


- 8 -

2. Predicting, investigating and reporting the end use water consumption and diurnal

patterns within a dual reticulated recycled water development region (i.e. Pimpama

Coomera).

In its entirety, the thesis consists of eleven chapters. This chapter introduces the research

through discussion on the research motivation and background, presented a summarised

overview of the research method and discussed the ‘thesis by publications’ layout of this study.

More importantly, the chapter presents the broad research objectives for the study which were

developed from the knowledge acquired through the literature review and established research

gaps. The research objectives directed the design of the research method and underpinned

investigations for the acquisition of results to meet the objectives.

Chapter 2 provides a detailed discussion and review of all literature relevant to water

consumption, integrated urban water management, water demand management, source

substitution, advanced water consumption monitoring technologies, end use studies and dual

reticulated recycled water schemes. Moreover, the chapter explores earlier research covering

fields of particular interest being water efficient devices, educational devices, attitudes and the

impact this has on behaviour, monitoring of dual reticulated recycled water and the variability in

results from worldwide end use studies. The chapter concludes through a research persuasion,

which summarises the reviewed literature and presents the key gaps that currently exist in the

body of knowledge. Additional critical reviews of literature are detailed within Chapters 5 to 10.

Chapter 3 details the research method and design, which stipulates the key theories relevant to

the research approach and discusses the analytical techniques adopted in this study. Initially,

this chapter presents the overarching methodological approach utilised to carryout the research

and then proceeds to detail each particular phase and stage of the method. Additional

discussions on key analytical techniques and methods specific to various papers within the

thesis are presented in Chapters 5 to 10. Chapter 3 is focused on presenting the core research

method and design.

The situational context and descriptive data of the research sample are detailed in Chapter 4.

This chapter describes the context within which the research was carried out, presents rainfall

and climatic data experienced over the research period and lists bulk water consumption data.

Furthermore, this chapter provides a detailed discussion on the characteristics of the recruited

research sample. Data from each of the end use data recording periods are also detailed. Hence,

Chapter 4 presents any details, which were considered influential on the results of this study and

provides a descriptive overview of the research sample and end use water consumption results.


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Chapter 5 is the first of the published peer reviewed paper chapters. This chapter presents the

preliminary findings from the research, aptly named the Gold Coast Watersaver End Use

(GCWSEU) study. The paper describes the purpose of the study, outlines some initial objectives

of the research program and specifies the timeline to undertake this research. The paper also

details end use data from winter 2008, compares findings with other national end use studies

and explores two highly variable end use distributions, namely shower and irrigation. This

chapter concludes by discussing the ongoing research program for the GCWSEU study.

Chapter 6 presents detailed data and discussion on the impact of socio-demographic factors such

as income, education status, family groups and socioeconomic regions, on end use water

consumption. Analysis on the effective end use water savings attributed to efficient devices is

presented. Examination on the payback period for the analysed water efficient devices was also

detailed. Chapter 6 concludes with discussion on the implications for water planning and urban

water demand forecasting.

Chapter 7 explores the relationship between environmental and water conservation attitudes and

end use water consumption behaviours. Initially, the chapter details the theory and development

of environmental and water conservation attitudinal factors from the literature. Socio-

demographic characteristics of the groups are also detailed. Detailed statistical analysis is then

described, which includes confirmatory factor analysis and cluster analysis. The paper presents

the determination of two distinct attitudinal groups being very high concern (VHC) and

moderately high concern (MHC) for both environmental and water conservation practices.

Results on the statistically significant relationship found between discretionary end use water

consumption and lower water consumption by the VHC group and higher water consumption by

the MHC group are presented. The results underpin the need for sustainable water conservation

attitudes to be instilled prior to implementing any water demand management measures.

Chapter 8 details an experimental investigation examining the performance of an alarming

visual display device on shower end uses. This paper presents the initial end use water

consumption found for showering and then details the experiment, which involved the

installation of an alarming shower monitor to reveal the effect on end use shower water

consumption. The paper details the significant volumetric savings attributed to the installation

of the shower device and also explores its effect on the duration and flow rate of showers. The

payback period, based on monetary water and energy savings related to the installation of the

device, is also presented.

Chapter 9 presents the first paper related to the measurement of the dual reticulated recycled

water scheme in Pimpama Coomera (PC), aptly named the Pimpama Coomera Dual


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Reticulation End Use Study. This chapter details the pre-commissioning baseline recycled water

consumption in the PC region and presents the development of a model which includes factors

reported to influence recycled water uptake from the literature. The model then predicts the

post-commissioning recycled water consumption for the PC region. The chapter concludes with

an overview of the additional research stages to be undertaken to measure actual post-

commissioning recycled water end use.

Chapter 10 presents the results from monitoring recycled water end use consumption post-

commissioning in the PC region. The chapter presents data from several logging periods along

with diurnal pattern consumption rates for recycled and potable water at an end use level. This

paper also compares actual end use consumption with the consumption values formulated by the

developed prediction model and the Pimpama Coomera Waterfuture (PCWF) Master Plan

predictions.

Finally, Chapter 11 summarises the key research outcomes, disseminates the contributions made

by the research to the existing body of knowledge and presents implications of results for the

water management field. The chapter also presents recommendations for implementation in the

water industry and the need for future research in this field and addresses any limitations of the

research. Supplementary information in the form of appendices are provided at the conclusion

of Chapter 11.

1.5 References

Barlow, M. (2009) Notes for Opening Keynote Australian Water Summit, 1 April 2009. Australian Water Summit.

Bates, B. C., Kundzewicz, Z. W., Wu, S. & Palutikof, J. P. (2008) Climate Change and Water - IPCC Technical Paper VI. Intergovernmental Panel of Climate Change (IPCC) Secretariat, Geneva.

Bouwer, H. (2000) Integrated water management: emerging issues and challenges. Agricultural Water Management, Vol 45:3, pp. 217-228.

Bouwer, H. (2003) Integrated water management for the 21st century: Problems and Solutions. Food, Agriculture & Environment, Vol 1:1, pp. 118-127.

Council of Australian Governments (COAG) (2009) Intergovernmental Agreement on a National Water Initiative. Canberra. Online article, accessed 23/03/09, available at: http://www.coag.gov.au/coag_meeting_outcomes/2004-06-25/index.cfm.

Creswell, J. W. (2008) Educational Research: planning, conducting, and evaluating quantitative and qualitative research, 3rd ed, New Jersey, Pearson Education, Inc.

Creswell, J. W. & Plano Clark (2007) Designing and conducting mixed methods research, USA, Sage Publications, Inc.


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CSIRO (2002) Perth domestic water-use study household ownership and community attitudinal analysis. NSW, Australian Research Centre for Water in Society CSIRO Land and Water

Giurco, D., Carrard, N., McFallan, S., Nalbantoglu, M., Inman, M., Thornton, N. & White, S. (2008) Residential end-use measurement guidebook: a guide to study design, sampling and technology. Prepared by the Institute for Sustainable Futures, UTS and CSIRO for the Smart Water Fund, Victoria.

Loh, M. & Coghlan, P. (2003) Domestic Water Use Study. Perth, Water Corporation.

Mayer, P. W. & DeOreo, W. B. (1999) Residential End Uses of Water. Denver, CO, Aquacraft, Inc. Water Engineering and Management.

Morse, J. M. (1991) Approaches to qualitative - quantitative methodological triangulation. Nursing Research, 40, 120-123.

Turner, A., White, S., Beatty, K. & Gregory, A. (2005) Results of the largest residential demand management program in Australia. Institute for Sustainable Futures, University of Technology. Sydney Water Corporation, Sydney, NSW

UN (2009) Majority of world population face water shortages unless action taken, warns Migiro. UN News Centre. Online multimedia, available at: http://www.un.org/apps/news/story.asp?NewsID=29796&Cr=water&Cr1=agriculture. New York, USA.

White, S. & Fane, S. (2001) Designing cost effective water demand management programs in Australia. Water Science and Technology, Vol. 46:6-7, pp. 225-232.

White, S. & Turner, A. (2003) The role of effluent reuse in sustainable urban water systems: untapped opportunities. National Water Recycling in Australia Conference. Brisbane, September 2003.

WSAA (2003) Urban Water Demand Forecasting and Demand Management: research needs review and recommendations. White, S. Robertson, J. Cordell, D. Jha, M. Milne, G. Institute for Sustainable Futures UTS for Water Services Association, Sydney.

WSAA (2009) Media Release (August 19, 2009) Australia the world leader in urban water efficiency. Water Services Association of Australia. Online article, available at: https://www.wsaa.asn.au/Media/Press%20Releases/20090820%20News%20Release%20-%20Report%20Card.pdf.


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Chapter 2

Literature Review This chapter presents background information and a review of literature pertinent to the

research. The topic is introduced through an overview of the water crisis and details of urban

water consumption with particular reference to the study region of the Gold Coast. A

description of integrated urban water resource management (IUWRM) is outlined along with

Gold Coast city’s example of this water management principle. Elements of IUWRM including

supply and demand management and source substitution are all presented. A thorough overview

of earlier research on water demand management and source substitution is presented to

determine prior research investigations of the effective water savings of these initiatives. A

summary of advanced water consumption monitoring technologies, earlier end use water

consumption studies and dual reticulated precincts is presented. The chapter concludes by

outlining current gaps in the body of knowledge and detailing the research approach for this

study. An overview of literature examined in this chapter is presented in Figure 2-1.

Figure 2-1 Overview of reviewed literature topics

Figure 2-1 demonstrates the structure of the literature review as detailed in this chapter.

Demand, supply and source substitution all stem from the IUWRM. There are several elements


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under each topic with blue shaded boxes indicating the topics focused on for this investigation.

The grey shaded boxes indicate the sub-topics which have been explored in significant detail. It

should be noted that more critical reviews of literature are presented in each of the peer

reviewed papers that form the subsequent chapters of the thesis. Background information and

reviewed literature are discussed.

2.1 The Water Conditions in Australia

Australia is the world’s driest inhabited continent with the most unpredictable rainfall patterns,

hence it is important to conserve the nations already finite water supply (Birrell et al., 2005;

Commonwealth of Australia, 2008c). The Intergovernmental Panel on Climate Change (IPCC)

state that ‘observational records and climate projections provide abundant evidence that

freshwater resources are vulnerable and have the potential to be strongly impacted by climate

change, with wide-ranging consequences for human societies and ecosystems’ (Bates et al.,

2008, pp. 3). There is mounting evidence that anthropogenic caused global climate change is

increasingly affecting weather patterns (Bates et al., 2008; CSIRO, 2010). This is predicted to

result in the alteration of river runoff and water availability and cause increased precipitation

variability and intensity (CSIRO, 2007). Such changes will trigger more extreme drought and

flood conditions, decrease water supply in glaciers and snow cover, increase water pollution due

to the extreme drought and flood conditions, instigate sea level rise and alter water quantity and

quality (Pittock, 2006; CSIRO, 2007; Solomon et al., 2007; Bates et al., 2008; Allison et al.,

2009).

Studies by the Australian Bureau of Meteorology suggest that since 1910, Queensland has

become increasingly hotter and drier (Commonwealth of Australia, 2010). The southern half of

Australia is also experiencing trends of reduced rainfall by up to 50 mm annually (Anderson,

1996; CSIRO, 2010). This reduced rainfall trend is occurring over concentrated urban centres

where most of the nation’s population resides. Reduced rainfall has resulted in many southern

cities and towns rainfall dependant water supplies falling to record low levels (Commonwealth

of Australia, 2008a; ABS, 2010). South East Queensland (SEQ) recently experienced the worst

recorded drought period for both length and rainfall deficiency. This drought period was known

as the ‘Millennium drought’ extended from 2001 to 2009, finally breaking in May 2009 when

significant rainfall occurred and the combined dam water storages reached 60% (QWC, 2009).

Trends and incidence of reduced rainfall and extended drought periods have resulted in the

management of water resources being a major concern for water authorities, public and private

industries and all levels of government in Australia (Inman and Jeffrey, 2006). Traditionally, the

supply of water for cities and towns placed a heavy reliance on dams, weirs or rivers but


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changing weather patterns, increasing urban demands and detrimental impacts to freshwater

sources from urban discharges have triggered a need to move beyond such traditional source

options (Barlow, 2009). Hence, the approach is now focused on planning and adopting new

ways to manage water to meet the short-term water supply deficiencies and aid in meeting long-

term demand (Turner et al., 2005; Webb, 2007; Barlow, 2009). A common conclusion from

recent investigations and reviews of urban water supply and demand forecasts is that Australia

must invest in adequate planning now, to ensure a secure and sustainable water supply for future

generations.

2.2 Water Consumption and Demand Forecasting in Urban Australia

Australians are some of the highest water consumers in the world despite the nations well

documented low average rainfall (CSIRO, 2006). Table 2-1 details Australia’s national water

consumption in 2004-05 being 18,767 gigalitres (GL), which was a drop of 14% from 2000/01

consumption levels. Although water consumption in Australia is primarily dominated by

agricultural use, the data presented in Table 2-1 demonstrate that households and the supply of

water for urban consumption accounts for 22% of Australia’s total water consumption or 4191

GL annually (highlighted in grey).

Table 2-1 Australia’s water consumption by sector 2004-05 (ABS, 2007)

2000-01 Volume

(GL)

% of total 2004-05

Volume (GL)

% of total

Agriculture 14,989 69.1 21,191 56.0

Household 2,278 10.5 2,108 11.2

Water Supply 2,165 10.0 2,083 11.1

Other industries 1,102 5.1 1,059 5.6

Manufacturing 549 2.5 589 3.1

Mining 321 1.5 413 2.2

Electricity and gas 255 1.2 271 1.4

Forestry and fishing 44 0.2 51 0.3

Total 21,703 100 18,765 100

Urban household water supply accounts for 22% of the nations water consumption (see Table

2-1), however, in individual urban cities and towns, residential households consume between

60-70% of the total bulk water supplied (WSAA, 2009b). In Queensland on the Gold Coast, a

city with a population of 0.5 million people, residents consume 75% (08/09) of the cities total

yearly water supply (GCW, 2009a). A study by Birrell et al. (2005), which investigated the

impact of demographic change and urban consolidation on domestic water use in Australian

cities indicates that between the years 2001 to 2031, water demand in major cities will increase


- 16 -

by 37%. Moreover, Australia’s population is estimated to rise from 22 million in 2009 to 34

million in 2050, a growth rate of 2.1%, with most of this growth experienced in urban cities

(Birrell et al., 2005). Such extensive residential growth and the increasing demand of water has

triggered the focus on understanding, predicting, forecasting, measuring and validating urban

water consumption.

Determining the water demand of a city requires consideration of water services historical

records, system performance and projected changes in demand patterns (DNRM, 2005). Factors

considered for water demand predictions include potable, waste and recycled water average

demand at source, level of treatment required and the level of distribution (DNRM, 2005).

Water demand modelling elements include peaking factors (maximum day, mean day maximum

month and maximum hour), diurnal patterns, end use water consumption, fire fighting

parameters, pressure parameters, system losses and non-revenue water (WSAA, 2003). Some of

the factors which influence urban water demand forecasting and need to be considered, are

demonstrated in Figure 2-2.

Water supply system

DEMAND FORECASTING Factors influencing peak

period and/or average bulk water demand

Demographics & land use

Water using equipment

Source Substitution

Water usage practices

Climate

WeatherTourism

Occupancy rate

Population

Residential lot size

Housing type, mix & age

Losses

Pressure

Other unaccounted

flow/non-revenue water

Equipment & appliance stock &

sales

Climate change

Income + Soci-cultural factorsWater/wastewater Pricing • Technical innovation •

Restrictions • Knowledge & awareness • Regulation

Rainwater tank

Greywater

Effluent reuse

Industrial reuse

evaporation

rainfall

Max day temp

Figure 2-2 Factors that influence demand (White and Turner, 2003; WSAA, 2008)

All of the forecast parameters displayed in Figure 2-2, are relevant for the accurate forecasting

of urban demand, especially residential, but all too often ‘demand forecasting studies have

relied on projections of historical metered data without considering end uses’ or by adopting end

use data from different locations or countries (WSAA, 2003, pp. 6). Because household water

consumption differs between countries, locations and populations, it is paramount that location

specific end use data is utilised for local demand forecasting (Turner et al., 2005; Inman and

Jeffrey, 2006). This is due to the location-specific variations in climate, tourism, residential


- 17 -

characteristics, stock, education, lot size, income, attitudes and behaviours of consumers all

impacting water demand (Nieswaidomy and Molina, 1989; Renwick and Archibald, 1998;

Mayer and DeOreo, 1999; Renwick and Green, 2000; WSAA, 2003; Inman and Jeffrey, 2006).

Thus, with all of these elements influencing local water demand, there is a growing requirement

for accurate data, at an end use level (Giurco et al., 2008a). The mounting demand on

Australia’s scarce water supplies, due to population increase, has also triggered the need for

determining local residential water consumption behaviours and demand to accurately forecast

future water requirements.

Forecasting and planning to ensure a secure supply of water for future urban populations

requires the integration and adoption of supply-side, demand-side and source substitution

measures, as demonstrated in Figure 2-2 (White and Turner, 2003; Bates et al., 2008). CSIRO

scientists state that ‘measures designed to help communities to cope with reduced water supply,

such as water conservation and recycling are necessary and indeed urgent’ (Pittock, 2006, pp 1).

Growing demand, diminishing supply, population growth, rainfall variability, issues of water

source pollution and the need to ensure continued releases of water for environmental flows for

the protection of surviving downstream ecosystems, have influenced thinking towards an

integrated urban water resource management approach (Turner et al., 2007a). This encompasses

a multitude of supply, demand and source substitution solutions to manage the increasing

pressure for the provision of a secure source of water.

2.3 Gold Coast City’s Solution to the Water Crisis

The Gold Coast is one of SEQs major urban growth regions with population projected to grow

from the current 0.5 million people to approximately 2.5 million in 2056. This equates to an

equivalent water demand increase from 185 mega litres per day (ML/d) to 466 ML/d by 2056

(GCW & GCCC, 2007). With such significant increases in population and water demand, the

water management authority for Gold Coast city, Gold Coast Water (GCW), has planned for

their water future using IUWRM principles.

The Gold Coast Waterfuture (GCWF) Master Plan was developed as the long term IUWRM

strategy to meet the projected urban water requirement of 466 ML/d for 2056. The GCWF

Master Plan incorporates a cohort of supply, demand and recycling initiatives to ensure the

projected water demand is satisfied. A graphical overview of the GCWF water balance is

presented in Figure 2-3 .


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Figure 2-3 Gold Coast Waterfuture Master Plan water balance 2007 (GCW & GCCC, 2007)

Each of the IUWRM initiatives in the GCWF Master Plan (Figure 2-3 is demonstrated in Table

2-2. Additionally, the water demand that each initiative satisfies along with alternative supplies

considered to meet Gold Coast’s 2056 water requirements are outlined (Table 1-3).

Table 2-2 Gold Coast Waterfuture Water Balance (GCW & GCCC, 2007)

Initiatives Water Balance 2007 Current Strategy

(ML/d)

Percentage of total demand (%)

Existing Supply Hinze Dam and Little Nerang Dam 191 41%

Desalination 111 24%

Pressure and leakage management 30 6.5%

Rainwater tanks 20 4%

Raising of Hinze Dam including water harvesting

34 7%

Recycled water 30 6.5%

Key Initiatives

Water conservation 50 11%

Greywater Local use

Ground water Local use

Indirect potable reuse Under investigation

Local and Emerging Initiatives

Stormwater harvesting Local use

Total water needs in 2056 466 100%

The existing supply measures, before 2007, were the Hinze and Little Nerang Dams, new

supply measures included raising the Hinze Dam and desalination (desalination plant at Tugun

was operational from March 2009) (Table 1-3). Demand management initiatives of the GCWF

Master Plan include pressure and leakage management and water conservation measures such as

water efficient devices, restrictions and education of consumers. The planned source


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substitution options include recycled water and rainwater augmentation to satisfy the projected

2056 water requirements. Table 2-2 demonstrates the supply sources that will satisfy 65% of the

city’s total water demand, while the remaining 35% will be satisfied through demand

management initiatives and source substitution measures. Measuring and monitoring the supply

of bulk water is relatively easy, while measuring the effectiveness of water demand

management and source substitution initiatives to ensure they satisfy the 35% reduction in

demand is not as simple. Carrying out this evaluation process is significantly more challenging

than measuring and monitoring bulk supply but is imperative to ensure that these estimated

demand reductions and source substitution targets are actually achievable (White and Turner,

2003).

2.4 Integrated Urban Water Resource Management

Traditionally, urban water utilities made decisions based primarily on finance and engineering,

but in the last decade, significant consideration has been placed on incorporating sustainability

principles into the process (Mitchell, 2006; WSAA, 2009c). The IUWRM process involves the

planning and integration of supply, demand and source substitution options for the sustainable,

secure and reliable supply of water to meet projected future water demands of cities or towns

(White, 2001; Inman and Jeffrey, 2006; Mitchell, 2006). The combination of socio-behavioural

and technological strategies to promote water conservation is the focus (Corral-Verdugo et al.,

2002). Some of the benefits of IUWRM include (Butler and Maksimovic, 1999; White and

Turner, 2003; Mitchell, 2006):

A reduction in potable demand;

Reductions in wastewater discharges;

Reduced stormwater flows;

Lower peak flows and flood damage;

Enhanced water efficiency;

Increased variation and diversification of supply sources through the introduction of

recycled, rain, grey or stormwater;

Improvement in stormwater quality (load and concentration); and

The incorporation of green infrastructure such as wetlands for wastewater treatment.

A framework for the planning and implementation of IUWRM is detailed in Figure 2-4. These

steps include the need to: calculate the demand-supply balance; determine options for supply,

demand and source substitution; implement these initiatives; and finally to monitor, evaluate

and review the effectiveness of implemented measures. Australian water entities have actively

planned and incorporated IUWRM principles for long term water security and have been


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recognised around the world as leaders especially in water efficiency and climate change

adaptation (WSAA, 2009c).

Significant progress in IUWRM in Australia has been made by Sydney Water Corporation, The

Water Corporation in Western Australia, Gold Coast Water (GCW), Melbourne Water and

Yarra Valley Water (WSAA, 2008). Turner and White (2006) suggest that while substantial

effort is placed on the first four steps of the IUWRM framework (see Figure 2-4) that often the

final step of monitoring, evaluating and review is not adequately undertaken. This final step

feeds necessary data and information back into the demand forecasting and options models to

assess how individual programs are contributing to the overall demand management target or

the supply-demand gap (Turner and White, 2006). White and Turner (2006) specify that

monitoring and evaluation should be undertaken on individual programs to alleviate the risk of

over estimating the actual savings achieved by the programs. This is paramount for accurate

planning. The following sections present details on supply solutions, demand management and

source substitution initiatives that embody the principles of IUWRM.

2.4.1 Supply sources

Supply solutions for IUWRM place a heavy reliance on dams, with new dams being

constructed, dam walls lifted and additional weirs added to increase original storage capacities.

A study by Turner et al. (2007a) of SEQs water supply and demand options revealed that one of

the proposed supply sources, the Mary River Traveston Crossing Dam, was not actually

required to meet projected water demand in the region. The dam was rejected in 2009 under the

Australian Environmental Protection and Biodiversity Conservation (EPBC) Act 1999 due to

the environmental threat and damage posed to endangered species like the Mary River turtle and

the Australian lungfish (ABC, 2009). While dams still play an very important part in the supply

of water for Australia, the extensive community protest against dams, as seen for the Traveston

Crossing dam, and the obvious detrimental impact to existing natural and built environments

from dam projects make them a less desirable supply option. Hence there is an increased focus

on other alternatives such as desalination, water recycling and raising walls on existing dams.


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Figure 2-4 Australian IUWRM framework (Turner and White, 2006)

Desalination of sea water for potable consumption has become a favoured and climate-

independent supply-side initative (Barron, 2006). Desalination is gaining popularity because it

is neither rainfall or climate-dependent. Queenslands first major desalination plant was built at

Tugun on the Gold Coast and is capable of supplying 125 ML of water per day to SEQ (QWC,

2008a). The desalination plant in Perth has been supplying 130 ML/d or 17% of the cities water

needs since November 2006 (Water Corporation, 2010) and Sydney’s wind powered


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desalination plant, which is due for commissioning in 2010, will supply 15% of Sydney’s total

water needs (NSW Government, 2010). Increased variability of rainfall has instigated a move

towards desalination plants as a preferred supply option to meet the future water demand of

communities in SEQ and across Australia. While desalination is emerging as a preferred

measure to dams, this supply source of water does not come without negatives. Desalination is a

highly energy intensive process with the resulting water requiring mixing to ensure the taste and

salt content is not to high for consumers. Desalination plants also require continuous operation

which means that in non-drought periods this energy intensive source of water will often still be

supplied. Other issues, such as long-term potential environmental impacts from the temperature

and salt content of the brine solution (waste stream of water) disposed of in deep sea outlets and

ongoing maintenace and replacement of components also require consideration. The recycling

of waste water is another alternative supply source solution examined later in text. It is argued

that managing and reducing water demand can offset the construction of supply infrastructure

by years or decades (White, 2001; Turner et al., 2007a).

2.4.2 Demand management

Water demand management (WDM) is a key element of IUWRM, which assists in delaying the

need for new supply infrastructure (White, 2001; Anderson, 2003). It has been a significant

focus for Australia’s municipal and private water utilities, and a range of programs have been

developed to manage and reduce both residential and industrial water consumption demands

(Sarac et al., 2002; Turner et al., 2005). Aspects of WDM include pricing, legislation, metering,

conservation and education. Demand reducing initatives such as water restrictions, regulations,

water efficient devices and behavioural change programs have been introduced extensively

across Australia.

An example of a successful Gold Coast WDM program was the ‘Home WaterWise Service’,

which was first introduced in the city in 2005 and expanded across SEQ in July 2006. The

household program involved the installation of new water efficient showerheads and tap

aerators, fixing of leaking taps and information and advice on how to make a home water

efficient at a cost of just $20 to the homeowner (valued at $150) (GCW & GCCC, 2007;

Queensland Government, 2008a). The scheme concluded in 2008 and was taken up by 228,551

households or one in every six homes across SEQ. Water savings were estimated through bulk

supplied and bulk recorded water values to be 4.7 gigalitres (GL or billion litres) per annum.

A pressure and leakage reduction program was another WDM initiative introduced across all

SEQ council regions. The aim of the project was to provide water savings of 10% or 60 ML/day

through repairing leakage and reducing supply pressures in residential areas (LGIS, 2009). Such

WDM programs have been in place for several years with bulk water savings estimated and


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reported. To date, no program specific monitoring, evaluation or review of actual savings has

been carried out, nor has there been verification of savings related to the individual demand

management initatives within the programs such shower rose replacement in the ‘Home

WaterWise Service’. As discussed, undertaking such assessment and review processes is critical

to ensure the estimated savings are achieved especially for demand forecasting predictions. The

final component of IUWRM is source substitution, details are presented in the following

section.

2.4.3 Source substitution

Anderson (2003) states that source substitution is a key element of IUWRM. Source supply

substitution involves substituting traditional potable water demand with an alternative source of

water which can be either recycled, rain, grey or storm water. Source substituted water is

generally utilised for ‘fit for use’ activities or non-potable consumption activities such as

irrigation, toilet flushing or clothes washing. An alternative source of water for residential

consumption is now legislated by Part MP 4.2 of the Queensland Development Codes 2007.

These codes stipulate that residential homes must achieve water savings of at least 5 kL or 3 kL

(depending on the dwelling type) with rainwater tanks (RWTs) suggested as the most common

means to meet these requirements (Queensland Government, 2008b). This regulation, and the

assortment of rebates offered over the past few years for the installation of RWTs for existing

dwellings, has seen 240,000 RWTs installed in SEQ as at November 2009 (Moore, 2009).

The introduction of recycled water as a substitution for potable water is occuring in various

ways. Recycled water is most commonly utilised as a ‘fit for use’ source through dual

reticulation which involves a separate pipeline supplying water for irrigation and toilet flushing

(Anderson, 2003; Council of Australian Governments, 2009). Another, indirect way of use, is

introducing recycled water into water reservoirs as purified recycled water (PRW) for treatment

and distribution through the potable supply system (Turner et al., 2007a). Although it still

remains controversial, dramatic improvement in community perceptions towards recycled water

reuse have occurred recently (Nancarrow et al., 2007). This improved perception and the need

to reduce the demand on potable supply sources have enhanced the introduction and acceptance

of recycled water as a source substitution alternative (Dimitriadis, 2006). Additional detail on

the specific elements of both water demand management and recycled water as a source

substitution alternative are presented in the following sections.

2.5 Water Demand Management

Water demand management (WDM) is defined as the practical ‘development and

implementation of strategies aimed at influencing demand to achieve efficient and sustainable


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use of a scarce resource’ (Savenije and van der Zaag, 2002, pp. 98). Managing and reducing

demand is based on reducing everyday average water consumption to minimise the pressure on

dwindling potable water supplies or to assist in filling the gap between supply and demand

(Tate, 1993; Deverill, 2001; Brooks, 2006; Turner et al., 2007b). Indoor WDM programs have

the additional benefit of reducing the volume of water discharged into sewerage systems

(WSAA, 2009c). Application of WDM is a particually important and useful initiative in rainfall

limited areas and its application is required throughout the world to meet the goal of sustainable

water and resource consumption. WDM measures are generally the most sustainable solutions

across environmental, social and economic factors, when considering the range of options

presented for water supply security (Turner et al., 2007b; White et al., 2007). WDM measures

focus on reducing end use consumption hence, offsetting the need for additional water supply

and wastewater treatment, which can be costly and environmentally and socially detrimental.

Demand management initiatives are focused on supplying tools, mechanisms and knowledge to

enable consumers to continually reduce their potable water consumption (Turner and White,

2006). The WDM approach relies heavily on consumers to understand how to reduce their water

consumption and to apply this understanding to everyday activities. There are numerous

elements of WDM which can be classified in various ways for example technological, financial,

legislative, operation and maintenance, and educational (Inman and Jeffrey, 2006). These are

commonly referred to as restrictions, regulations, efficient devices, and educational behaviour

altering tools (White, 2001). A description on this array of WDM initatives is detailed in the

following sections some of which are not directly related to this research but are included to

give an overarching view of demand management.

2.5.1 Water metering

Water metering, a technological or engineering initiative, was the first major WDM measure to

be broadly implemented across Australia. Its introduction arose largely from the well

established maxim of ‘if you can’t measure it, you can’t manage it’ (Mitchell, 2006). Metering

water consumption and charging per unit (kilolitre) of water used, gives water a dollar value and

signifies to users that the more they consume the more they are charged (Inman and Jeffrey,

2006). Research across the world has demonstrated that reductions of up to 56% can occur after

the installation of water meters although consumption behaviour may not remain consistently

low as consumers grow accustomed to metering (Linaweaver et al., 1966; USEPA, 1998;

Maddaus, 2001; Inman and Jeffrey, 2006). Water metering of residential consumption occurs in

almost all Australian cities. Metering water consumption at the residential boundary is a well

established and effective WDM initiative which has been shown to reduce water consumption

(UKWIR, 1996; Inman and Jeffrey, 2006) hence, this was not a focus of this research.


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2.5.2 Enforcement

Water Restrictions

Water restrictions, regulations and environmental labelling are all enforcement initiatives

applied to achieve water savings. Water restrictions are the most common WDM introduced

nationally to reduce residential water consumption due to the fact that external water use is

generally considered nonessential in times of drought (Syme et al., 2004; Brennan et al., 2007).

Australian water restrictions focus on limiting outside watering and stipulating the time of day

for watering or defining external water use fixtures allowed for use i.e. a hose or bucket

(Barrett, 2004). Recent severe drought conditions in SEQ have resulted in restrictions

stipulating the amount or volume of water used internally and externally. For example, each

person has a daily allocation of 140 to 230 litres per person per day (L/p/d). The water

restriction levels becomes more severe or restricting with dropping supply sources i.e. 60%

capacity in the dam allows for a daily allocation of 230 L/p/d while 20% capacity in the dam

results in the allocation of 140 L/p/d. Earlier research by Nancarrow et al. (2002) determined

that while residents are supportive of regular low level restrictions (i.e. watering 2 to 3 days per

week over summer) they were not supportive of permanent or severe restrictions (i.e. no

external water use or bucketing water only for long periods). Water restrictions are very

effective in reducing water consumption (Barrett, 2004) and have been in place in Australia for

decades. The effectiveness of restrictions was investigated by the United Kingdom Water

Industry Research (UKWIR, 1998) and Inman and Jeffrey (2006), with savings of up to 49%

recorded. The effectiveness of water restrictions as a potable water saving mechanism has been

well established hence this is not a focus of the research.

Regulation and Legislation

Regulating and legislating the use of new efficient water use fixtures and stipulating demand

reductions in building codes has been found to to be a very effective enforcement measure

(Barrett, 2004). The Queensland Development Code (2007) Part MP 4.1 mandates that all new

houses and townhouses (class 1 buildings) and units (class 2 buildings) must have minimum of

3-star Water Efficiency Labelling and Standards Scheme (WELS) rated toilets and showerheads

(Queensland Government, 2009). In fact, all new detached households in SEQ must meet water

saving targets of 70 kilolitres per year (kL/yr) while Class 2 dwellings must save 42 kL/yr

(Queensland Government, 2008b). Suggestions to achieve these savings include the installation

of low flow shower heads, dual flush toilets and RWTs (Queensland Government, 2007).

Research into quantifying the water savings attributed to mandatory installation of rainwater

tanks is being undertaken by Beal et al. (2010).


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Labelling The Australian Water Efficiency Labelling and Standards Act 2005 is the Australian Act which

stipulates water efficiency labelling and regulates water efficiency standards (Commonwealth of

Australia, 2005). The Australian WELS scheme was introduced under the Act in July 2006 to

register and label products with water efficiency ratings, Figure 2-5 demonstrates a label

awarded through WELS (Commonwealth of Australia, 2009).

Figure 2-5 WELS water rating label (Commonwealth of Australia, 2009)

The introduction of WELS is estimated to result in a 5% annual reduction of domestic water use

through informed consumer selection of the most appropriate and water efficient product

(Commonwealth of Australia, 2009). Exhibiting certified water consumption information on

water use devices ensures that the consumer understands the device or fixture’s consumption

when purchasing products. Monitoring the effect of national regulations and environmental

labelling would require an Australia wide investigation, hence this has not been included in the

scope of this research.

2.5.3 Water pricing

Water is one of the lowest priced resources when compared to other resources like electricity or

fuel. When pricing for water per kilolitre was first introduced in Australia, it was suggested that

it may reduce residential water consumption by approximately 30% (Barrett, 2004). Researchers

predicted that pricing water per unit and hence payment for what water consumers actually use,

would be an effective economic demand management option (Inman and Jeffrey, 2006).

However, it was found that in most cases, water demand is price inelastic because of its low cost

(Espey et al., 1997; Renwick and Archibald, 1998; Hoffmann et al., 2006). Barrett (2004)

reports that the review of 30 residential water price demand studies resulted in almost all

indicating price inelasticisities. However, the effect of water pricing has been found to differ

between location, income and other demographic related parameters. Thomas and Syme (1988)

and Barrett (2004) state that consumers with larger external use were more likely to be sensitive

to price changes while, indoor use is relatively unaffected by cost. Therefore, increasing the cost

of water will have some impact on certain consumers but for pricing to have a significant impact


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on residential water consumption the cost of water must be greatly increased (Barrett, 2004). On

the Gold Coast, the cost for water in the 2009/2010 financial year is $2.24 per kilolitre ($/kL).

Within five years, water prices in South East Queensland have been predicted to rise to between

$3 and $4/kL (Hertl, 2009). This predicted increase on the cost of water may justify future

research to determine the point at which water consumption would be influenced by price. Such

an investigation would need to be carried out on a city wide scale.

2.5.4 Engineered water efficient devices

Pertinent to the research is the application and measurement of effective savings related to

engineered water efficient devices. Advances in technology have seen the development and

introduction of highly efficient low water use devices. New engineered water use fixtures

include low flush toilets consuming just 3 litres (L) (half) or 4.5 L (full) per flush, clothes

washing machines using as little as 42 L per load, shower heads using as little at 5 L per minute,

taps with aerators that use 1.5 L per minute and dishwashers which use as little as 7 L per wash

(Commonwealth of Australia, 2009). The efficiency of these devices is regulated by WELS. The

use of water efficient devices in households is regulated by the Queensland Development Codes

(2007), hence many existing, and all new dwellings are taking up more water efficient devices.

Retrofitting households with water efficient devices has proved to be very successful, with

savings of 12-50% reported (DeOreo et al., 2001; Mayer et al., 2004; Inman and Jeffrey, 2006).

In the USA, an end use study by Mayer et al. (2004) found that water savings were highest in

toilets and clothes washers with leakage primarily from toilets, significantly reduced. This

investigation involved a pre and post measurement of end use water consumption in 26 homes

in Tampa, USA. This is the only reported retrofit measurement utilising end use water

consumption data in the literature. A larger sample size would assist to confirm the findings and

additional local Australian examples of retrofit investigations would assist to validate the

reported savings.

In Australia, information on the effective water savings achieved by WDM programs is quite

limited and significant differences in both usage and savings are observed between research

findings (Sarac et al., 2002). Estimations of water savings from water efficient devices are often

made in laboratories without consideration of the human behavioural influence on actual water

savings (Biermayer, 2006). These estimations are generally based on American data which

significantly differ from Australian water consumption, for example toilet consumption is

significantly higher in America, average of 13-15 L/flush, than Australia, average of 6-9 L/flush

(Mayer et al., 2004; Roberts, 2005).

Sarac et al. (2002) undertook an investigation to determine the effective bulk water savings

attributed to three separate demand management programs in New South Wales, Australia to


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provide some local data on WDM effectiveness. A comparison group analysis technique was

adopted to estimate the potential impact of WMD programs, which included the ‘house tune up

program’, ‘pilot retrofit program’ and the ‘smart showerhead program’. Before initiatives were

implemented, the groups had relatively similar bulk water consumption. Those residents who

participated in any of the three WDM initiatives were found to consume significantly less bulk

water than those in the control group who had not participated in the WDM initatives. Details of

this invesigation is presented in Table 2-3 (Sarac et al., 2002).

Table 2-3 Savings from various WDM measures (Sarac et al., 2002, pp. 7)

Measures Installed Estimated Savings (kL/a)

Efficient showerhead 14.5 ± 10.3*

Tap aerator / regulator 20.2 ± 40.0

Cistern weight / flush arrestor 11.0 ± 22.3

Tap aerator / regulator and cistern weight / flush arrestor 11.0 ± 18.1

Efficient showerhead and cistern weight / flush arrestor 18.4 ± 7.8*

Efficient showerhead and tap aerator / regulator 19.6 ± 7.8*

Efficient showerhead and cistern weight / flush arrestor and tap aerator / regulator

23.3 ± 6.5*

*significant reduction at a 0.05 level of significance

As displayed in Table 2-3, estimated bulk water savings still have significant error values, due

to the small sample sizes which produced a high variance for estimated savings and confidence

intervals (Sarac et al., 2002). The Sarac et al. (2002) investigation demonstrates the need for

larger sample sizes for evaluating the effective savings attributed to water efficiency of devices

and also triggers the need for more effective and accurate measurement of water consumption

and savings, moving beyond the use of bulk meter read data to more accurate measurement

technologies.

Another Australian study was carried out by Kidson et al. (2006) to estimate water savings from

retrofitting a 4A rated front loading washing machine. A comparison of pre and post bulk water

consumption of households against a control group utilising a regression correction model

technique for the impact of restrictions and climate was adopted to determine end use water

savings. Kidson et al. (2006) calculated water savings of 23.2 ± 5.7 kL/household/annum, which

is a 25% variation. This again demonstrates the need for the accurate measurement of savings

beyond bulk water meters. Stewart et al. (2005) have also made predictions on achievable SEQ

water savings attributed to water efficiency programs with findings stating that a 100%

utilisation of water efficient devices would be likely to reduce internal water demand by 32%.

This estimation is made from end use data from Perth and Yarra Valley and other non-disclosed

literature sources. Again, the reported efforts to understand the effectiveness of initatives often

involves monitoring at a bulk water consumption level, the utilisation of data from different

locations or modelling of water savings without consideration of where, how and why water


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savings were occuring. The error and variance demonstrated in the measured or calculated water

saving potential of efficient devices underlines the need for accurate data measurement of actual

water savings beyond bulk water consumption.

As previously outlined, the Queensland ‘SEQ Home Waterwise Sevice’ retrofit program was

estimated to result in savings of 4.7 GL/yr or 13.14 ML/d for the 228,511 retrofits completed by

November 2008 (QWC, 2008b). However, no analysis or assessment has been reported in the

literature to determine if this estimated figure is valid, nor has there been any reported follow up

to assess individual household water savings. A similar program in Sydney was evaluated

through bulk meter readings by Turner et al. (2005) with savings of 20.9 ± 2.5 kL saved per

annum. Attempts were made to assess the savings attributed to the individual initiatives in the

program although this was on a bulk meter read scale (Turner et al., 2005). This earlier research

reports that the evaluation of water efficiency in Australia has generally relied on bulk water

meter read data, modelling or estimations to calculate savings.

The importance of monitoring the impact of individual initatives is justified through examples

of water efficient devices actually resulting in an increase in water consumption. Inman and

Jeffrey (2006) report a case where exchanging to lower flow showerheads resulted in increased

bulk water consumption due to the users believing that because they had a water efficient

device, they could shower for a longer duration. Other cases of higher water consumption in

households with water efficient fixtures in eco-friendly subdivisions in SEQ have been reported

by Beal et al. (2008). These examples of increased water consumption, indicates that education

and awareness of sustainable water practises is an crucial component of WDM and that

accurately evaluating and measuring water savings attributed to WDM initatives is vital.

The best example of measuring the water savings attributed to efficient devices is presented by

Roberts (2005) in Yarra Valley who undertook an end use study which detailed the difference in

water consumption for various efficiency levels of shower heads, toilets and clothes washers in

2004. The efficiency of devices was determined through a survey of household water usage

stock in 2003 (Roberts, 2003), followed by the measurement of residential end use in 2004 of

100 homes using smart metering and Trace Wizard© to establish end use water consumption

(Roberts, 2005). Data analysis was carried out by the USA company AquaCraftTM with the

water savings attributed to efficient devices determine through their end use consumption

volumes. While Roberts (2005) investigation is the most accurate measurement of the efficiency

of devices in Australia, it did not consider the impact of residential attitudes on consumption or

the effect of retrofitting and analysis was undertaken by experts from a country with very

different water consumption for devices and households. The differences in location based

consumption, uptake of efficient fixtures and advances in efficiency technology since 2004


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necessitate the need to undertake further research in this field. Mayer et al. (2004) state that the

effective water savings related to WDM initiatives is highly dependent on the characteristics of

water consumers, which consists of attitudes, beliefs and behaviours towards water and the

environment in general. Hence, to understand local water demand and residential consumption it

is imperative to understand the behavioural characteristics of consumers.

2.5.5 Education and awareness

Education of consumers on water conservation practices is essential to encourage and develop

sustainable water consumption behaviour. Knowledge transfer is a key component for changing

behaviour and attitudes towards water use (Webb, 2007). Attitudes and beliefs of consumers

have been found to impact on water use behaviours which, in turn, is linked to water demand

(Hassell and Cary, 2007). Education and awareness of water conservation has been found to

reduce public water usage with earlier research indicating a reduction in water consumption

through education resulting in between 2 – 12.3% savings annually (Nieswaidomy, 1992; Inman

and Jeffrey, 2006). However, determining the effective water savings related to improved

awareness is difficult as this WDM initative is intrinsically linked with other WDM strategies

(Corral-Verdugo et al., 2003). Encouraging residents toward sustainable water consumption

practices requires the instilling of awareness, understanding and appreciation of the environment

and water. Determining motives for saving water and understanding the link between attitudes

and actual behaviour is also paramount when considering educational water saving strategies

(Lant, 1993; Howarth and Butler, 2004).

The connection between attitudes and beliefs concerning water and the environment and their

relationship on actual water consumption behaviour has been established, however empirical

studies quantifying this link are limited (Nancarrow et al., 1996; Hassell and Cary, 2007). For

example, Lawrence and McManus (2008) undertook an investigation to determine the impact of

sustainable lifestyle workshops on water consumption in households. Questionnaires and bulk

meter read household water consumption were utilised with results indicating that the

sustainability programs did not result in significant water savings for residents. This indicated

that the relationship between improved environmental behaviour and actual water savings is not

as straightforward as previously assumed (Lawrence and McManus, 2008). This finding also

suggests that the use of bulk supplied water consumption data may not be suitable for evaluating

the relationship between consumer attitudes and water consumption. Lawrence and McManus

(2008) recommended the use of real and accurate water consumption data rather than bulk meter

read data or estimations derived for assumed behaviour change. Another study conducted by the

CSIRO (2002) revealed that attitudinal variables do affect external or outdoor water

consumption but explicit description of the link between attitudinal factors and actual indoor

end use water consumption was left undescribed. Hence, there is a strong need for further


- 31 -

investigation into the effect of attitudes on end use water consumption due to the lack of

empirical studies in the current body of knowledge. This research aims to redress this gap in the

literature and state of knowledge.

2.6 Source Substitution with Recycled Water

Water conservation and the reuse of wastewater and storm water is encouraged by the

Australian National Water Initiative (COAG, 2009). As discussed, alternative sources of water

are critical in augmenting the diminishing supply of potable fresh water (Dimitriadis, 2006;

Dolnicar and Schafer, 2006). Demand reduction and management assist in delaying the need for

new supply sources, however, these alone cannot resolve the pressure on diminishing water

supplies. Alternative sources of water must be made available for consumption as populations

grow and rainfall patterns become increasingly irregular (Dolnicar and Schafer, 2006).

Currently, Australia only recycles between 9 to 14% of all produced wastewater, which is a very

small percentage especially when almost 50% of the water needs of irrigators and urban water

users could be supplied by recycled water (WSAA, 2009a). Australian legislation and standards

specify that a minimum of 20% water reuse should occur by 2012 in individual states or

territories (Shaw, 2009). Actions are underway to achieve this goal with continued investment

in recycling schemes, such as source substitution, resulting in an increase in recycled water

reuse of 118% between 2002 and 2009 (WSAA, 2009a).

In the urban environment, recycled water is defined by the National Water Commission (2006,

pp. 23) as ‘treated effluent that is used by either the water utility itself, a business supplied by

the water utility, or supplied through a third pipe system for urban reuse’. The reuse or recycling

of wastewater for residential use generally occurs through source substitution of potable water

with an alternative ‘fit for use’ water source which does not necessarily require potable water,

for example irrigation, toilet flushing or clothes washing (Hurlimann and McKay, 2006b).

Source substitution has become a well accepted, favoured and utilised method to alleviate the

escalating demand, due to increasing populations, on potable water sources and is promoted as

sustainable and a viable component of the urban water cycle (White and Howe, 1998;

Commonwealth of Australia, 2002; Brown and Davies, 2007). In Australia, one of the most

significant focuses of ‘fit for use’ water substitution and recycled water reuse is through the

application of dual reticulated water supply in new developments (Hurlimann and McKay,

2006a). Recycling or reclaiming water for reuse in specified end uses through a dual reticulation

supply system is well accepted as an effective and sustainable measure of water conservation

(Anderson, 1996; Marks and Zadoroznyj, 2005; Po et al., 2005).


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2.6.1 Dual reticulation

Residential reuse of recycled water occurs through the provision of an additional supply

pipeline referred to as dual reticulated infrastructure. Dual reticulation is a water supply system

comprising of two separate main supplies to the consumer; one potable drinking water and the

other non-drinking recycled water (WSAA, 2002; Gold Coast Water, 2004). In dual reticulated

residential regions, each supply pipe connects to appropriate end uses within the household,

with recycled water supplied for toilet flushing and all outdoor irrigation uses with the exception

of filling pools and spas (Gold Coast Water, 2004; Marks and Zadoroznyj, 2005; Kidson et al.,

2006). The recycled water pipe has a distinctive purple colour to avoid any confusion between

supply pipes.

In Australia’s drought prone environment, the introduction of an additional reclaimed source of

water through dual reticulation enables outdoor use when water restrictions are in place

allowing households the freedom to irrigate externally. Other benefits associated with the reuse

of recycled water include: the utilisation and reuse of a once considered ‘waste’ form of water,

decreasing waste water discharges to the environment and reducing the need to obtain more

potable water (Dimitriadis, 2006; Hurlimann and McKay, 2006b). The downside to having a

second piped supply system is the cost of the second reticulated network and additional

household plumbing required to safeguard against cross connections (Anderson, 1996). The cost

to supply recycled water via dual reticulation has been estimated as $AUD2.50/kL (Anderson,

1996).

2.6.2 The Pimpama Coomera Waterfuture Master Plan

A significant portion of Gold Coast’s residential population growth has been projected to occur

in Pimpama Coomera (PC) in the northern region of the Gold Coast (Po et al., 2003). As this

region was largely undeveloped, GCW set about introducing numerous sustainable water

solutions for the greenfield development. Hence, the Pimpama Coomera Waterfuture (PCWF)

Master Plan was developed by GCW and Gold Coast City Council (GCCC) to ensure the supply

of sustainable water and wastewater services to one of Australia’s fastest growing residential

areas (Po et al., 2003). The population in PC is expected to reach 150,000 by 2056, hence

sustainable IUWRM planning for this region was required (Gold Coast Water, 2008c). The

PCWF Master Plan integrates dual reticulation, rainwater tanks, water conservation through

WDM measures, stormwater management and smart sewers to ensure the sustainable use and

management of water in the region. Figure 2-6, depicts a home with ‘fit for use’ water sources

in the PCWF region.


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Figure 2-6 Pimpama Coomera Master Plan – household water uses (Gold Coast Water, 2008b)

The PCWF dual reticulation scheme is a centralised distribution system whereby wastewater is

collected in smart sewers (lower infiltration) and treated in a central wastewater treatment plant

(WWTP) (Figure 2-6). This water is then treated to Class A+ recycled water, the highest quality

of recycled water for non-drinking purposes in Queensland, at a recycled water treatment plant

(RWTP) located in Pimpama. Dispersal of Class A+ recycled water to the region occurs through

a separate recycled water line (purple) to all houses within the PC area for approved end uses,

noted in Table 2-4. Class A+ water in the PC region is used for external uses such as irrigation,

car washing or water features, as well as toilet flushing (WSAA, 2002). Detailed in Table 2-4

are recycled water uses for the PC region.

Table 2-4 Class A+ recycled water uses (GCW, 2009b)

Class A+ can be used for Class A+ cannot be used for Irrigation of lawns, gardens, fruit trees and

vegetable crops (fruit and vegetables should be rinsed in drinking water before consumption)

Flushing toilets Washing cars, houses and other similar

outdoor uses Filling ornamental ponds, water features and

fountains Approved commercial, construction and

industry uses Fire fighting

Drinking Cooking or kitchen purposes Personal washing such as baths, showers,

bidets and hand basins Domestic evaporative coolers Washing clothes Swimming pools and spas Recreation, such as playing under sprinklers

and water toys A water source for pets and livestock Filling rainwater tanks or other storages


- 34 -

The PCWF scheme is the first in Australia to deliver dual reticulation to a greenfield region

through a centralised distribution scheme. Other residential dual reticulated schemes are

generally introduced on a development by development basis. Initial planning predicted a

reduction in potable water consumption of 84% for households in the PCWF region compaired

to existing communities. Details of predicted water savings are listed in Table 2-5.

Table 2-5 Water use in Pimpama Coomera versus existing communities (Gold Coast Water, 2004)

Existing Communities Pimpama Coomera Master Plan Community Use Water

Source % Water

Used Use Water Source % Water

Used Kitchen, bathroom, laundry, hot water system and external uses

Drinking (potable) water

100% Kitchen and trickle feed to RWT when empty

Drinking (potable) water

16%

Bathroom, laundry, hot water system

Rainwater tank (RWT)

25%

Toilet flushing and external uses

Recycled water 45%

Water saving through WDM measures

14%

It can be seen from Table 2-5 that 45% of existing community consumption is to be replaced by

recycled water and that another 14% of the water demand in 2056 will be met or removed due to

water conservation measures (Gold Coast Water, 2004). The use of rainwater makes up the final

potable water augmentation of 25%. Planning for the scheme was finalised in 2004 with

recycled water coming online in December 2009. Table 2-5 demonstrates where demand

management and source augmentation measures are applied to various end uses. Unfortunately,

the proposed use of rainwater for hot water consumption was not approved which, has altered

the ultimate water savings achievable by the PCWF scheme. To quantify and validate that the

PCWF Master Plan is meeting the estimated water savings, research at an end use level is

necessary to identify the effectiveness of individual initiatives. This research investigation,

described throughout the following chapters, will monitor end use water consumption in the PC

region and determine the effective potable water savings attributed to WDM measures and dual

reticulation. Earlier studies in the dual reticulation and end use water consumption domains

were explored to determine where additional knowledge could be provided.

2.6.3 Overview of dual reticulated schemes in Australia

Numerous residential developments adopting dual reticulation have been implemented in

Australia. Some of the more prominent schemes include Mawson Lakes (Adelaide), New Haven

Village (Adelaide), Rouse Hill (Sydney Water), Aurora (Melbourne), Marriott Waters

(Melbourne) and the PCWF scheme (Gold Coast). Table 2-6 presents an overview of Australia’s


- 35 -

in-ground dual reticulation schemes and details estimates or measurements of actual potable

water savings being achieved from the introduction of recycled water.

Table 2-6 Summary of dual reticulated schemes in Australia

Scheme Description Recycled water end uses

Predicted/actual potable water savings

Rouse Hill, Sydney (Sydney Water, 2008)

Online 2001 Will serve up to 36,000 homes Centralised supply system

Toilet & Outdoor uses

Predicted = 40% Actual = 35-40% reduction on total demand

Mawson Lakes, Adelaide (Hurlimann and McKay, 2006b)

Online 2005 Will serve up to 3500 homes


Prediction = 50% of householder’s water demand (265 kL/year)

New Haven Village, Adelaide (Fearnley et al., 2004)

65 homes Toilet & Outdoor uses

Prediction = 30-40% Actual = 50%

Aurora (VicUrban), Melbourne (Baldwin, 2008)

8,500 lots Development onsite collection & reuse


Prediction = Up to 45% (recycled water & conservation)

Pimpama Coomera, SEQ (Gold Coast Water, 2004)

Online end 2009 Will serve up to 45,000 homes Centralised supply system


Prediction = 35-45%

Marriott Waters, Melbourne (Victorian Government, 2009)

Online February 2009 Currently 100 homes On completion 1000 homes Dual reticulated development supply


Prediction = Up to 40%

The data presented in Table 2-6 demonstrate that recycled water is well utilised in operational

dual reticulated regions and that predictions of uptake have been similar to those measured for

mature schemes. Residents in New Haven Village in Adelaide are using up to 50% of their total

water consumption as recycled water (Fearnley et al., 2004). Residents of Rouse Hill use

between 35-40% of their total household water consumption as recycled water (Kidson et al.,

2006; Sydney Water, 2008). The price of recycled water was determined to be an important

issue especially in Rouse Hill where residents were consuming higher volumes of total water

than residents in conventional single reticulated suburbs when the price of recycled water was

just 28 cents/kL compaired with potable water at 98 cents/kL.

As demonstrated, numerous dual reticulation schemes have been planned and implemented with

the potential demand of recycled water estimated and bulk metered water consumption figures

reported on when available. To date, no investigation has been undertaken in Australia or the

world, to detail the end use consumption of recycled water in dual reticulated regions (WSAA,

2002). It is important to undertake such investigations to determine what percentage of water is

consumed through irrigation and toilet flushing so this data can assist in the determination of the

variation in supply required in peak and low demand times.


- 36 -

This research seeks to fill this gap in knowledge by investigating the potable and recycled end

use water consumption of the greenfield dual reticulated Pimpama Coomera scheme located in

the Gold Coast, Queensland. To meet this objective, advanced water consumption monitoring

technologies were adopted.

2.7 Advanced Water Consumption Monitoring Technologies

Advanced water consumption monitoring technologies, such as smart metering, allow for the

collection of detailed water consumption data. As discussed, gaining empirical evidence of how

and where water is used and determining the effectiveness of specific WDM strategies and

source substitution initiatives is critical for planners, utilities and conservation professionals.

Planning a secure supply of water for future demand, requires the use of a range of consumption

estimations and assumptions on the effective savings attributed to demand management

initiatives or substituted supplies (Turner and White, 2006). Advanced water consumption

monitoring technologies provide a platform to collect accurate data to verify some of the

estimations made in water planning process. Details on current advanced water consumption

monitoring technologies are presented.

2.7.1 Smart metering

Smart meters provide additional high quality water use information, such as end use or leakage

data, which benefits water utilities and policy makers alike (Giurco et al., 2008b). Smart

metering couples two distinct elements for the collection of such disaggregated water

consumption data: technologically advanced meters that capture water use information, and a

communication system which both captures and transmits usage information in real or almost

real time intervals (New York State Energy Research and Development Authority, 2003). The

three essential functions performed by smart water meters are: automatic and electronic data

capture, collection, and the communication of water usage data (real time or almost) (Idris,

2006). In practice, a smart water meter configuration involves a high resolution water meter

linked to a data logger, which captures water use data that can be downloaded as an electronic

signal and analysed using available technology (Britton et al., 2008; Stewart et al., 2009). The

electronic signals from smart meters can also be transferred to computers or central data hubs

via data distribution technologies like the GSM network (Hauber-Davis and Idris, 2006). An

example of a smart water metering set up is displayed in Figure 2-7.


- 37 -

Figure 2-7 Typical smart meter set up in residential household (Stewart et al., 2009)

Smart metering technology has enabled the accurate and reliable measurement of water

consumption data of a range of resolutions, which is useful for identifying the effectiveness of a

variety of WDM measures. The resolution of the water meter and data loggers utilised in the

smart metering system determines the richness of data obtained. Current, large scale smart

metering systems utilised for leak detection, peak demand identification and time-of-use tarriffs

have lower resolution water meters and only log at hourly intervals as this is adequate for the

information required (Stewart et al., 2009). Detailed end use water consumption data requires a

smart metering system with higher resolution water meters and data loggers that record

information in 5-10 second intervals (Giurco et al., 2008a). Figure 2-8 demonstrates several

WDM and source substitution initatives with the need for smart metering to determine effective

water savings indicated. More than half of the displayed initiatives require a smart metering

approach to effectively determine and measure the water saving potential.

New Dwelling Development City

Existing Dwelling

Pricing

Restrictions

Volumetric charges, seasonal, time of use

Optimise rules for frequency and duration, drought pricing

Recycling

Desalination $

Stormwater

Efficiency

Rain tanks $

Leaks Role for smartmetering

SCALE

Figure 2-8 Potential for demand reduction and alternative supply options across scales (Stewart et al.,

2009)


- 38 -

Figure 2-8 shows that obtaining high level disaggregated data through smart metering allows for

identification of actual water savings of differing WDM or source substitution initiatives (Inman

and Jeffrey, 2006). Figure 2-9 demonstrates the increasing cost and complexity required to

measure various WDM initiatives, which instigates the need for more complex advanced smart

metering configurations.

Figure 2-9 Matching technologies to objectives (Giurco et al., 2008a)

Advanced smart metering technology allows for the capture of high resolution end use water

consumption data, which is necessary to ascertain the water savings attributed to individual

WDM programs. Figure 2-9 further demonstrates that end use data is imperative to determine

the effectiveness of most demand management measures such as efficiency and education, and

is also required for restrictions and pricing effectiveness. End use monitoring is also useful for

evaluating, measuring and validating planning the demand and supply of water (White and

Fane, 2001).

2.7.2 End use studies

Water end use studies provide the necessary data for the determination of where, when, how and

why residents consume water in the home (White, 2001; Giurco et al., 2008a). The purpose of

an end use study is to determine water consumption in individual household end uses which

include shower, toilet, tap, irrigation, clothes washer, dish washer, leaks and evaporative air

conditioners (Gato, 2006). Figure 2-10 details household water end uses.


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Figure 2-10 Household end uses of water

End use studies allow for the dissemination of technological and behavioural aspects of water

consumption and they offer ‘significant opportunities for providers to improve water service

delivery and long term planning’ (Giurco et al., 2008a, pp. 1). End use studies also provide

(Gato, 2006; Giurco et al., 2008a):

Valuable information on daily demand patterns;

Seasonal variations in water consumption;

The split of indoors versus outdoor consumption;

The actual water use for fixtures and fittings;

Information for water planning and design;

The ability to measure the effectiveness of WDM initatives, geographical or community

variations in consumption; and

Assistance in detecting leaks.

Such data are pertinent for daily demand forecasting and for the refinement in the planning and

management of water demand and supplies for regions (Gato, 2006; Schlarfrig, 2008). Giurco et

al. (2008a) emphasise that there is limited data on end uses in Australian cities and towns

despite the fact that several end use studies have been undertaken in the country. This is due to

the unique climate, tourism and consumption characteristics of each city or town and also the

dramatic changes seen in water consumption over years. Schlarfrig (2008) states that there is


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increasing recongnition for the need of more comprehensive and frequent end use studies.

Giurco et al. (2008a) and WSAA (2003) recommend further research in the end use water

consumption field. Mayer and DeOreo (1999) also stipulate the need for location and country

based research due to per capita consumption being significantly variable between regions and

populations within the world.

The first recorded end use study was undertaken in the USA by Brown and Caldwell (1984)

with the objective of measuring end uses of water in residential structures through

instrumentation and laboratory testing. This investigation of 200 homes determined water use

for fixtures and water conservation devices with estimations made on the frequency of use,

duration and flow rate. The result of the investigation saw estimated savings of water

conservation devices spanning a range of 300%, hence Mayer and DeOreo’s (1999) observation

on the need for precise end use water consumption data on individual residential water uses

measured through advanced metering techniques. The concept of measuring residential end uses

of water through the collection of instantaneous water consumption flow data was realised by

AquaCraft® between 1994 and 1996 in the USA (DeOreo and Mayer, 1994). AquaCraft

developed the Trace Wizard© software to automatically disaggregate flow traces into household

end uses (DeOreo et al., 1996), they subsequently carried out the USA AWWA (1999) and

Tampa (Mayer et al., 2004) end use studies. Some critisism occurred from Koeller and Gauley

(2004) on the data logging and Trace Wizard© methodology used to determine water end use.

Koeller and Gauley (2004) reported a pilot trial from a single (1) home focussing on toilet

flushing and stated that errors occur in the program when simultaneous events (an event on top

of another) occurred. This resulted in the underestimation of the volume and number of events

for toilets and tap use. It was recommended that the Trace Wizard© software was refined to

allow the user to visually inspect and allocated overlapping or simultaneous events (Koeller and

Gauley, 2004). DeOreo and Mayer (2004) responded to this through the presentation of results

from end use studies which demonstrated consistency of end use results, that the number of

toilet flushes were accurate, that toilet flush volumes were recorded at a 95% confidence

interval and they presented the upgraded version of Trace Wizard©, which had refined the

simultaneous events issue, was avaliable at the time of the Koeller and Gauley (2004) report.

DeOreo and Mayer (2004) report that the accuracy of end use analysis was improved through

program refinement. It was also suggested that improved end use data accuracy can be obtained

through independent analysis of data by several analysts and through undertaking a home visit

or audit to assist in determining water use fixtures and behaviours of the home being analysed.

The question of the accuracy of Trace Wizard© is acknowledged with the developers further

discussing the accuracy and limitations of the software. The result of this debate was the

continued use of Trace Wizard© as the worldwide end use analysis tool.


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End use studies have also occurred in Yarra Valley (Melbourne), Perth and Toowoomba in

Australia and the Kapiti Coast in New Zealand. Table 2-7 summarises the results from the most

recent worldwide end use studies. Reported data is from single detached households only all

analysed using Trace Wizard©.

Table 2-7 Summary of findings from other water end use studies

Author Study title Country Region No. homes

Avg. consumption (L/p/day)

End use or additional factors investigated

Mead (2008)

Investigation of Domestic End Use

Australia Toowoomba

10 Indoor & outdoor = 122

End use only

Heinrich (2007)

Water End Use and Efficiency Project (WEEP)

New Zealand

Kapiti Coast

12 Indoor & outdoor = 184.2 Summer: 203.9 Winter: 168.1

End use only

Roberts (2005)

Residential End Use Measurement Study (REUMS)

Australia Yarra Valley

100 Indoor = 169 Outdoor = extra 20% = 34

End use only

Mayer et al. (2004)

Tampa Water Department Residential Water Conservation Study

United States of America

Tampa 26 Pre retrofit = 752.9 Post retrofit = 403.9 (indoor & outdoor)

End use and retrofitting

Loh (2003)

Domestic Water Use Study

Australia Perth 124/ 120

Indoor = 155 Outdoor = extra 54% = 83.7

End use only

AWWA (1999)

Residential End Uses of Water (REUW)


12 regions

1188 Indoor = 262.3 Indoor & outdoor = 650.3

End use only

Table 2-7 demonstrates the variability between the sample sizes, ranging from as little as ten

homes to an impressive 1188 homes along with the average consumption in litres per person per

day (L/p/d). Indoor consumption between the Yarra Valley and Perth studies differ just slightly

by 14 L/p/d, while the most recent Toowoomba study recorded just 122 L/p/d of indoor use,

which is significantly less than that found previously. Significant drops in average water

consumption, advances in efficiency technology and the most recent end use study in

Toowoomba together stress the need to undertake further research in this field. Outdoor usage

varies significantly between the Australia studies with a range of 0 – 54% demonstrated (0% in

Toowoomba due to extreme drought and outdoor restictions). When comparing countries, the

total, indoor and outdoor water consumption rates differ significantly. Such sizeable

consumption differences in total, indoor and outdoor end use consumption between the location

specific end use studies reiterate the need for region and local based end use research. The end

use breakdown of the Asia-Pacific studies is displayed in Table 2-8.


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Table 2-8 Comparison of Asia-Pacific end use water consumption studies

Previous studies Perth (2003) Melbourne (2005)

Yarra Valley Auckland (2007) Toowoomba

(2008) L/p/d Percent L/p/d Percent L/p/d Percent L/p/d Percent Clothes washer 42.0 13% 40.4 19% 39.9 24% 27.7 22.7% Shower 51.0 15% 49.1 22% 44.9 27% 53.1 43.5% Tap 24.0 7% 27.0 12% 22.7 14% 18.9 15.5% Dishwasher NA NA 2.7 1% 2.1 1% 2.6 2.1% Bathtub NA NA 3.2 2% 5.5 3% 3.4 2.8% Toilet (total) 33.0 10% 30.4 13% 31.3 19% 15.6 12.8% Irrigation (total) 180† 54% 57.4† 25% 13.9 8% 0.5 0.4% Leak (total) 5.0 1% 15.9 6% 7.0 4% 0.5 0.4% Other NA NA 0.0 0% 0.8 0% 0 0% Total Consumption

335.0 100% 226.2 100% 168.1 100% 122.2 100%

†Note: Irrigation volume per person calculated from provided volumes per household and end use break downs.

Table 2-8 demonstrates the variability between the breakdown for end uses in both percentage

and volume. One example is the percentage use for showering which ranges from 15% in Perth

to 43% in Toowoomba but when considering shower volumetric consumption Toowoomba

residents use 53.1 L/p/d and Perth residents use 51 L/p/d which is not significantly different.

Again, this variance between indoor and outdoor consumption demonstrated from earlier end

use studies reiterates the need for location specific research. To date, no statistically significant

end use investigation has been undertaken in Queensland, Australia as the Toowoomba study

only evaluated ten homes. Queensland has a unique climate and community with shifting water

consumption patterns, water use fixtures, attitudes and behaviours. The Toowoomba evaluation

demonstrates the differences in consumption between other Australian locations and

Queensland. The fact that no statistically significant end use study has been carried out in

Queensland warrants the need for this research.

2.8 Research Justification

This section outlines the need for this research by summarising the current state of knowledge

and emphasising the gaps in the literature. A trend of lower rainfall and more frequent drought

periods in southern Australia combined with growing populations, has triggered the need for

integrated urban water resource management. Planning and implementation of supply, demand

and source substitution water measures has occurred throughout the nation but the monitoring,

evaluation and review of these initiatives has not (Turner and White, 2006).

Turner and White (2006), Turner et al. (2007b) and WSAA (2008) document the importance of

water utilities evaluating and monitoring source substitution and demand management programs

to determine the actual water savings achieved. This assists in ensuring the improvement of


- 43 -

water management programs for the realisation of the desired long term savings. Chambers et

al. (2005, p 35) state that ‘more data and information should be collated on the effectiveness and

sustainability of demand management techniques, to improve long term forecasting’. Turner et

al. (2007b) state that very little evaluation has been undertaken on the millions of dollars spent

to implement water management programs, and that the ongoing evaluation of savings,

participation rates and costs as well as customer satisfaction of demand management programs

is essential to ensure that predicted savings are achieved, maintained and that costs are

minimised. This is supported by WSAA (2003) and Turner and White (2006). Hence, it is

strongly suggested that gaining empirical evidence of how and where water is used and

determining the effectiveness of specific WDM strategies is critical for planners, utilities and

conservation professionals. Data with high levels of disaggregation, such end use water

consumption data are required to achieve this (Turner et al., 2005; Inman and Jeffrey, 2006).

Gathered information can be fed into future water demand and supply forecasting models for

increased accuracy of water services planning (WSAA, 2003; WSAA, 2008).

2.8.1 Water end use and demographics

Water end use data is collected through advanced water metering technology, which involves a

high resolution water meter and data logger configeration. End use water consumption data

demonstrates when, where and how water is being used in the home. Such data is also pertinent

for daily demand forecasting and for refinement of the planning and management of water

demand and supply for regions (Gato, 2006). End use studies have occurred in Yarra Valley,

Perth and Toowoomba in Australia and across the world in the USA and New Zealand. The

need to undertake location specific end use studies is particularly critical due to the differences

in per capita consumption and individual end use consumption reported in earlier studies

(Mayer and DeOreo, 1999; White and Fane, 2001; Turner et al., 2005).

Despite several end use studies having occurred in Australia, Both Giurco (2008a) and WSAA

(2003) state that there is limited end use data available and recommend further research in the

end use water consumption field. Schlarfrig (2008) states that end use studies of greater

comprehensiveness and frequency are needed. Household consumption has been found to be

influenced by the number of people in the house, the age of residents, education levels of

residents, lot size of properties, residents’ income, efficiency of water consuming devices (i.e.

clothes washers, shower heads, tap fittings, dishwashers and toilets) and the attitudes, beliefs

and behaviours of consumers (Nieswaidomy and Molina, 1989; Renwick and Archibald, 1998;

Mayer and DeOreo, 1999; Renwick and Green, 2000; Inman and Jeffrey, 2006).

To date, no statistically significant end use investigation has been undertaken in Queensland,

Australia with the Toowoomba study only evaluating ten (10) homes. This study satisfies the


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need for a statistically significant end use water consumption investigation in South East

Queensland. Data will be utilised to improve demand forecasting, to understand the

consumption characteristics of residents on the Gold Coast and to determine the effectiveness of

various water demand management and source substitution initatives.

2.8.2 Engineered efficient devices, consumer attitudes and water end use

Engineered water efficient devices have been introduced throughout Australia with estimations

made on the relative water savings attributed to these devices. These water savings are often

determined under laboratory conditions, estimated from bulk water meter read consumption data

and calculated through modelling. While this approach is often applied to determine

effectiveness, it is well documented that to understand the actual water savings attributed to

demand management measures such as water efficient devices, end use water consumption data

is required (Mayer et al., 2004; Turner et al., 2005; Giurco et al., 2008b). Only one end use

study reported the effectiveness of various device efficiencies (Roberts, 2005). This study was

completed in 2004 with significant changes in total consumption, consumer attitudes and

advances in efficiency occurring between 2004 and today. End use data is necessary to

determine the effectiveness of other demand management measures such as restrictions, the

efficiency of devices, behaviour change initiatives and pricing. A case of efficient showerhead

exchange which resulted in an increase in water consumption due to the belief that water

savings would occur specifically because of the efficient device was reported by Inman and

Jeffrey (2006). This example triggers the importance of understanding behavioural and

attitudinal characteristics of residents on consumption, which also requires monitoring at an end

use level. The connection between attitudes and beliefs concerning water and the environment

and their relationship on actual water consumption behaviour has been established however

empirical studies divulging this link are limited (Nancarrow et al., 1996; Hassell and Cary,

2007). Lawrence and McManus (2008) recommend the use of real consumption data not

estimations derived from assumed behaviour change.

This study will investigate the effect of water efficient devices, educational devices, and

behaviours and attitudes on end use water consumption. A significant gap is present in the body

of knowledge of just how these factors influence end use water consumption. Data from this

research can be used to improve the design of conservation programs, provide justification for

continued support of programs and will assist in the development of the most effective water

demand management programs for continued water savings. Similar research on the

effectiveness of source substitution is also essential.


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2.8.3 Recycled water end use

Recycled water reuse is strongly encouraged in Australia (COAG, 2009). One of the preferred

methods of recycled water supply for residential consumption is through dual reticulated

infrastructure, which supplies recycled water to specified end uses. In Australia, there are six

operating recycled water dual reticulation supply schemes with several bulk meter read water

consumption figures detailed. To date, no investigation has been undertaken in Australia or the

world, to detail the end use consumption of recycled water in dual reticulated regions (WSAA,

2002). It is imperative to undertake such investigations to determine what percentage of water is

consumed through different end uses like irrigation or toilet flushing. This study will provide

much needed data on the variation in supply required in peak and low demand times for

recycled water infrastructure. This research seeks to fill this gap in knowledge by investigating

the potable and recycled end use water consumption of the greenfield dual reticulated Pimpama

Coomera scheme located in the Gold Coast, Queensland. Inherently, this study will also

determine the water savings ascribed to the greenfield Pimpama Coomera Waterfuture scheme.

This data will assist in determining the water savings attributed to source substitution through

recycled water and the potable water savings related to water demand management initiatives, in

turn assisting to verify design assumptions.

To summarise, this research involves the monitoring, evaluation and review of several demand

management and source substitution initiatives at an end use level. In Australia, no end use

water consumption investigations have been carried out to establish the water savings attributed

to water efficient devices since 2005, educational devices or the impact of attitudes and

perceptions on actual water use behaviour. Furthermore, no statistically significant end use

water consumption investigation has been undertaken in Queensland, Australia. This is also the

world’s first investigation to monitor, evaluate and review the end use water savings attributed

to a dual reticulated greenfield scheme.

2.9 Chapter Summary

This chapter provided a review of literature pertinent to the topics surrounding the water

situation in Australia, intergrated urban water resources management, water demand

management, source substitution and advance water monitoring technology for monitoring end

use water consumption. It is well documented that the management of water to ensure a secure

supply for growing populations is pertinent. The principles of IUWRM have involved the

introduction of supply, demand and source substitution options throughout the nation. While

IUWRM has been introduced throughout Australia, minimal investigation has been undertaken

to determine the effective water savings attributed to demand and source substitution planning

mechanisms. Research that has been reported, is based on bulk metered read data or estimations


- 46 -

and modelling. Empirical evidence of the effective water savings attributed to the various

demand and source subsitution initatives is very limited. Moreover, the importance of

undertaking local specific research is paramount due to the variations in local consumption,

fixtures, behaviours and attitudes. Adopting an end use investigation is justified and indeed

required to assess the effectiveness of WDM initatives and to provide detail on the effectiveness

of source substitution measures. While several end use investigations have been undertaken in

Australia, the requirement and call for more data and research is this area is well reported. This

review of the literature provided the required knowledge and understanding of all relevant

IUWRM, WDM, source substitution and end use areas. The determination of current gaps in the

body of knowledge assisted in focusing this research. The chapter concluded with a summary of

current gaps and a formulated research approach motivating this research investigation. The

research method adopted to undertake this research is detailed in Chapter 3.

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Chapter 3

Research Method and Design This chapter details the research methodology and design adopted for this study. Specified

within are the research approach, design and analytical techniques adopted to satisfy the

developed research objectives. An explanatory mixed methods design was selected as the most

suitable approach to suit the diverse research objectives. An overview of this design is presented

together with specific details on the quantitative and qualitative methods and techniques

utilised. The overarching mixed method framework highlighting the three project phases is

presented initially. Detailed diagrammatic models and discussion then follows for the three

primary research phases and the individual stages within each phase of the research.

3.1 Overview of Research Method and Design

This study adopts a mixed method design through the collection, analysis and combination of

both quantitative and qualitative data and research approaches through the various phases of the

research process. The amalgamation of quantitative and qualitative approaches provides a better

understanding of the research questions and problem, strengthens the research design and

completes the research through the provision of more detailed qualitative data to complete the

quantitative component of the research (Creswell and Plano Clark, 2007; Creswell, 2008).

Brewer and Hunter (1989, pp. 28) state that mixed methods is a ‘legitimate inquiry approach’

while the combination of quantitative and qualitative data is said to provide a ‘very strong mix’

(Miles and Huberman, 1994, pp. 42). Mixed methods offset the weaknesses of both quantitative

and qualitative research providing strength to the methodology; it assists in answering questions

which cannot be answered by one method alone; it provides comprehensive evidence for

research problems; and allows the use of multiple methods to address research problems

(Creswell and Plano Clark, 2007). Mixed methods can also be considered as ‘merging,

integrating, linking or embedding’ both the quantitative and qualitative strands of research

(Creswell, 2008, pp. 552). A mixed method approach was adopted due to the array of data types

required to meet the developed research objectives. The explanatory mixed method design was

determined to be the most applicable of the four potential mixed method approaches, to satisfy

the research objectives (Creswell, 2008).


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3.1.1 Explanatory mixed method design

Creswell’s (2008) ‘explanatory design’ for mixed methods was determined to be the most

appropriate design for this research. The primary purpose of the explanatory mixed methods

design is that ‘qualitative data help to explain or build upon initial quantitative results’ to

explain significant or non-significant results and surprise or outlier results (Morse, 1991;

Creswell and Plano Clark, 2007, pp. 71). Figure 3-1 demonstrates the basis of the explanatory

mixed methods research design.

Figure 3-1 The explanatory mixed methods design (Creswell and Plano Clark, 2007)

Figure 3-1 demonstrates the emphasis on quantitative data and results (hence in capitals) while

qualitative data is used to help identify, refine and further investigate relationships in the

quantitative data. This process is required due to the researcher needing to understand the

quantitative data and the contributing factors before undertaking qualitative data analysis to help

build or explain the quantitative results (Creswell, 2005).

Creswell and Plano Clark (2007, pp. 72) introduce two variations of the explanatory design

being the ‘follow-up explanations model (QUAN emphasized)’ and the ‘participant selection

model (QUAL emphasized)’. The explanatory design suited for this research was the ‘follow-up

explanations model’ which is used when emphasis is placed on the quantitative data with

qualitative data required to expand or explain the quantitative results. A diagrammatic

representation of the follow-up explanations model for mixed methods as utilised in this

research is presented in Figure 3-2.

Figure 3-2 Explanatory design: follow-up explanations model (QUAN emphasised) (Creswell and Plano

Clark, 2007)

Figure 3-2 demonstrates the prioritisation on quantitative data collection, analysis and results

with qualitative data collection, analysis and results used as a follow-up. This process is vital to

strengthen or help explain the central quantitative data. The characteristics of explanatory

research, specifically the follow-up explanations model are detailed below, adapted from

Creswell and Plano Clark (2007) and Creswell (2008, pp 560):


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Both quantitative and qualitative data is collected sequentially in different phases i.e.

quantitative data is firstly collected followed by the collection of qualitative data;

Generally quantitative data is collected first and to help ‘explain or elaborate’

quantitative data, qualitative data is then collected in succession;

Basically the qualitative data is needed to extend, explain or refine the general picture

of the research problem established through the quantitative data;

A priority is placed on the collection and analysis of quantitative data, the second phase

of the research consists of a smaller qualitative component;

Qualitative data is used to refine the results or findings from the quantitative data; and,

The explanatory design captures the best of both quantitative and qualitative data.

All research methodologies possess certain strengths and weaknesses. Table 3-1 details the

relevant strengths and weaknesses of the explanatory mixed methods design.

Table 3-1 Strengths and weaknesses of Explanatory Mixed Methods (Creswell, 2008)

Strengths Weaknesses

Most straight forward mixed method approach A large amount of time required

Conducted in two methods in separate phases

Only one type of data collected at a time

Qualitative phase will take longer than quantitative phase

Single researcher can carry out method

Reporting can occur in two phases

Multiphase investigations

Appeals to quantitative researchers as strong quantitative origin

Researcher needs to determine whether to use the same individuals for both phases

Researcher cannot specify how individuals will be selected for qualitative phase leading to problems with internal review

Researcher determines who to select for qualitative phase

The strengths of the explanatory mixed method design, detailed in Table 3-1, assisted in the

resolution that this was the most appropriate mixed methodology for the research. The

weaknesses presented Table 3-1 were overcome by the use of research assistants, using the

same research sample for quantitative and qualitative analysis and project management and

planning to ensure sufficient time to undertake the qualitative component of the research.

Data analysis for this study followed the traditional explanatory research design through the

collection and basic analysis of quantitative data and then the collection, analysis and use of

qualitative data to assist in strengthening the results of the quantitative data. Quantitative data

were in the form of natural science end use water consumption data, with the collection of

qualitative water consumption behaviours data through household water audits. Further

quantitative and qualitative data was also collected through demographic and attitudinal


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surveys. A brief overview on theory supporting specific quantitative and qualitative research

methods is described below.

3.1.2 Quantitative research

Creswell (2007, pp. 74) defines quantitative research as ‘a type of research where the researcher

decides what to study; asks specific, narrow questions; collects quantifiable data from

participants; analyses this numerically, usually with statistics; and conducts the inquiry in an

unbiased, objective manner’. Quantitative research aims to test an existing theory and either

refute or support it (Creswell, 2008). Literature plays a major role in justifying the problem and

identifying questions and hypotheses (Creswell and Plano Clark, 2007). Quantitative research

tests specific variables and aims to explain the relationship between variables, with closed

questions asked to test this (Creswell and Plano Clark, 2007). Precisely testing hypotheses and

measuring variables linked to causal relationships is the aim of quantitative researchers

(Creswell and Plano Clark, 2007). Data consist of measurable, numeric and observable data

while data collection is often through predetermined instruments and a large number of

participants are investigated (Neuman, 2003). Analysis and interpretation of data is statistical

and involves trend analysis of variables, determination of variable relationship, hypothesis

testing and comparisons with past studies (Creswell and Plano Clark, 2007). Quantitative

research generally produces objective and unbiased reports due to the predictable pattern,

procedures and controls which eliminate bias (Creswell, 2008). The use of quantitative methods

aims to verify results of past research, the subjects, settings and methods will vary but concept

testing will be the same (Vogt, 2007).

In this study, quantitative end use water consumption data and closed-ended survey questions

were completed. This data was analysed to determine key trends or significant factors with,

qualitative water stock and behavioural audits and open-ended survey questions utilised to assist

in the analysis of the collected quantitative data and to explore and further understand trends

displayed in the data.

3.1.3 Qualitative research

Creswell (2008, pp. 232) defines qualitative research as ‘a type of research in which the

researcher relies on the views of participants; asks broad, general questions; collects data

consisting largely of words (or text) from participants; describes and analyses these words for

themes; and conducts the inquiry in a subjective, biased manner’. Qualitative research aims to

learn the views of participants on particular phenomenon and to examine social processes

(Creswell, 2005). Literature plays a minor role in qualitative research but aids in justifying the

research problem (Neuman, 2003; Creswell, 2008). The aim of qualitative research is to gain an


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understanding of participants experiences and to understand the intricacy of the phenomena; to

achieve this open-ended questions are asked (Sekaran, 2000). The empirical data is in the form

of words, gestures and tones and observation of behaviours which are collected from

participants and analysis consists of determination of patterns, themes and generalisations

(Creswell, 2008). Validity of qualitative research relies on the researcher and is often reflective,

without due attention hence, the research has the potential to be biased (Neuman, 2003;

Creswell and Plano Clark, 2007).

Qualitative methods were applied in this research to gain valuable ethnographic data to assist in

determining water use behaviours and activities of participants. The explanatory mixed

methodology defines qualitative data as data that ‘helps explain or build upon initial quantitative

results’ (Creswell, 2008). Hence, the qualitative research methods discussed in this section and

in subsequent sections have been selected to compliment and add value to the quantitative

components of the study.

3.1.4 Explanatory mixed methods: follow-up explanations model design

The research was undertaken with a mixed methods approach due to the multifaceted objectives,

which dictate the requirement of both quantitative and qualitative approaches and data. The

research method utilised was an explanatory mixed methods approach. The research design

serves as a blueprint to meet the developed objectives hence it is imperative to ensure that it is

robust. The research design involves a series of rational decision making choices including the

type of sample and data collection methods, the variables to be measured and determination on

the analysis techniques for the concepts and variables. The ‘follow-up explanations model’

design was adopted as the most appropriate approach to meet the research objectives.

The broader explanatory mixed methods follow-up explanations design and activities are

demonstrated in Figure 3-3. This mixed methods design is separated into three distinct phases

with the first being the acquisition of knowledge required to undertake the research. The

following two phases are based on satisfying the primary objectives of the research being to

investigate water end use and the effect of demand management initiatives and an investigation

into the end use water consumption in a dual reticulated recycled water region. The research

output from each research phase, in the form of a chapter or referred publications, is detailed.


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PUBLICATION








consumption






Australia



Pub

Pub

Pub

Pub

Pub

Pub



As demonstrated in Figure 3-3, Phase 1 involved the accumulation of knowledge, the

development of research objectives and determination of the research method and design. Phase

2 focused on determining potable water end use and the assessing the effectiveness of demand

management initiatives. Phase 3 comprised the development of a predictive model for recycled

water use and then measurement of actual end use uptake of recycled water in the Pimpama

Coomera dual reticulated greenfield region. Conclusions, limitations and future research are


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addressed in the final chapter. Sections 3.2 to 3.4 elaborate on each of the three phases of the

wider research design through comprehensive individual phase and stage diagrams and an

associated discussion.

3.2 Phase 1: Knowledge Acquisition

The objective of Phase 1 of the research was to undertake a literature review of national and

international literature, to develop research objectives and to determine the most appropriate

design for the research methodology. Figure 3-4 demonstrates the research activities undertaken

to achieve the objectives of this phase.

Figure 3-4 Phase 1 research activities and output

An extensive review of past literature was carried out to accumulate knowledge and to

determine current gaps in the field of research, as detailed in Figure 3-4. Numerous topics were

investigated such as: the water situation, integrated urban water resource management, water

demand management, source substitution, dual reticulated recycled water, advanced water

metering and end use water consumption. Chapter 2 details all of the explored topics of

literature. Moreover, Chapter 5 to 10 provide concise literature reviews associated with the

refereed publications. The obtainment of knowledge through the literature review allowed for

the determination of current gaps in the field which resulted in the development of research

objectives. After the determination of research objectives, additional literature was reviewed to

ascertain the most applicable research method and design to meet the objectives. Resolution on

an explanatory mixed methods approach occurred due to the multiple data sources required to

satisfy the quantitative and qualitative objectives. Phase 1 of the research, displayed in Figure

3-4, resulted in the determination of gaps in the body of knowledge, development of the


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research objectives and the determination on the explanatory mixed methodology as an

appropriate research design. Each stage in Phase 1 was necessary before commencing Phases 2

and 3.

3.3 Phase 2: Water End Use and Demand Management

The purpose of Phase 2 was to undertake an end use investigation of potable water consumption

and to determine the effective end use water savings attributed to various water demand

management initiatives. A model presented by Guirco et al. (2008a) for designing end use

measurement studies was utilised in the initial stages of Phase 2 (Figure 3-5).

Figure 3-5 End use measurement study design cycle (Giurco et al., 2008a)

True to this model, the design of the end use measurement study involved the definition of

research objectives, practical determination of the data requirements and the technology

required to satisfy the objectives of the research. Determination of the sample size and any

constraints on the chosen end use measurement path concluded the study design. The final

research design for Phase 2 resulted in seven stages being required to investigate all facets and

interrelationships between the water end use and demand management components of the study.

These phases included obtaining end use water consumption for the consenting sample, to

carryout stock and behavioural investigations, complete questionnaires and to investigate the

impact of various WDM initiatives. Phase 2 involves the consideration and determination of the

end use research design, data requirements, technology, sample size and other aspects of the end

use measurement and demand management research. The stages within Phase 2 keep to the

explanatory mixed methods ‘follow-up explanation model’ through the adoption of quantitative

processes followed by the employment of qualitative techniques for improved explanation and

outcomes. An overview of the Phase 2 research method and design is demonstrated in Figure

3-6.


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End use water consumption design & technology

Industry experts & past literature

INPUT RESEARCH ACTIVITY OUTPUT

Residential end use study design: data requirements & technology

Research size & potential participants

Determine sample size, research region & pilot group

Develop participant recruitment material

Design of recruitment letters, incentives & consent form

Literature, past research & industry experts

Consenting sample obtainedRecruitment approach



End use consumption monitoring process

Residential end use study design

Raw end use water consumption data

Monitoring end use water consumption

Industry experts & past literature


Detailed water audit & interview questions

Water audit & interview design

Qualitative data of water use fixtures & behaviours

Qualitative data collection

Literature, past research & academic experts

Water use validationDetermine efficiency, fixture use

& behavioural profile

Stage 2d: Stock survey & water use behaviour audit

Data set of residential end use water consumption

Trace Wizard© analysis of end use data

End use water consumption profiles

Validation of end use breakdown & calculations

Tuition from industry expert, fixture & water use behaviours


Survey quesionnaireQuestionnaire development

Data set from the survey of residential water consumers

Questionnaire survey

Literature and academic/industry expert review

Descriptive resultsDescriptive data analysis

Stage 2f: Questionnaire development, distribution & analysis

Validated resultsMeasurement model analysis

(CFA & cluster analysis)

Consenting sample obtainedParticipant recruitment & data

collection design

Installation of shower monitors Purchase shower monitor units &

determine installation process

Academic & industry literature & research sample

Post shower monitor end use water consumption

Collect end use data, statistical analysis (descriptive & t-test)

Stage 2g: Educational shower monitor device


Figure 3-6 Phase 2 research activities and output

Figure 3-6 details the seven quantitative and qualitative stages which occurred during Phase 2 of

the research. Each stage of Phase 2 resulted in outcomes relevant for subsequent stages in the

design; all stages are discussed in detail in the following sections.


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3.3.1 Stage 2a: End use water consumption design

The first stage of Phase 2 was the design of the end use measurement study. Figure 3-7

demonstrates the inputs, research activities and outputs for Stage 2a.

Figure 3-7 Stage 2a: End use water consumption design

The main components of this stage were to determine the data type and technology necessary to

collect end use water consumption. The research objectives of this study stipulate the need for

high resolution water end use consumption data to assist in determining all individual events

within homes such as showering, irrigation or leakage. The most relevant example of a national

end use water consumption study was carried out by Yarra Valley Water in Melbourne in 2005.

Roberts (2005) utilised data measurement technology which enabled the reading of volumes of

water as small as 0.014 litres. An investigation into water metering and data logger technology

was carried out considering this study as well as other domestic end use studies completed

throughout the world (Mayer and DeOreo, 1999; Loh and Coghlan, 2003; Mayer et al., 2004;

Heinrich, 2007; Mead, 2008).

Water meter and data logger technology assessment

The water meter utilised by Roberts (2005) remained the highest resolution water meter

available on the market. Other products considered included the Pryde SPX-075 low flow meter

and high resolution meters sourced directly through Manuflo. Consequently an Actaris CT5

water meter, pulse rate 2 pulses/litre or 0.5 litres/pulse was purchased through Actaris and

modified by Manuflo to result in the CT5-S water meter which pulsed at rate of 72.5 pulses/litre

or 0.014 litres/pulse. Research was also undertaken to determine the latest developments in data

logging technology. Products considered included the SBS Systems Halytech Spider with

Waveflows, E-State Automation Waveflow wireless meter monitors and Moneta R-Series data

loggers. Mayer (2005) made use of a USA technology, the F.S. Brainard's Meter-Master© Flow

Data Loggers and software.

Again, Roberts (2005) work was utilised as a benchmark to determine the most appropriate

Australian data logging technology. Roberts (2005) utilised the Monatec Data Monita XT data

loggers but the failure of some of these devices resulted in the use of the Monita D-Series data

logger which had similar specifications; this Monita D data logger was still one of the best

products on the market. The Monita D series logger was selected as it was capable of recording


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up to 2 million end use data points and allowed for the input of four (4) different channels and

had a battery life of ten (10) years. Such a large memory capacity was required as data was to be

downloaded manually after each logging period and logging was occurring in dual reticulated

areas which meant the input of two channels from the potable and recycled water meters. While

technology had developed to enable remote readings of data (through GSM or other networks)

the significantly increased cost per data logging unit, the cost of transmitting data back to a

central hub, the range at which homes were located from each other or from the central hub and

power supply all lead to the decision to undertake manual downloads. Since the initiation of the

study in 2007, the, cost and technology of remotely read data loggers has significantly improved

the feasibility of remote data downloads.

End use analysis technology

The end use analysis program utilised by previous studies including those carried out in

Melbourne, Perth, Toowoomba, Tampa and (USA) across twelve regions the USA, was Trace

Wizard©. This software was developed by AquaCraft in the USA specifically to undertake this

analysis activity. The Trace Wizard© software was selected as the most appropriate analysis

tool due to its suitability for Windows environments, the ease of undertaking flow trace analysis

and the reasonable price for the software package. The Trace Wizard© program was specifically

modified by AquaCraft Inc® for this study to enable the software package to receive data from

the four channels of the Monita D series loggers. Giurco et al. (2008a) recommend Trace

Wizard© as the principal end use water consumption analysis tool.

Logging period

The logging period and time steps of earlier end use studies have varied. Roberts (2005) logged

at 5 second intervals over two week periods while Mayer and DeOreo (1999) and Mayer et al.

(2004) logged at a 10 second intervals. Mayer and DeOreo (1999) state that the 10 second time

interval results in accurate data to ‘quantify and categorise’ individual end uses. Hence, a 10

second interval was selected for the end use study due to considerations of data storage and

management (note: decreasing the interval from 10 – 5 seconds doubles the data points).

Logging periods were selected to occur in winter and summer with two week periods of data for

analysis. Additional data was to be recovered for reference or further investigation if time

permitted.


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3.3.2 Stage 2b: Obtain consenting sample

Stage 2b of Phase 2 was to determine the sample size and to obtain a consenting sample with

which to carryout the research. Figure 3-8 demonstrates the inputs, research activities and

outputs of Stage 2b.

Figure 3-8 Stage 2b: Obtain consenting sample

Literature, past research and industry experts were all consulted to assist in determining the

sample size, the research region, recruitment material and the approach to recruit participants.

Sample size

To ensure the research findings are representative of a population, an appropriate sample must

be selected (Howell, 2004). For statistical significance and appropriate representativeness of end

use for the Gold Coast city, a large sample size of households would be required. This is due to

the variation in water consumption which can be exhibited by a large population. The

population of the Gold Coast at commencement of the research was 485,000 or approximately

177,000 households. A representative sample from this population would be 266 households

when assuming a confidence level of 95% and a confidence interval of six (6) (three (3) steps

from either side of the mean which is generally the lowest acceptable confidence interval)

(Howell, 2004). Decreasing the confidence interval and increasing the confidence level both,

increase the sample size. This is due to the increase in precision and accuracy with which the

results can be applied to the total population.

For end use sampling in this research, a total of eight (8) end uses will be determined (clothes

washer, shower, tap, toilet, dishwasher, bathtub, irrigation and leak) as well as a total

consumption figure. Giurco et al. (2008a) specify that when determining the required sample

size for an end use study it is important to understand the mean and standard deviation (SD) of

the various end use results. Field (2005), states that SD is a measure of how well the mean

represents the observed data. Data with smaller SDs more adequately represent the sample due

to less dispersion of the data points around the mean. This is reiterated by Giurco et al. (2008a)

who specify that if the researcher wants to discern six (6) end uses with a small and precise SD


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of 10L (compared to average of 143L) the sample size would be as high as 1,200. If the

precision can be reduced to moderate (20L) or lower (30L) precision then samples sizes of 300

and 130 are adequate respectively.

Some end uses are more variable in volumetric use and hence, have a higher SD values. When

examining winter 2008 end use data from this research, dishwashing and toilet flushing have SD

values under 10L due to the relative consistency in volumes as stipulated by the efficiency of

the device. Other end use SDs are more variable with tap use SD being 12.51 L/p/d while,

irrigation possessed the highest SD of 35.37 L/p/d with a mean of 18.58 L/p/d. The most precise

end use is dishwashing with a mean of 2.22 L/p/d and SD of 2.4 L/p/d. With a sample size of

151 households one can be 95% certain that the true population mean falls within the range of

1.84 to 2.6 L/p/d (confidence level of 0.38). If this low confidence interval was adopted to

determine the initial sample size for Gold Coast city (n=177,000 homes) more than 48,000

homes would be required. A highly variable end use is irrigation with a mean of 18.58 L/p/d and

a SD of 35.37 L/p/d. With a sample size of 151, it is 95% certain that the true population mean

falls within the range of 12.94 to 24.22 L/p/d for irrigation (confidence interval of 5.64). If this

confidence interval was acceptable, with irrigation being the most unpredictable and variable

end use, a sample size of 301 homes would be representative of the Gold Coast residential

population of 177,000 homes. The confidence interval of irrigation is just under the largest

acceptable confidence interval of 6. As irrigation was found to be the most variable and

unpredictable end use, an initial sample size between 301 and 266 homes for the Gold Coast

should accurately represent the usage of the Gold Coast population. This is still a large sample

size especially when considering the cost and feasibility of recruiting, sampling and analysing

this much end use data hence, further research was undertaken to establish sample sizes used in

earlier end use studies.

When undertaking end use sampling the accuracy and precision of results must be considered

alongside cost due to the average household cost to collect end use data being approximately

$1500 (Giurco et al., 2008a). Earlier end use studies have ranged in sizes from ten to 1188

homes across twelve (12) municipal areas (Mayer and DeOreo, 1999; Mead, 2008). Roberts

(2005) and Mayer and DeOreo (1999) both determined that a sample size of 100 households per

water utility service area was sufficient and representative for end uses within homes based on

their resulting means and standard deviations. Further discussions with end use expert Peter

Mayer (2007), reiterated that a sample size of 100 households was sufficient to undertake end

use water consumption analysis in a region. Consideration on the need for the representativeness

of the end use data for the Gold Coast region, the cost to carry out end use analysis and the

feasibility of obtaining a sample size between 301 and 266 homes, resulted in the decision on a

smaller sample size of 200. While this sample size is lower than the original statistically


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representative value required (n=266) and lower than that required to meet the confidence

interval of the most variable end use, irrigation (n=301), it is higher than that specified by end

use experts and fits within the moderate precision of standard deviation for end use data

collection (Giurco et al., 2008a). Moreover, a sample size of 200 is feasible in terms of cost and

is also a manageable size for participant recruitment, data collection and analysis.

Research region

The primary research region was Pimpama Coomera due to the objective of undertaking

analysis of end use water consumption in a dual reticulated area. Because of this objective, a

stratified approach was utilised which resulted in the selection of three (3) district metered

developments within Pimpama Coomera. Socio-economic status was a primary consideration

for these areas to ensure the sample included a range of household incomes. The demographic

characteristics of Pimpama Coomera were investigated through ABS 2006 statistics. Pimpama

Coomera local area demographics were quite unique due to the high number of renters with

high incomes, which differed in comparison to the wider Gold Coast characteristics. PC also

possessed a higher number of people per household and a high number of parents with young

children which skews the trend toward a younger population (see Appendix A).

The control or comparison group, not within the dual reticulated region, was determined

through a comparison of 2006 ABS demographic statistics between Pimpama Coomera and

other local areas within the Gold Coast (Appendix A shows details). Mudgeeraba was selected

as this local area that demonstrated similar demographic characteristics to Pimpama Coomera.

Within Mudgeeraba, a district metered area that had been developed in the last five (5) years

was selected to ensure the water use fixtures and fittings were relatively comparable.

Design of participant recruitment material

The recruitment of participants is a challenging activity hence the material used to undertake

this process should be professionally and meticulously prepared. For the purpose of this study

an introductory letter, a consent form and a frequently asked questions factsheet were

developed. An incentive in the form of a $20 voucher was also offered along with a chance to

win a major prize valued at $1000. Brase et al. (2006) specify that the best participant

recruitment rates were obtained when incentives or payments were given for participation.

Study recruitment material was developed through the examination of similar recruitment

information for earlier research investigations and with the professional assistance of the

community engagement team at Gold Coast Water. This team added significant value through

their extensive experience in communicating with the Gold Coast community and their

understanding of the community’s response to such research and distribution materials. The


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participant recruitment letter outlined the details of the research and activities that would be

undertaken as part of the investigation, Appendix B presents the letter. The frequently asked

questions factsheet, detailed in Appendix C, provided more specific information on the

equipment used, where and what the data would be used for, information required from

participants as well as the protection of this information. The consent form was the contract

between the participant and the researchers that reiterated all the activities to be undertaken

along with verification that all information was condoned by the University Ethics Committee

(see Appendix D). Obtaining permission from the participants and university were paramount

for the collection and protection of data. Completed participant recruitment material enabled

commencement of the recruitment process.

Participant recruitment approach

The participant recruitment design was a purposely structured approach. Participant recruitment

consisted of the mail distribution of all material to households (Appendix A-D) followed up by

the door knocking of all homes which had received this research information. A verbal approach

for door knocking was developed and utilised throughout the recruitment period. Households

that received the information were visited until the researcher met face-to-face with a resident to

determine their interest in voluntary participation. The information that was distributed to

households was carried by door-knockers along with consent forms and incentives. A gift

voucher of $20 and a gift bag from GCW was presented to each participant upon completion of

the consent form. When households consented to be involved in the research, a few general

questions were asked which included the estimated length of time residing in the household,

ownership status, the number of people in the home and a contact phone number. This

information assisted to determine if the household would be a full or reserve research

participant. Reserve participants were those that indicated that they would not be in the region

for longer than one year. Responses from householders differed significantly with the most

frequent responses listed below:

Household had received and read the information about the research and signed up

without hesitation or handed over a completed consent form;

Household had received the information but not read it and signed up after further

discussions with the door-knocker;

Household had received the information and had read through it but was not interested

in participating even after further discussions with the door-knocker; and

Household refused to participate or discuss with the door-knocker as they were not

interested in research.


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Overall, householders in all regions were very friendly and receptive to door-knockers. It should

be noted that on certain participant recruitment days some households had as many as five door-

knockers from different companies which was challenging for recruitment researchers. The next

process was the installation of equipment for consenting households and monitoring end use

water consumption.

3.3.3 Stage 2c: Potable end use water consumption data

Stage 2c involved testing the end use consumption data collection process through the design of

the installation and monitoring process and the obtainment of actual end use water consumption

data. The processes included in this stage are detailed in Figure 3-9.

Figure 3-9 Stage 2c: Potable end use water consumption data acquisition testing

Figure 3-9 demonstrates the testing and verification process for the installation of equipment

and the collection and analysis of end use water consumption data. Particulars on the end use

study design are discussed.

Equipment and monitoring

The installation of high resolution water meters was carried out through GCWs water meter

exchange program which involved the distribution of a notification letter to residents and

subsequent water meter exchange. High resolution data loggers were installed by the research

team through individual visits to each home and manual installation of data loggers in water

meter boxes. As mentioned, each data logger was able to receive up to four (4) inputs hence

only one (1) data logger was required for both single and dual reticulated homes. Testing of the

end use water consumption monitoring design occurred through the verification that each water

meter and connected data logger was actually recording end use data i.e. data was recorded from

households. This testing process resulted in the determination that end use data was not being

obtained for some households, with investigations determining the main cause as faulty reed

switches in the water meters as well as water intrusion in data loggers. Negotiations with

equipment manufactures assisted in resolving these issues although water intrusion remained a

serious issue throughout the study.


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Data collection and analysis

Collection and analysis of end use water consumption data involves numerous steps. Firstly raw

end use data is downloaded through the data logger ‘Command’ software. This data is then

processed into readable Microsoft ‘txt’ files which can be directly uploaded into the Trace

Wizard© analysis program. This process results in the obtainment of flow-based water

consumption data for each household within the study. The Trace Wizard© templates provided

with the program were developed with data from the USA hence, the software’s built-in

automated selection of different end uses within homes was not compatible when applied to

Australian fixtures. For example, Mayer and DeOreo (1999) noted that the average toilet flush

from end use investigations in the USA is 3.48 gallons (13.17 litres) per flush. In Australia,

toilet flushing in new houses ranges from 3 to 9 litres per flush hence, to utilise and verify the

end uses within each Gold Coast household additional information on the water use fixtures and

water use behaviours of residents was required. A detailed diagram outlining the end use data

downloading procedure is presented in Figure 3-10.

Connect.lnk

Trace Wizard Pro.lnk

Processed end use data

Uploaded end use water consumption

dataRaw end use data

0402EA010A0000002203080A1C011E080F000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

011413,28/10/08 16:12:58,10,0,0,0,0011413,28/10/08 16:13:08,10,35,146,0,0011413,28/10/08 16:13:18,10,1,169,0,0011413,28/10/08 16:13:28,10,0,125,0,0011413,28/10/08 16:13:38,10,0,51,0,0011413,28/10/08 16:13:48,10,0,20,0,0011413,28/10/08 16:13:58,10,0,7,0,0011413,28/10/08 16:14:08,10,0,4,0,0011413,28/10/08 16:14:18,10,1,3,0,0

Water Meter: CTS-5

Data Logger:

Monita D series

Equipment

Downloading Data

Raw end use data process software

End use analysis software

Figure 3-10 End use data downloading procedure

As demonstrated in Figure 3-10, the end use data downloading procedure results in non-

categorised end use flow traces. In order to accurately categorise end uses a stock inventory and

water audit was undertaken to reveal the fixtures/appliances and water consumption behaviours

within individual households.


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3.3.4 Stage 2d: Stock survey and water use behaviour audit

Stage 2d, the stock survey and water use behaviour audit, was the principal qualitative

procedure in the research methodology. The stock survey and water use behaviour audit, was

undertaken with almost every household to determine basic demographic information, the water

use stock present within the home, the efficiency of water use stock, and the water use activities

and behaviours of residents. Initially, it was thought that only a few households would need to

be audited but once the complexity of uses and behaviours within each home was realised it was

determined that the application of this qualitative process to the entire sample would provide the

most accurate water end use information. This stage was pertinent to assist in the analysis and

verification of end use water consumption within each household. Figure 3-11 details the

processes of Stage 2d.

Figure 3-11 Stage 2d: Stock survey and water use behaviour audit

Figure 3-11 demonstrates that literature, past research and academic experts were consulted to

assist in the development of the water audit and interview design. Being a qualitative process,

open ended questions were primarily used as discussion points for the researcher with the

resident. Appendix E shows the water audit in its entirety. The water audit consisted of

determining some basic demographic information for the household, determining the water use

fixtures and fittings within the household and asking for residents to explain how, when and the

duration of water fixture use and associated behaviours. This process enabled the establishment

of the current water usage stock within the community and allowed for the understanding of

how and when residents consumed water within the home.

Collection of this qualitative data occurred through visits to each of the homes at a pre-

determined time convenient for the resident. Researchers talked through each question with the

residents and walked around the home looking at and recording water stock and enquiring about

the use of each device. Residents were asked to elaborate on any interesting comments or

thoughts on water use in their home or in general. This process resulted in a qualitative database

of water use fixtures, fittings and behaviours within the sample. Data collected through the

water audit was used in conjunction with the WELS website to determine the water


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consumption and efficiency of the devices that are easily determined i.e. clothes washers,

showers, dishwashers and some toilets. Qualitative water use activities and behaviours outlined

by residents were used to inform and develop water usage profiles for each home. For example,

a resident stated:

“I use my clothes washer on the weekend and do at least two loads” and “I generally

shower for about seven minutes every night”.

Such statements were used in collaboration with the average consumption listed for the recorded

clothes washer model and shower rose to assist in determining the household water use profile

and efficiency of devices. The data from this qualitative process was used to analyse the end use

water consumption in each of the households. This data was imperative in the determination of

fixtures and fittings within homes, the relative efficiency of fixtures, the perceived time of day

and duration of use, and the water usage patterns and behaviours unique to each household. This

data enabled the development of Trace Wizard© templates for each home, was used for

determining the efficiency of fixtures and to carryout end use water consumption data analysis.

3.3.5 Stage 2e: Potable end use water consumption

Stage 2e of the research method was the actual analysis of end use water consumption data

through the integration of collected end use water consumption data and the stock survey and

water use behaviour audit. Stage 2c was the collection of end use water consumption data and

resulted in the determination that a qualitative process was required to assist in understanding

this data. Stage 2d was the collection of water fixture and usage behaviours pertinent to the

establishment of end use water consumption profiles for each household. Stage 2e collectively

unified the earlier research stages to enable data analysis using the Trace Wizard© software to

result in a validated data set of residential end use water consumption data for the sampled

households (Figure 3-12).

Figure 3-12 Stage 2e: Potable end use water consumption

The quantitative data analysis procedure shown in Figure 3-12 included visual inspection of the

data, checking for consumption trends and representation of results in tables and figures. Peter

Mayer, the developer of Trace Wizard© and end use analysis expert also provided training on


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the software. Once the data set or template was established for each home, a validation process

occurred through the revisiting of water audit information and a cross-check with bulk meter

water consumption data from GCWs billing system. This assisted to ensure that daily and

weekly end use water consumption data was on par with the households bulk metered water

consumption data. Stage 2e resulted in end use water consumption data for each household in

the research sample to meet one of the research objectives. Further stages were carried out to

meet additional research objectives.

3.3.6 Stage 2f: Questionnaire development, distribution and analysis

Stage 2f included the development and execution of a questionnaire survey to assist in

determining the effect of socio-demographics, perceptions, attitudes and understanding on end

use water consumption behaviour. Questionnaires consist of pre-formulated written questions

which respondents answer following stipulated protocols (Sekaran, 2003). Surveys aid in

describing trends; in determining individual opinions and knowledge; in the identification of

beliefs and attitudes; the establishment of characteristics and expectations; and, they can

evaluate the effectiveness of programs (Neuman, 2003; Creswell and Plano Clark, 2007).

Researchers utilise surveys as a deductive approach to measure variables, to statistically

examine their effect and to rule out alternative explanations (Neuman, 2003). Surveys ensure

empirical measurement and data analysis results from a theoretical or applied research problem

(Neuman, 2003). The survey design utilised for this research was in the form of a questionnaire

survey with closed and open-ended questions, which was designed for participants to complete

and return to the researcher. It is important to note that only one questionnaire survey was

completed per household. The head of each household was requested to convene a meeting with

other residents, and consultatively respond to the questionnaire items, thus providing a response

which was representative of the group. In cases where members could not attend or were young

children, they were requested to provide a perceived rating which reflects their perception of the

household’s overall attitude to the listed items.

Qualitative or open-ended questions in survey research or questionnaires allows respondents to

express their individual beliefs and feelings and to clarify their responses to quantitative

questions (Neuman, 2003). They allow the researcher to determine what is important to the

respondent, how and what they are thinking and also results in answers to questions that the

research may not have thought of previously (Neuman, 2003). Mixing both open- and closed-

ended questions changes the pace of the questionnaire and also provides a richness of data

(Neuman, 2003). Some notable disadvantages of open-ended questions are that analysis and

comparison can become very difficult, different degrees of responses are given and a greater

amount of time is required by residents who may be intimidated by questions (Neuman, 2003).


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Details on the process of questionnaire development, execution and analysis are presented in

Figure 3-13.

Figure 3-13 Stage 2f: Questionnaire development, distribution and analysis

The design of the questionnaire survey occurred through a review of related survey literature

and followed the survey development guidelines authored by Dillman (2000). The draft survey

was revised through an academic and industry expert-review process whereby four university

researchers and two industry experts refined the questions and checked the theoretical

constructs. The final survey can be viewed in Appendix F. The purpose of the questionnaire

survey was to test the relationships between end use water consumption (dependent variable)

and other variables such as demographics; awareness and use of water efficient devices;

preference of water source for water use activities; understanding of water consumption within

homes; attitudes towards the environment, water and water efficient devices; and attitudes and

understanding of dual reticulation (independent variables). Figure 3-14 demonstrates a

diagrammatic overview of the variables developed for testing in the questionnaire survey. The

variables tested through the experimental research (end use water consumption data) included;

educational awareness devices, household understanding of water efficiency, attitudes towards

the environment and water, and demographics. The questionnaire investigation assisted in

determining the causal relationships between the experimental data and questionnaire survey

data.

A five-point Likert-type measurement scale was adopted for the respondents’ rating of

attitudinal items, with 1 representing strongly disagree and 5 representing strongly agree.

Earlier survey investigations have determined that a five-point scale is comparable with a seven

or nine-point scale and that increasing the rating scale will not improve the dependability of

ratings (Neuman, 2003; Creswell, 2008).


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Figure 3-14 Diagram of relationships between dependent and independent questionnaire survey variables

Questionnaire distribution and collection

The questionnaire survey was distributed via postal mail to all households, for which

researchers had analysed end use water consumption data for (n=151). A letter describing the

purpose of the questionnaire and stipulating the receipt of a $20 gift voucher upon the return of

a completed questionnaire was also included (see Appendix G). Of the 206 surveys sent, a total

of 151 completed responses were returned which equates to a response rate of 73.3%. Such a

high response rate was achieved through the inclusion of an incentive, the household’s prior

signed consent to be a part of a number of research activities, and through follow-up phone calls

made by the research team to encourage residents to return their completed questionnaire.

Questionnaire survey data analysis

The objective of undertaking a questionnaire survey was to ascertain demographic information,

determine awareness of numerous water related topics and to establish the use of water efficient

devices. The survey also assisted to understand perceptions/attitudes of respondents in relation

to water efficiency and the environment. The determination of these elements assisted in

revealing the impact of the independent variables on end use water consumption behaviour.

Multivariate statistics were utilised to quantitatively analyse data collection in the questionnaire

survey. Such techniques were considered suitable as they provided an analysis method for the

complicated data set which included numerous independent variables (Tabachnick and Fidell,

2007).


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Questionnaire survey data was transformed into a readable form through data entry into the

statistical analysis program AMOS (version 17.0). Initially, descriptive data analysis was

undertaken to determine the characteristics of the sample. Analysis included the examination of

respondent profiles, as well as data screening through assessing means, normality, frequencies

and standard deviations. Details and results of descriptive analyses are presented in Chapter 4.

Following this, ‘Cronbach’s alpha’ was employed to measure scale reliability which indicated

how consistent responses were across the measured items. Factor analysis was also adopted to

assess the validity of the measurement scale using the ‘Confirmatory Factor Analysis (Giurco et

al.) technique. CFA was employed to assess constructs validity and unidimensionality. In

essence, CFA is a way of testing how well a priori factor structure and its respective pattern of

loadings match the actual data (Hair et al., 2006). Cluster analysis was utilised and is described

by Hair et al (2006), as an exploratory data analysis tool for solving classification problems. The

purpose of cluster analysis is to categorise cases into groups or clusters so that each case is very

similar to others in its clusters. This analysis technique was adopted to determine if distinct

groups were evident in the research sample. Detailed discussion and results of statistical

investigations are presented in Chapters 6, 8 and 9.

3.3.7 Stage 2g: Educational shower monitor device

Stage 2g involved a quantitative experimental investigation to determine the end use water

consumption savings attributed to an educational shower monitor device. Experimental research

is commonly applied across the sciences as a quantitative and ‘pure’ form of positivist research

(Neuman, 2003, pp 440). ‘Positivist’ here denotes the scientific method approach for testing a

hypothesis. Experiments aim to test an idea and to determine the influences on an outcome or

dependent variable by keeping a group in its original state and altering another group to

compare the differences (Creswell, 2008). Neuman (2003) delineates that experimental research

follows three steps, being:

1. Begin the experiment with a hypothesis;

2. Modify something in the experiment; and

3. Compare the outcomes pre and post modification.

An experimental research technique is the ‘strongest for testing causal relationships because the

three conditions for causality (temporal scale, association, and not alternative explanations) are

clearly met in experimental designs’ (Neuman, 2003, pp. 441). Experimental research also has

practical advantages in comparison to other techniques and weaknesses such as basic logic,

narrow scope and practical restraints which need to be overcome through the application of

other research techniques (Creswell, 2005). Establishing possible cause and effect between the

independent and dependent variables is the main purpose of experimental research (Neuman,

2003). Comparing, determining and measuring the differences between the independent and


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dependent tested variables, allows the researcher to establish strong and weak relationships

between the variables (Neuman, 2003). For the purpose of this stage of the research,

manipulation of one independent variable occurred true to the experimental design framework

(Punch, 2000). Figure 3-15 demonstrates the design for the experimental investigation.

Figure 3-15 Stage 2g: Shower monitor investigation

The purpose of this experiment was to determine the effect on end use shower behaviour

including total consumption volumes, shower duration and flow rate pre and post the

installation of the educational shower monitor device. An important aspect of experimental

research is to determine the statistical significance and influence on the dependent variable, end

use water consumption, by the manipulation of the independent variable namely, the shower

monitor (Neuman, 2003). Statistical techniques applied for this experiment included descriptive

statistics and the application of the independent sample t-test. Additional information on the

data analysis techniques and the outcome of this quantitative experiment are illustrated in

Chapter 7.

3.4 Phase 3: Dual Reticulated Recycled Water

Phase 3 involved the development of a predictive recycled water uptake model, the monitoring

of end use recycled water post implementation and the validation of a model for recycled water

end use consumption for dual reticulated regions. Figure 3-16 details the three stages of Phase 3.

Phase 3 is a quantitative research phase with the application of an experimental design to

determine the water savings attributed to the introduction of recycled water. A detailed

overview of the research method and design for Phase 3 is demonstrated in Figure 3-16. Each

stage in Phase 3 involved numerous processes to achieve the stated objectives of the design, as

described in the below sections.

3.4.1 Stage 3a: Predictive dual reticulated recycled water uptake model

The purpose of Stage 3a was to develop a predictive model for recycled water uptake in dual

reticulated regions. End use water consumption data was collected in Phase 2 of the research


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pre-implementation of recycled water distribution to households in the Pimpama Coomera

region. This data, questionnaire survey data, uptake in other dual reticulated regions and

influencing factors such as water restrictions, climate, price, lot size and marketing were all

considered in the development of the predictive model as demonstrated in Figure 3-17. This

study adopted a possibility/fuzzy set theory approach due to the inherent fuzziness of future

predictions of water use for a new supply source (i.e. A+ recycled water) in a new context (e.g.

Gold Coast, Queensland, Australia). This theory was adopted as the necessary data sets required

for predictive assessments, such as probability theory, Monte Carlo simulation and sensitivity

analysis, were not available.

Literature on dual reticulated consumption

INPUT RESEARCH ACTIVITY OUTPUT


Stage 3b: Dual reticulated recycled water end use consumption data collection and analysis

Verification of recycled water end use consumption in dual

reticulation region

Compare potable and dual reticulated recycled water end

use

Validation of potable end use water savings in a dual

reticulated recycled water region

Comparative analysis of PC dual reticulation demand forecast

model

End use water consumption profiles for recycled water



End use water consumption data (single vs. dual) & bulk

billing data

Baseline end use water consumption for dual reticulaton

Validation of end use breakdown for dual vs. single reticulated

Comparison of usage between schemes

Validation of historical uptake rates of recycled water

Other regions end use water consumption data

Comparison of end usage between investigations

Determination of approximate irrigation as percentage of

consumption

Water restriction data Determination of influence on

consumptionInfluence of restrictions

Survey dataAnalysis of outdoor water use

activities and preferential water source

Preferential influence on water consumption type

Literature and data on recycled water pricing, climate,

lot size & marketing

Influence of variables on water consumption

Final prediction of recycled water uptake in dual reticulated region

Data set of residential recycled end use water consumption

Trace Wizard© analysis of end use data with water audit

End use water consumption profiles for recycled water

Validation of end use breakdown & calculations

End use templates, data & processes from Phase 2

Raw recycled end use water consumption data

Monitoring recycled end use water consumption

End use diurnal patterns for recycled & potable water use

Development of diurnal pattern tool for end use water

consumption data

Figure 3-16 Phase 3: Detailed overview of research activities and output


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Applying the possibility/fuzzy set theory, the influence of all the obtained data was determined

by an expert panel to result in a lower value, most likely value and upper value of recycled

water consumption in the dual reticulated Pimpama Coomera region post-distribution of

recycled water. Further details on the method, analysis and results associated with this stage of

the study are presented in Chapter 8.

Figure 3-17 Stage 3a: Predictive dual reticulated recycled water uptake model

3.4.2 Stage 3b: Dual reticulated recycled end use data collection and analysis

Stage 3b involved the utilisation of an experimental design to determine actual recycled end use

water consumption in a dual reticulated region pre and post distribution of recycled water Figure

3-18.

Figure 3-18 Stage 3b: Dual reticulated recycled end use water consumption data collection and analysis


- 81 -

The experimental design used to establish the end use potable water savings attributed to the

introduction of recycled water via dual reticulation is displayed in Figure 3-18. Common to all

experimental designs, a before and after test was carried out to determine the change attributed

to the independent variable.

End use water consumption data obtained in Phase 2 of the research method was adopted as the

baseline information as this data was collected before recycled water was distributed through

the dual reticulation infrastructure. End use water consumption was collected post

implementation of recycled water to the dual reticulated region with the Mudgeeraba region

remaining as a control group. End use analysis and validation was undertaken using the same

approach as detailed in Phase 2. This process resulted in the obtainment of end use water

consumption data post implementation of recycled water in the dual reticulated recycled water

region. Further detail on the process and results of this design are presented in Chapter 9.

3.4.3 Stage 3c: Dual reticulated recycled water end use consumption

The final stage of the research method was the measurement of end use water consumption data

post-commissioning of recycled water in the PC dual reticulated areas. The purpose of Stage 3c

was to combine the data obtained from Stage 3b into the predictive model developed in Stage 3a

while adopting a developed diurnal pattern tool to finalise a usable end use model for dual

reticulated recycled water regions. This stage also allowed for the comparative assessment of

pre- versus post-commissioning end use water consumption data. Details of the design process

are demonstrated in Figure 3-19.

Figure 3-19 Stage 3c: End use model for dual reticulated recycled water consumption

As illustrated in Figure 3-19, data from previous stages were utilised to assist in the validation

of end use water consumption for dual reticulated recycled water regions. Initially, a

comparison of end use water consumption data was undertaken against the single and dual

reticulated regions. This enabled the verification of recycled water end use consumption in the

PC region once recycled water was supplied.


- 82 -

A comparative assessment was carried out to determine the differences between the recycled

water up-take predicted in the pre-commissioning phase (see Section 3.4.1) against the actual

post-commissioning recycled water consumption recorded. This involved analysis of end use

water consumption particularly for recycled water end uses (irrigation, toilet and leak) against

that predicted. This resulted in the verification of end use water consumption for the potable and

recycled water lines post-commissioning of recycled water to the PC region.

A diurnal pattern software tool was developed to assist in the collaboration and analysis of end

use water consumption data files (Trace Wizard©/MS Access). Tabulated data sourced through

the software can be grouped within user selected time periods from hourly (24 graph points)

through to five minute intervals (288 graph data points). This enables data collaboration and

display of various ranges of data as prescribed by the operator. The diurnal software also allows

for weekday and weekend comparison to determine the differences between these distinct time

periods. The development of the diurnal software enabled the determination of hourly diurnal

patterns of use, at an end use level, for single and dual reticulated water supply regions. Chapter

9 details further discussion on the methodology adopted and the results from Stage 3c analysis.

3.5 Chapter Summary

This chapter examined the overarching research design and each aspect of the explanatory

mixed methods approach adopted to satisfy the developed research objectives. The application

of both quantitative and qualitative methods was necessary to strengthen the research design and

to address all research objectives. Quantitative methods including: questionnaire surveys, stock

inventory surveys and field experiments were utilised to satisfy research objectives. The follow-

up explanations model adopted for this study was true to character with emphasis being placed

on quantitative methods with qualitative data utilised to enhance the understanding on the

collected quantitative data. As a final note, this chapter was intended to provide an overarching

view of the numerous research methods applied. Each refereed publication chapter also provides

a detailed description on the specific research methods applied and the associated statistical

techniques adopted (e.g. factor analysis, cluster analysis, t-tests etc.). The following Chapter 4 is

dedicated to detailing the situational context in which the research (i.e. region, environmental

conditions, etc.) was undertaken and to describe in detail the research sample characteristics and

the end use data results from throughout the study.

3.6 References

Brase, G. L., Fiddick, L. & Harries, C. (2006) Participant recruitment methods and statistical reasoning performance. Journal of Experimental Psychology, 59:5, pp. 965-976.


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Brewer, J. & Hunter, A. (1989) Multimethod research: A synthesis of styles, Newbury Park, CA: Sage.




Dillman, D. A. (2000) Mail and Internet Surveys: The Tailored Design Method, 2nd edn, John Wiley, New York.

Field, A. (2005) Discovering statistics using SPSS, 2nd edn, SAGE Publications, London.


Hair, J. F., Black, W. C., Babin, B. J., Anderson, R. E. & Tatham, R. L. (2006) Multivariate Data Analysis, 6th edn, Pearson Prentice Hall, Upper Saddle River, N.J.

Heinrich, M. (2007) Water End Use and Efficiency Project (WEEP) - Final Report. BRANZ Study Report 159. Judgeford, New Zealand, Branz.

Howell, D. C. (2004) Fundamental Statistics for the Behavioural Sciences, Thompson Brookes/Cole, Belmont, CA.


Mayer, P. (2007) Discussions with Peter Mayer from AquaCraft on end use water consumption studies. IN WILLIS, R. (Ed.) Gold Coast, Australia.


Mayer, P. W. & DeOreo, W. B. (1999) Residential End Uses of Water. Aquacraft, Inc. Water Engineering and Management, Boulder, CO.


Miles, M. B. & Huberman, A. M. (1994) Qualitative data analysis: A sourcebook for new methods, (2nd ed.). Thousand Oaks, CA: Sage.

Morse, J. M. (1991) Approaches to qualitative - quantitative methodological triangulation. Nursing Research, 40, 120-123.

Neuman, W. L. (2003) Social Research Methods: Qualitative and Quantitative Approaches, USA, Pearson Education Inc.

Punch, K. F. (2000) Introduction to Social Research: Quantitative and Qualitative Approaches, London, Sage Publications Inc.


- 84 -


Sekaran, U. (2000) Research Methods for Business: A skill-building approach, USA, John Wiley & Sons Inc.

Sekaran, U. (2003) Research Method for Business: A Skill-Building Approach, 4th edn, Wiley, New York.

Tabachnick, B. G. & Fidell, L. S. (2007) Using Multivariate Statistics, 5th edn, Pearson Education Inc, Boston.

Vogt, W. P. (2007) Quantitative Research Methods for professionals, Illinois State University, Pearson.

Chapter 4: Situational Context and Descriptive Data Analysis

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Chapter 4

Situational Context and Descriptive Data

Analysis The purpose of this chapter is to present the research circumstances experienced over the duration of the

study including climatic conditions, water restriction regimes and supplied bulk water. Moreover, this

chapter provides a detailed description of the recruited research sample through discussions on the

distinct research areas, the number of participants involved in the various aspects of the research stages

and descriptive socio-demographic characteristics of the group. All end use water consumption data

collected throughout the research is presented with additional discussion. The chapter begins with

Section 4.1, which provides an overview of the research sample location, the sample participation in

various research stages (questionnaire survey, water audits) and presentation of the spatial layout of

homes in the various areas. Section 4.2 details the characteristics of the research areas through

descriptive statistics. Section 4.3 presents the climatic, water restrictions and water supply context within

which the research was carried out. Section 4.4 presents detailed information and discussion on the end

use water consumption data collected over the duration of the research.

4.1 Research Sample Group

The research sample group was obtained from three areas within the Pimpama Coomera (PC) dual

reticulated recycled water region and one area in the single reticulated Mudgeeraba region between

February and May 2008. Figure 4-1 illustrates the location of the four study areas within the context of

Gold Coast City. As seen, three of the four research areas fall within the Pimpama Coomera region,

while just one is located in the wider Gold Coast. The reason for the higher utilisation of dual reticulated

region participants was to meet the research objective of measuring end use water consumption in a dual

reticulated area. Further detail of each research area with participating households is presented in Figure

4-2.

As demonstrated in Figure 4-2, each research area has participants scattered throughout. Some areas have

clusters of households (i.e. Mudgeeraba) while others are more spaced throughout the entire area (i.e.

Crystal Creek). A total of 206 full participant households and 59 reserve participant households were

recruited across the PC and Mudgeeraba areas. Details of the number of participants in the four areas at

time of recruitment are presented in Table 4-1.


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Figure 4-1 Research areas for the Gold Coast Watersaver End Use study


- 87 -

Figure 4-2 Research areas and participating households


- 88 -

Each of the full participants (206) was contacted by phone and asked to participate in a qualitative water

audit, as detailed in Chapter 3. A total of 160 (out of 206) water audits were undertaken from August to

November 2008, a take-up rate of 77.7%. Moreover, questionnaire surveys were distributed to each

recruited household in November 2008, with a total of 151 returned. This equates to a response rate of

73.3% for the total sample (n=206) or a response rate of 93.8% for those that participated in the water

audit (n=160). Table 4-1 details the rates of participation in the water audits and questionnaire surveys

for the study sample.

Table 4-1 Overview of research area and recruited participants

Research area No. of Full

Participants

No. of Reserve

Participants

No. of Water

Audits

No. of Surveys

Mudgeeraba 51 4 43 36

Cassia Park 51 21 41 42

Crystal Creek 52 16 37 38

Coomera Waters 52 18 39 35

Totals 206 59 160 151

Table 4-1 shows that at least one additional household was recruited in each research area. Generally, the

uptake and participation in the various consensual research activities, including the qualitative water

audit and the questionnaire survey, was high. The water audits were carried out three to six months after

recruitment ceased, while the survey was distributed in November 2008, six months after the final

participants had been recruited. This may be the reason for the slight drop in attrition rate between the

two data collection activities. Socio-demographic characteristics obtained from the questionnaire survey

are discussed in Section 4.2.

4.2 Research Sample Characteristics

Participating households were requested to complete a questionnaire survey developed to assist in

determining the socio-demographic characteristics and socioeconomic status of households. These

surveys also assisted in determining environmental and water conservation perceptions and attitudes of

consumers. The completed questionnaire surveys (n=151) were entered into Predictive Analytics

Software 18.0 (PASW formally SPSS), a statistical analysis program (SPSS, 2010). PASW 18.0 is a

popular data storage platform and statistical analysis software with researchers and businesses.

Descriptive statistical enquiries were carried out to determine the socio-demographic characteristic of the

research sample. Section 4.2.1 divulges the socio-demographic characteristics and details the

classification of socioeconomic status for each research area.


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4.2.1 Socioeconomic status of areas

Socioeconomic status (SES) refers to the level of people’s social and economic position in society, which

can be measured through numerous social and economic indicators. Social indicators can include

education, employment, type of job, housing and health, while economic indicators can include income,

home ownership and asset level (Vyas and Kumaranayake, 2006; NSW DET, 2009). For the purpose of

this research SES was determined through the examination of the ownership status, education level of

household adults, and household income, family types along with employment statuses, which were

utilised to cross examine the average weekly income with employment type.

Table 4-2 Overview of research area and socioeconomic status indicators

Research area Socioeconomic classification

Total no. of Households

Average property size

(m2)

Average income

Education status

Mudgeeraba Lower Middle to Middle Class

36 646.8 AUD$1387 Mainly High School and Technical

Cassia Park Lower Middle to Middle Class


Crystal Creek Lower Middle to Middle Class

38 655.6 AUD$1606 Mainly Technical and Tertiary

Coomera Waters

Middle to Upper Middle Class

35 806.4 AUD$1987 Mainly Tertiary

151 695.1 AUD$1677

The four research regions included in the sample were predominately from the middle class range (i.e.

lower middle to upper middle class). Initially, the research sample was believed to contain lower to

higher SES groups, albeit descriptive statistics demonstrate that this is not the case and that all research

areas fall within middle class SES. As demonstrated in Table 4-2, the number of households that

responded to the survey in Mudgeeraba was 36. The average property size, obtained from GCW mapping

records, was 646.8m2. The income level in Mudgeeraba was the lowest recorded of the areas at $1387

per week. In contrast to this, Mudgeeraba contained the highest percentage of retired couples (17%) as

well as a high percentage of mature couples working part time (see Table 4-3). This high percentage of

retired and part-time working couples significantly decreased the average weekly income of the area. The

education status of the area was primarily high school and technical education, Table 4-3 provides

specific details. The combination of these socioeconomic indicators resulted in Mudgeeraba being rated

as a lower middle to middle class area.

As demonstrated in Table 4-2, the number of households that responded to the survey in Cassia Park was

42. The average property size, obtained from GCW mapping records, was 671.7m2. The income level in

Cassia Park was high at $1730 per week. The education status of the area was primarily high school and


- 90 -

technical education, Table 4-3 provides specific details. The combination of these socioeconomic

indicators resulted in Cassia Park being rated as a lower middle to middle class area.

The number of households that responded to the survey in Crystal Creek was 38 (Table 4-2). The

average property size, obtained from GCW mapping records, was 655.6m2. The income level in Crystal

Creek was $1606 per week. The education status of the area was primarily technical and tertiary, Table

4-3 provides specific details. The combination of these socioeconomic indicators resulted in Crystal

Creek being rated as a lower middle to middle class area.

As illustrated in Table 4-2, the number of households that responded to the survey in Coomera Waters

was 35. The average property size, obtained from GCW mapping records, was 806.4m2. The income

level in Coomera Waters was the highest of all the research areas at $1987 per week. The education

status of the area was mostly tertiary, Table 4-3 provides specific details. The combination of these

socioeconomic indicators resulted in Coomera Waters being rated as middle to upper middle class SES

area. Section 4.2.2 presents detailed demographics of the total sample.

4.2.2 Descriptive statistic characteristics of the total research sample

Table 4-3 presents descriptive statistical information on the research sample as a whole (total sample),

the single and dual reticulated regions and each individual research area. The total research sample has

an average of 3.4 people per household with areas ranging across lower middle to upper middle class

socioeconomic status areas (see Section 4.2.1 for details). The total research sample contains 62%

owners (n=94) and 26% renters (n=39) with 12% (n=18) of the sample not responding to this question.

Family types ranged from single persons, couples, small and large families, families with borders and

share houses. The most common family type was small families with 43% of participating households

within this family characteristic type (Table 4-3). Large families were the second most frequent family

type within the sample with 15% or 23 households. Mature couples formed 11% of the total sample,

retired couples 7%, single and young couples 3% each and families with borders and share houses 2%

each. Only 14% did not note their family type. The most frequent education level of the total research

sample was high school education (30%), followed closely by technical education at 29%, and tertiary

the least frequent at 22%. Only 1% of the sample was educated to lower than high school level, while

18% did not divulge their education status (Table 4-3).


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Table 4-3 Descriptive statistics of research regions

Total sample

(n=151)

Single Reticulated

Region (MU n=36)

Dual Reticulated Regions

(CP/CC/CW n=115)

Mudgeeraba

(n=36)

Cassia Park

(n=42)

Crystal Creek

(n=38)

Coomera Waters

(n=35)

Average no. of people in HH 3.4 2.6 3.7 2.6 3.8 3.6 3.6

Ownership status Total % Total % Total % Total % Total % Total % Total %

Rent 39 26 8 22 31 27 8 22 12 29 15 39 4 12

Own 94 62 25 70 69 60 25 70 26 62 17 45 26 74

No response 18 12 3 8 15 13 3 8 4 9 6 16 5 14

Family type

Single person 5 3 3 8 2 2 3 8 0 0 1 3 1 3

Young couple 5 3 1 3 4 3 1 3 1 2 2 5 1 3

Mature couple 17 11 5 14 12 10 5 14 3 7 7 18 2 6

Retired couple 10 7 6 17 4 4 6 17 2 5 2 5 0 0

Small family 65 43 13 36 52 45 13 36 19 45 12 32 21 60

Large family 23 15 1 3 22 19 1 3 12 29 6 16 4 11

Family with border 3 2 1 3 2 2 1 3 0 0 2 5 0 0

Share house 3 2 2 5 1 1 2 5 1 2 0 0 0 0

No response 20 14 4 11 16 14 4 11 4 10 6 16 6 17

Education status

Mainly lower than high school 2 1 0 0 2 2 0 0 0 0 2 5 0 0

Mainly high school 46 30 16 44 30 26 16 44 17 40 8 21 5 14

Mainly technical 43 29 9 25 34 30 9 25 15 36 10 26 9 26

Mainly tertiary 33 22 5 14 28 24 5 14 4 10 9 24 15 43

No response 27 18 6 17 21 18 6 17 6 14 9 24 6 17

Socioeconomic classification Lower Middle to

Upper Middle

Class

Lower Middle to Middle

Class

Lower Middle to Upper Middle

Class

Lower Middle to

Middle Class

Lower Middle to

Middle Class

Lower Middle to

Middle Class

Middle to Upper

Middle Class


- 92 -

4.2.3 Descriptive statistic characteristics of individual research areas

Mudgeeraba (MU), Cassia Park (CP), Crystal Creek (CC) and Coomera Waters (CW) were

selected as research sample target areas. Details of demographic variations between the areas

are presented in Table 4-3. The socioeconomic status are lower middle to middle class in

Cassia Park, Crystal Creek and Mudgeeraba, while Coomera Waters is classified as middle to

upper middle class. There is a significant difference between Mudgeeraba and the other areas

for the average number of people within each household, with means ranging from 2.6 in

Mudgeeraba to 3.8 in Cassia Park. The reason for these differences is seen in family type

statistics. Mudgeeraba possesses the highest percentage of single and coupled households,

(42%), while the other areas, Cassia Park, Crystal Creek and Coomera Waters, possess 14%,

31% and 12% of respectively. Small families are the highest frequency family type in all

areas ranging between 32% for Crystal Creek to 60% for Coomera Waters. Large families

were highest in Cassia Park, making up 29% of the area. Mudgeeraba and Crystal Creek had

the highest percentage of mature couples (14-18%), and families with borders (3-5%). In

general, Mudgeeraba and Crystal Creek possessed similar family type distributions with just

retired couples and large families varying. Coomera Waters contained the highest percentage

of small families (60%), followed by large families at 11%. No response ranged from 10-17%

across the areas.

The trend of more owners than renters was consistent throughout the areas. In terms of

ownership status Mudgeeraba and Cassia Park were similar, renters 22% and 29% and owners

69% and 62% respectively, while Crystal Creek contains more renters (39%) and less owners

(45%), and Coomera Waters had the highest percentage of owners (74%) and a low

proportion of renters (12%). For education status, Mudgeeraba and Cassia Park had similar

frequency distribution with mostly high school educated persons, 44% and 40%, followed by

technical education, 25% and 36%, with tertiary education lowest at 14% and 10%

respectively. Crystal Creek had a reasonably even spread across the education levels, ranging

from 21% high school, 26% technical, 24% tertiary, while 24% of people did not respond.

Coomera Waters possess significantly more households with formal tertiary education, with

43% of the area educated to this level. Similar levels of technically educated persons were

present when comparing Coomera Waters to other areas (26%), while this suburb possessed

the lowest percentage of high school educated people (14%). The descriptive statistics

detailed between the areas demonstrate that some general trends are present, which include a

higher number of owners than renters; the highest family type is small families while the level

of formal education alters with each area. Generally, young couples, single people, families

with borders and share houses only represent a small percentage of the research sample; this


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indicates that these areas are more densely populated with small and large families, mature

and retired couples. Section 4.2.4 discusses the descriptive statistical differences between the

single and dual reticulated areas.

4.2.4 Comparing single and dual reticulated regions

Objectives of the research included determining the difference in water consumption between

single and dual reticulated regions and, to establish the potable water savings attributed to a

dual reticulated recycled water development. As described in Chapter 3, effort was made to

determine a single reticulated region in the wider Gold Coast City, which comprised of

similar demographic characteristics to those found in PC. ABS demographic statistics were

investigated and Mudgeeraba was found to be the most similar suburb in terms of socio-

demographics. Details of the descriptive socio-demographic statistics of the single reticulated

Mudgeeraba region and the dual reticulated PC regions are presented in Table 4-3.

As detailed in Table 4-3, one of the most significant differences between the single and dual

reticulated regions is the average number of people in households. The single reticulated

region contains 2.6 and the dual reticulated region contains 3.7 people per household. This

data demonstrates that on average, there is at least one more person living in PC households

than those in the Mudgeeraba areas. Because of this difference, end use data is detailed in per

person consumption to eliminate errors. The most common family type in both the single and

dual reticulated regions was small families, which make up 36% and 45% respectively. Some

significant differences are seen between the single and dual reticulated regions between both

retired couples and large families, with 17% versus 4% and 3% versus 19% respectively. This

variation between retired couples and large families explains the higher number of people per

household in the dual reticulated areas. There is also a higher percentage of sole person in the

single reticulated region, 8% versus 2%, while share households make-up 5% in the single

and just 1% in the dual reticulated region. These variations in family type have the potential

to impact on end use water consumption, so again per person values were utilised to aid in all

comparisons.

When comparing the education status of participants some differences are seen between those

educated to high school level and tertiary level between the single and dual reticulated

regions. The single reticulated region participants had 44% of households educated to a high

school level, 25% educated to technical level and 14% educated to a tertiary level. The PC

dual reticulated region had 26% educated to high school level, 30% to technical and 24% to

tertiary level. Generally the dual reticulated region participants were formally educated to


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higher levels than those in the single reticulated region. The impact of education status on end

use water consumption was considered an interesting point for investigation; Chapter 7 details

how education level influences end use water consumption. These statistics demonstrate the

unique make-up of the dual reticulated PC region when compared with other regions of the

wider Gold Coast. Overall, there is little difference between ownership status between the

regions and while the breakdown of family types is relatively similar, noteworthy differences

are seen between the proportion of retired couples and large families between the regions. The

formal education status of those in the dual reticulated region was generally higher than those

in the single reticulated region. Efforts to minimise the effect of these socio-demographic

variations has been made through detailed explanation of the sample group when end use data

is presented. Understanding the socio-demographics of the research regions assisted in

utilising this data across Gold Coast City. Information outlining the data collection periods,

water restriction regimes, climatic data and total end use water consumption values is

presented in Section 4.3.

4.3 Situational Context of Study

This study involved the collection of end use water consumption data from winter 2008

through to summer 2010 hence the need to explain the context. The three significant data

collection periods occurred in winter 2008, summer 2008 and summer 2009/10. An originally

planned winter 2009 log was not carried out due to the delay in the supply of recycled water

to the PC region but a smaller sub-sample was collected primarily for the educational shower

monitor investigation. Detailed in this section, are water restriction regimes since 2006 and an

overview of monthly climatic trends experienced on the Gold Coast over the past ten years.

Comprehensive climatic data, bulk supplied water consumption and total end use

consumption data for the research period is also presented. All of these conditions were

considered pertinent due to their potential to influence water consumption.

4.3.1 Water restriction regimes over the data collection period

End use water consumption data has been collected over a two year period and throughout

that time water restriction levels have altered. Water restrictions set rules for outdoor watering

and, in times of extreme drought, also aim to restrict internal water consumption. Water

restriction levels on the Gold Coast were originally determined by the local water authority

(i.e. GCW). The Queensland Water Commission (QWC) was established in 2006 and is now

responsible for setting water restriction levels across SEQ. Table 4-4 lists the variations in


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water restriction levels throughout the research period and provides a description of each

level.

Table 4-4 Gold Coast water restriction overview and timeframe

Level of restriction Description of restriction level Dates active

Level 4

Lawn Watering Ban

Lawn Watering Ban No lawn watering; Hand held hoses only; Odds & evens system applies to residential & non

residential gardens; No watering between 9am and 4pm; No garden watering at all on Mondays; and, Buckets anytime.

1 November 2006

Level 5

Once Per Week Watering

Once per week watering Saturday for odds and Sunday for evens for

residential and non-residential gardens; No Lawn Watering; Hand Held Hoses Only; No watering between 9am and 4pm; and, Buckets anytime.

10 April 2007

Level 6

Total Outdoor Ban

Total outdoor ban Outside hosing or sprinkling is completely banned;

and, Buckets anytime.

23 Nov 2007

Restrictions Lifted Restrictions Lifted No restrictions on indoor or outdoor watering in

place.

9 February 2008

Medium Level Target 200 Hand held hoses only between 4pm & 4.30pm ; Odds & evens system applies to residential & non

residential gardens; Bucket or watering can allowed but not between

8am and 4pm; and, No garden watering at all on Mondays.

27 October 2008

Restrictions Lifted Restrictions Lifted No restrictions on indoor or outdoor watering in

place.

7 January 2009

Permanent Water Conservation Measures

Target 200 (revised from T230) Efficient sprinklers (less than 9 L/minute) and hoses

can be used between 10am & 4pm except on Mondays ;

No garden watering at all on Mondays; Use a bucket or watering can at any time; Pools can be topped up when no alternative supply

source (rainwater tanks) are available; and, High Res programme threshold at 1200 L/day per

household.

1 December 2009

Table 4-4 demonstrates that over the past four years, Gold Coast residents have had a

multitude of different restriction regimes. Restrictions have changed from lawn watering


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bans, to complete outdoor watering bans, to no restriction level and currently, water

restrictions fall under QWCs Permanent Water Conservation Measure Target of 200L/p/d. As

discussed in Chapter 2, restrictions have been found to significantly influence water

consumption levels hence it is important to be aware of the water restriction level in place

when collecting and analysing consumption data. Over the research period, the most severe

water restriction regime Gold Coast City has experienced is Target 200 L/p/d. Therefore,

Gold Coast residents have been able to irrigate within designated times or with no time

restrictions throughout the entire study. Details on the restriction level experienced over the

data collection period are always outlined when discussing time specific end use data sets due

to the potential impact this may have on the total sample and individual household end use

consumption. Water restriction levels are dictated by the available water supply for the city

which relies heavily upon rainfall hence, an overview of rainfall and other climatic data

assists in understanding the need for water restrictions and the potential demand for irrigation.

Detailed rainfall, temperature and water consumption data experienced through the end use

data collection periods is presented in Section 4.3.2.

4.3.2 Temperature and rainfall patterns on the Gold Coast

Weather patterns on the Gold Coast follow the sub-tropical characteristics of low temperature

and rainfall in winter and high temperature and rainfall in summer. After experiencing a

severe drought period from late 2006 to early 2008, rainfall on the Gold Coast normalised and

has been relatively consistent throughout the research and data collection periods. Figure 4-3

illustrates the monthly recorded rainfall and temperature from 2001 until 2010. Apparent in

Figure 4-3, are the climatic trends of temperature peaks in January and February while the

lowest temperatures are experienced in June and July. Rainfall in the Gold Coast, on average,

is highest between December and March. Rainfall is at its yearly low between July and

October coinciding with the lowest yearly temperatures. Data relevant to the research period,

from winter 2008 to early 2010, demonstrates quite high rainfall throughout 2008/09 and high

rainfall in February 2010 with this being the sixth highest recorded monthly rainfall across the

ten year period. Temperature patterns are reasonably consistent throughout the ten year

period. The 2008/09 and 2009/10 maximum temperatures follow the yearly trend quite

consistently with just August 2009 experiencing slightly higher temperatures than normal.

Details on climatic conditions experienced over the data collection period are always outlined

when discussing time specific end use data sets due to the potential impact this may have on

the total sample and individual household end use consumption. Specific climatic data from

the collection periods along with the bulk supplied water consumption and total recorded end

use water consumption data are discussed in Section 4.3.3.


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Long Term Average Max Temperature and Rainfall vs Actuals

0

5

10

15

20

25

30

35

Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun

Month

Tem

per

atu

re

0

100

200

300

400

500

600

700

800

Rai

nfa

ll (m

m)

2001/02 Rainfall 2002/03 Rainfall 2003/04 Rainfall2004/05 Rainfall 2005/06 Rainfall 2006/07 Rainfall2007/08 Rainfall 2008/09 Rainfall 2009/10 RainfallLTA Average Max Temp 2001/02 Max Temp 2002/03 Max Temp2003/04 Max Temp 2004/05 Max Temp 2005/06 Max Temp2006/07 Max Temp 2007/08 Max Temp 2008/09 Max Temp2009/10 Max Temp LTA Mean Rainfall

Figure 4-3 Yearly temperature and rainfall patterns for the Gold Coast, Queensland


- 98 -

4.3.3 Climate, bulk recorded supply and end use data throughout the study period

End use data was collected at various intervals over the duration of the study. As noted, the major data

collection periods occurred in winter 2008, summer 2008 and summer 2009/10. Additional end use data

was collected throughout 2009 to determine the extent to which the introduction of an educational

shower monitor device reduced shower end use water consumption. Temperature and rainfall can

significantly influence water consumption, particularly outdoor irrigation hence a detailed description of

the average temperatures and rainfall over the duration of the study is presented in Table 4-5. Gold Coast

City monthly bulk supplied water consumption data is detailed in per capita consumption. This figure is

calculated by GCWs demand forecaster, using the daily water volumes supplied to the city with

adjustments made for assumed losses, the forecasted population, the percentage of population served and

the percentage of consumption predicted to be used by residents. Additionally potable and recycled, bulk

supplied water consumption data for the PC dual reticulation region is also presented separately and as a

combined total per capita consumption. This data was extracted from GCW quarterly bulk billing records

hence, the same PC data is presented for each month within that quarter. Table 4-5 also demonstrates the

end use data collection periods, highlighted in grey, with total per capita end use consumption data

presented. All data detailed in Table 4-5 is for single detached residential households only.

Climatic trends presented in Table 4-5 mirror those seen in Figure 4-3, with high rainfall and

temperatures throughout summer and low temperatures and rainfall in winter. Table 4-5 shows that the

first data collection period in winter 2008, fell within an un-seasonally high rainfall period. This is

reflected in both the city wide bulk supplied and end use data being the lowest recorded over the study

period. The PC bulk supplied data is higher than the recorded end use total but this would be due to the

amalgamation of the quarterly data not reflecting the true consumption for the month of July.

Considering the average PC combined consumption between the month of June and July (i.e.

(136+199)/2 = 169 L/p/d) the end use value seems on par again, demonstrating the difficulty in

comparing end use data to three month billing records. Both the end use data and the bulk supplied data

from winter 2008 demonstrate that residents in the PC area were consuming more than those in single

reticulated regions across Gold Coast City.

Significantly high rainfall in November 2008 and relatively high rainfall in December 2008 resulted in

low bulk supply and end use water consumption data. The end use water consumption data collected in

this period was significantly lower than that recorded through the city wide monthly bulk supply and the

PC combined supply. The reason for this may have been the end use data collection two week period

occurred when the highest rainfall days were recorded for the month, hence minimal irrigation use and

much lower end use water consumption volumes than the bulk supplied data.


- 99 -

Table 4-5 Climatic, bulk supply and end use water consumption data from Gold Coast City

Year Month Mean

Max.

Temp.

Mean

Min.

Temp.

Total

Rainfall

Mean

number of

days of

rain >1mm

GC City Wide

Pot. Bulk

Supplied Res.

Water (L/p/d)

PC Dual

Retic. Pot.

Bulk Supplied

Res. Water

(L/p/d)

PC Dual

Retic. Rec.

Bulk Supplied

Res. Water

(L/p/d)

PC Dual Retic.

Combined Bulk

Supplied Res.

Water (L/p/d)

End Use Water

Consumption

Single Retic.

(L/p/d)

End Use Water

Consumption

Dual (PC)

Retic. (L/p/d)

End Use Water

Consumption

Combined

(L/p/d)

2008 June 22.99 13.0 95.8 7 164.81 109 27 136

July 21.05 11.35 129.8 10 161.90 161 38 199 153.4 (n=38) 158.5 (n=113) 157.2 (n=151)

August 22.36 9.87 0.8 0 171.30 161 38 199

September 24.42 15.51 74.8 8 169.63 161 38 199

October 26.15 16.22 107.6 8 177.64 146 36 182

November 27.32 19.11 440.6 14 173.67 146 36 182

December 29.74 20.4 123.8 11 176.85 146 36 182 158.3 (n=29) 143.5 (n=98) 150.9 (n=127)

2009 January 29.65 22.08 93.2 10 196.31 148 39 187

February 29.80 21.74 167.4 13 176.56 148 39 187

March 28.58 20.78 91.4 13 181.02 148 39 187

April 26.76 18.14 385.6 11 189.81 128 35 163

May 23.83 14.99 183.4 9 186.99 128 35 163 172.5 (n=7) 163.4 (n=27) 168.0 (n=34)

June 21.40 12.25 139.8 11 180.58 128 35 163

July 21.37 11.36 7.2 2 188.93 155 37 192

August 24.58 13.56 0.8 2 204.08 155 37 192

September 25.29 14.3 13 2 214.00 155 37 192

October 26.60 16.45 20.8 5 222.28 146 43 189

November 28.66 19.95 52 7 213.25 146 43 189

December 28.85 18.4 107.8 8 224.36 146 43 189 205.3 (n=7) 282.4 (n=24) 243.9 (n=31)

2010 January 30.37 22 73.8 7 221.54 162 39 201

February 29.26 22.11 299.8 15 194.67 162 39 201

March 28.08 21.51 185.2 14 191.93 162 39 201 146.9 (n=27) 155.4 (n=73) 153.1 (n=100)

April 27.23 19.19 56.4 7 192.10

- 100 -

The end use data collected in this period showed that PC residents were consuming less than

those in single reticulated regions (Table 4-5). While this is not reflected in the bulk supplied

data evidence exists in the following month.

A small end use sample was collected in May 2009 for the purpose of the educational shower

monitor investigation. While the original research scope included a winter 2009 end use data

log, this did not occur due to the delay in recycled water supply. The May 2009 end use data

was collected over a relatively high rainfall period for this month (Figure 4-3). The end use data

collected is reasonably aligned with the data presented from the city wide bulk supply and very

closely aligned to the PC bulk billed supply data. The end use data corresponds with the bulk

supply data with single reticulated residents consuming more than those in the PC area (Table

4-5).

Data collection over summer 2009/10 occurred twice to capture high and low rainfall periods. In

December 2009, a sample of 31 homes end use was captured within the highest bulk supplied

consumption period over the period of the study. The reason for the small sample size (n=31)

was due to significant failures in equipment. Data was collected in the first two weeks in

December just after the supply of recycled water to the PC region and before rain occurred in

the final week of the month. Table 4-5 demonstrates that the end use data from December

captured the highest consumption experienced on the Gold Coast in two years. Interestingly,

end use data in Table 4-5 reflects that residents in the PC region consumed significantly more

total water than those in the single reticulated region although this is opposite to that captured

by the bulk supply data. The reason for the significantly higher total end use consumption value

was because much of the data was collected in the highest socioeconomic region of Coomera

Waters. This area has much larger lot sizes and hence they were consuming significantly more

water externally for irrigation. The bulk recorded data for the PC region also contains numerous

multi and dual occupancy households with small external spaces, hence the significantly lower

value.

The second collection phase in March 2010 fell within a high rainfall period with 185.2mm of

rainfall recorded with 14 rainfall days over 1mm. Bulk supplied consumption for the wider Gold

Coast City was 191.93 L/p/d, which is higher than 2009 March consumption but lower than

summer consumption. Combined water consumption (potable + recycled) in the PC region

based on three month billing data was 201 L/p/d with 162 L/p/d being potable use and 39 L/p/d

being recycled water use. Combined bulk recorded water consumption in the PC region was

higher than that recorded for Gold Coast City. The bulk billing figures demonstrate that 80.6%

of total consumption is potable water, while 19.4% is recycled water. The end use data collected


- 101 -

during this month was significantly lower than that recorded through bulk billing. The single

reticulated end use monitored consumption was 146.9 L/p/d, which is 23% lower than that

recorded through bulk consumption. The dual reticulated area consumption demonstrated even

higher discrepancies between end use and bulk billing data with 155.4 L/p/d end use

consumption recorded and 201 L/p/d of bulk use recorded. The reason for these discrepancies

may be due to the collection period falling within the higher rainfall time interval, the sample

size being too small to reflect the average city wide consumption or due to the differences in

actual end use data versus bulk supplied and bulk billed data.

Overall, the end use data collected across the two year period follows the trends presented in the

bulk supplied and bulk billed data. There is evidently a difference between the end use water

consumption data and bulk supplied and billed data. Many factors could be contributed to these

differences. Some of which could be:

The end use data collection period of two weeks falling within a high or low rainfall

period of the month or a high or low temperature period when bulk data is looking at

monthly averages. The variation in rainfall and temperature was found to significantly

influence end use water consumption totals, namely through external usage. The March

2010 end use logging period was a good example of how data collection in the wetter

part of the month resulted in a difference of 21% when compared against monthly bulk

supplied averages.

The bulk supply and bulk billing data contains numerous estimations and assumptions

on the number of people that water is being supplied to or the per person consumption.

These population averages are based on Gold Coast’s desired standards of service

calculations and population estimates within Infrastructure Demand Models. The end

use per person consumption is based on household surveys and hence posses

significantly higher accuracy than citywide population data. For example, the average

occupancy of households within the GCWSEU study was 3.4 (see Table 4-2) while the

average occupancy in Gold Coast’s Desired Standards of Service is 2.73 (GHD, 2009).

If single reticulated data is used for comparison at a household level then the bulk

supplied consumption is 524 L/HH/d (191.93 L/p/d x 2.73) and the end use water

consumption is 499 L/HH/d (146.9 L/p/d x 3.4) then the variation in these consumption

values is just 5% not 23%. Hence, the level of accuracy obtained through the end use

study gives a more representative indication of actual per person consumption within a

household.

The research sample may not reflect the Gold Coast city wide consumption as the

recruited sample group may not represent the general consumption behaviours across

the city. Unfortunately it is often the case that more willing residents participate in

research projects which is often due to perceived belief of displaying the correct


- 102 -

behaviour which, in this case is being water efficient. To ensure a representative sample

was obtained, the total end use consumption of the recruited sample group were

analysed to evaluate representativeness. Chapter 5 presents details of this investigation

which demonstrated that a wide range of water consumers were present within the

sample group.

The research sample population changed significantly throughout the research period.

Due to the long sampling timeframe of the research, it is apparent that the sample group

recruited at the beginning of the research would vary by the end. To ensure the most

accurate population data, the local billing system was checked and additional phone

calls/on-site discussions occurred to clarify occupancy rates within sampled households.

In depth breakdowns of end use water consumption data in each of the data collection periods

noted above are presented in Section 4.4.

4.4 End Use Water Consumption Data

Collection of end use water consumption data occurred in winter 2008, summer 2008 and

summer 2009/10. This section presents the detailed end use water consumption data from each

of these collection periods.

4.4.1 Winter 2008

The winter 2008 end use water consumption data collection period occurred in July. Gold Coast

City was not on any level of water restrictions but the city had recently experienced a severe

drought period which involved complete outdoor watering bans and an array of successful

demand management initiatives to reduce residential consumption. At this point in time,

residents still seemed to be consuming at low levels between 160 and 165 L/p/d (Table 4-5). In

July 2008, Gold Coast city experienced un-seasonally high rainfall of 129.8mm; with ten days

in this month incurring rain above 1mm. Bulk supplied residential consumption was 161.9

L/p/d, just slightly higher than June consumption but 10 L/p/d less than in August 2008. There

was no recycled water supplied to the PC region at this time. Figure 4-4 details the total end use

water consumption break down for the research sample (n=151) for winter 2008.


- 103 -

Figure 4-4 Average daily per capita consumption for total sample in winter 2008 (n=151)

The break down of end use water consumption for the total Gold Coast sample (n=151) is

shown in Figure 4-4. The average consumption for the sampled homes was 157.2 L/p/d. Shower

end use consumption was the highest at 32% or 49.7 L/p/d followed by clothes washer at 19%

or 30.0 L/p/d. Tap use, toilet flushing and irrigation account for end use percentages of 17%,

13% and 12%, respectively. Bath use, dishwashing and leaks make up a small component of

water end use with percentages ranging from 1% to 4%. The break down of the single and dual

reticulated regions is detailed in Figure 4-5 and Figure 4-6. The figures present both potable and

recycled water consumption as these water sources are still supplied and recorded through two

separate water meters for all data logging periods including winter 2008.

As previously noted, recycled water was not yet supplied to the PC region in winter 2008.

Figure 4-5 and Figure 4-6 illustrate the single and dual reticulated end use water consumption

respectively. The total consumption for the single reticulated region was 153.4 L/p/d while the

dual reticulated region was slightly higher at 158.5 L/p/d. The consumption volumes are

relatively similar between the two areas for shower, clothes washer, tap, toilet and dishwasher.

Difference is seen between the volumetric use for bathtub perhaps due to more small and large

families in the PC region. Combined irrigation is also somewhat higher in the PC dual

reticulated region (Figure 4-6). Leakage is higher in the single reticulated region. Overall, the

winter 2008 data log demonstrated that the end use water consumption of the single and dual

reticulated regions was quite similar and hence comparison between the two regions was

reasonable.

Clothes Washer

30.0L/p/d19.1%

Shower49.7 L/p/d

31.6%

Tap27.0L/p/d

17.2%

Dishwasher2.2L/p/d

1.4%

Bathtub6.5 L/p/d

4.2%

Toilet (total)21.1 L/p/d

13.4%

Irrigation (Total)

18.6L/p/d11.8%

Leak (Total)2.1L/p/d

1.3%

Average Daily Per Capita Consumption (L/p/day): Single+Dual (n=151)

Total = 157.2 L/p/d


- 104 -

Figure 4-5 Average daily per capita consumption for single reticulated region in winter 2008 (n=38)

Figure 4-6 Average daily per capita consumption for dual reticulated region in winter 2008 (n=113)

Table 4-6 details the end use water consumption break down for the individual research areas. It

should be noted that there are two single reticulated homes in the PC region. These were the

existing homes in place before the dual reticulated PCWF Master Plan was implemented. These

homes are included in the single reticulated figures but remain in their equivalent socio-

demographic area for the tables, as seen in Table 4-6.

Clothes Washer

26.8 L/p/d17.5%

Shower55.4 L/p/d

36.2%

Tap30.1 L/p/d

19.6%

Dishwasher1.8 L/p/d

1.2%

Bathtub3.2 L/p/d

2.1%

Toilet (Pot)19.3 L/p/d

12.6%

Irrigation (Pot)13.9 L/p/d

9.1%

Leak (Pot)2.7 L/p/d

1.8%

Average Daily Per Capita Consumption (L/p/day): Single Reticulation (n=38)

Clothes Washer

31.1 L/p/d19.6%

Shower47.7 L/p/d

30.1%

Tap26.0 L/p/d

16.4%

Dishwasher2.4 L/p/d

1.5%

Bathtub7.6 L/p/d

4.8%

Toilet (Rec)21.7 L/p/d

13.7%


6.3%

Irrigation (Rec)10.2 L/p/d

6.4%

Leak (Pot)1.2 L/p/d

0.7%

Leak (Rec)0.7 L/p/d

0.4%

Average Daily Per Capita Consumption (L/p/day): Dual Reticulation (n=113)

Total = 158.5 L/p/d

Total = 153.4 L/p/d


- 105 -

Table 4-6 Winter 2008 end use data for research regions

End use category Mudgeeraba (n=36)

Cassia Park (n=42)

Crystal Creek (n=38)

Coomera Waters (n=34)

L/p/d Percent L/p/d Percent L/p/d Percent L/p/d Percent Clothes washer 27.3 17.6% 32.2 21.2% 31.4 20.1% 28.5 17.2% Shower 56.3 36.2% 50.2 32.9% 44.2 28.3% 48.2 29.1% Tap 30.4 19.5% 24 15.8% 27.8 17.8% 26.5 16% Dishwasher 1.9 1.2% 1.8 1.2% 2.7 1.7% 2.6 1.5% Bathtub 3.4 2.2% 8.7 5.7% 6 3.8% 7.7 4.6% Toilet (Pot) 19.2 12.3% 0.8 0.5% 0.3 0.2% 0 0% Toilet (Rec) NA NA 20.6 13.5% 21.4 13.7% 22.1 13.3% Irrigation (Pot) 14.5 9.3% 5.9 3.9% 10.3 6.6% 14.2 8.5% Irrigation (Rec) NA NA 6.2 4% 10.9 6.9% 13.7 8.3% Leak (Pot) 2.6 1.7% 1.1 0.7% 1 0.6% 1.7 1.1% Leak (Rec) NA NA 0.8 0.5% 0.5 0.3% 0.6 0.4% Total (Pot) 155.6 100% 124.7 82.0% 123.7 79.1% 129.4 78.0% Total (Rec) NA NA 27.6 18.0% 32.8 20.9% 36.4 22.0% Total (Pot + Rec)

155.6 100% 152.3 100% 156.5 100% 165.8 100%

Note: Pot = potable supply line, Rec = recycled supply line

In Mudgeeraba, recycled consumption for toilet, irrigation and leak are not applicable as this is

the single reticulated region without recycled water supply. Clothes washer use is higher in

Cassia Park and Crystal Creek; the lower and middle dual reticulation regions (Table 4-6).

Showering is the highest end use across all the regions with the highest consumption occurring

in Mudgeeraba and the lowest in Crystal Creek. Dishwasher use is highest in the middle and

high socioeconomic areas Crystal Creek and Coomera Waters due to higher ownership in these

areas. Toilet use is generally consistent across the regions. Combined irrigation use is the

highest in Coomera Waters followed by Crystal Creek, Mudgeeraba and Cassia Park. This trend

is consistent with greater use in higher socioeconomic areas.

4.4.2 Summer 2008

The summer 2008 end use water consumption data collection occurred primarily through

December. At this point in time, Gold Coast city was on QWC medium level restrictions of

Target 200 L/p/d. Before this data collection commenced, November 2008 experienced extreme

monthly rainfall totalling 440.6mm with, 14 rainfall days above 1mm (Table 4-5). This was the

third highest rainfall month on the Gold Coast between 2001 and 2010. December 2008 also

saw reasonably high rainfall of 123.8mm and 11 rainfall days with over 1mm of rain.

Understandably, bulk supplied residential consumption was low in December being just 176.9

L/p/d, this increased to 196.3 L/p/d the next month of January 2009. Recycled water was not

supplied to the PC region for this data collection period. Figure 4-7 details the total end use

water consumption breakdown for the research sample (n=127) for summer 2008.


- 106 -

Figure 4-7 Average daily per capita consumption for total sample in summer 2008/09 (n=127)


presented in Figure 4-7. The average consumption for the sampled homes was 150.9 L/p/d.

Figure 4-7 shows that shower end use consumption remained the highest at 32% or 48.4 L/p/d

followed by clothes washer at 19% or 29.0 L/p/d. These consumption values are almost the

same as those recorded in the winter 2008 data log. Tap use, toilet flushing and irrigation

account for end use percentages of 18%, 14% and 9%, respectively. Bath use, dishwashing and

leaks make up a small component of water end use with percentages ranging from 1% to 5%.

Figure 4-8 and Figure 4-9 detail the single and dual reticulated end use water consumption

respectively. The total consumption for the single reticulated region was 158.3 L/p/d while the

dual reticulated region was 9% lower at 143.5 L/p/d. Again, the consumption volumes are

relatively similar between the two areas for shower, clothes washer, tap, toilet and dishwasher.

In this data logging period, total irrigation consumption is almost equal with the single

reticulated region consuming 12.7 L/p/d or 8% and the dual reticulated region using 13.1 L/p/d

(potable + recycled) or 9%. The outstanding differentiator between the two regions is the high

leakage in the single reticulated region. This accounts for 13.0 L/p/d or 8% of total end use,

while the dual reticulated region only experienced a combined leakage of 2.1 L/p/d or 1.5%.

This large leakage volume was due to one single reticulated house having an ongoing leak

across the entire data collection period. This high leakage volume is the reason for the higher

water consumption in the single reticulated region in summer 2008. Apart from leakage, most

end uses have very similar volumetric consumption values in both the single and dual

Clothes Washer

29.0 L/p/d19.2%

Shower48.4 L/p/d

32.1%

Tap27.4 L/p/d

18.2%

Dishwasher2.1 L/p/d

1.4%

Bathtub2.0 L/p/d

1.3%

Toilet (Total)21.5 L/p/d

14.3%

Irrigation (Total)

12.9 L/p/d8.6%

Leak (Total)7.5 L/p/d

5.0%

Average Daily Per Capita Consumption (L/p/day):Single + Dual (n= 127)

Total = 150.9 L/p/d


- 107 -

reticulated regions. Table 4-7 details the individual areas end use water consumption in summer

2008.

Figure 4-8 Average daily per capita consumption for single reticulated region in summer 2008/09 (n=29)

Figure 4-9 Average daily per capita consumption for dual reticulated region in summer 2008/09 (n=98)

Table 4-7 Summer 2008/09 end use data for research regions

Clothes Washer

28.3 L/p/d17.9%

Shower51.1 L/p/d

32.3%

Tap28.6 L/p/d

18.1%

Dishwasher2.1 L/p/d

1.3%

Bathtub1.4 L/p/d

0.9%


13.4%


8.0%

Leak (Pot)13.0 L/p/d

8.2%

Average Daily Per Captia Consumption (L/p/day):Single Reticulation (n= 29)

Total = 158.3 L/p/d

Clothes Washer

29.7 L/p/d20.7%

Shower45.6 L/p/d

31.8%

Tap26.3 L/p/d

18.3%

Dishwasher2.2 L/p/d

1.5%

Bathtub2.6 L/p/d

1.8%


15.3%


4.8%


4.3%

Leak (Pot)1.4 L/p/d

1.0%

Leak (Rec)0.7 L/p/d

0.5%

Average Daily Per Capita Concumption (L/p/day):Dual Reticulation (n= 98)

Total = 143.5 L/p/d


- 108 -

End use category Mudgeeraba (n=27)

Cassia Park (n=36)



L/p/d Percent L/p/d Percent L/p/d Percent L/p/d Percent Clothes washer 29 20% 28.5 19.8% 28.8 19.7% 31.3 20.8% Shower 51.3 35% 42.5 29.5% 47.6 32.5% 47.5 31.6% Tap 28.2 19% 23.2 16.1% 29.5 20.2% 26.9 17.9% Dishwasher 2.1 1% 1.4 1% 2.5 1.7% 2.7 1.8% Bathtub 1.5 1% 2.9 2% 2.9 1.9% 1.9 1.3% Toilet (Pot) 20.2 14% 1.4 0.9% 0.6 0.4% 0 0% Toilet (Rec) NA NA 19.7 13.7% 21.2 14.5% 23.9 15.9% Irrigation (Pot) 12.3 8% 7.6 5.3% 6 4.1% 7.9 5.3% Irrigation (Rec) NA NA 5.8 4% 5.7 3.9% 6.8 4.5% Leak (Pot) 3.5 2% 10.4 7.2% 1 0.7% 0.3 0.2% Leak (Rec) NA NA 0.6 0.4% 0.5 0.4% 0.9 0.6% Total (Pot) 148.1 100% 117.9 81.9% 118.9 81.2% 118.5 79.0% Total (Rec) NA NA 26.1 18.1% 27.4 18.8% 31.6 21.0% Total (Pot + Rec)

148.1 100% 144 100% 146.3 100% 150.1 100%

Table 4-7 demonstrates that significant leakage occurred in a single reticulated home in Cassia

Park. Leakage across the other areas was low with Mudgeeraba experiencing the highest

leakage of the other three areas. Across the areas clothes washing volumes are consistent with

Coomera Waters being just slightly higher than the others. Shower use is highest in Mudgeeraba

followed by Coomera Waters, Crystal Creek and Cassia Park. Toilet use is very similar across

the areas, while irrigation is again highest in the high socioeconomic region followed by

Mudgeeraba. Total consumption is relatively similar across the areas with the highest

socioeconomic region consuming the most (i.e. Coomera Waters at 150.1 L/p/d) followed by

Mudgeeraba, Crystal Creek and Cassia Park.

4.4.3 December 2009

End use water consumption data was collected in a high use period and lower use period in

December 2009 and March 2010 to capture the differences in recycled water consumption. The

data collection period in December 2009 contained a small sample due to significant equipment

failures from water intrusion in the water meters and data loggers. As at the 1st of December

2009, the Gold Coast City was on the QWC Permanent water conservation target level of 200

L/p/d. For almost a year, the city was not under any water restriction level and the progressive

rise in monthly water consumption can be seen across 2009 (Table 4-5). When comparing 2008

and 2009 Gold Coast City monthly water consumption, 2009 consumption is always higher than

the equivalent 2008 month. Higher temperatures and low rainfall resulted in city wide

consumption going above 200L/p/d in August 2009, with bulk supplied water consumption

peaking in December 2009 at 224.36 L/p/d. Recycled water consumption was at its highest

recorded from January to March 2010. December 2009 experienced high rainfall volumes of

107.8mm but this occurred in the last week of the month after high temperatures and no rainfall

in the first three weeks of December, hence just eight rainfall days over 1mm noted. As at 1st of

December 2009, recycled water was supplied to the PC region. The commissioning of recycled


- 109 -

water was launched with an extensive awareness campaign promoting the supply and use of

recycled water in the PC region. It is believed that these high temperatures, no rainfall and

promotional campaign for recycled water supply encouraging use is why end use water

consumption in the dual reticulated areas was so high. Further detail of the break down of

internal versus external irrigation (Table 4-8) in the dual reticulated recycled water areas

demonstrates significant irrigation usage. Figure 4-10 details the total end use water

consumption break down for the research sample in this period (n=33), Figure 4-11 and Figure

4-12 detail the end use consumption in the single and dual reticulated regions in December

2009. Table 4-8 demonstrates the research areas individual end use water consumption details.

Figure 4-10 Average daily per capita consumption total sample December 2009 (n=33)


demonstrated in Figure 4-10. The average consumption for the sampled homes was 243.9 L/p/d

an increase in consumption of 66% since the summer 2008/09 end use data log. Figure 4-10

details that irrigation was the highest end use in the home at 39% or 95.7 L/p/d a significant

increase in irrigation when compared with other end use data logging periods. The reason for

this high irrigation use was the hot and dry climatic conditions combined with the supply and

encouragement of recycled water use in the PC region. Volumetric shower consumption

remained similar to that seen in summer 08/09 at 46.2 L/p/d. Clothes washing end use increased

when compared to summer 08/09, to 38.7 L/p/d of total use. Again, tap and toilet volumetric

consumption remained similar to those recorded in other end use logging periods at 28.7 or 24.2

L/p/d respectively. Bathtub, dishwasher and leakage in December 2009 were low, ranging

between 1-2% of total use. The significant increase in total water consumption in December

2009 was the result of high irrigation use. While some other end uses increased slightly such as

Clothes Washer

38.7 L/p/d15.9%

Shower46.2 L/p/d

18.9%

Tap28.7 L/p/d

11.8%

Dishwasher2.2 L/p/d

0.9%

Bathtub3.3 L/p/d

1.3%


9.9%

Irrigation (Total)

95.7 L/p/d39.2%


2.0%

Average Daily Per Capita Concumption (L/p/day):Single + Dual (n= 33)

Total = 243.9 L/p/d


- 110 -

clothes washer, the large consumption increase is primarily a result of irrigation. Capturing this

high total consumption and irrigation consumption is pertinent for the consideration of peak use

periods in modelling and planning water infrastructure. The break down of the single and dual

reticulated regions end use consumption is demonstrated in Figure 4-11 and Figure 4-12.

Figure 4-11 Average daily per capita consumption single reticulated region in December 2009 (n=7)

Figure 4-11 and Figure 4-12 detail the single and dual reticulated end use water consumption

respectively. Only seven homes were captured in the single reticulated region with data

demonstrating that shower use remained highest, followed by clothes washing and irrigation.

Data from the dual reticulated region showed that irrigation on the recycled water line was by

far the highest end use at 91.8 L/p/d or 33% of total use. This data demonstrates successful

uptake and preference of recycled water use for irrigation in the dual reticulated areas. Irrigation

on the potable line was the next highest in the dual reticulated region at 54.6 L/p/d or 19%.

Clothes washer and shower use was lower in volumetric consumption than that in the single

reticulated region although this difference may be due to the low sample sizes in each group.

Tap, toilet and dishwasher consumption were reasonably similar, while leakage and bathtub end

use was higher in the dual reticulated region as has been the trend throughout. Table 4-8 details

the December 2009 end use breakdown for each individual area.

Clothes Washer

47.4 L/p/d23.1%

Shower51.9 L/p/d

25.3%

Tap32.0 L/p/d

15.6%

Dishwasher2.2 L/p/d

1.1%

Bathtub2.6 L/p/d

1.3%


10.8%


21.9%

Leak (Pot)2.0 L/p/d

1.0%

Average Daily Per Captia Consumption (L/p/day):Single Reticulation (n= 7)

Total = 205.3 L/p/d


- 111 -

Figure 4-12 Average daily per capita consumption dual reticulated region in December 2009 (n=26)

Table 4-8 Summer December 2009 end use data for research regions

End use categories

Mudgeeraba (n=5)

Cassia Park (n=5)

Crystal Creek (n=7)


L/p/d Percent L/p/d Percent L/p/d Percent L/p/d Percent Clothes washer 43.8 23.8% 23.7 19.4% 32.3 15.3% 32.5 8% Shower 45.2 24.5% 37 30.1% 33.7 16% 49.9 12.2% Tap 25.3 13.7% 19.1 15.6% 25.8 12.2% 30.5 7.4% Dishwasher 2.2 1.2% 1.5 1.3% 3.1 1.5% 1.9 0.5% Bathtub 2.6 1.4% 3.3 2.7% 4.8 2.3% 3.4 0.8% Toilet (Pot) 18.3 9.9% 5.5 4.5% 0 0% 0 0% Toilet (Rec) NA NA 17.5 14.3% 25.1 11.9% 29.3 7.2% Irrigation (Pot) 45 24.4% 5.9 4.9% 14.7 7% 104.9 25.7% Irrigation (Rec) NA NA 8 6.5% 70.6 33.5% 140.1 34.3% Leak (Pot) 1.8 1% 0.6 0.5% 0.3 0.2% 0.8 0.2% Leak (Rec) NA NA 0.2 0.2% 0.5 0.2% 15.2 3.7% Total (Pot) 184.2 100% 96.6 79% 114.7 54.4% 223.9 54.8% Total (Rec) NA NA 25.7 21% 96.2 45.6% 184.6 45.2% Total (Pot + Rec)

184.2 100% 122.3 100% 210.9 100% 408.5 100%

The December 2009 end use data logging period contain a very small sample size, Table 4-8

details the relevant number of homes monitored in each area. Such a small, non-significant

number of homes mean that end use data cannot be relied upon hence; general comments will be

made but are not considered applicable for the individual areas. Clothes washer use is highest in

Mudgeeraba, followed by Coomera Waters, Crystal Creek and Cassia Park. Shower use is

highest in Coomera Waters with Mudgeeraba and Cassia Park the next highest. Tap use is not as

consistent as normally seen across the various areas demonstrating the need for a larger sample

size to make appropriate conclusions. Of interest is the irrigation use across the suburbs.

Coomera Waters, the highest socioeconomic region with the largest property sizes, consumed

Clothes Washer

30.1 L/p/d10.7%

Shower40.5 L/p/d

14.3%

Tap25.4 L/p/d

9.0%

Dishwasher2.2 L/p/d

0.8%

Bathtub3.9 L/p/d

1.4%


9.3%


19.3%


32.5%

Leak (Pot)0.5 L/p/d

0.2%

Leak (Rec)7.2 L/p/d

2.6%

Average Daily Per Capita Concumption (L/p/day):Dual Reticulation (n= 26)

Total = 282.4 L/p/d


- 112 -

by far the highest irrigation volume on both the potable and recycled water lines. In fact,

recycled and potable irrigation in Coomera Waters accounted for 60% of the total end use for

that area. Irrigation on the recycled water line is higher across all of the dual reticulated areas

ranging from 8 L/p/d in Cassia Park to 140.1 L/p/d in Coomera Waters. While the data in Table

4-8 is not significant, it does present some interesting trends. Data from the March 2010 end use

logging period is now presented.

4.4.4 March 2010

As stated, two end use data collection periods were undertaken when recycled water was

supplied to the PC dual reticulated areas. The March 2010 log contained a higher sample size

than the December 2009 log as equipment was repaired, a total of 100 homes were captured.

The QWC Permanent Water Conservation target of 200 L/p/d was still applied in March 2010.

The month of March experienced average temperatures and high rainfall of 185.2mm with 14

days experiencing more than 1mm of rainfall. The rainfall was twice that in March 2009 and

higher than rainfall volumes historically experienced within the month of March. Effort was

made to record in lower rainfall periods albeit rainfall was quite consistent throughout the

month. The bulk supplied single reticulation water consumption volume for the city was 191.93

L/p/d, just slightly lower than consumption in April 2010. Recycled water consumption in the

PC region, as per bulk supplied data, was 201 L/p/d in total with 162 L/p/d consumed through

the potable supply and 39 L/p/d consumed on the recycled water supply. Figure 4-13 details the

total end use water consumption break down for the research sample in March 2010 (n=100),

Figure 4-14 and Figure 4-15 detail the end use consumption in the single and dual reticulated

regions in December 2009. Table 4-9 demonstrates the research areas individual end use water

consumption details.

The break down of end use water consumption for the total Gold Coast sample in March 2010

(n=100) is demonstrated in Figure 4-13. The average consumption for the sampled homes was

153.1 L/p/d which is significantly lower than the bulk supplied single reticulation consumption

of 191.93 L/p/d. Figure 4-13 details that shower was the highest end use in the home at 29.9%

or 45.8 L/p/d which is consistent with shower end use consumption recorded in other data

logging periods. Irrigation significantly decreased from that recorded in December 2009 due to

the high rainfall volume and days. Total irrigation accounted for just 8.7% of end use or 13.3

L/p/d. Tap use and clothes washing accounted for the next highest end uses after shower, being

30.8 L/p/d and 30.2 L/p/d respectively. Clothes washing were somewhat lower than that

recorded in December 2009 but consistent with volumetric end use recorded in other data

logging periods indicating that clothes washing increases in hot, dry conditions.


- 113 -

Figure 4-13 Average daily per capita consumption total sample March 2010 (n=100)

Tap use was consistent with earlier end use recording periods. Again toilet volumetric

consumption remained similar to those recorded in other end use logging periods at 27.4 L/p/d.

Bathtub, dishwasher and leakage in March 2010 were low ranging between 1.1-1.3% of total

use. The break down of the single and dual reticulated regions end use consumption is

demonstrated in Figure 4-14 and Figure 4-15.

Figure 4-14 Average daily per capita consumption single reticulated region in March 2010 (n=27)

Clothes Washer

30.2 L/p/d19.7%

Shower45.8 L/p/d

29.9%

Tap30.8 L/p/d

20.1%

Dishwasher2.0 L/p/d

1.3%

Bathtub1.9 L/p/d

1.2%


17.9%

Irrigation (Total)

13.3 L/p/d8.7%


1.1%


Total = 153.1 L/p/d

Clothes Washer

30.3 L/p/d20.7%

Shower47.1 L/p/d

32.1%Tap

31.0 L/p/d21.1%

Dishwasher1.1 L/p/d

0.8%

Bathtub1.4 L/p/d

0.9%


14.2%


9.8%

Leak (Pot)0.7 L/p/d

0.4%


Total = 146.9 L/p/d


- 114 -

Figure 4-14 demonstrates that shower use remained the highest at 47.1 L/p/d, followed by

clothes washer and tap use at 30.3 and 31.0 L/p/d respectively for the 27 single reticulated

homes. These end use volumetric consumption volumes were similar to those found in earlier

data logging periods. Irrigation was slightly higher in the single reticulated region, accounting

for 14.4 L/p/d or 9.8% of total use, when compared with the dual reticulated region of 12.9

L/p/d or 8.3% of total use.

Figure 4-15 Average daily per capita consumption dual reticulated region in March 2010 (n=73)

In dual reticulated region showering was the highest end use consumption at 45.3 L/p/d

followed equally by tap use and clothes washer at 30.7 and 30.1 L/p/d. Table 4-9 details the

March 2010 end use breakdown for each individual area.

The March 2010 end use data logging period saw the logging of an equal number of properties

in each research region. The consumption rates across the different regions are relatively similar

with the lowest total consumption at Mudgeeraba and the highest at Coomera Waters. The

highest recycled water consumption was at Cassia Park due to toilet use. The highest recycled

water irrigation was at Coomera Waters being 8.5 L/p/d or 5.4%. Shower was the highest end

use event accounting for between 47.8, 49.2, 44.2 and 41.4 L/p/d in Mudgeeraba, Coomera

Waters, Crystal Creek and Cassia Park respectively. Clothes washing use remained highest in

Mudgeeraba, followed by Crystal Creek, Cassia Park and Coomera Waters. Tap and toilet usage

followed as next highest end uses. Total irrigation was significantly lower in March with the

highest usage being 16.4 L/p/d or 10.5% at Coomera Waters, followed by 15.4 L/p/d or 10.2%

at Mudgeeraba. Total irrigation at Cassia Park and Crystal Creek only accounted for 7% and

6.9% respectively.

Clothes Washer

30.1 L/p/d19.4%

Shower45.3 L/p/d

29.2%

Tap30.7 L/p/d

19.8%

Dishwasher2.3 L/p/d

1.5%

Bathtub2.1 L/p/d

1.3%


19.2%


4.1%


4.2%

Leak (Pot)1.0 L/p/d

0.7%

Leak (Rec)1.1 L/p/d

0.7%


Total = 155.4 L/p/d


- 115 -

Table 4-9 March 2010 End use data for research regions

End use categories

Mudgeeraba (n=25)

Cassia Park (n=25)



L/p/d Percent L/p/d Percent L/p/d Percent L/p/d Percent Clothes washer 32.3 21.5% 28.6 18.8% 32.5 21.1% 27.4 17.5% Shower 47.8 31.8% 41.4 27.3% 44.2 28.8% 49.7 31.8% Tap 31.1 20.7% 32.7 21.5% 28.9 18.8% 30.5 19.6% Dishwasher 1.0 0.6% 2.1 1.4% 2.8 1.8% 1.9 1.2% Bathtub 1.5 1.0% 0.5 0.3% 3.4 2.2% 2.2 1.4% Toilet (Pot) 20.7 13.8% 1.1 0.8% 0.7 0.5% 0 0% Toilet (Rec) NA NA 32.4 21.3% 28.6 18.6% 26.1 16.7% Irrigation (Pot) 15.4 10.2% 5.2 3.4% 5.5 3.5% 7.9 5.1% Irrigation (Rec) NA NA 5.5 3.6% 5.2 3.4% 8.5 5.4% Leak (Pot) 0.7 0.4% 1.1 0.7% 1.3 0.9% 0.6 0.4% Leak (Rec) NA NA 1.4 0.9% 0.6 0.4% 1.3 0.8% Total (Pot) 150.4 100% 112.8 74.2% 119.3 77.6% 120.2 77.1% Total (Rec) NA NA 39.3 25.8% 34.4 22.4% 35.9 22.9% Total (Pot + Rec)

150.4 100% 152.1 100% 153.7 100% 156.1 100%

4.4.5 Summary of all end use water consumption data

Sections 4.4.1 to 4.4.4 detailed the end use water consumption data for each individual data

collection period. Numerous similarities are evident when comparing end use water

consumption data from the various data collection periods, particularly for indoor consumption.

Presented in this section, is the overall indoor and outdoor consumption for the entire study

period. Figure 4-16 illustrates the average indoor end use water consumption from the entirety

of the research duration. All data from single and dual reticulated households has been included

to determine this average indoor consumption.

Figure 4-16 demonstrates that shower usage is the highest end use water consuming activity,

accounting for 47.5 L/p/d or 34.6% of average indoor water usage. Clothes washing follows as

the second highest end use at 21.9% or 30.1 L/p/d. Tap and toilet use account for 27.7 and 23.0

L/p/d respectively. Leakage is the highest of the smaller indoor end uses at 3.1 L/p/d or 2.2%.

Bathtub and dishwasher account for 3.9 and 2.1 L/p/d respectively. While irrigation

consumption altered over the data collection periods due to climatic and other influencing

factors, an average of indoor and outdoor consumption for the entire study duration was

considered pertinent (Figure 4-17).


- 116 -

Clothes Washer

30.1 L/p/d18.6%

Shower47.5 L/p/d

29.4%

Tap27.7 L/p/d

17.2%

Dishwasher2.1 L/p/d

1.3%

Bathtub3.9 L/p/d

2.4%


14.2%

Irrigation (Total)

24.1 L/p/d14.9%


1.9%

Average Daily Per Capita Consumption Total Study (L/p/day):

Single + Dual (n=412)

Figure 4-16 Gold Coast indoor water consumption for entire study period (n=412)

Figure 4-17 Gold Coast total (indoor and outdoor) water consumption for entire study period (n=411)

As seen in Figure 4-17, the inclusion of irrigation alters the percentage distribution across the

end uses while volumetric use remains the same. Shower still remains the highest end use at

47.5 L/p/d or 29.4% of total end use. Clothes washer is the next highest end use at 30.1 L/p/d or

18.6% of the total end use. Irrigation accounts for 24.1 L/p/d or 14.9% of total end use. Tap and

toilet use still account for 27.7 and 23.0 L/p/d or 17.2% and 14.2% respectively. Leak, bathtub

and dishwasher remain low with the same volumetric use and percentages of 1.9%, 2.4% and

Total = 161.5 L/p/d

Clothes Washer

30.1 L/p/d21.9%

Shower47.5 L/p/d

34.6%

Tap27.7 L/p/d

20.2%

Dishwasher2.1 L/p/d

1.6%

Bathtub3.9 L/p/d

2.8%


16.7%


2.2%

Average Daily Per Capita Consumption Total Study Indoor (L/p/day):

Single + Dual (n=412)

Total = 137.4 L/p/d


- 117 -

1.3% respectively. As seen in earlier sections, irrigation is very dependent on climatic

conditions while indoor consumption remains relatively consistent throughout.

4.5 Chapter Summary

This chapter examined the situational context and described the research sample through

descriptive statistical analysis. The chapter also presented detailed end use water consumption

data from each of the logging periods and a summary of total end use from the entirety of the

study’s duration. Spatial images demonstrated the location of the research areas in relation to

Gold Coast city and within each study area. The sample sizes from the individual research

activities showed relatively high uptake. Research sample characteristics allowed for labelling

and classification of research areas based on their socioeconomic status. The descriptive

statistics of research areas and participants described household densities, ownership status and

family types. All relevant research context variables were presented, which included water

restrictions levels and climatic conditions including rainfall and temperature. Detailed data on

supply and consumption from bulk meter read data were also divulged. Overall, this chapter

presented data and conditions considered pertinent to the remaining peer-reviewed paper

chapters. Chapter 5 presents the first peer-reviewed paper chapter which introduces the Gold

Coast Watersaver End Use study and details initial end use water consumption results.

4.6 References

NSW DET (2009) What is socio-economic status? State of New South Wales, Department of Education and Training and Charles Sturt University. Online article. Available: http://www.hsc.csu.edu.au/ab_studies/rights/global/social_justice_global/sjwelcome.status.front.htm.

Rooy, E. & Engelbrecht, E. (2003) Experience With Residential Water Recycling At Rouse Hill. Sydney Water, Sydney.

SPSS (2010) Data Collection Family: PASW. Online article. Available: http://www.spss.com/software/data-collection/ SPSS: An IBM Company, Chicago.

Vyas, S. & Kumaranayake, L. (2006) Constructing socio-economic status indicies: how to use principal components analysis. Health Policy and Planning, Vol 26:6, pp. 459-468.

Chapter 5

Gold Coast Domestic End Use Study This chapter is a reformatted version of a peer-reviewed article completed by the author which,

has been published in the Water Journal of Australian Water Association Vol 36:6 (2009) pp.

84-90.

5.1 Abstract

This paper presents the preliminary findings of the Gold Coast Watersaver End Use Project

which was conducted in winter 2008, for 151 homes on the Gold Coast, Australia. Specifically,

the paper includes a break down of water end use consumption data, compares this with results

of previous national studies, and explores the degree of influence of household socioeconomic

regions on end use. Two highly variable water end use distributions, namely shower and

irrigation, were examined in detail, clustered and are discussed herein. The paper concludes

with a brief description of the greater ongoing research program.

5.2 Introduction

Following a long-standing drought, many regions in south east Queensland are experiencing

strict water restrictions and have seen the introduction of a portfolio of other demand

management and supply initiatives to ensure the provision of a secure water supply. Residential

water consumption is often dependent on the fixtures or device stock within a house, household

makeup, region location and psychosocial influences. A study of end use water consumption

aids water planners and users to identify where and when water is used in a household hence

assisting to drive proactive reductions in consumption (Loh and Coghlan, 2003).

In Australia, two major end use studies have been undertaken in Perth (Loh and Coghlan, 2003)

and the Yarra Valley, Melbourne (Roberts, 2005). Internationally, several studies have been

conducted in the United States of America (Mayer and DeOreo, 1999; Mayer et al., 2004) and

recently in New Zealand (Heinrich, 2007). However, the end use models determined by these

studies differ depending on a range of factors including the year conducted, climate, restriction

regime, yard size, water using devices or fixtures and the household makeup (Roberts, 2005).

In addition, it has been acknowledged that community attitudes and behaviours can also

influence the effectiveness of water savings resulting from water demand management

Chapter 5: Gold Coast Domestic End Use Study

- 119 -

strategies (Corral-Verdugo et al., 2002). In the USA, Mayer and DeOreo (1999) explored

certain relationships between water consumption and demographic variables at the end use

level. Their research suggested that demographic variables such as family size and age

distribution, wealth or income, ownership status, and household attitudes towards using and

conserving water, influence household water consumption (Mayer and DeOreo, 1999; Taverner

Research, 2005; Turner et al., 2005; Kenney et al., 2008). However, in Australia, minimal

research has been undertaken on investigating end use water consumption with relation to

demographic variables within monitored homes.

5.3 The Gold Coast Watersaver End Use Study

There are no end use water consumption models currently available for South East Queensland.

This region has a sub-tropical climate and has recently experienced severe drought conditions

which forced both State and Local Governments to develop numerous strategies to reduce water

usage. Griffith University and Gold Coast Water have collaborated under an Australian

Research Council (ARC) grant to conduct an investigation of end use water consumption in the

Gold Coast area. Other primary objectives of the research are to examine the effectiveness of

dual reticulation and education as potable water saving mechanisms. The research will result in

datasets of end use water consumption, demographic information and attitudinal data, diurnal

patterns for potable and recycled supplies, and data on the effective potable water savings

attributed to dual reticulation and developed education initiatives. As stated by Kenney et al.

(2008, pp. 196), the collection and integration of such datasets especially ‘household level

consumption data with demographic data about the people and house’, rarely occurs. Figure 5-1

presents the schedule and key deliverables for the Gold Coast Watersaver End Use research

project. This paper only reports findings from the pre-intervention phase of the study, which

includes the winter 2008 end use data recorded before the supply of recycled water to Pimpama

Coomera.

5.4 Research Method

The selected dual reticulated region was segregated into three socioeconomic categories to assist

in obtaining a reliable overview of the population. A single reticulated region was selected for

comparison. The date of estate development of the single reticulated region was similar to that

of the dual reticulated region (i.e. 5-10 years) to ensure higher efficiency fixtures were present

in both regions and leakage within households was comparable.


- 120 -

Figure 5-1 Gold Coast Watersaver End Use study project schedule

Data was collected in winter 2008 during which time there were no water restrictions in place

due to the Gold Coast’s primary water source, the Hinze Dam, being greater than 95% capacity.

In total, 151 houses were monitored which included 38 single reticulated and 113 dual

reticulated households. No recycled water (Class A+ is Queensland’s highest quality for

recycled water, not intended for drinking purposes) was being supplied as the Pimpama recycled

water treatment plant had not yet been commissioned. Moreover, no awareness campaign had

been launched to encourage the uptake of recycled water in the dual reticulated region. Thus,

the two datasets were treated as one sample for the purpose of this present study (Willis et al.,

2009a). Once recycled water is commissioned (3rd quarter of 2009), it is expected that a clear

distinction will be present between single and dual reticulated households, predominately due to

higher irrigation use within the latter sample. The Future Work section details consideration of

this change.

Participants were recruited through a multi-staged process of letters and door knocking.

Selection of participants was based on criteria which included: household ownership status

(renting/owning); household makeup; willingness to be involved in research for two years;

acceptance of multiple water consumption monitoring periods and surveys with potential

interventions and; involvement in a water fixture/appliance stock audit. It should also be noted


- 121 -

that historical household volumetric readings were analysed for the consenting sample to ensure

that they were representative of the region and the broader Gold Coast.

Upon recruitment completion, existing standard residential water meters were replaced with

high resolution water meters and data loggers to enable obtainment of end use water

consumption data. The modified Actaris CTS-5 water meters pulse at a rate of 72 counts per

litre of water consumed, this equates to an individual recording every 0.014 L of water use.

Aegis DataCell D-CZ21020 data loggers were connected to water meters to record water

consumption. Data loggers were set to record information every ten seconds over a two week

period which resulted in fourteen days of end use data for each household. Figure 5-2

demonstrates the equipment configuration and section 5.4.1 outlines the water end use trace

analysis process.

Basic surveys focusing primarily on demographic information were distributed to sample

households. Surveys were conducted to solicit household demographic information, including:

(1) household address and region; (2) resident numbers, gender, age, employment, weekly

income, education status and relationship of people within the house; and (3) household

ownership status. This paper focuses on analysing the relationship between water consumption

patterns within the following socioeconomic regions of the Gold Coast: (a) Cassia Park: low

socioeconomic group; (b) Mudgeeraba: low to middle socioeconomic group; (c) Crystal Creek:

middle socioeconomic group; and (d) Coomera Waters: middle to high socioeconomic group.

The water end use information for the listed socioeconomic groups was clustered to enable

comparative analysis to determine whether relationships between demographic groupings and

water consumption exist.

5.4.1 End use analysis process in brief

The reed switch on traditional volumetric water meters is modified to collect a high resolution

record of water use (i.e. from the traditional 2 to 72 pulses per litre or 0.014 litres per pulse)

which can then be disaggregated into individual water use events using a flow trace analysis

software tool (e.g. Trace Wizard©). The high resolution water measurement information from

the meter is then captured by attached high data capacity loggers (i.e. 2 million readings)

recording information at a pre-set time intervals (e.g. 10 seconds). Time scaled flow recording

information is then collected in-situ through infrared cables or wirelessly through a mobile

phone network. Once a representative sample of data is collected the flow trace analysis

software tool is applied to disaggregate flow traces into a list of component events assigned to a

specific end use appliance or fixture (e.g. shower, toilet, washing machine, etc.). Stock and

behaviour surveys are typically utilised to help the analyst develop templates which encapsulate

the appliance properties of end use events and ensure accurate end use categorisation. Once


- 122 -

trace analysis is completed and confirmed, a database registry of all end use events occurring

during the sampled period is established and subsequently utilised for water planning and

management research as demonstrated herein. Readers should refer to the Residential End Use

Measurement Guidebook for further information (Giurco et al., 2008).

Figure 5-2 Data loggers and collection technique

5.5 Results and Discussion

5.5.1 Water end use on the Gold Coast

The break down of water end use consumption, on a per person basis, for the sampled

households in the Gold Coast (n=151) is presented in Figure 5-3. The average consumption for

sampled Gold Coast households is 157.2 L/p/d (n=151). The highest end use is showering with

each person consuming almost 50 litres of water a day equating to 33% of total use. Clothes

washing follows equating for 19% of total consumption or 30 L/p/d. Tap use, toilet flushing and

irrigation account for end use percentages of 17%, 13% and 12%, respectively. Bath use,

dishwashing and leaks make up a small component of water end use with percentages ranging

from 1% to 4%.

5.5.2 End use comparison with previous studies

Table 5-1 shows a comparative summary of Australian and Pacific end use studies including the

Gold Coast results.


- 123 -

Figure 5-3 Average daily per person consumption (L/p/d): combined sample (n=151)

Table 5-1 Comparison between national and pacific water end use consumption studies

Previous studies Present study End use category

Perth (2003) Melbourne (2005) Auckland (2007) Gold Coast (2008)

L/p/d Percent L/p/d Percent L/p/d Percent L/p/d Percent Clothes washer 42.0 13% 40.4 19% 39.9 24% 30.0 19% Shower 51.0 15% 49.1 22% 44.9 27% 49.7 33% Tap 24.0 7% 27.0 12% 22.7 14% 27.0 17% Dishwasher NA NA 2.7 1% 2.1 1% 2.2 1% Bathtub NA NA 3.2 2% 5.5 3% 6.5 4% Toilet (total) 33.0 10% 30.4 13% 31.3 19% 21.1 13% Irrigation (total) 180† 54% 57.4† 25% 13.9 8% 18.6 12% Leak (total) 5.0 1% 15.9 6% 7.0 4% 2.1 1% Other NA NA 0.0 0% 0.8 0% 0.0 0% Total Consumption

335.0 100% 226.2 100% 168.1 100% 157.2 100% †Note: Irrigation volume per person calculated from provided volumes per household and end use break downs.

Table 5-1 demonstrates that total consumption and certain end use percentages vary between

regions. Gold Coast consumption is the lowest recorded consumption of all studies being 157.2

L/p/d. The general trend is a reduction in total water consumption over time (i.e. 2003 to 2008).

This reduction is probably due to the mounting intensity of water restrictions and increasingly

frequent exposure to information on sustainable water consumption. This paradigm shift of

societal water values has influenced water consumption, though elasticity will tighten in the

future.

Irrigation end use percentages and volume vary significantly between each study. Perth

recorded the highest irrigation volumes of up to 54% or 180 L/p/d. Auckland recorded the

lowest irrigation consumption due to winter data collection, followed by the Gold Coast. Gold

Clothes Washer

30.0L/p/d19.1%

Shower49.7 L/p/d

31.6%

Tap27.0L/p/d

17.2%

Dishwasher2.2L/p/d

1.4%

Bathtub6.5 L/p/d

4.2%


13.4%

Irrigation (Total)

18.6L/p/d11.8%


1.3%


Total = 157.2 L/p/d


- 124 -

Coast irrigation is low as data was recorded during a winter with unseasonably high rainfall;

recording and analysis of summer data will assist in verifying this deduction. Evidently,

irrigation volumes play a key role in altering end use percentages.

Generally, leakage makes up a very small component of water end use. Melbourne recorded the

highest leakage factor of 6% (15.9 L/p/d), whilst leakage at the Gold Coast only made up 1%

(1.4 L/p/d). This should be due to the fact that monitored Gold Coast households were all

constructed in the last five years, whereas Melbourne’s housing stock is much older.

5.5.3 End use comparison: percentage or volume?

On first inspection of Table 5-1, with the exception of Perth (due to high irrigation volumes),

the percentage break down for end uses appear relatively similar for clothes washing, tap use,

dishwashers and toilets whilst variation of end use percentages are evident for showers,

irrigation and leakage. Recorded shower consumption was the highest in the Gold Coast (2008)

at 33% and the lowest in Perth (2003) at 15%. However, on closer inspection, shower

volumetric consumption was relatively equal being 51.0 L/p/d in Perth and 49.7 L/p/d in the

Gold Coast. This raises contention of simply using percentage figures for comparison. The

variability between volumetric and percentage consumption observed for showers is repeated

for clothes washing which, makes up 13 to 19% of end use in Perth, Melbourne and the Gold

Coast. On closer examination, the actual volume of consumption for clothes washing is quite

varied. A similar trend exists for toilet flushing with end use percentages being relatively

comparable ranging between 10 to 14% of end use but when comparing volumetric rates, the

Perth study recorded 33 L/p/d and the Gold Coast study found toilet consumption at 21.1 L/p/d.

Again this reinforces the concept that volumetric consumption should be utilised as a basis of

comparison rather than end use percentages.

The key contributor to the reduction in volumes evident in the more recent Gold Coast study

would be the installation of modern efficient toilets and washing machines, largely driven by

recently ceased State and local government rebate schemes for efficient fixtures and appliances.

As a final note, tap and dishwasher percentages and volumetric consumption were relatively

comparable across the studies.

5.5.4 End use comparison for individual households

Figure 5-4 demonstrates the end use water consumption break down for each of the measured

151 households. It also illustrates the proportion of sampled households within each of the

Queensland Water Commission (QWC) restriction regime categories, upon which the Gold


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Coast Local Government Area must conform (i.e. Target 140: Extreme Level; Target 170: High

Level; Target 200: Medium Level; and Target 230: Permanent Water Conservation Measures).

0.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

450.00

Household ID

L/p

c/d

Leak (Total)

Irrigation (Total)

Toilet (Total)

Bathtub

Dishwasher

Tap

Shower

Clothes Washer

Queensland Water Commission Target Ranges (140, 170, 200 and 230 L/pc/d)<230 201 - 230 171 - 200 141 - 170 <140

21 homes(14%)

13 homes(9%)

20 homes(13%)

27 homes(18%)

70 homes(46%)

Figure 5-4 Household daily per capita consumption: activity break down

While there were no restrictions during data collection on the Gold Coast, Figure 5-4

demonstrates that almost half of the research population (46%) consumed less than 140.0 L/p/d.

Water consumption is highly varied between individual households with the highest per capita

use equating to 390.0 L/p/d whilst the lowest use was as little as 38.4 L/p/d. The substantial

difference between the highest and lowest per capita consumption volumes demonstrates that a

range of water users are present in the research sample. Considerable variation between

individual end use is also demonstrated in Figure 5-4.

The variation in clothes washer use between individual households seen in Figure 5-4 is largely

due to the diversity of clothes washing machines within homes, as established through stock

surveys. The water volume consumed by a single load of clothes washing can vary from 42

L/wash to 176 L/wash (Commonwealth of Australia, 2008d) this obviously has a significant

impact on resulting consumption. Water use for bathtubs appears to be minimal and scattered

across the sample. Generally, baths were taken in houses with young children whereas older

children and adults typically showered. Toilet and tap consumption varies and does not seem to

be dependent on other end uses. Dishwasher use varies between individual households, as it is

highly dependent on residential behaviours. No visible reduction in tap use is present in

households that have dishwashers although this is a trend to investigate further. Figure 5-4

illustrates that the more discretionary shower and irrigation end uses can be core contributors to

the total consumption level of households. The water use patterns of these two activities are

further explored in Figure 5-5 and Figure 5-6, respectively.


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0.00

50.00

100.00

150.00

200.00

250.00

Household ID

L/p

c/d

Daily Per Capita Distribution: Shower

10%

40%

19% 18%

13%

0%

5%

10%

15%

20%25%

30%

35%

40%

45%

<20 21-40 41-60 61-80 >80

L/pc/d

Rel

ativ

e F

req

uen

cy (

%)

13% of homes use 30% of total shower water


Figure 5-5 Household daily per capita consumption: shower only

Figure 5-5 shows that 13% of households consumed 30% of the total water utilised for

showering. This highlighted sub-sample (13%) constitutes a non-linear shower use pattern as

opposed to the remaining research population (87%) which shows a relatively linear rate of

change in consumption. The distribution of shower use, as illustrated in the Figure 5-5 insert,

demonstrates that half of the population used less than 40 L/p/d of water for showering which is

equivalent to a 5 minute shower at 8L/min. For the remaining categories, 37% of households

use between 41 to 80 L/p/d with the high user group (13%) consuming more than 80 L/p/d in

the shower.

0.00

50.00

100.00

150.00

200.00

250.00

Household ID

L/p

c/d

Daily Per Capita Distribution: Irrigation

76%

11%6% 7%

0%

10%

20%

30%

40%

50%

60%

70%

80%

<20 21-40 41-60 >61

L/pc/d

Rel

ativ

e F

req

uen

cy (

%)

24% of homes use 80% of total irrigation water

Figure 5-6 Household daily per capita consumption: irrigation only

Figure 5-6 demonstrates that 24% of the sampled households contribute to an exponential rate

of change in water consumption for irrigation. This represents a group of high users consuming

80% of the total irrigation water of the entire sample, with the maximum consumption level as

high as 225.9 L/p/d. In addition, the per capita distribution presented in the inset of Figure 5-6

shows that the majority of households (76%) used less than 20 L/p/d of water for irrigation.

Maximum = 173.4L/p/d

Maximum = 225.9L/p/d


- 127 -

End use comparison: households from different socioeconomic regions

For the purpose of this study, four socioeconomic regions were selected and compared, namely:

(a) low (Cassia Park: n=42); (b) low to middle (Mudgeeraba: n=36); (c) middle (Crystal Creek:

n=38); and (d) middle to high (Coomera Waters: n=35). Figure 5-7 displays the end use values

for these four socioeconomic regions.

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0

180.0

L/p

c/d

Leak (Total)

Irrigation (Total)

Toilet (Total)

Bathtub

Dishwasher

Tap

Shower

Clothes Washer

Leak (Total) 1.9 2.6 1.5 2.4

Irrigation (Total) 12.1 14.5 21.1 27.8

Toilet (Total) 21.4 19.2 21.6 22.1

Bathtub 8.7 3.4 6.0 7.7

Dishwasher 1.8 1.9 2.7 2.6

Tap 24.0 30.4 27.8 26.5

Shower 50.2 56.3 44.2 48.2

Clothes Washer 32.2 27.3 31.4 28.5

Cassia Park Mudgeeraba Crystal Creek Coomera Waters

155.6152.2156.2

165.8

Figure 5-7 Average daily per capita water consumption: socioeconomic regions

Previous studies have suggested that high volume water consumers are wealthier, older and live

in new and larger homes (Kim et al., 2007; Kenney et al., 2008). Residents in Coomera Waters

(higher socioeconomic region) were the largest consumers per capita, using 165.8 L/p/d with

Crystal Creek residents (middle socioeconomic region) following consuming 156.2 L/p/d.

Water consumption of Mudgeeraba residents (low to middle socioeconomic region) was 155.6

L/p/d while Cassia Park residents (lower socioeconomic region) consumed the least being 152.2

L/p/d. While these differences are not significant, they support previous research.

The volume of water used for clothes washing is lowest in Coomera Waters and Mudgeeraba

being 28.5 L/p/d and 27.3 L/p/d respectively. Cassia Park recorded the highest clothes washing

consumption at 32.2 L/p/d whilst Crystal Creek residents consumed 31.4 L/p/d for clothes


- 128 -

washing. It is suggested that households with higher income levels are more likely to purchase

higher efficiency washing machines hence the differences in consumption.

Shower consumption seems to oppose this trend, although not significantly. The lower

socioeconomic regions (Cassia Park and Mudgeeraba) showed higher consumption. This trend

may be attributed to lower efficiency of shower roses or variations in shower behaviour. The

trend of lower shower consumption volumes with more efficient devices has previously been

established (Mayer et al., 2004).

Irrigation usage is notably lower in Cassia Park with only 12.1 L/p/d being consumed compared

with 14.5 L/p/d in Mudgeeraba, 21.1 L/p/d in Crystal Creek, and 27.8 L/p/d in Coomera Waters.

This could be attributed to the fact that lower socioeconomic groups tend to have smaller lot and

garden sizes and minimal ownership of pools. Finally, there is no significant difference in bath

and toilet consumption among the four suburbs, suggesting no relationship between this

particular water use activity and the change in socioeconomic regions.

5.6 Conclusion

This paper presented initial findings from the Gold Coast Watersaver End Use Study based on

data collected in winter 2008. It was established that end use water consumption varies

significantly between individual households and noticeably between socioeconomic regions.

The data demonstrates the lowest recorded end use water consumption per person in comparison

to previous national and pacific end use studies. Future data collection periods over summer aim

to capture increased consumption attributed to seasonal use. Overall, the data provided

confirmation that high socioeconomic regions consume more water per capita than lower

socioeconomic regions. Details of ongoing and planned research activities are briefly discussed

below.

5.7 Future Work

Figure 5-1 detailed the numerous components of the Gold Coast Watersaver End Use Study to

be undertaken over the coming year. Recycled water (Class A+ is Queensland’s highest quality

for recycled water, not intended for drinking purposes) will be supplied to the Pimpama

Coomera region in 2009. Summer end use data collection will be completed to ascertain the end

use uptake of recycled water. This data will assist in verifying end use assumptions made in the

planning phases of the Pimpama Coomera development. Moreover, a world first dual

reticulation end use model including diurnal patterns in both the potable and recycled water

supply pipelines will be completed. Variation in diurnal patterns between single and dual (i.e.


- 129 -

recycled water also supplied) reticulated homes will also be explored. This data will provide a

comprehensive understanding of water consumption at a given time providing greater

understanding on the individual end uses affecting peak loads.

The impact of a range of education or awareness demand management interventions will also be

tested. One such intervention program includes the evaluation of an alarming visual display

monitor device on shower event durations, flow rates and volumes, thus providing quantitative

evidence on the influence of this initiative on shower water conservation behaviours. Other

programs will involve the provision of detailed end use information to users and the effect this

has on consumption.

The above stated components of the end use study will culminate in the development of a

comprehensive domestic end use model for the Gold Coast as well as evidence that supports, or

otherwise, the effect of water demand management measures, principally dual reticulation and

awareness/education programs, for conserving precious potable water supplies.

For further information on the Gold Coast Watersaver End Use Study please visit either:

http://www.griffith.edu.au/engineering-information-technology/centre-infrastructure-

engineering-management/gold-coast-watersaver-end-use-project or

http://www.goldcoastwater.com.au/t_gcw.asp?PID=7591

5.8 References

Commonwealth of Australia (2008) Water Efficiency Labelling and Standards Scheme: Product Search (Clothes Washing Machine). Available online: http://www.environment.gov.au/wels_public/searchPublic.do, accessed 14/12/08.

Corral-Verdugo, Bechtel, R. & Fraijo-Sing, B. (2003) Environmental beliefs and water conservation: An empirical study. Environmental Psychology, 23, pp 247–257.



Kenney, D., Goemans, C., Klein, R., Lowrey, J. & Reidy, K. (2008) Residential water demand management: lessons from Aurora, Colorado. Journal of the American Water Resources Association, Vol. 44:1, pp. 192-207.

Kim, S. H., Choi, S. H., Koo, J. K., Choi, S. I. & Hyun, I. H. (2007) Trend analysis of domestic water consumption depending upon social, cultural, economic parameters. Water Science and Technology: Water Supply, Vol 7, No 5-6, pp. 61-68.


- 130 -





Taverner Research (2005) Survey of Household Water Attitudes. Surry Hills, NSW, Taverner Research.


Willis, R., Stewart, R., Chen, L. & Rutherford, L. (2009) Water end use consumption analysis into Gold Coast dual reticulated households: Pilot. Australia’s National Water Conference and Exhibition: OzWater'09, Melbourne Convention & Exhibition Centre, Melbourne, March 16-18, 2009. Melbourne.

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Chapter 6

End use water consumption in households: impact of socio-demographic factors and

efficient devices

This chapter is a reformatted version of a peer-reviewed article completed by the author, under

review (October 2010) for publication in the Journal of Cleaner Production.

6.1 Abstract

Assessing water savings in households using efficient devices and how savings vary between

different sectors of the community, requires high resolution end use water consumption data

(i.e. disaggregating water use for showers, toilets, clothes washers and garden irrigation etc.).

This paper reports selected findings from the Gold Coast Watersaver End Use Study (Australia),

which focussed on the relationship between a range of socio-demographic and household stock

efficiency variables and water end use consumption levels. A mixed methods approach was

executed using qualitative and quantitative data. The study provided evidence as to the potential

savings derived from efficient appliances as well as socio-demographic clusters having higher

water consumption across end uses. The payback period for some water efficient devices was

also explored. The study has implications for urban water demand management planning and

forecasting.

6.2 Introduction

6.2.1 Improving urban water security

The strong emphasis on ensuring a secure water supply for the population of Australia has been

brought to light by the increasing frequency, severity and duration of drought events throughout

the nation. Drought, coupled with growing populations has lead to numerous instances of many

water supply reservoirs in South-East Queensland (SEQ) dropping below 20% over the last

decade. This has forced State and Local government to implement alternative water supply

schemes, along with a range of demand management interventions, in order to improve urban

water security. Innovative water re-use and decentralised supply solutions are becoming

increasingly viable technologies to meet city water needs but there are often many financial,

behavioural and regulatory barriers to their diffusion in practice (Partzsch, 2009; Giurco et al.,

2010; Krozer et al., 2010). Planning studies employing holistic Integrated Water Resource


- 132 -

Management (IWRM) models (Dvarioniene and Stasiskiene, 2007) have been applied and

demonstrated that high efficiency water fixtures and appliances are a least cost planning strategy

for water conservation and a good starting point for policy makers before higher cost water

supply or demand solutions are commissioned (Stewart et al., 2010).

6.2.2 Domestic water consumption and conservation

In the case at the Gold Coast, Australia residential water consumption accounts for

approximately 66% of the City’s total supply (07/08). In Brisbane total residential consumption

is 57%. Residential water consumption has previously been determined to be influenced by

seasonal changes and water demand management (WDM) strategies such as water metering,

water restriction levels, water efficient devices and education (Nieswaidomy, 1992; Mayer et

al., 2004; Inman and Jeffrey, 2006). Although prior research in these areas has occurred it is

well established that there is a requirement for specific country and location based research due

to different community attitudes and behaviours which can influence the effectiveness of WDM

strategies (Corral-Verdugo et al., 2002; Turner et al., 2005). To grasp the effectiveness of

WDM strategies high quality data is required. The development of smart metering technologies

and end use analysis techniques allowed for the acquisition of such data.

6.2.3 Advent of smart water metering

In the case at the Gold Coast, Australia – a city of 510,000 people – residential water

consumption accounts for approximately 66% of the City’s total supply (2007/2008).

Residential water consumption has previously been determined to be influenced by seasonal

changes and Water Demand Management (WDM) strategies such as water metering (compared

with unmetered homes), water restriction levels, water efficient devices and education (Inman

and Jeffrey, 2006; Mayer et al., 2004; Nieswaidomy, 1992). Although prior research in these

areas has occurred, it is well established that there is a requirement for specific country and

location based research due to different community attitudes and behaviours which can

influence the effectiveness of WDM strategies (Corral-Verdugo et al., 2002; Turner et al.,

2005). To evaluate the effectiveness of WDM strategies high quality data is required. The

development of smart metering technologies and end use analysis techniques allowed for the

acquisition of such data in this study.

6.2.4 Overview of Gold Coast End Use Study

The Gold Coast Water End Use (GCWSEU) Study commenced in 2007 as an ARC funded

collaborative research investigation by Griffith University, Gold Coast Water and the Institute

for Sustainable Future (University of Technology, Sydney). The purpose of this study was to

identify end use water consumption in Gold Coast homes and to evaluate the effectiveness of

Chapter 6: End use water consumption in households: impact of socio-demographic factors and efficient devices

- 133 -

WDM strategies namely the application of water efficient devices and education as well as

understanding water use differences between varying socio-demographic groups. Smart

metering was implemented to ascertain end use water consumption data, to enable comparative

analysis between varying household socio-demographic clusters and to understand the water

saving potential of efficient devices. These aspects represent two objectives of the GCWSEU

study explored in this paper.

6.2.5 Engineered water efficiency

Engineered efficiency or the development of higher efficiency water using devices has seen

effective reductions in water consumption. In Tampa, USA Mayer et al. (2004) determined that

the retrofitting of water efficient devices can result in a reduction of up to 49.7% of water use

per capita; a highly significant reduction. Inman and Jeffrey (2006) report that the

comprehensive replacement of household appliances (such as showers, toilets and clothes

washers) with highly water efficient appliances can reduce indoor water consumption by

between 35-50%. Not only does this reduction in demand serve to preserve water supply

security for future generations but reduces the life cycle cost of potable water treatment and

distribution, as well as energy intensive wastewater treatment (Barrios et al., 2008; Mahgoub et

al., 2010) and ultimately the ecological footprint of the city or nation (Friedrich et al., 2009;

Hubacek et al., 2009).

6.2.6 Influences of socio-demographic factors

There are several previously reported socio-demographic factors that can influence water

consumption. The result of the socio-demographic variable investigations by the ARCWIS

(2002) indicated that owner occupied properties, higher income families and households with

swimming pools consumed more water for irrigation. Loh and Coghlan (2003) reported a strong

relationship between income level and outdoor water use. The occupancy and make up of

dwellings, lot size and the age of water using devices have also been found to influence water

consumption with larger lot sizes generally consuming more water (Mayer and DeOreo, 1999).

6.2.7 Research objectives

The objectives of this paper are to:

1. Determine a household and per capita water consumption end use break down for a sample

of Gold Coast households;

2. Explore the relationship between household stock survey efficiency rating clusters and

water end use consumption levels; and


- 134 -

3. Ascertain demographic information of water users and determine if socio-demographic

factors influence water consumption.

The multifaceted objectives of the GCWSEU study required the application of a mixed methods

research design to obtain the required data types.

6.3 Method

To achieve the desired objectives of the study, a mixed methods data collection procedure

including a stock survey of water using fixtures/appliances in households, end use water

consumption study and a questionnaire survey, were concurrently undertaken with 151

households on the Gold Coast City, Australia.

6.3.1 Mixed method study design

The study adopts a mixed method design through collecting, analysing and mixing quantitative

and qualitative research approaches and processes. This mixed methods approach allows the use

of multiple methods to address research objectives (Creswell and Plano-Clark, 2007). A mixed

method approach was embarked upon as an array of data types are required to meet the

developed research objectives. Namely, natural science data in the form of end use water

consumption data, quantitative statistical survey data for demographic information, quantitative

stock survey information, and, qualitative water behaviour data were required.

6.3.2 Sample

A sample of 151 homes was recruited across Gold Coast City, Australia, including the

Pimpama-Coomera and Mudgeeraba suburbs. As noted by Willis et al. (2009b), regions were

selected according to differing socio-demographic makeup. Comparative investigation of

demographic factors including household makeup and ownership status assisted in confirming

the selected regions. Age of infrastructure was also considered with all homes subsequently

being developed in the past five years (Willis et al., 2009b).

6.3.3 Water consumption end use study

The relationship between smart metering equipment, household stock inventory surveys and

flow trace analysis is shown in Figure 6-1. Essentially, a mixed method approach was used to

obtain and analyse water use data. Two aligned main processes were adopted: physical

measurement of water use via smart meters with subsequent remote transfer of high resolution

data; and documentation of water use behaviours and compilation of water appliance stock via

individual household audits and self-reported water use diaries.


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Figure 6-1 Schematic illustrating water end use analysis process

The collection of end use water consumption data requires the application of a smart metering

set-up. The GCWSEU study smart metering set-up includes high resolution Actaris CTS-5

water meters, 72 pulses per litre or a pulse every 0.014L of water used, connected to Aegis Data

Cell D data loggers which are set to collect pulse counts every ten seconds. Downloaded raw

data files were in the ASCII format, which were then modified into .txt files for subsequent

trace flow analysis.

End use data in .txt file form was analysed by Trace Wizard© software version 4.1. Stock

appliance audits were used to help identify flow trace patterns for each household. Once a

template was created for each household, data for a sampled two-week period was analysed.

Trace Wizard© software was used in conjunction with the stock appliance audits to analyse and

disaggregate consumption into a number of end uses including toilets, irrigation, shower,

clothes washer and taps (faucets). An MS Excel™ spreadsheet was generated as a final output

for a more detailed statistical trend analysis and the production of charts.

6.3.4 Questionnaire survey

Questionnaire surveys were developed to obtain socio-demographic information of each

household to allow for clustering and analysis between varying demographic indicators. Surveys


- 136 -

were distributed to each smart metered household with information entered into SPSS (i.e.

statistical analysis program).

6.3.5 Household appliance stock survey and water behaviour investigation

Household stock surveys have previously been undertaken to gain a snapshot of water

consuming devices in regions (Roberts, 2003). A household water audit was undertaken for the

GCREUS study to determine water using devices within the household, to assist in carrying out

end use data analysis with Trace Wizard©, and to obtain a qualitative understanding of when

people undertook certain water consuming activities in their home. A research officer visited

homes and noted down model and serial numbers for clothes washers, dishwashers and toilets;

determined the efficiency of water shower heads; the inclusion of tap flow restrictors and

recorded volumes of rainwater tanks (if applicable). The research officer also asked questions as

to when clothes washing or showering generally occurred, inquired about the number of

showers or baths, irrigation use and a whole range of other questions surrounding water use

behaviour within the home.

The Water Efficiency Labeling and Standards (WELS) website4 was consulted to obtain

relevant water usage volumes for different fixtures particularly clothes washers, shower heads

and dishwashers to assist in data analysis and to determine the relative water efficiency of

devices.

6.3.6 Water end use analysis and comparison

End use data analysis was undertaken with Trace Wizard© to establish when and where water

was being used in each home within the Gold Coast sample. Based on a winter 2008 data

collection for the sampled Gold Coast households (n=151) the average water consumption was

157.2 litres per person per day (L/p/d) (Willis et al., 2009). Figure 6-2 displays the end use

water consumption across the 151 households. Showering accounted for the highest use being

33% or almost 50 L/p/d with clothes washing being the next highest end use at 19% or 30 L/p/d.

Irrigation was much lower than previously conducted end use studies being only 18.6 L/p/d or

12% of total per capita consumption, this may have been due to higher rainfall over the

monitoring period.

4 http://www.waterrating.gov.au


- 137 -

Figure 6-2 Average daily per capita consumption (L/p/d): combined sample (n=151)

An overview of water end use for the GCWSEU study and previous end use studies can be seen

in Table 6-1. The finalised end use values, socio-demographic survey data and water audit data

were all entered into SPSS to enable a comparative analysis between varying socio-

demographic groups and household water device efficiency.

Table 6-1 Comparison between national end use water consumption studies (Willis et al., 2009b)

Previous studies Present study End use category

Perth (2003) Melbourne (2005) Auckland (2007) Gold Coast (2008)

L/p/d Percent L/p/d Percent L/p/d Percent L/p/d Percent Clothes washer 42.0 13% 40.4 19% 39.9 24% 30.0 19% Shower 51.0 15% 49.1 22% 44.9 27% 49.7 33% Tap 24.0 7% 27.0 12% 22.7 14% 27.0 17% Dishwasher NA NA 2.7 1% 2.1 1% 2.2 1% Bathtub NA NA 3.2 2% 5.5 3% 6.5 4% Toilet (total) 33.0 10% 30.4 13% 31.3 19% 21.1 13% Irrigation (total) 180† 54% 57.4† 25% 13.9 8% 18.6 12% Leak (total) 5.0 1% 15.9 6% 7.0 4% 2.1 1% Other NA NA 0.0 0% 0.8 0% 0.0 0% Total Consumption

335.0 100% 226.2 100% 168.1 100% 157.2 100%


6.4 Results

6.4.1 Influence of socio-demographic factors

Analysis determined that a range of collected socio-demographic factors influenced end use

water consumption levels, namely, location of household, lot size, Rain Water Tank (RWT)

Clothes Washer

30.0L/p/d19.1%

Shower49.7 L/p/d

31.6%

Tap27.0L/p/d

17.2%

Dishwasher2.2L/p/d

1.4%

Bathtub6.5 L/p/d

4.2%


13.4%

Irrigation (Total)

18.6L/p/d11.8%


1.3%


Total = 157.2 L/p/d


- 138 -

ownership, household income and household characterisation. Some of these relationships are

explored in this paper and are presented succinctly below.

Socio-demographic region of households

Several regions in differing areas of the Gold Coast were selected to ensure that the combined

water end use sample was representative. For the purpose of the GCWSEUS study, four socio-

demographic groups in distinct regions were selected and compared: (a) low (Cassia Park:

n=42); (b) low to middle (Mudgeeraba: n=36); (c) middle (Crystal Creek: n=38); and (d) middle

to high (Coomera Waters: n=35). displays the end use water consumption for these four socio-

demographic regions.

Previous water consumption research indicates that individuals that are wealthier, older and live

in new and larger homes consume more (Kim et al., 2007; Kenney et al., 2008). Such findings

were not substantiated in this study. Figure 6-3 demonstrates that generally lower socio-

demographic groups tended to use slightly more water than those in higher socio-demographic

groups across most end use categories. One outlying variable to this trend is irrigation. Coomera

Water residents, the highest of the recorded socio-demographic regions, were the highest

consumers per capita for irrigation, using 27.84 L/p/d with Cassia Park, the lowest socio-

demographic group consuming the lowest irrigation volume of 12.07 L/p/d. This opposing trend

of higher socio-demographic region translating to higher irrigation end use consumption could

be attributed to lot size or higher concern for garden aesthetics.

Figure 6-3 Impact of socio-demographic area on end use water consumption

Lot size and rainwater tank ownership

The effect of lot size (total land area) and rainwater tank (RWT) ownership on outdoor

irrigation was examined (n=121). Figure 6-4 illustrates increased irrigation with increasing lot


- 139 -

size for households without RWTs (n=86). This result is consistent with that found by Loh and

Coghlan (2003). Interestingly, houses with RWTs (n=35) actually decreased irrigation

consumption from the mains supply as lot sizes increased. Meaning that, irrigation was highest

for smaller lot sizes with RWTs with those of large lot sizes consuming the least. The reason for

this phenomenon is still unknown and may be due to error caused by a lower sample in the

higher lot size clusters. One hypothesis is that the larger lot owners may have invested in higher

volume RWT with pump features and irrigation lines whilst those in smaller lots may not utilise

their tanks since they are small with no pump facility making householders less inclined to use

this source of water. A larger sample size across all lot size clusters would be required to

confirm this hypothesis.

Figure 6-4 Impact of lot size and RWT installation on irrigation end use

Household Income

108 households stated the incomes of individuals within their residences on the survey. These

households were divided into three categories based on weekly household income to investigate

the influence of household income on water consumption. The categories were defined as: (a)

less than $1200 per week (n=31); (b) between $1200 and $2000 per week (n=45); and (c) more

than $2000 per week (n=36). Figure 6-5 indicates that as income increased, so does water

consumption. Interestingly, the water consumption of the middle to upper household income

clusters was very similar and no significant difference could be interpreted. Lower income

households were shown to consume approximately 8% less than the average water consumption

for the Gold Coast City sample (i.e. 157.2 L/p/d as per Table 6-1), however lower socio-

demographic profiles (which consider factors beyond income) were shown in Section 6.4.1. to

use more water for end uses other than irrigation – in this case, the lower irrigation component

leads to lower overall usage.


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Figure 6-5 Impact of family income on water consumption

Household resident typology

The impact of household typology (i.e. resident makeup) on end use water consumption was

also investigated. Households (n=126) were divided into four categories, namely: (a) single

person (n=5); (b) couple (n=34); (c) small family with four or less people (n=64); and (d) large

family with more than four people (n=23). Total per capita consumption was 211.4 L/p/d, 183.5

L/p/d, 140.6 L/p/d and 135.6 L/p/d for household typologies a, b, c and d, respectively. Figure

6-6 indicates that there is a general decrease in consumption per capita as family size increases.

Clothes washer and toilet end use consumption oppose this trend with these end uses being

higher in large families than small families. This may be due larger families being more likely

to have very young children requiring extensive washing and a higher utilisation of the toilet

due to increased time spent at home.

Figure 6-6 Relationships between household resident typologies and water end use consumption

6.4.2 Stock efficiency versus end use consumption

Table 6-1 demonstrates that shower use and clothes washing account for the highest end uses of

water on the Gold Coast, being 33% and 19% of total average consumption, respectively.

Further analysis was undertaken to examine trends for water saving when considering the

engineered efficiency of water use devices.


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Influence of showerhead efficiency

Sample average per capita shower end use was 49.7 L/p/d or 32% of total water use which was

157.2 litres per household per day (L/hh/d). This was the highest water consuming activity on

the Gold Coast as often reported elsewhere. It is well established that the installation of high

efficiency, low flow showerheads can save considerable volumes of water (Mayer et al., 2004).

The Australia WELS requires products to be registered and labelled with their water efficiency

in accordance with the standard set under the national WELS and Standards Act 2005

(Commonwealth of Australia, 2008). These standards list that three star rated water efficient

showerheads (formerly AAA) use as little as 6-7 L/min, medium efficient showerheads (AA)

consume between 9-15 L/min and the standard non-efficient showerheads (A) can use as much

as 15-25 L/min. Different dwellings have a high variation in the efficiency of their showerheads

and often showerheads differ within households. Due to the variation of showerhead efficiencies

within dwelling bathrooms a weighting system was applied in this study. The weighting system

provided each bathroom showerhead with a rating as follows: (a) AAA rated showerheads

allocated a score of 5: (b) AA rated showerheads a rating of 3; and (c) A rated shower heads and

less a score of 1. Each dwelling total score was averaged (w) based on number of showerheads.

The weighting system allowed for the categorisation of households into three shower efficiency

clusters which match the AAA, AA and A, WELS ratings, namely Low, Medium and High

efficiency, Table 6-2 demonstrates the results.

Table 6-2 Showerhead efficiency cluster comparisons

Description Showerhead efficiency clusters Efficiency category Low Medium High

Weight range 5 ≤ w ≤ 4 4 ≤ w ≤ 3 3 ≤ w ≤ 1 No. of households in cluster (n=151) 59

(39%) 42

(27.8%) 50

(33.2%) No. of people in cluster (n=495) 181

(36.6%) 124

(25%) 190

(38.4%) Per capita shower consumption per day (L/p/d) 64.7

(1.93) 46.8

(1.39) 33.6 (1)

Household shower consumption per day (L/hh/d) 245.7 (2.38)

138.1 (1.34)

103.1 (1)

Per capita shower consumption per annum (kL/p/a) 23.6 (1.93)

17.1 (1.39)

12.3 (1)

Household shower consumption per annum (kL/hh/a) 89.7 (2.38)

50.5 (1.34)

37.6 (1)

Table 6-2 provides evidence that by changing low efficient showerheads (A) to high efficient

showerheads (AAA) in each household in the Gold Coast could result in annual per capita water

savings of 11.3 kL or 48%. Annual household savings were slightly higher being 52.1 kL or

58%. The ratio of savings between the High and Medium categories (1.34-1.39) and High to

Low categories indicates that a changeover to AAA rated showerheads yields far greater

savings. The savings identified herein were at the higher end of the range determined in other

studies such as Melbourne at 27%, Perth at 22% and in South-east Queensland (SEQ) at 31-54%


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(Roberts, 2005; Loh and Coghlan, 2003). As detailed in a later section, showerhead retrofits

represent one of the least cost water demand management initiatives available to water

businesses and government.

Influence of clothes washer efficiency

The end use water consumption for clothes washing for the Gold Coast sample was determined

as 30 L/p/d. Clothes washing consumption was the second highest water use after showering.

WELS star rating for clothes washers was based on loading type, load capacity, water

consumption per wash, brand and model name. The Commonwealth of Australia (2008) state

that water efficient washing machines can use a third of the water required by an inefficient

model. The WELS website details the rate of water consumption per wash for each brand and

model of clothes washing machine on the Australian market. Household water audits

established the specific model details (i.e. brand, model, year, etc) to assist in determining

clothes washer load volumes. Household clothes washers were allocated efficiency categories

based on per load water consumption; Table 6-3 demonstrates the results of the comparative

clothes washer water end use levels for each efficiency cluster category.

Table 6-3 Clothes washer efficiency comparisons

Description Clothes Washer Efficiency Clusters Efficiency category Low Medium High

Star rating range 1 – 2.5 3 – 3.5 4 – 6 Category (L/wash) 120 - 170 80 - 119 40 – 79

No. of households in cluster (n=148) 38 (26%)

40 (27%)

70 (47%)

No. of people in cluster (n=486) 148 (30%) 119 (25%) 219 (45%) Per capita clothes washer consumption per day

(L/p/d) 53.0

(3.68) 36.3

(2.52) 14.4 (1)

Household clothes washer consumption per day (L/hh/d)

206.4 (4.57)

108.0 (2.51)

45.2 (1)

Per capita clothes washer consumption per annum (kL/p/a)

19.4 (3.66)

13.3 (2.52)

5.3 (1)

Household clothes washer consumption per annum (kL/hh/a)

75.3 (4.57)

39.4 (2.51)

16.5 (1)

Table 6-3 demonstrates that replacing a low efficiency clothes washer with a high efficiency

model can save a staggering 14.1 litres per person per annum (L/p/a) or 73%. Annual household

savings are also equally significant at 58.8 kL. It should be noted that these savings are

significantly higher than those listed on the WELS web site and are higher than those previously

identified in Melbourne and SEQ. Replacing traditional washing machines with those with a

high star rating is a highly recommended water demand management activity.

Influence of rainwater tanks on irrigation end use

Irrigation has long been identified as a high water end use, accounting for up to 54% in some

regions (Loh and Coghlan, 2003). RWTs are considered by some water demand management


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professionals as an effective way to reduce the demand on potable supplied water. The Gold

Coast end use study included a number of households (n=39; 25.8%) with an installed RWT. It

should be noted that these RWT were not internally plumbed and were mainly for outdoor use

purposes only (i.e. irrigation, pool top-up, etc.). Whilst RWT metering was not included in the

scope of this study, household water audits identified whether a tank was installed, enabling

comparison between irrigation end use volumes for households with or without a RWT (Table

6-4).

Table 6-4 Rainwater tank cluster comparisons

Description Rainwater Tank Clusters

Category Households with RWT

Households without RWT

No. of households in cluster (n=151) 39 (25.8%)

112 (74.2%)

No. of people in cluster (n=495) 114 (23%)

381 (77%)

Per capita irrigation consumption per day (L/p/d) 10.1 (1)

19.6 (1.94)

Household irrigation consumption per day (L/hh/d) 29.6 (1)

66.6 (2.25)

Per capita irrigation consumption per annum (kL/p/a) 3.7 (1)

7.2 (1.94)

Household Irrigation consumption per annum (kL/hh/a)

10.8 (1)

24.3 (2.25)

Table 6-4 provides evidence that the introduction of a RWT can significantly impact on

irrigation water end use consumption. The installation of a RWT can result in an annual

household saving of 13.5 kL. Seasonal variations need to be explored in future research to

examine whether this saving could be higher. The study herein provides some evidence to the

argument that RWT may be an effective strategy where water supply security is not guaranteed.

Given that RWT installations are potentially more expensive than other options capital payback

periods need to be explored.

Combined household efficiency savings

The combined influence of introducing water efficient showerheads, clothes washers and

installing RWTs was modelled to estimate total potential household savings by

retrofitting/installing to higher efficiency appliances/fixtures. The estimated savings, resulting

from the introduction of this array of demand management measures, amounted to an average

annual household water consumption reduction of 38.6% or from 512.2 L/hh/d to 322.1 L/hh/d.

While these are significant water savings, it is considered prudent for both consumers and water

managers to determine monetary aspects. Additionally, whilst outside the scope of this paper, in

the age of climate change mitigation, the energy implications of WDM decisions should also be

investigated as water savings may come at a higher energy cost.


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Financial benefits of efficient appliances

Often the understanding of relative water savings attributed to water efficient devices is not

enough to encourage consumers to outlay the capital cost to upgrade fixtures. Information about

the payback period associated with upgrading appliances is another way of displaying

information to encourage uptake. Based on the 2008/2009 financial year water billing price (i.e.

A$(AUD) 1.87/kL) the retrofitting of a low to high efficiency showerhead can potentially

deliver an annual water consumption saving of A$97 for Gold Coast residential households.

This increases to A$175 by 2018 which equates to a A$1331 cumulative saving per household

over this period (A$ 1.87/kL, 10% annual increase, 3% discount factor, N=10 years). Based on

a A$60 capital cost for the supply and installation of water efficient showerheads, a six (6)

month payback period was determined. This is an extremely good payback period and provides

evidence to support the recent Gold Coast Water and Queensland Government strategies to

retrofit appliances across SEQ in the recent drought (e.g. GCW & SEQ Home Water wise

Service).

Replacement of low efficiency washing machines to those with higher efficiency also has the

potential to deliver annual water savings of A$110 in 2009, increasing to A$199 in 2018. This

equates to a cumulative saving of A$1510 per household over this period. Hence, a 6.5 year

payback period was calculated based on a conservative capital cost of A$900 for a water

efficient washing machine. Again, this represents a reasonable payback period supporting the

upgrade of washing machines.

The use of RWTs could potentially deliver an annual water consumption saving of A$25 in

2009 increasing to A$135 in 2033 equating to a A$1660 cumulative saving per household over

this period (A$1.87/kL, 10% annual increase, 3% discount factor, N=25 years). Based on a

A$1200 capital cost for a 2000-4000L RWT a 21 year payback period was determined. This

payback period is high for the average homeowner, providing evidence to the argument that

RWT installation that are not internally plumbed, is not low hanging fruit in the least cost

planning framework. Understanding payback periods for the replacement of efficient water use

devices provides important information to allow consumers to make economically informed

decisions. These payback periods can also help support the introduction, or otherwise, of rebate

schemes targeting the highest water savings at a reasonable price as part of a broader

consideration of the social environmental and economic cost savings to the utility (through

reduced pumping and treatment as well as lower infrastructure upgrade costs) as well as the

consumer in a total resource cost approach to option evaluation (White et al., 2008).


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6.5 Conclusion

Smart metering has enabled the collection of highly accurate end use water consumption data.

The mixed method acquisition of this data in association with socio-demographic and stock

survey information, allowed for the relationship between these factors and individual water end

uses to be revealed. As discussed, socio-demographic factors such as household income,

household resident typologies, lot size and RWT ownership, were examined in this study and

had an influence on relevant end uses. End use data demonstrated that actual water savings

associated with the installation of efficient water use devices was generally at the higher end of

ranges reported in previous research investigations. This may be due to the extreme drought

conditions experienced in SEQ in 2008 influencing water consumption habits or a range of other

contributing factors. The payback period of showerheads occurs within half a year or less, while

clothes washer and RWT payback periods were determined as 6.5 and 21 years respectively.

These findings support the continuation of rebates particularly for showerheads and clothes

washers.

6.6 Acknowledgements

The GCWEUS study is conducted through a larger ARC collaboration. The Institute for

Sustainable Futures, University of Technology, Sydney; Wide Bay Water and the Queensland

Water Directorate are acknowledged for their involvement in the research collaboration.

6.7 References

ARCWIS, 2002. Perth domestic water- use study household ownership and community attitudinal analysis. NWS. Australian Research Centre for Water in Society CSIRO Land and Water.

Barrios, R., Siebel, M., van der Helm, A., Bosklopper, K., Gijzen, H. 2008. Environmental and financial life cycle impact assessment of drinking water production at Waternet. Journal of Cleaner Production 16, 471-476.

Britton, T., Cole, G., Stewart, R., Wisker, D., 2008. Remote diagnosis of leakage in residential households. Journal of Australian Water Association 35 (6), 89-93.

Commonwealth of Australia, 2008. Water Efficiency Labelling and Standards Scheme: WELS Products. http://www.waterrating.gov.au/products/index.html.

Corral-Verdugo, V. Bechtel, R., Fraijo-Sing, B., 2002. Environmental beliefs and water conservation: An empirical study. Environmental Psychology 23, 247–257.

Creswell, J.W., Plano Clark, V.L., 2007. Designing and conducting mixed methods research. USA. Sage Publications, Inc.


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Dvarioniene, J., Stasiskiene, Z. 2007. Integrated water resource management model for process industry in Lithuania. Journal of Cleaner Production 15, 950-957.

Friedrich, E., Pillay, S., Buckley, C.A. 2009. Carbon footprint analysis for increasing water supply and sanitation in South Africa: a case study. Journal of Cleaner Production 17, 1–12.

Giurco, D., Bossilkov, A., Patterson, J., Kazaglis, A. 2010. Developing industrial water reuse synergies in Port Melbourne: cost effectiveness, barriers and opportunities. Journal of Cleaner Production, doi:10.1016/j.jclepro.2010.07.001.

Goulburn Mulwaree Council, 2008. Council removes signs but Level 3 Water Restrictions remain. http://goulburn.local-e.nsw.gov.au/news/ pages/7901.html.

Hubacek, K., Guan, D., Barrett, J., Wiedmann, T. 2009. Environmental implications of urbanization and lifestyle change in China: Ecological and water footprints. Journal of Cleaner Production 17, 1241-1248.

Inman, D., Jeffrey, P., 2006. A review of residential water conservation tool performance and influences on implementation effectiveness. Urban Water Journal 3 (3), 127- 143.

Kenney, D., Goemans, C., Klein, R., Lowrey, J., Reidy, K., 2008. Residential water demand management: lessons from Aurora, Colorado. Journal of the American Water Resources Association 44 (1), 192 – 207.

Kim, S.H., Choi, S.H., Koo, J.K., Choi, S.I., Hyun, I.H., 2007. Trend analysis of domestic water consumption depending upon social, cultural, economic parameters. Water Science and Technology: Water Supply 7 (5-6), 61-68.

Krozer, Y., Hophmayer-Tokich, S., van Meerendonk, H., Tijsma, S., Vos, E. 2010. Innovations in the water chain – experiences in The Netherlands. Journal of Cleaner Production 18, 439-446.

Loh, M., Coghlan, P., 2003. Domestic Water Use Study. Perth. Water Corporation.

Mahgoub, M.E.M., van der Steen, N.P., Abu-Zeid, K., Vairavamoorthy, K. 2010. Towards sustainability in urban water: a life cycle analysis of the urban water system of Alexandria City, Egypt. Journal of Cleaner Production 18, 1100–1106.

Mayer, P., DeOreo, W., Towler, E., Martien, L., Lewis, D., 2004. Tampa Water Department residential water conservation study: The impacts of high efficiency plumbing fixture retrofits in single-family homes. Tampa. Aquacraft, Inc Water Engineering and Management.

Mayer, P. W., DeOreo, W. B., 1999. Residential End Uses of Water. Boulder, CO. Aquacraft, Inc. Water Engineering and Management.

Moore, T., 2008. Level six restrictions here to stay. Brisbane. http://www.brisbanetimes.com.au/articles/2008/01/10/1199554825143.html.

Nieswaidomy, M.L., 1992. Estimating urban residential water demand: effects of price structure, conservation, and education. Water Resources Research 28, 600-615.

Partzsch, L. 2009. Smart regulation for water innovation – the case of decentralized rainwater technology. Journal of Cleaner Production 17, 985-991.

Roberts, P., 2003. Yarra Valley Water 2003 Appliance Stock and Usage Patterns Survey. Melbourne. Yarra Valley Water.


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Roberts, P., 2005. Yarra Valley Water 2004 Residential End Use Measurement Study. Melbourne. Yarra Valley Water.

Stewart, R.A., Willis, R., Giurco, D., Panuwatwanich, K. and Capati, G. 2010. Web based knowledge management system: linking smart metering to the future of urban water planning. Australian Planner, 47 (2), 66-74.

Turner, A., White, S., Beatty, K., Gregory, A., 2005. Results of the largest residential demand management program in Australia. Institute for Sustainable Futures, University of Technology, Sydney. Sydney Water Corporation, Level 16, 115-123 Bathurst Street, Sydney, NSW.

White, S., Fane, S.A., Giurco, D. & Turner, A.J. 2008. Putting the economics in its place: decision-making in an uncertain environment, in C. Zografos and R. Howarth (eds), Deliberative Ecological Economics, Oxford University Press, New Dehli, India, pp. 80-106.

Willis, R., Stewart, R., Panuwatwanich, K., Capati, B., Giurco, D., 2009b. Gold Coast Domestic Water End Use Study. Journal of Australian Water Association 36 (6). September 2009.

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Chapter 7

Quantifying the influence of environmental and water conservation attitudes on household end use water

consumption

This chapter is a reformatted version of a peer-reviewed article completed by the author, in-

press (accepted March 2011) for publication in the Journal of Environmental Management,

Elsevier.

7.1 Abstract

Within the research field of urban water demand management, understanding the link between

environmental and water conservation attitudes and observed end use water consumption has

been limited. Through a mixed method research design incorporating field-based smart metering

technology and questionnaire surveys, this paper reveals the relationship between environmental

and water conservation attitudes and a domestic water end use break down for 132 detached

households located in the Gold Coast, Australia. Using confirmatory factor analysis, attitudinal

factors were developed and refined; households were then categorised based on these factors

through cluster analysis technique. Results indicated that residents with very positive

environmental and water conservation attitudes consumed significantly less water in total and

across the behaviourally influenced end uses of shower, clothes washer, irrigation and tap, than

those with moderately positive attitudinal concern (n=78; 169.0L/p/d). The paper concluded

with implications for urban water demand management planning, policy and practice.

7.2 Introduction

An escalating demand on potable water resources resulting from increasing populations,

droughts and unpredictable weather patterns due to climate change is commonplace in many

parts of the world (Bates et al., 2008; Commonwealth of Australia, 2008c). As a result, the

sustainable management of urban water has become imperative, particularly for countries prone

to severe droughts such as Australia. Australia receives the lowest average annual rainfall of all

inhabited continents and is experiencing strong population growth in urban areas (Birrell et al.,

Chapter 7: Quantifying the influence of environmental and water conservation attitudes on household consumption

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2005; Commonwealth of Australia, 2008b). In response a range of sustainable water

management practices and principles have been introduced to ensure the secure supply of urban

water. Notably, water demand management (WDM) initiatives are utilised to assist in shifting

consumers towards sustainable water consumption behaviour. WDM is defined as the practical

‘development and implementation of strategies aimed at influencing demand’ (Savenije and van

der Zaag, 2002, pp. 98). It is characterised by reducing average water consumption to ensure

efficient and sustainable use of the resource (Tate, 1993; Deverill, 2001; Brooks, 2002; Brooks,

2006). WDM measures are generally the most sustainable solutions across environmental, social

and economic factors, in the range of options presented for water supply security (White et al.,

2007). WDM measures focus on reducing end use consumption hence offsetting the need for

additional water supply and wastewater treatment measures which are costly and can be

environmentally and socially detrimental. Initiatives for WDM are focused on supplying tools,

mechanisms and knowledge to enable residents to continually reduce their potable water

consumption (through the reduced use of water-using devices or uptake of water-efficient

devices). The WDM approach relies heavily on consumers to understand how to reduce their

water consumption and to apply this understanding to everyday activities to consume

sustainably.

Past research has determined that water consumption within households is dependent on

numerous factors, which include: the number of people in the house, the age of residents,

education levels of residents, lot size of properties, residents’ income, efficiency of water

consuming devices (i.e. clothes washers, shower heads, tap fittings, dishwashers and toilets) and

the attitudes, beliefs and behaviours of consumers (Nieswaidomy and Molina, 1989; Renwick

and Archibald, 1998; Mayer and DeOreo, 1999; Renwick and Green, 2000; Inman and Jeffrey,

2006).

The pricing of water was initially predicted to influence consumption but this belief has more

recently been dispelled, with research demonstrating that in most cases residential water

demand is largely price inelastic because of its low relative cost when compared to other life

essentials (Worthington and Hoffmann, 2008; Barrett 2004). Barrett’s (2004) investigation of 30

residential water price demand studies revealed that most indicated price inelasticity, with

evidence that only very large external users being more likely to be sensitive to price changes.

Earlier end use studies have demonstrated that households with very high incomes consume

more water externally while, the variation of internal water consumption remains similar and is

not statistically significant between income levels (Mayer and DeOreo, 1999; Loh and Coghlan,

2003). External consumption is the end use detailed to be most effected by income and the cost

of water (Mayer and DeOreo, 1999). Mayer and DeOreo (1999) have reported a positive

relationship between larger lot sizes and higher outdoor water consumption in the USA while,


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Loh and Coghlan (2003) found that this was not the case in Australia. In fact there was no

evidence of a relationship between irrigable area and external household usage present (Loh and

Coghlan, 2003). Elements which were found to increase external water use in both studies were

the ownership of automated irrigation systems and swimming pools (Mayer and DeOreo, 1999;

Loh and Coghlan, 2003).

In relation to WDM, the last group of factors (i.e. attitudes, beliefs and actual behaviours of

consumers) are particularly relevant as water management initiatives often include pressure on

residents to reduce household water consumption through undertaking more sustainable water

consumption practices. Shifting residents toward sustainable water consumption practices thus

requires the instilling of awareness, understanding and appreciation of the environment and

water. Establishing a connection between attitudes and beliefs concerning water and the

environment and their relationship on actual water consumption behaviour has been undertaken

previously (Nancarrow et al., 1996; Hassell and Cary, 2007). However, empirical studies that

quantify the nature of such a relationship are still largely lacking within the current body of

knowledge. To fill this gap, the herein described research was aimed to empirically investigate

how attitudes and beliefs influence urban end use water consumption behaviour.

The objectives of this research include:

Developing measurable research propositions relating to attitudes and domestic end use

water consumption behaviour;

Undertaking a field-based smart metering study and subsequent flow trace analysis

process to disaggregate domestic water end uses for a statistically significant sample;

Exploration of the characteristics of consumers with respect to their attitudes towards the

environment and water conservation;

Investigation on the relationship between a confirmed taxonomy of attitudinal constructs

and end use water consumption; and,

Confirming the environmental and water conservation attitudes of residential households

that significantly affect behaviourally influenced (i.e. life style choice such as longer than

required showers) end use water consumption levels.

Meeting these objectives will enable water professionals to effectively target WDM education

and awareness programs, thus yielding higher water savings for such initiatives. Ultimately,

research outcomes could be subsequently integrated into national water planning and

management strategies to enhance long term WDM practices. The paper presents the theoretical

background relevant to understanding the attitudes and behaviours that affect domestic water

consumption and conservation. Following this is a description of research propositions. The


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adopted research method is detailed along with data analysis and results. Key findings are

discussed with the paper concluding by deliberating on managerial implications.

7.3 Theoretical Background

7.3.1 Water consumption attitudes and behaviour

Determining motives for saving water are key when designing educational urban water saving

strategies; hence at the outset, an understanding of consumption and attitudes towards water is

vital (Corral-Verdugo et al., 2003). It has been previously established that the attitudes and

beliefs of consumers directly impact on water use behaviours which are closely linked to water

demand (Hassell and Cary, 2007). To understand the embodiment of people’s attitudes and

behaviour, and their association with water consumption, Ajzen and Fishbein’s (1980) theory of

reasoned action was adopted as a point of departure.

Ajzen and Fishbein’s theory conceptualises the linkages between beliefs, attitudes, perceived

social norms and behaviours by building on the expectancy value theory through the

incorporation of normative social influence on behavioural intention (Hassell and Cary, 2007).

This theory was employed to assist in the establishment of a baseline model to undertake

attitudinal analysis. Several earlier research studies adopted the same approach to investigate

attitudes and their impact on water consumption behaviour. For example, Syme and Nancarrow

(1992) and Po et al. (2005) have applied Ajzen and Fishbeins’ theory of reasoned action to

explain the extent to which intended behaviour could predict actual consumer responses to

water supply systems. When considering risks and other social elements, the model was

particularly useful for predicting behaviour associated with the delivery of potable water

(Hassell and Cary, 2007).

To better understand and capture the above attitudinal concept, two main factors were identified

as having an influence on water consumption from a review of earlier research, being: (1)

Concern for Environment (CE); and (2) Water Conservation Awareness and Practice (WC).

Following Nancarrow et al. (1996), these two primary attitudinal factors can be used to assess

the ‘way in which people think about water’. Past research on the effect of such attitudinal

factors on water consumption is examined in the following sections.

Concern for environment

The link between general environmental beliefs and conservation behaviour has been detailed

by DECC (2007), Kordiatis et al. (2004) and Corral-Verdugo et al. (2003). Surveys undertaken

by Kordiatis et al. (2004) determined that attitudes towards environmental issues were in fact

reliable predictors of environmental behaviour. Corral-Verdugo et al. (2003), drawing on the

instrument commonly used to measure general environmental beliefs, namely, the New


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Environment Paradigm-Human Exception Paradigm (NEP-HEP), exclusively investigated the

relationship between general environmental beliefs and water conservation behaviour. In

Sonora, Mexico, surveys were undertaken to establish environmental beliefs in general as well

as environmental beliefs specific to the connection of water as a natural resource, along with

demographic details with water consumption recorded and estimated through a diary approach

(Corral-Verdugo et al., 2003). The results supported the hypothesis that general environmental

beliefs significantly influence domestic water consumption behaviour when beliefs and

behaviours are assessed at a corresponding level of specificity (Corral-Verdugo et al., 2003).

More recently, Gilg and Barr (2006) carried out a study of 1,265 households in Devon, UK

exploring the relationship between environmental attitudes and behaviours focussing on total

urban water use as the primary interest. The research examined if there were substantive links

between environmental actions and water saving behaviour to determine behavioural variations

associated with environmental activist classification (Gilg and Barr, 2006). Results indicated

that committed environmentalists and main stream environmentalists were most likely to engage

in energy and water saving activities regularly. Recent longitudinal research by DECC (2007),

assessing public attitudes to the environment including water related issues across Australia, has

determined a growing concern for environmental and water issues with respondents identifying

a willingness to undertake sustainable actions or behaviours.

The review of prior research assisted in establishing a derived factor representing environmental

concern consisting of eight indicators being: protection of natural environment for future

generations; community responsibility for reducing water consumption; concern for

environmental problems; joint responsibility of government and community to ensure water

security; acknowledgement of water being a valuable resource; acknowledgement of one’s role

in creating a sustainable water future; valuing recycling, composting and other environmentally

sustainable activities; and acknowledgement of humans role as caretaker for environment.

Details of these indicators along with their associated references are presented in Table 7-1.

These listed elements are refined and confirmed in the latter part of the paper to ensure they are

appropriate measurable indicators of the derived environmental concern factor.

Water conservation awareness and practice

Water conservation awareness and practice involves understanding the efficiency, opportunities

and impacts of certain water saving activities as well as the desire to continually reduce

consumption (Nancarrow and Syme, 1989; CSIRO, 2002; Gilg and Barr, 2006; Heinrich, 2007).

Water conservation relating to concern for water as a scarce resource was investigated in a

major study by Nancarrow et al. (1996), who determined from the investigation that the ways

people think about water does not predict their water consumption, contradicting the findings


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from other studies in the field (Middlestadt et al., 2001; CSIRO, 2002). Nancarrow and

colleagues reasoned that this outcome may be due to the adopted method of recording water

consumption data at a household level through a diary approach, while survey data was

collected as individual responses.

Table 7-1 Measurement items for concern for environment factor

Concern for environment (CE)

Code Measurement item Description References

CE1 Protection of natural environment for future generations

Examining the way in which individuals view the importance of protecting the natural environment.

Corral-Verdugo et al. (2003); CSIRO (2002).

CE2 Community responsibility for reducing water consumption

Enquiry of community responsibility for conserving water sources by reducing consumption.

CSIRO (2002); Nancarrow (2002); Corral-Verdugo et al. (2003); DECC (2007).

CE3 Concern for environmental problems

Investigation of care or concern for the general environment

Hurlimann (2008) ; Corral-Verdugo et al. (2003); DECC (2007).

CE4 Joint responsibility of government and community to ensure water security

Inquest into water security being the responsibility of both the government and the community.

Nancarrow (2002); DECC (2007).

CE5 Acknowledge water as being a valuable resource

Query of the scarcity of water and acknowledgement of its value as a resource.

CSIRO (2002); Hurlimann (2008) ; Nancarrow et al. (1996); Nancarrow (2002); Corral-Verdugo et al. (2003).

CE6 Acknowledge role in creating a sustainable water future

Comprehension of the role of people as consumers and the need to use resources sustainably to ensure availability in the future.

Hurlimann (2008)

CE7 Valuing recycling, composting and other environmentally sustainable activities

Evaluation the value of recycling, composting and other environmentally sustainable activities to consumers.

Gilg and Barr (2006); DECC (2007); Korfiatis et al. (2004).

CE8 Acknowledge humans role as caretaker for environment

Viewpoint on humans being responsible for sustaining the environment in its natural form

Corral-Verdugo et al. (2003); Syme et al. (2000).

Middlestadt et al. (2001) similarly explored the relationship of knowing or having the

knowledge on how to conserve water and whether this translated into actual behaviour. The


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research determined that students who were taught and understood water conservative

behaviours more regularly performed these behaviours. The CSIRO (2002) carried out an

extensive study in Perth, utilising both diary and end use monitoring methods, to determine

attitudes of consumers and water consumption with investigations indicating that attitudinal

variables affect external or outdoor water consumption (CSIRO, 2002). Unfortunately, the link

between attitudinal factors and indoor end use water consumption was not reported on. Hence,

this study set out to examine the influence of attitudes on indoor and outdoor domestic water

end use.

Through an extensive review of literature, nine indicators were uncovered that serve to represent

the derived water conservation awareness and practice factor, being: awareness of

opportunities to save water in household; awareness of the water saving benefits of retrofitting

to water efficient fixtures and appliances; water meter reading competency; monitoring of water

use; awareness of the relationship between behaviour and water consumption; water saving

know-how; perception on efficiency of household water use practices/behaviours; seeking

continuous savings in water consumption over the longer term; and regular water meter reading.

These items are described succinctly in Table 7-2, and are assessed in the latter part of the paper

to ensure they are appropriate measurable indicators of the derived water conservation and

practice factor. Once confirmed, this, along with the environmental concern factor were

subsequently utilised to determine the effect of attitudes on domestic end use water

consumption.

7.3.2 Water end use monitoring

Effective water monitoring techniques are essential for understanding domestic water

consumption behaviour (Stewart et al., 2010). Many water authorities provide information on

how to read a water meter to consumers with the belief that knowledge of water consumption

will assist in conserving water. Determination of water consumption within a household,

however, requires specific knowledge on how, where, when and who consumes water within

them. Initially, determining such elements of consumption relied on the honesty and vigilance

of residents through diary recording methods. Water consumption studies utilised a diary

recording method to establish end water usage. The diary method involves a member of the

household noting down every water consuming event i.e. a shower, toilet flush or tap use. The

nominated recorder would also note who carried out the event and the event duration (CSIRO,

2002; Cordell et al., 2003). Issues such as the subjectivity of measurements, consistency of

people to record all information and the influence on behaviour through recording methods led

to the development of a less intrusive and more accurate measurement method in the form of

smart metering (Cordell et al., 2003). The development of smart metering technology has


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eliminated the error of the older end use recording methods being, diary records, resulting in

accurate records of end use water consumption within residential households.

Table 7-2 Measurement items for water conservation awareness and practice factor

Water conservation awareness and practice (WC)

Code Measurement item Description References

WC1 Awareness of opportunities to save water in household

Understanding of the numerous opportunities or practices to conserve water in the household.

Nancarrow and Syme (1989); CSIRO (2002); Gilg and Barr (2006); DECC (2007); Mayer and DeOreo (1999).

WC2 Awareness of the water saving benefits of retrofitting to water efficient fixtures and appliances

Examining the understanding of the reduction in water use which can be achieved through the application of water efficient fixtures and devices.

Nancarrow and Syme (1989); CSIRO (2002); Heinrich (2007); Mayer and DeOreo (1999).

WC3 Water meter reading competency

Query of the ease of reading the household water meter and understanding the values.

Gold Coast Water (2008a)

WC4 Monitoring of water use Analysis of perception of knowing and monitoring how much water is used.

CSIRO (2002); DECC (2007); Heinrich (2007).

WC5 Awareness of the relationship between behaviour and water consumption

Enquiry on the relationship between water use activities and actual water consumption.

Nancarrow (2002); Gilg and Barr (2006); DECC (2007).

WC6 Water saving knowhow Examination of the application of activities to save water in the home.

Middlestadt et al. (2001); CSIRO (2002); DECC (2007).

WC7 Perception on efficiency of household water use practices/behaviours

Exploring the perceptions of respondents on their practices or behaviours which contribute to being an efficient water user.

CSIRO (2002); Gilg and Barr (2006).

WC8 Seeking continuous savings in water consumption over longer term

Determination on water conservation being a long or short term consideration.

Syme et al. (2000); CSIRO (2002); DECC (2007).

WC9 Regular reads water meter Need work around understanding & monitoring consumption with use of water meters.

Gold Coast Water (2008a)

The advent of smart water metering enabled water consumption to be monitored at an end use

level, resulting in the identification of individual water use events, such as shower, toilet

flushing, tap use or irrigation, through the use of appropriate software (Willis et al., 2009b).


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Smart metering involves the application of a high resolution water meter and a data logger to

obtain a continuous record of accurate water consumption data. This smart metering approach

has been utilised in many water end use studies conducted worldwide. Details of the results of

the more significant end use studies conducted throughout the world are presented in Table 7-3.

Table 7-3 Results from domestic end use studies

Previous studies USA (1999)

Mayer & DeOreo

Perth (2003) Loh & Coghlan

Melbourne (2005) Roberts

Auckland (2007) Heinrich

L/p/d Percent L/p/d Percent L/p/d Percent L/p/d Percent Clothes washer 56.8 8.7% 42.0 13% 40.4 19% 39.9 24% Shower 43.9 6.8% 51.0 15% 49.1 22% 44.9 27% Tap 41.3 6.3% 24.0 7% 27.0 12% 22.7 14% Dishwasher 3.8 0.6% NA NA 2.7 1% 2.1 1% Bathtub 4.4 0.7% NA NA 3.2 2% 5.5 3% Toilet 70 10.8% 33.0 10% 30.4 13% 31.3 19% Irrigation 381.6 58.7% 180† 54% 57.4† 25% 13.9 8% Leak 36.0 5.5% 5.0 1% 15.9 6% 7.0 4% Other 12.5 1.9% NA NA 0.0 0% 0.8 0% Total Consumption

650.3 100% 335.0 100% 226.2 100% 168.1 100%


Table 7-3 shows that in the Australia-Pacific region, the highest residential end uses are

showers, clothes washing, irrigation, toilet and tap use (Loh and Coghlan, 2003; Roberts, 2005;

Heinrich, 2007). These earlier studies established end use water consumption in their respective

regions and undertook analysis exploring the differences in end use consumption due to the

influence of socio-demographic variables. These studies, however, did not demonstrate or

provide any statistical indication of the influence of the abovementioned attitudinal factors on

various types of end use water consumption.

Understanding water consumption at the end use level is critical due to the fact that overall

domestic water consumption is made up of different water end use events. Broadly, water use

can be categorised into two main areas: non-discretionary and discretionary end uses

(ACTCOSS and CCSERAC, 2003). Traditionally, non-discretionary water use is defined as the

water used within the house to meet daily consumption and sanitation needs (e.g. shower,

clothes washing); whereas discretionary end uses are additional non-essential water use

activities (e.g. irrigation, pool use). However, lifestyle changes towards over consumption have

shifted many essential water end uses to include a large discretionary component, where use can

be well beyond what is required or considered publically acceptable for the activity. For

example, showering is now often utilised as a leisure or relaxation activity rather than simply

being used for sanitation needs. This behavioural shift epitomises the ‘Human Exception

Paradigm’, a belief that humans are above nature and therefore do not have to regard the


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environment when they consume resources (Bechtel et al., 1999). Therefore, this research

argues that discretionary water end uses should refer to those end use events that are likely to be

dependent and influenced by the lifestyle and behaviour of an individual. While certain volumes

of use are required for basic sanitation needs in shower, clothes washing and tap end uses, usage

above and beyond a reasonable sanitation requirement is argued to be discretionary. The World

Health Organization (WHO) stipulates that basic long term sustainable water consumption for

emergencies requires between 40 to 70 litres per person per day (L/p/d) for personal drinking,

sanitation and additional activities such as house cleaning, growing food and waste disposal

(WHO, 2005). A detailed investigation into basic water requirements to meet human needs by

Gleick (1996) also determined that 50 L/p/d of clean water is a fundamental human right. While

everyday living and consumption in a developed country cannot be based on WHO guidelines,

these figures emphasise that modern households in developed nations consume far more than

what is reasonably required for basic sanitation and consumption needs. Based on the core end

use categories mentioned above, irrigation, shower, tap, and clothes washing could be

considered uses that have a significant discretionary component, and toilet non-discretionary

when considering this refined definition of discretionary end uses (i.e. toilets are a fixed

consumption end use with limited behavioural influence). Leakage is not considered

discretionary or non-discretionary as this use is not a basic need nor is it influenced by

behaviour.

7.3.3 Research propositions

It is evident from the preceding sections that several investigations have established the

importance of environmental and water conservation attitudes on consumption behaviour. Most

demonstrate that positive attitudes and commitment towards the environment and water

conservation result in undertaking sustainable water conservation behaviours which, in turn,

results in lower water consumption. Hence, the following research proposition was developed:

Proposition 1: Households with higher levels of environmental concern and positive

attitudes towards water conservation will have significantly lower levels of total water

consumption.

In addition, since smart metering techniques allow for the accurate recording of water

consumption in specific end use categories, the relationships between behavioural attitudes and

various household end uses was further examined. Theoretically, because certain water

consumption end uses tended to be highly influenced by attitudes and behaviour, additional

propositions were formulated to provide specific understanding on the impact of attitudinal

factors on end use water consumption behaviour:


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Proposition 2a: Households with higher levels of environmental concern and positive

attitudes towards water conservation will have significantly lower levels of water

consumption across behaviourally influenced end uses (i.e. there is a significant

discretionary component to particular water end use such as showering, irrigation, etc.).

Proposition 2b: There is no significant difference in the consumption of water end uses

which have a lower behavioural influence (e.g. toilet flushing), between households that

have different levels of environmental concern and attitude towards water conservation.

These end uses generally have a fixed and/or low water consumption volume per event.

The following section presents the research method undertaken to test the above detailed

research propositions.

7.4 Research Method

The research forms a component of the Gold Coast Watersaver End Use (GCWSEU) study.

This element of the study integrates and compares end use water consumption data and

attitudinal questionnaire survey data to obtain an understanding of the influence of attitudes on

actual water end use consumption. Two concurrent research activities were carried out being:

(1) water end use data collection and analysis, utilising smart metering technologies and flow

trace analysis software for event disaggregation, respectively; and (2) the development,

application and statistical analysis of an attitudinal and demographic questionnaire survey.

7.4.1 Situational context

Water security is of critical concern in the urbanised South East Queensland (SEQ) region of

Australia. SEQ includes the populations in and between Brisbane, the Gold Coast, Sunshine

Coast and Toowoomba, with the total current population of above 2.8 million people. In the

Gold Coast (population half a million people), residential water consumption accounts for

approximately 75% of the City’s total supply (2008/2009) compared with 57% in nearby

Brisbane City (population 1.8 million people). These high residential water consumption

percentages triggered a focus on residential water users to continually reduce consumption.

Relative to the SEQ water supply situation, the water restriction level and awareness messages

on water are constantly changing hence it is important to set the context during the data

collection period. Leading up to the data collection period, the Gold Coast had been on Level 6

water restrictions which dictate a total outdoor watering ban and encourage residents to

consume 140 L/p/d. Drought breaking rainfalls then occurred, which led to all water restriction

levels being lifted before the data collection period. This relaxation of restrictions was due to the

Hinze Dam, the Gold Coast’s primary water source, being at greater than 95% capacity.


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Leading up to and during the data collection period, frequent messages on saving water in the

home, using 140 L/p/d and rebates programs for installing water efficient devices such as the

‘Home Watersaver’ were in place. End use data was collected from the sampled single detached

households in July 2008. There were no water restrictions in place during the data collection

period. The month of July saw 129.8mm of rain fall, with ten rainfall days above 1mm recorded.

Bulk supplied single detached residential consumption in the Gold Coast for July was 161.9

L/p/d.

7.4.2 Research sample

Data collection was undertaken in four suburban regions within the Gold Coast City. These four

regions were selected based on their apparent differences in socioeconomic classification. The

dates of estate development of all the regions were similar thus ensuring the fixtures and fittings

within homes were relatively comparable.

In total, an initial end use study sample of 151 single detached residential households was

obtained. The extensive research sample was obtained through a multi-staged process of letters

and door knocking. Selection of participants was based on a number of criteria including:

household ownership status (renting/owning) and household makeup (i.e. number of

householders, age of occupants, etc); willingness to be part of the research for a period of two

years; acceptance of multiple water consumption monitoring periods and several surveys with

potential interventions; as well as involvement in a household water appliance stock audit

(Willis et al., 2009b). Historical household volumetric readings for the consenting sample were

also analysed to ensure that the recruited sample’s water use frequency distribution was

representative of the region and City. As a final note, the useable sample for the purposes of this

specific mixed method study was 132, due to the requirement for aligned questionnaire survey

responses, as detailed in a later section.

7.4.3 End use smart metering approach

Standard water meters in the Gold Coast study area were exchanged with Actaris CTS-5 high

resolution water meters. These meters pulse at 72 counts/litre which accounts to a pulse read

every 14mL of water used. DataCell D-CZ21020 data loggers were attached to water meters to

record end use water consumption data (Willis et al., 2010b). Data loggers were set to record

data points in ten (10) second intervals. Data were downloaded from data loggers manually with

laptops via infrared cables. The data were then checked for validity with a two week timeframe

selected for analysis. In home stock inventory surveys, water consumption behaviours and basic

demographic descriptive statistic reports were undertaken to ascertain water devices and usage

behaviours in households. The acquired end use data were analysed with the Trace Wizard™


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software in order to disaggregate flow data into a repository of individual end use water

consumption records for each home. Data analysis involves trained researchers conducting the

end use analysis process of verifying signature traces for each water use activity occurring in the

household, the stock and behavioural surveys aided this process.

7.4.4 Questionnaire development and survey

In addition to monitoring water end use consumption, demographic and attitudinal surveys were

developed and distributed to all the sampled households. The main purpose of the survey was to

solicit respondent ratings for the two attitudinal constructs, namely CE and WC, and to obtain

an understanding on the demographic characteristics of residential water consumers making up

each household. Measurement items contained in the questionnaire evolved from the

abovementioned literature review and factor operationalisation process (Table 7-1 and Table

7-2). A five-point Likert-type measurement scale was adopted for the respondents’ rating of

attitudinal items, with 1 representing strongly disagree and 5 representing strongly agree. Postal

mail was the method for questionnaire distribution. It is important to note that only one

questionnaire survey was completed per household. The head of each household was requested

to convene a meeting with other residents, and consultatively respond to the questionnaire

items, thus providing a response which was representative of the group. In cases where

members could not attend or were young children, they were requested to provide a perceived

rating which reflects their perception of the household’s overall attitude to the listed items. Data

obtained from the survey together with the logged water meter data disaggregated into a

repository of all end use events, were compiled into SPSS version 17.0 for the purpose of

statistical analysis, as presented in the following section.

7.5 Data Analysis and Results

7.5.1 Descriptive statistics

Of the 151 surveys sent, a total of 132 usable responses were received, representing an effective

response rate of 87%. This response rate was high as participants had already consented to being

a part of a two year end use study and had their water meters replaced with those of a higher

resolution and loggers connected. It should be noted that only the water end use data from these

usable 132 survey respondents was used in the subsequent analyses since this was a mixed

method study, whereby both a completed questionnaire survey and water end use data was

required.

The demographic characteristic of survey responses was classified based on household types

and socioeconomic areas. In terms of household types, the majority were made up of small and


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large families (67%), followed by couples (25%). The remaining 8% was a mix of households

with a single person, share house and family with border. The four research regions included in

the sample were predominately from the middle class range (i.e. lower to upper middle class).

Some socioeconomic descriptive variables have been provided in Table 7-4 to shed light on the

characteristics of the sample.

Table 7-4 Socioeconomic descriptive statistics for sampled regions

Research area

Socioeconomic classification

Total no. of Households

Average property size

(m2)

Average income

Education status

Mudgeeraba Lower Middle to Middle Class

36 646.8 AUD$1387† Mainly High School and Technical

Cassia Park Lower Middle to Middle Class


Crystal Creek Lower Middle to Middle Class

38 655.6 AUD$1606 Mainly Technical and

Tertiary Coomera Waters

Middle to Upper Middle Class

35 806.4 AUD$1987 Mainly Tertiary

151 695.1 AUD$1677 † Note: May 2010 exchange rate was AUD0.821=1USD (i.e. AUD$1387=$1139USD)

Based on the data obtained from the 132 survey respondents, descriptive statistical analysis was

firstly performed on factor measurement items to examine the mean, standard deviation, as well

as the reliability of the measurement scale used in the questionnaire. The results are presented in

Table 7-5. The Cronbach’s Alpha coefficient of 0.91 calculated from the complete set of items

indicates a high level of internal consistency (i.e. reliability) of the scale used in the survey

(Hair et al., 2006).

7.5.2 Measurement model assessment

In addition to assessing the consistency of the scale presented in the preceding section,

Confirmatory Factor Analysis was employed to assess the scale’s construct validity and

unidimensionality. In essence, CFA is a way of testing how well a priori factor structure and its

respective pattern of loadings match the actual data (Hair et al., 2006). CFA can be used to

refine an existing theoretical perspective, support an existing structure, and test a known

dimensional structure in an additional population (DiStefano and Hess, 2005). For the purpose

of this study, CFA was used to confirm the developed factor structure (referred to as

“measurement model”) that represented the set of attitudes toward the environment and water

conservation, respectively, for the study sample (Table 7-1 and Table 7-2). To achieve this,

CFA requires an assessment of model fit, and an indication of how well the hypothesised

measurement model (i.e. the factors and associated indicators presented in Table 7-1 and Table

7-2) represents the data obtained from the survey. This was conducted on the basis of five


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common model fit indices: normal chi-square (2/df); goodness-of-fit index (GFI); comparative-

fit index (CFI); incremental-fit index; and root mean square error of approximation (RMSEA).

To be considered as having an adequate fit, all the indices were measured against the following

criteria: 2/df < 3.00; GFI, CFI, and IFI > 0.90; and RMSEA < 0.08 (Hair et al., 2006).

Table 7-5 Measurement items mean value and standard deviation.

Item code

Item description Mean S.D.

Factor 1: Concern for environment (CE)

CE1 Protection of natural environment for future generations 4.64 0.59

CE2 Community responsibility for reducing water consumption 4.45 0.67

CE3 Concern for environmental problems 4.19 0.73

CE4 Joint responsibility of government and community to ensure water security 4.30 0.69

CE5 Acknowledge water as being a valuable resource 4.52 0.64

CE6 Acknowledge role in creating a sustainable water future 4.24 0.78

CE7 Valuing recycling, composting and other environmentally sustainable activities

4.22 0.72

CE8 Acknowledge humans role as caretaker for environment 4.36 0.64

Factor 2: Water conservation awareness and practice (WC)

WC1 Awareness of opportunities to save water in household 4.41 0.59

WC2 Awareness of the water saving benefits of retrofitting to water efficient fixtures and appliances

4.24 0.73

WC3 Water meter reading competency 3.44 0.88

WC4 Monitoring of water use 3.08 0.92

WC5 Awareness of the relationship between behaviour and water consumption 4.06 0.70

WC6 Water saving knowhow 4.23 0.69

WC7 Perception on efficiency of household water use practices 3.84 0.85

WC8 Seeking continuous savings in water consumption over longer term 4.11 0.75

WC9 Regular reads water meter 3.62 0.76

Note: Cronbach’s alpha (17 items) = 0.91

CFA was conducted using AMOS version 17.0, employing the maximum likelihood estimation

(MLE) method for parameter estimation. The initial results indicated that the measurement

model did not fit the data well. To improve the model fit, a refinement procedure was carried

out, which mainly involved removing items that had insignificant or low factor loading (<0.50),

and low reliability (R2 < 0.50). This procedure led to the elimination of items WC3, WC4 and

WC5. Table 7-6 presents the results of the refined measurement model analysis, showing the

loading, t-value and R2 of each item along with the composite reliability and average variance


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extracted of each factor. As shown in the table, all of the remaining items have loadings on their

respective factors greater than 0.50, with all t-values being significant at p < 0.001, indicating

convergent validity of the model (Hair et al., 2006). In terms of item reliability, several items

had R2 values lower than the common acceptable level of 0.50, suggesting potential for

elimination. However, since their loadings were meaningful (greater than 0.50) and highly

significant, these items were retained in the measurement model (Koufteros, 1999).

Furthermore, both factors were shown to have a composite reliability well above 0.60, and

average variance extracted being greater than 0.50 (Bagozzi and Yi, 1988). The fit indices of

this model (presented underneath Table 6) also show an acceptable level of fit according to the

criteria mentioned above (2 = 140.59; df = 76; 2/df = 1.85; GFI = 0.86; CFI = 0.93; IFI = 0.94;

RMSEA = 0.08). Therefore, the model was deemed the final measurement model, as illustrated

in Figure 7-1. The figure shows the model’s structure of the factors and their associated items,

correlation between both factors, and the final loadings of all items on their respective construct.

Table 7-6 Measurement model analysis results

Items Loading t-value† R2 Composite Reliability

Average Variance Extracted

Factor 1 (CE) 0.90 0.60 CE1 0.74 f.p. 0.55 CE2 0.81 9.38 0.65 CE3 0.78 9.04 0.61 CE4 0.63 7.14 0.39 CE5 0.63 7.16 0.40 CE6 0.76 8.71 0.57 CE7 0.73 8.39 0.53 CE8 0.74 8.53 0.55 Factor 2 (WC) 0.84 0.55 WC1 0.82 f.p. 0.67 WC2 0.73 9.20 0.53 WC3 Removed WC4 Removed WC5 Removed WC6 0.77 9.82 0.59 WC7 0.56 6.65 0.32 WC8 0.62 7.53 0.39 WC9 0.55 6.42 0.30

Model fit indices: 2 = 140.59; df = 76; 2/df = 1.85; GFI = 0.86; CFI = 0.93; IFI = 0.94; RMSEA = 0.08. f.p., Parameter is fixed for estimation purpose. †All t-values are significant at p < 0.001.

It should be further noted that the high correlation between the two factors (0.95) indicated their

ability to represent aligned concepts (Kline, 2005). However, combining them proved to weaken

the model fit indices. Furthermore, the discriminate validity of the model (i.e. CE and WC

existed as two separate factors rather than one) was supported by the significant Chi-Square

difference statistic between the models with unconstrained and constrained (fixed at 1.00)

correlation coefficients between the two factors (Koufteros, 1999). All of the above results

suggested that this final measurement model (Figure 7-1) possesses adequate convergent


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validity (i.e. all items reliably represented their respective factor), unidimensionality (i.e. all

items only represented their respective factor not the other) and discriminant validity (i.e. two

factors rather than one). The final measurement model’s underlying factor structure was

therefore used in the subsequent analyses.

Concern for Environment

Water Conservation Awareness and

Practice

CE6

CE7

CE8

WC1

WC2

WC6

WC7

0.95

WC8

WC9

0.82

0.73

0.77

0.56

0.62

0.55

CE3

CE4

CE5

CE1

CE20.74

0.81

0.78

0.63

0.63

0.76

0.73

0.74

e1

e2

e3

e4

e5

e6

e7

e8

e9

e10

e11

e12

e13

e14

Concern for Environment

Water Conservation Awareness and

Practice

CE6

CE7

CE8

WC1

WC2

WC6

WC7

0.95

WC8

WC9

0.82

0.73

0.77

0.56

0.62

0.55

CE3

CE4

CE5

CE1

CE20.74

0.81

0.78

0.63

0.63

0.76

0.73

0.74

e1

e2

e3

e4

e5

e6

e7

e8

e9

e10

e11

e12

e13

e14

Figure 7-1 CFA model

7.5.3 Exploration of clusters

Once the factor structure had been refined and confirmed by the CFA, all the retained items

were used as a basis for determining whether there were any distinct groupings evident in the

sample that shared similar patterns of ratings for both the concern for the environment and

water conservation awareness and practice factors. To achieve this objective, cluster analysis

was adopted. According to Hair et al. (2006), cluster analysis is an exploratory data analysis

tool for solving classification problems. Its purpose is to categorise cases into groups or clusters

so that each case is very similar to others in its clusters. Two major stages of the cluster analysis

procedure were carried out in this research: (1) partitioning; and (2) interpretation. The

partitioning stage is the process of determining the number of clusters that may be developed.

The interpretation stage is the process of understanding the characteristics of each cluster and

developing a name or label that appropriately defines its nature (Hair et al., 2006). SPSS version

17.0 for Windows was employed to perform the analysis.

Number of clusters and final centroids


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The hierarchical cluster analysis procedure, incorporating Ward’s method, was conducted on all

fourteen (14) items included in the final measurement model as presented in Figure 7-1. This

clustering procedure involves a combination of the objects into a hierarchy or a treelike

structure, as represented by a dendrogram. A dendrogram provides an indication of

heterogeneity change (average within-cluster distance) for all possible combinations of clusters.

A decision on the final number of clusters is usually based on the combinations that do not yield

a substantial increase in heterogeneity (Hair et al., 2006). From an inspection of the

dendrogram, it was found that a division of two clusters represented the best solution. The final

centroids of the two clusters based on the fourteen items are plotted in Figure 7-2. The cluster

centroids are the mean values for each item that represent the general characteristics of a cluster

(Yeung et al., 2003). Additionally, the results from One-way Analysis of Variance (ANOVA)

showed that the final centroids of both clusters were significantly different across all items.

Figure 7-2 Profiles of clusters’ final centroids

Interpretation of clusters

The characteristics of both uncovered clusters were interpreted through the cluster profiles

presented in Figure 7-2. From the figure, it can be observed that the centroids within Cluster 1

are consistently very high across all items, indicating that this group of respondent had a very

high concern for environment and water conservation. Thus Cluster 1 was labelled VHC. For

Cluster 2, the centroids value for both factors ranged between moderate to high levels,

suggesting that this group of respondents had a moderate to high level of concern for the

environment and water conservation. Hence, Cluster 2 was labelled MHC. To better understand

the characteristics of the clusters, socio-demographic information for the households categorised

within each cluster was subsequently examined with the goal to extract any distinctive features

that could explain the two groups.

2

2.5

3

3.5

4

4.5

5

CE1 CE2 CE3 CE4 CE5 CE6 CE7 CE8 WC1 WC2 WC6 WC7 WC8 WC9

Water conservation awareness and practice (WC)

Cluster 1

Cluster 2

Concern forEnvironment (CE)

Very High

Moderate

Low

Item Centroid

Measurement Item


- 166 -

Examination of the demographic information for both clusters revealed that the VHC group has

a higher proportion of small and large family households (74%) than that of the MHC cluster

(62%). On the other hand, the percentage of households with couples in the VHC group (21%)

was lower than that of the MHC group (27%). The average household lot sizes for the two

clusters were very similar, being 683m2 and 691m2, for MHC and VHC, respectively. The VHC

cluster had a lower average income (AUD$1584; USD$1300 May 2010) than the MHC cluster

(AUD$1744; USD$1431). Whilst, this difference is not statistically significant due to the

relatively small sample size (F=1.370; p=0.244), it could provide some indication that

environmental and water conservation concern may become less important to greater

proportions of people in the upper middle and higher classes. An attempt to shed some light on

the influence of socioeconomic factors on the relationship between attitudes and water

consumption behaviours is provided later.

7.5.4 Water consumption end use analysis

Overall end use consumption

The breakdown of end use water consumption for the total sampled households in the Gold

Coast (n=132) is presented in Figure 7-3. The overall average consumption for the sampled

Gold Coast households (n=132) was 152.3 L/p/d. It should be noted, that while attitude ratings

and water end use comparisons are made at the household entity level, total water consumption

and end use break downs are necessarily presented as L/p/d in order to level consumption

volumes considering household size.

Figure 7-3 Average daily per capita consumption per end use: total sample (n=132)

The highest end use is showering, with each person consuming just over 47 litres of water per

day or 31% of total use. The next highest end use is clothes washing accounting for 20% of total

Shower47.1 L/p/d

31%

Clothes Washer30.0 L/p/d

20%

Tap26.6 L/p/d

17%

Dishwasher

2.2 L/p/d1%

Bathtub5.5 L/p/d

4%

Toilet20.9 L/p/d

14%

Irrigation18.0 L/p/d

12%

Leak

1.8 L/p/d1%

Total = 152.3 L/p/d


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consumption or 30 L/p/d. Tap use, toilet flushing and irrigation follow with end use percentages

of 17%, 14% and 12%, respectively. Bath use, dishwashing and leaks make up a small

component of water end use with percentages ranging from 1% to 4%. Figure 7-4 demonstrates

the end use water consumption breakdown for each of the measured 132 households.

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

140

100

167

173

199

45

191

56

51

41

200

23

185

163

103

111

74

192

36

152

106

75

124

127

33

50

130

115 1 69

89

67

24

68

150 4 94

144

79

114

110

176

82

88

120

85

170

93

156

71

81

177

149

131

46

62

105

136

178

165

73

20

13

143

80

10

Per Capita Con

sumption (L/p/d)

Household ID

Leak

Irrigation

Toilet

Bathtub

Dishwasher

Tap

Clothes Washer

Shower

Figure 7-4 Household daily per capita consumption distribution with water end use breakdown: total sample (n=132)

Clustered water consumption end use

Two attitudinal clusters for the sampled households, namely VHC and MHC, were determined

earlier based on the household residential perceptions regarding their concern for environment

and water conservation awareness and practice. The VHC cluster denotes the group of

households with a very high level of concern, whereas the MHC cluster represents the group

with a moderate level of concern for the environment and water conservation awareness and

practice. Further examination and comparison of the end use consumption levels, between the

two clusters, could thus provide a basis for understanding the relationship between the herein

measured environmental and water conservation attitudinal levels of concern and the actual end

usage of water. To achieve this, the flow trace analysed average daily per capita end use

consumption (i.e. L/p/d) for each household associated with the two extracted clusters (i.e. VHC

and MHC) was assigned and compared.

Figure 7-5 shows the breakdown of average daily per capita consumption (L/p/d) of the

households in the VHC cluster (n=54). The VHC average total water use was 128.2 L/p/d,

which is less than that for the combined 132 household sample (152.3 L/p/d). When considering

individual end use activities, it was found that the volumetric consumption for all categories was

lower than that of the total sample, with the exception of dishwasher. It can be further observed

that the proportion of average daily per capita consumption (i.e. percentage) of most end use

categories between the VHC cluster and the total sample is similar. However, of note is the

proportion of irrigation use for the VHC cluster (8%), which is considerably less than that of the

total sample (12%); as discussed the lot sizes of the two clusters is not significantly different.

Max = 375.6 L/p/d

Average = 152.3 L/p/dMin = 38.4 L/p/d


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Figure 7-6, presents the VHC clusters’ descending profile for each individual households’ water

end use consumption breakdown, indicating that the majority of households in this sub-sample

consumed water less than 150 L/p/d. Two excessively high users are present, whose average

consumption was in the order of 350 L/p/d. These two outliers potentially represent households

whose reported attitudes do not adequately reflect their actual behaviours.

Figure 7-5 Average daily per capita consumption: VHC cluster (n=54)

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

140

167

45

56

116

103

15

75

53

60

64

181

54

69

67

24

171

68 4

30

70

114

134

176

25

198

11 2

170

93

107

156

42

71

95

177

57

83

133

46

49

166

14

136

178

154

190

73

55

20

13

145

80 3

Per Capita Consumption (L/p/d)

Household ID

Leak

Irrigation

Toilet

Bathtub

Dishwasher

Tap

Clothes Washer

Shower

Figure 7-6 Household daily per capita consumption distribution profile: VHC cluster (n=54)

The break down of average daily per capita consumption (L/p/d) for the households in the MHC

cluster (n=78) is presented in Figure 7-7. It can be observed that the proportion of all the

average end use categories of this cluster is similar to that of the total sample presented in Table

7-3. For this cluster, the average total water use was 169.0 L/p/d, being higher than that of the

total 132 sample consumption (152.3 L/p/d). Similarly, the end use consumption for all

categories, except dishwasher, is also higher than that of the total sample. Figure 7-8 presents

the MHC clusters’ descending profile for each individual households’ water end use

Shower41.5 L/p/d

32%


20%

Tap

22.9 L/p/d18%

Dishwasher2.3 L/p/d

2%

Bathtub

4.5 L/p/d4%

Toilet19.9 L/p/d

15%

Irrigation

10.8 L/p/d8%

Leak

1.3 L/p/d1% Total = 128.2 L/p/d

Max = 375.6 L/p/d

Average = 128.2 L/p/d

Min = 38.4 L/p/d


- 169 -

consumption break down. It can be seen that more than half of the households in this sub-

sample consumed more than 150 L/p/d.

Figure 7-7 Average daily per capita consumption: MHC cluster (n=78)

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

19

100

28

101

173

148

199

119

132

191

72

161

51

187

41

77

200

40

23

43

185

163

52

196

111 8

74

160

192

39

36

122

152

106

32

124

129

127

17

33

50

158

130

115 1

162

89

35

155

65

150

66

94

84

144

79

92

175

110

82

88

108

120

85

141

81

47

149

131

62

105

180

165

29

143

86

139

10

Per Capita Consumption (L/p/d)

Household ID

Leak

Irrigation

Toilet

Bathtub

Dishwasher

Tap

Clothes Washer

Shower

Figure 7-8 Household daily per capita consumption distribution profile: MHC cluster (n=78)

Clustered comparative analysis

Results from the preceding section provided illustrative evidence that end use water

consumption varies depending on the environmental attitudes of consumers. Further

investigation was undertaken to determine the level of statistical difference for each end use

category. To achieve this, an independent sample t-test was carried out using the two extracted

clusters as input samples. The results from this test, as presented in Table 7-7, show that total

water consumption volumes for these two clusters are statistically different, with the VHC

cluster having 24.1% lower consumption (128.2 L/p/d) than that of the MHC (169.0 L/p/d).

Furthermore, consumption levels for the four defined discretionary end use categories (i.e.

shower, clothes washer, tap and irrigation) are all significant at 0.05 level, suggesting that there

Shower51.0 L/p/d

30%


20%Tap

29.2 L/p/d17%

Dishwasher

2.1 L/p/d1%

Bathtub6.2 L/p/d

4%

Toilet

21.7 L/p/d13%

Irrigation

23.0 L/p/d14%

Leak

2.2 L/p/d1%

Total = 169.0 L/p/d

Max = 355.4 L/p/d

Average = 169.0 L/p/d

Min = 41.4 L/p/d


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is a relationship between the households’ levels of water conservation and environmental

concern, and actual water end use consumption. Irrigation represents the most significant

difference, where the VHC cluster (i.e. 10.8 L/p/d) has a 12.2 L/p/d or 53.0% reduction from the

MHC cluster (i.e. 23.0L/p/d). Expectedly, Table 7-7 also shows that the two non-discretionary

end uses such as dishwasher and toilet, which are largely not affected by household behaviours

due to their mechanical nature, were not significantly different. A discussion on total,

behaviourally influenced water consumption end use differences, along with an exploratory

analysis on the socio-demographic factors underpinning these differences, is outlined below.

Table 7-7 Clustered comparative analysis results.

Average daily per capita water consumption (L/p/d)

Cluster comparison statistics (MHC versus VHC)

End use category

Overall (n=132)

MHC (n=78)

VHC (n=54)

Difference (L/p/d)

Difference(%)†

p-value

Significant at 0.05

level (Y/N)?

Discretionary Shower 47.1 51.0 41.5 9.5 18.6% 0.043 Y Clothes Washer

30.1 33.6 25.0 8.6 25.6% 0.031 Y

Tap 26.6 29.2 22.9 6.3 21.6% 0.002 Y Irrigation 18.0 23.0 10.8 12.2 53.0% 0.049 Y Non-discretionary

Dishwasher 2.2 2.1 2.3 0.2 -9.5% 0.609 N Bathtub 5.5 6.2 4.5 1.7 27.4% 0.314 N Toilet 20.9 21.7 19.9 1.8 8.3% 0.333 N Leak 1.8 2.2 1.4 0.8 36.4% 0.105 N Total consumption

152.2 169.0 128.3 40.7 24.1% 0.001 Y

†Relative to average daily per capita consumption of the MHC group (positive percentage represents a reduction in consumption)

7.6 Discussion

7.6.1 Overview on water consumption and attitudes

Cluster analysis results indicated that survey respondents could be classified into two

environmental attitudinal groups, namely VHC and MHC. Residents clustered in the VHC

group reported very high levels of understanding and concern for the environment and water

conservation, whereas those in the MHC cluster reported only a moderate level. Total water

consumption, as well as the disaggregated water end uses categories that sum to this total, were

aligned with household attitudinal ratings and compared. Three propositions were established

and the calculated statistical results support the view that water end use consumption levels can

significantly differ depending on the resident’s level of concern toward the environment and

water conservation. Both the VHC and MHC groups displayed differing end use water

consumption levels and possessed divergent characteristics. The following sections provide


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further discussion, which outlines the supportive evidence for the listed propositions as well as

proposes some of the underlying factors contributing to the current situational context.

Relationship between attitudes and total water consumption

It was hypothesised in this research that households with higher levels of environmental concern

and attitude towards water conservation will consume significantly less water in total. The

analysis results provided empirical evidence which supports the first proposition (Proposition 1)

by demonstrating that the VHC cluster households consumed significantly less water than the

MHC cluster households. This finding provides further support to previously reported research

studies (Nancarrow et al., 1996) by revealing the link between positive attitudes and

commitment towards the environment and water conservation. These supportive attitudes often

result in improved water conservation behaviours which, in turn, lead to lower levels of total

water consumption in households.

Relationship between attitudes and discretionary end use consumption

The smart metering approach employed enabled the monitoring of water end use events. Of

these end uses, five were considered to be strongly influenced by behavioural aspects: shower,

clothes washer, tap, bathtub and irrigation. Results from the clustered comparative analysis

indicated significant differences in water consumption in all behaviourally influenced end uses,

with the exception of bathtub, demonstrating that VHC residents consumed significantly less

water in these end uses than the MHC residents. This finding provides empirical support for

Proposition 2a, demonstrating that households with higher levels of environmental concern and

positive attitude towards water conservation have significantly lower levels of consumption in

behaviourally influenced water end uses. It should be noted that the reason water use in bathing,

despite being considered moderately influenced by behaviours, showed no significance

difference between the two clusters could be due to the fact that only a few households in the

sample undertook this activity, thus making statistical comparisons less reliable.

Importantly, the above findings imply that there is a positive relationship between attitudes

towards the environment and water conservation and water end use consumption across

behaviourally influenced end uses. As discretionary end use consumption varies entirely based

on the decision of water users to consume beyond what is necessary, those water users with

positive attitudes towards environmental sustainability would tend to be more cautious when

using water than those who do not highly value or consider the environment. Examples of

sustainable activities potentially undertaken by the VHC residents could include: (1) showering

over smaller durations with high efficiency showerheads; (2) washing clothes in water efficient

washing machines and residents waiting until they have a full load before commencing


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washing; (3) only watering outdoors when absolutely necessary; (4) not continuously running

taps for rinsing dishes; and (5) turning off taps when brushing teeth or washing vegetables.

The potential water savings achievable across certain end uses, through transforming

households’ attitudes, is highly evident (Table 7-7). Improving the attitudes of MHC residents

could mean the reduction in water consumption across discretionary end uses, ranging from

approximately 18.6% to 53.0%. Such savings, when translated across entire cities, would ensure

greater urban water security in a time where climate variability is becoming more prevalent.

This benefit, however, needs to be further examined in future research through a longitudinal

study implementing and monitoring the influence of education programs to improve the

attitudes of water users.

Relationship between attitudes and non-discretionary end use consumption

Because non-discretionary end uses are those water use activities that tend to be consumed to

satisfy basic need or function without being much affected by the users’ behaviour, it was

hypothesised in this research that there will be no significant differences in non-discretionary

water end uses between households having different attitudes towards the environment and

water conservation (Proposition 2b). The two end use events that considered as non-

discretionary are toilet and dishwasher. As anticipated, these end uses did not have any

significant difference across the VHC and MHC clusters, thus providing empirical support for

this proposition. This finding demonstrates that differences in attitudes towards the environment

and water conservation are not associated with the consumption of non-discretionary water end

uses.

Leakage was not classified as either a discretionary or non-discretionary end use. It is

worthwhile noting that the levels of leakage did not differ between the two clusters. Some

visible components of leakage such as rectifying continuously running cisterns are affected by

behaviours, but less visible leakage was not considered to be affected by behaviours. Due to the

small number of households with significant leakage, and the resulting low volumes within each

cluster, it is difficult to reliably assess this relationship in the present study. Nonetheless, some

of the urban water researchers associated with this study is examining such an issue in a

separate investigation (Britton et al., 2008; Britton et al., 2009).

7.6.2 Linking socio-demographic variables with attitudes

In addition to examining the relationship between attitudes and water consumption, the

interpretation of clusters revealed some demographic characteristics that had higher

representation in each identified cluster. The VHC residents consisted of a larger proportion of

families whereas the MHC cluster had a lower proportion of families and higher proportion of


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singles and couples. This suggests that families may have higher awareness or understanding of

the environment and water conservation practices and higher application of such knowledge.

The study indicated that there was no difference between the average lot sizes of the two

clusters, indicating that irrigable area was not a contributing factor to the difference in irrigation

end use volumes. As discussed previously there was a difference between the average incomes

for the two clusters, albeit not statistically significant. Nonetheless, this difference does provide

some persuasion for future research to explore whether households that have higher disposable

incomes (i.e. upper middle and high classes) are more likely to have less regard for resource

conservation, particularly low cost resources such as potable water.

Other studies have indicated that affluence may play a significant part in higher water

consumption behaviours (CSIRO, 2002; Kim et al., 2007; Kenney et al., 2008). In summary,

whilst the authors acknowledge that a wide range of other contributing factors, beyond

environmental/water attitudes such as pricing or demographics, contribute to water consumption

behaviours, the study provides strong indications that attitudes play a predominant role in water

conservation. Further research on attitudes towards environment and water conservation across

different socio-economic groups could provide additional insight into domestic water

consumption behaviour and would assist in triggering the development of targeted awareness

messages.

7.7 Conclusions and Implications

This paper presented findings from a component of the GCWSEU. The herein discussed

component of the greater research program was focused on establishing if attitudes influence a

range of end use water consumption levels; such a mixed method study has not been reported in

the literature. The research findings provided empirical support to the propositions that pro-

environmental and water conservation attitudes result in household total water savings, and

across the majority of discretionary end uses, respectively.

Two attitudinal constructs, concern for the environment and water conservation awareness and

practice, were statistically validated following a measurement reliability and scale analysis

process. Subsequently, cluster analysis uncovered two distinct groups of households, being

those with very high concern (VHC) and those with moderate to high (MHC) concern. Smart

meters were utilised to collect high resolution (0.014 L/pulse) flow data, which was then

disaggregated into end uses for the 132 households involved in the study. Three research

propositions were developed and tested. Overall, it was established that strong positive

environmental and water conservation attitudes resulted in significantly (p < 0.05) lower total

water consumption as well as for the behaviourally influenced end use categories (i.e. shower,


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clothes washing, irrigation and tap use). Bath use was not affected by attitudes potentially due to

the small number of household residents partaking in this activity. Non-discretionary toilet and

dishwasher use was not influenced by attitudes as predicted. Leakage being categorised as

neither a discretionary or non-discretionary use was also not shown to be impacted by attitudes;

however, examining this end use category was outside the scope of this research. Residents with

a high level of concern or attitude towards the environment had a higher representation of

families than couples and slightly higher incomes, although this was not at a significant level.

The results from this research provide water demand management professionals with an

understanding on where educational programs should be targeted to obtain the highest effective

household water savings. Significant water savings in high end uses within homes can be

achieved if pro-environmental attitudes can be effectively instilled. This research supports the

development of directed awareness information focused on improving the current level of

understanding of sustainable shower, clothes washing, irrigation and tap use behaviours. Such

targeted programs will result in significant reductions in water consumption within residential

households. The study provides empirical evidence to support the view that if society at large

values water and is actively concerned with how it is being consumed, significant reductions in

consumption levels can occur. This in turn will lead to a reduced requirement for

environmentally adverse water supply alternatives (e.g. desalination plants) to support demand.

As a final note, the findings and herein described research methods could also be applied to

investigate relationships between attitudes and resources (i.e. water, energy and materials) and

conservation in the commercial and industrial sectors.

7.8 Acknowledgements

The research forms a component of the Gold Coast Watersaver End Use (GCWSEU) study, a

research collaborative between Griffith University and Gold Coast Water under an Australia

Research Council (ARC) grant. Gold Coast Water is acknowledged for their financial and in-

kind support to the herein described study. The Institute for Sustainable Futures, Wide Bay

Water Corporation and the Queensland Water Directorate are also acknowledged for their

involvement in the research collaborative. Lastly, the authors appreciate the invaluable

comments from the anonymous reviewers of an earlier version of this paper

7.9 References

ACTCOSS & CCSERAC (2003) Saving our Water Resources and equitable and sustainable policy for the ACT. ACT Council of Social Services and Conservation Council of the South East Region and Canberra. Canberra.


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Bagozzi, R. P. & Yi, Y. (1988) On the evaluation of structural equation models. Journal of the Academy of Marketing Science, 16, 74-94.


Bechtel, R., Corral-Verdugo, V. & Pinheiro, J. (1999) Environmental belief systems: United States, Brazil, and Mexico. Journal of Crosscultural Psychology, Vol 30, pp. 122–128.



Britton, T., Stewart, R. A. & O'Halloran, K. (2009) Smart metering providing the foundation for post meter leakage management. IWA Specialist Conference - Efficient 2009, 25th to 28th October 2009. Sydney, Australia.

Brooks, D. B. (2002) Water: Local-Level Management. Ottawa: International Development Research Centre.


Commonwealth of Australia (2008a) Drought. Online article, accessed 20/03/08, available at http://www.bom.gov.au/lam/climate/levelthree/c20thc/drought.htm Bureau of Meteorology.


Cordell, D., Robinson, J. & Loh, M. (2003) Collecting residential end use data from primary sources: do's and dont's. Institute For Sustainable Futures, University of Technology, Sydney,.



DECC (2007) Who Care About Water and Climate Change in 2007? Department of Environment and Climate Change. November 2007.


DiStefano, C. & Hess, B. (2005) Using confirmatory factor analysis for construction validation: an empirical review. Journal of Psychoeducational Assessment, 23, 225-241.

Gilg, A. & Barr, S. (2006) Behavioural attitudes towards water saving? Evidence from a study of environmental actions. Ecological Economics, Vol 57, pp. 400-414.

Gleick, P. (1996) Basic water requirements for human activities: Meeting basic needs. Water International, Vol 21, pp. 83-92.




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Kim, S. H., Choi, S. H., Koo, J. K., Choi, S. I. & Hyun, I. H. (2007) Trend analysis of domestic water consumption depending upon social, cultural, economic parameters. Water Science and Technology: Water Supply, Vol 7:5-6, pp. 61-68.

Kline, R. B. (2005) Principles and Practice of Structural Equation Modeling, New York, Guilford Press.

Korfiatis, K. J., Hovardas, T. & Pantis, J. D. (2004) Determinants of Environmental Behavior in Societies in Transition: Evidence from five European Countries. Population and Environment, Vol. 25:6.

Koufteros, X. (1999) Testing a model of pull production: a paradigm for manufacturing research using structural equation modeling. Journal of Operations Management, 17, 467-488.



Middlestadt, S., Grieser, M., Hernandez, O., Tubaishat, K., Sanchack, J., Southwell, B. & Schwartz, R. (2001) Turning Minds on and Faucets Off: Water Conservation Education in Jordanian Schools. The Journal of Environmental Education, Vol 32:2, pp. 37-45.


Nancarrow, B. E. & Syme, G. J. (1989) Improving Communication with the Public on Water Industry Policy Issues. UWRAA Research Report No. 6.







Syme, G. & Nancarrow, B. (1992) Predicting public involvement in urban water management and planning. Environment and Behaviour, Vol 24. pp. 738-758.

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WHO (2005) Minimum water quantity needed for domestic use in emergencies. WHO - Technical Notes for Emergencies, World Health Organization, Switzerland.

Willis, R., Stewart, R., Panuwatwanich, K., Capati, B. & Giurco, D. (2009) Gold Coast Domestic Water End Use Study. Journal of Australian Water Association Vol 36:6, pp. 79-85.

Willis, R. M., Stewart, R. A., Panuwatwanich, K., Jones, S. & Kyrakides, A. (2010) Alarming visual display monitors affecting shower end use water and energy conservation in Australian residential households. Journal of Resources, Conservation and Recycling, Vol 54:12, October 2010, pp. 1117-1127, doi:10.1016/j.resconrec.2010.03.004.

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Chapter 8

Alarming visual display monitors affecting shower end use water and energy

conservation in Australian residential households

This chapter is a reformatted version of a peer-reviewed article by the author published in the

Journal of Resources, Conservation and Recycling, Vol 54:12, pp. 1117-1127, DOI:

10.1016/j.resconrec.2010.03.004.

8.1 Abstract

Sustainable urban water consumption has become a critical issue in Australian built

environments due to the country’s dry climate and increasingly variable rainfall. Residential

households have the potential to conserve water, especially across discretionary end uses such

as showering. The advent of high resolution smart meters and data loggers allows for the

disaggregation of water flow recordings into a registry of water end use events (e.g. showers,

washing machine, taps, etc.). This study firstly reports on a water consumption end use study

sample of 151 households conducted in the Gold Coast, Australia, with a focus on daily per

capita shower end use distributions. A sub-sample of 44 households within the greater sample

was recruited for the installation of an alarming visual display monitor locked at 40 litres

consumption for bathroom showers. All sub-sample shower end use event durations, volumes

and flow rates were then analysed and compared utilising independent sample t-tests pre- and

post intervention. The installation of the shower monitor instigated a statistically significant

mean reduction of 15.40 litres (27%) in shower event volumes. Monetary savings resulting from

modelled water and energy conservation resulted in a 1.65 year payback period for the device.

Furthermore, conservative modelling indicated that the citywide implementation of the device

could yield 3% and 2.4% savings in total water and energy consumption, respectively.

Moreover, a range of non-monetary benefits were indentified, including the deferment of water

and energy supply infrastructure, reduced resource inflationary pressures, and climate change

mitigation, to name a few. Resource consumption awareness devices like the one evaluated in

this study assist resource consumers to take ownership of their usage and individually tackle

individualistic and/or society driven conservation goals, ultimately helping to reduce the

ecological footprint of built environments.

Chapter 8: Alarming visual display monitors affecting shower end use water and energy conservation

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8.2 Background

8.2.1 Climate change and improving urban water security

In many parts of the world, an escalating demand on potable water resources resulting from

increasing populations has become commonplace (Willis et al., 2009a). While this has triggered

higher water consumption, water availability is also becoming increasingly variable due to the

global change of climate (Inman and Jeffrey, 2006). In Australia, a recent drought period

between 2001 and 2004 touched most of the continent and demonstrated the severe localised

impacts of climate change. Moreover, after almost five years of continued lower-than-average

rainfall across most of the eastern part of the Australian continent, many Australian cities and

towns continue to face drought conditions with some water supply reservoirs at their lowest

recorded levels.

A recent report by the Australian National Climate Centre showed trend annual rainfall

decreasing by up to 50mm per year over the southern half of the continent (CSIRO, 2007).

Coupled with such water scarcity is increasing urbanisation, which intensifies the concern over

the existing urban water resources and places a strain on future water security. A study by

Birrell et al. (2005) on the impact of demographic change and urban consolidation on domestic

water use in Australian cities revealed that, during 2001-2031, water demand in major cities will

increase by an average of 37%. Such evidence of dwindling supplies and increasing demand has

triggered water industries and all levels of government to seriously reconsider the management

of water resources in Australia. Hence, a significant investment in adequate planning and the

adoption of smarter approaches to water management is required to ensure a sustainable water

future.

From a worldwide perceptive, many governments and public utilities who are similarly affected

by water crises, are investing significant funds in the development and implementation of water

strategies to ensure future water demands can be met. Predictions and estimations of future

demand and potential savings through the introduction of demand management strategies or

source substitution options are now commonplace. Demand management strategies include

water metering, water restrictions, rebate programs for water efficient devices, water efficiency

labelling, water conservation or education programs and pressure and leakage management

(Inman and Jeffrey, 2006). Source substitution or ‘fit for use’ water involves replacing specific

potable end uses such as toilet flushing and irrigation with recycled, grey or storm water. Water

savings achievable from such programs are calculated through a variety of assumptions but,

once in place, limited consideration is given to determining the actual water savings associated

with these strategies. It is well documented that more data and information should be collated on

the effectiveness and sustainability of demand management techniques, to improve long term


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forecasting (Chambers et al., 2005). After decades of inadequate metering of water use,

organisations have come to the realisation that it is impossible to manage water resources

without having adequate measuring and monitoring practices (Hearn, 1998).

8.2.2 Domestic water consumption and conservation

Residential water consumption can account for up to 66% of the total supplied water as was the

case at the Gold Coast, Australia in the 2007-2008 monitoring period. Residential water

consumption has previously been determined to be effected by seasonal changes and water

demand management (WDM) strategies such as water metering, water restriction levels, water

efficient devices and education (Nieswaidomy, 1992; Mayer et al., 2004; Inman and Jeffrey,

2006). Although prior research has occurred, it is well established that there is a need for

specific country and location based research as different community attitudes and behaviours

can influence the effectiveness of WDM strategies (Corral-Verdugo et al., 2002; Turner et al.,

2005). To grasp the effectiveness of WDM strategies high quality data is required, hence the

development of smart metering techniques.

8.2.3 Advent of smart water metering and end use analysis

The need for smart water metering stemmed from the fact that traditional systems do not

provide real-time water consumption data or sufficient data points to determine usage patterns.

Conventional water meters count litres of water as it passes through the meter without the

ability to record when (i.e. time of day) and where the consumption takes place (e.g. clothes

washing, leakage, shower use, etc.). Water consumption readings are generally recorded

manually on a quarterly or half yearly basis. Under most situations, a whole year’s worth of

water consumption data is described by only two to four data points (Britton et al., 2008). No

further information is available to draw upon should there be any queries (Hauber-Davis and

Idris, 2006). Obviously, this conventional water metering system produces limited, delayed

water consumption information and is unable to provide effective support for water planning

and management processes. Moreover, it is not adequate to meet the increasing level of

government scrutiny on the utilisation of water resources or the effectiveness of WDM

strategies and does not assist society at large to address the pressing water security issues

associated with climate change.

The concept of smart metering embraces two distinct elements: (1) meters that use new

technology to capture water use information; and (2) communication systems that can capture

and transmit water use information as it happens, or almost as it happens. Smart water meters

essentially perform three functions; they automatically and electronically capture, collect and

communicate up-to-date water usage readings on a real-time basis (Idris, 2006). To achieve this


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objective, the reed switch on traditional volumetric water meters is modified to collect a high

resolution record of water use (i.e. from the traditional 2 to 72 pulses per litre or 0.014 litres per

pulse) which can then be disaggregated into individual water use events using a flow trace

analysis software tool (e.g. Trace Wizard©). The high resolution water measurement

information from the meter is then captured by attached high data capacity loggers (i.e. 2

million readings) recording information at a pre-set time interval (e.g. 5 seconds). Time scaled

flow recording information is then collected in-situ through infrared cables or wirelessly

through a mobile phone network. Once a representative sample of data is collected, the flow

trace analysis software tool is applied to disaggregate flow traces into a list of component events

assigned to a specific end use appliance or fixture (e.g. shower, toilet, clothes washing, etc.).

Stock and behaviour surveys can also be utilised to help the analyst develop templates which

encapsulate the appliance properties of end use events and ensure accurate end use

categorisation. Once analysis has been completed a database registry of all end use events

occurring during the sampled period is established and can subsequently be utilised for water

planning and management research as demonstrated herein.

Hence, a smart meter is a high resolution water meter (e.g. 72 pulses per litre) linked to a device

(a data logger) that allows for the continuous reading of water consumption. Smart metering

allows for communication of captured data to a broad audience, e.g. utility managers,

consumers and facility authorities. Smart metering is an established technology which is now

cost-effective enough to be applied to collect, store and distribute real-time water consumption

data (Hauber-Davis and Idris, 2006). An automated meter reading system with this capability

provides benefits for both consumers and water authorities for monitoring and controlling water

consumption. Understanding and collecting empirical evidence of where and how water is used,

through smart metering, allows planners and conservationists to determine the relative water

saving of WDM strategies.

8.2.4 Engineered water conservation appliances and fixtures

The development of water efficient devices such as low flow shower roses or dual flush toilets

has led to effective water savings within households. Several studies have been undertaken to

determine the relative water savings attributed to the installation of engineering water

conservation fixtures and appliances. The replacement of high water consuming devices with

those of engineered water efficiency has resulted in indoor water consumption savings between

35 - 50% (Mayer et al., 2004; Inman and Jeffrey, 2006).

A variety of water saving devices are available on today’s market which attempt to reduce water

end use consumption. Such devices include toilet dams, AAA rated shower roses, dual flush

toilets (3/4.5 L/flush), water pressure limiting devices, and tap aerators, to name a few. With


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respect to showers, the trend of lower shower consumption volumes with more efficient devices

has previously been established by Mayer et al. (2004). In more recent times, the development

of visual display technologies and alarming devices designed to influence both water and energy

conservation responses at the end use level have become more readily available. Therefore, in

addition to retrofitting appliances and fixtures with those of a higher efficiency, such display

technologies provide a dynamic feedback to resource consumers, ultimately influencing

behaviours.

8.2.5 Visual display technologies and alarming devices influencing resource

conservation behaviour

While houses with water saving devices typically demonstrate reduced end use water

consumption, evidence also which indicates that engineered savings can often be diminished by

human behaviour. For instance, a study by Inman and Jeffrey (2006) resulted in an increase in

water consumption after the installation of water saving devices. This was due to the resident’s

misguided belief that they were saving water through their efficient devices and hence took

longer showers which often resulted in higher consumption volumes. The “Human Exception

Paradigm” is a basic belief that humans are above nature and therefore do not have to regard it

as they consume resources (Bechtel et al., 1999). Thus, these primitive beliefs can serve to

inhibit conservational behaviour. A study into the link between environmental behaviour and

water conservation behaviour determined that general environmental beliefs affected the

specific beliefs regarding the use of water, which in turn, correlated with the measure of water

consumption (Corral-Verdugo et al., 2003). Waisbord (1999, p. 2) states that ‘interventions are

needed to provide people with information to change behaviour’ and that it is a lack of

knowledge which contributes to problems in development. Education is a key component for

changing behaviour and attitudes towards water use (Webb, 2007). If people are made aware of

their water usage, more importantly their water wastage, they are much more likely to actively

reduce their consumption.

Essentially, the use of electronic visual and/or alarming monitoring devices provides immediate

feedback to resource users. Compared with written feedback such as quarterly bills, electronic

devices provide quicker and more frequent feedback, thus better informing the consumer of the

consequence of their specific behaviours (Midden et al., 2007; Darby, 2006). It is especially

effective when information is given frequently which is the case with continuous electronic

feedback (Abrahamse et al., 2007). In general, feedback enables people to be more conscious of

the relevance and affect of their own behaviour. When resource consumption is closely linked to

specific appliances and activities, the relevance and direct affect of behaviour becomes clearer.

Through appliance-specific feedback, the consumer can determine how a certain appliance or a

particular way of using it affects the amount of water or energy resource consumed. This allows


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the consumer to curb poor behaviours and to use resource consuming appliances more

effectively to achieve higher savings and shift towards sustainable consumption habits (Fisher,

2008).

In the electricity sector, immediate feedback through electronic devices has been regarded to be

very effective in helping to conserve energy (Wood and Newborough, 2003; Fischer, 2008).

Specifically, electronic visual displays have proven to be useful in promoting energy

conservation behaviour in people, based on extensive research conducted worldwide. In the US,

McClelland and Cook (1979-1980) carried out a study using the Fitch Energy Monitor (FEM)

that displays the total electricity usage and reported a 12% reduction in electricity usage in

households with the FEM compared with those without it. Similarly, in Canada, Dobson and

Griffin (1992) investigated the use of the Residential Electricity Cost Speedometer (RECS)

system, which measured household electricity consumption and presented cost and electricity

consumption for various end uses displayed on an hourly, daily, monthly and annual basis. The

results showed that the use of the RECS system helped reduce the average daily energy

consumption by 12.9%. The above findings appear to be consistent with those found in Japan by

Ueno et al. (2005, 2006), who conducted a series of experiments on the use of a computerised

interactive “energy consumption information system” that displays daily energy consumption

for all the domestic appliances within a household. They found that the use of such a tool led to

9-12% reduction in power consumption, and that energy-conservation awareness affected not

only the power consumption of the appliances explicitly shown on the display monitor, but also

other household appliances implying a change in consumption behaviours. In the UK, Wood

and Newborough (2003) compared the effectiveness of providing paper-based energy-

use/saving information with electronic feedback of energy-consumption via smart meters and

energy consumption indicator (ECI) displays. The findings showed that the average reduction

for households employing an ECI was 15%, whereas those that were only given paper-based

energy saving information reduced their electricity consumption, on average, by only 3%.

In the water sector, research on the impact of visual displays and alarming devices on water

conservation is still limited. In the US, Arroyo et al. (2005) developed a device called

“WaterBot” that presents immediate feedback in the form of visual and auditory reminders. The

device is to be installed on household faucets to motivate people to turn off the tap when the

water is not being used. Although there has been no systematic experiment conducted to

quantify the water savings from installing the device, pilot studies through observations and user

reports suggested a behavioural change that could reduce water consumption by the presence of

the device. Recently, Kappel and Grechenig (2009) developed a shower water meter (show-me)

that displays the amount of water used during one shower in the form of LEDs assembled on a

stick, and installed the device in several households in Austria. The results showed a decrease in


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the mean shower water consumption of approximately 10 litres. This suggested a promising

water saving potential in the shower with regards to using visual displays for delivering

feedback.

In the case of this study, the WaiTEK® Shower Monitor© is an innovative device that provides

the alarming visual feedback intervention (Figure 8-1). This educational engineering device

provides a digital read-out of shower parameters such as flow rate, duration and temperature.

While most water saving devices physically limit the volume or flow rate of water that can be

used, this monitor does not affect the shower in any way. Rather, it simply provides the

information necessary to allow households to shower more efficiently. At the end of the

predetermined shower duration, it will beep for duration of one minute to indicate that it is time

to get out of the shower. This device aims at educating the public on their shower water

consumption as it is essential to encourage and develop behaviour leading towards sustainable

water consumption. Therefore the effectiveness of the monitor far supersedes any other water

saving device on the market as it addresses the underlying issue of first changing the beliefs and

behaviours of the shower users, rather than simply enforcing a restriction. Armed with this

information, shower users can supervise their own habits to ensure they adequately conserve

water.

Figure 8-1 Alarming visual display device

8.2.6 Overview of Gold Coast Watersaver End Use study

Currently, there are no end use water consumption models for the urban South-east Queensland

(SEQ) region of Australia. This region has a sub-tropical climate and has recently experienced

severe drought conditions, forcing both State and Local Governments to develop numerous

strategies to reduce water usage. In this respect, gaining empirical evidence of how and where

water is used and determining the effectiveness of specific WDM strategies is critical for

planners, utilities and conservation professionals. This information can be used to improve the

design of conservation programs and can provide justification for continued support of

conservation efforts (Mayer and DeOreo, 1999). As mentioned, per capita consumption varies


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significantly throughout regions within the world, hence the need for location and country based

research is necessary to determine the effectiveness of WDM (Turner et al., 2005; Inman and

Jeffrey, 2006). In addition, it has been acknowledged that community attitudes and behaviours

can also influence the effectiveness of water savings resulting from WDM strategies (Corral-

Verdugo et al., 2002). In the US, Mayer and DeOreo (1999) have explored some relationships

between water consumption and demographic variables at the end use level. Their research

suggested that demographic variables such as family size and age distribution, wealth or

income, ownership status and household attitudes towards using and conserving water,

influence household water consumption (Mayer and DeOreo, 1999; Taverner Research, 2005;

Turner et al., 2005; Kenney et al., 2008). However, in Australia, there has been minimal

research on investigating end use water consumption with relation to demographic variables

within monitored homes.

Motivated by the above research demand, Griffith University and Gold Coast Water have

collaborated under an Australian Research Council (ARC) grant to conduct an investigation of

end use water consumption in the Gold Coast region. This investigation is aptly named the Gold

Coast Watersaver End Use (GCWSEU) study. Other primary objectives of the research are to

examine the effectiveness of dual reticulation and education as potable water saving

mechanisms. Dual reticulation is a water supply system which consists of two separate main

supplies to the consumer: one drinking or potable water; and the other non-drinking or recycled

water (Water Services Association of Australia (WSAA), 2002). The research also aims to

establish a dataset which compiles end use water consumption data, demographic information,

and attitudinal data. As stated by Kenney et al. (2008), the collection and integration of these

datasets, especially household level consumption data with demographic data about the people

and house, rarely occurs. The utilisation of these datasets allows for the investigation of the

effect of demographic variables, attitudes and behaviours on water consumption.

This paper reports findings from the pre-intervention phase of the study, which included the

winter 2008 end use data for 151 households along with the water end use for shower events

post implementation of the WaiTEK® Shower Monitor© (Figure 8-1). Study objectives and the

scope of the herein focused study are presented below.

8.3 Research Objectives

WDM and 'fit for purpose' water consumption has changed the current focus to demand, rather

than supply side measures, to meet the ever increasing requirement on diminishing water

resources. WDM strategies such as water metering, water restrictions, rebate programs for water

efficient devices, water efficiency labelling, water conservation education programs, and the


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application of recycled, grey and stormwater for specified end uses have been introduced

throughout Australia and the world. However, water authorities still have vague indications on

the effectiveness of these programs. This paper provides an in-depth investigation into an

alarming visual display device, namely the WaiTEK® Shower Monitor©, on shower water end

use properties.

The key objectives of this research are to:

Determine baseline water consumption end uses for a sample of households;

Establish baseline shower end use event characteristics (e.g. volume, duration, flow

rate) for 151 households in the Gold Coast residential end use study;

Evaluate the water savings potential of the WaiTEK® Shower Monitor© in a sub-

sample of households participating in the GCWSEU study;

Determine households’ response to the alarming visual display device through reduced,

or otherwise, shower durations or flow rate;

Quantify water and energy savings (i.e. hot water for showering purposes) achieved in

the sub-sample;

Model the payback period and annualised return for the device; and

Model the monetary and non-monetary benefits achievable from the citywide

implementation of the device.

Research outcomes provide water authorities and government officers with the decision support

systems to accurately predict the monetary and non-monetary benefits of installing such

alarming visual display devices; ultimately preserving water sustainability. The research method

adopted to achieve the above mentioned objectives are described below.

8.4 Research Method

The greater GCWSEU study participants (n=151) were recruited through a multi-staged process

of letters and door knocking. Selection of participants was based on a number of criteria

including: household ownership status (renting/owning) and household makeup; willingness to

be part of the research for a period of two years; acceptance to having water consumption

monitored over period; several questionnaire surveys; involvement in a range of potential

interventions; and involvement in a household water fixture/appliance stock audit. It should also

be noted that historical household volumetric readings were analysed for the consenting sample

to ensure that they are representative of Gold Coast City.

Upon completion of recruitment, the existing standard residential water meters were replaced

with high resolution water meters and data loggers to obtain end use water consumption data.


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The modified Actaris CTS-5 water meters pulse at a rate of 72 counts per litre of water

consumed; this equates to an individual recording every 0.014 L of water use. Aegis DataCell

D-CZ21020 data loggers were connected to water meters to record water consumption. Data

loggers were set to record information every ten seconds over a two week period. This resulted

in fourteen days of end use data for each household. Trace Wizard© software was utilised to

synthesise data into water end uses. This software provides the analyst with powerful processing

tools and a library of flow trace patterns for recognising a variety of residential fixtures. Once

the raw data has been downloaded from the data logger and processed, it can then be loaded into

Trace Wizard©. This software displays the data via a flow rate verse duration graph, whereby

any consistent flow pattern or event can be isolated, quantified and categorised based on an

established series of end use templates with specific information regarding a particular

household’s water usage patterns. Summary data for each water event is then calculated,

including, duration, volume, peak flow rate, mode flow rate, mode flow frequency, as well as

start and stop times for each episode. The software also has the ability to recognise two

simultaneous events. Once analysis has been completed, the file is converted to a database

format, whereby a complete registry of end use event information is stored. For the purposes of

this study, this database allowed researchers to create relative and cumulative frequency

distributions for shower end use event durations, volumes and flow rates.

The baseline data utilised in this paper was collected during winter 2008. During this time there

were no water restrictions in place on the Gold Coast as its primary water source (i.e. Hinze

Dam) was higher than 95% capacity. In total, the 151 monitored households included 38 single

reticulated and 113 dual reticulated water supplies. It should be noted that recycled water was

not supplied to the dual reticulated region during the monitoring period as the treatment plant

had not been commissioned. Thus, potable water was supplied to the appropriate end uses (i.e.

toilet and selected outdoor taps), which in the future (late 2009) will be supplied by recycled

water. Shower end use is only ever supplied by potable water, thus the affect of dual reticulation

has no bearing on the study’s objectives and subsequent outcomes.

In addition to monitoring water consumption, questionnaire surveys soliciting descriptive

information were developed and distributed to all the sample households. Surveys were

conducted to solicit household demographic information, including: (1) household address and

region; (2) resident numbers, gender, age, employment, weekly income, education status and

relationship of people within the house; and (3) household ownership status. Household stock

surveys were also conducted to ascertain the nature of water fixtures and appliances as well as

hot water heating systems.


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A sub-sample from the 151 households in the GCWSEU study was recruited to participate in

the herein mentioned shower monitor retrofit study. A total of 49 households consented to be

apart of this aligned sub-study and have shower monitors fitted to their utilised showers. The

initial sub-sample total water consumption and shower end use data, along with their socio-

demographic statistics was screeded to ensure that the final selected sub-sample was as

representative of the population as possible (given the feasible sample size). Five consenting

households were removed as the initial sub-sample was over represented by retired couples.

Upon completion of the recruitment and sample screening process, a total of 44 households

were included in the sub-sample, and all of their utilised showers were fitted with the alarming

visual display device (Figure 8-1) that was locked to a 40L shower event (i.e. based on a 5

minute shower at a flow rate of 8L/min). The device was set to alarm after the 40L volume was

consumed so individuals would know when it was time to get out of the shower. The monitor is

programmed to automatically turn on once water is flowing through the shower. The monitor

displays a bar graph which decreases over time of water consumption. Monitors were also set

for a delay time of 1 minute. The delay time is the time in which the person must wait between

showers so that the monitor can reset itself. If a person starts another shower before the 1 minute

is over, the monitor will start beeping. The shower monitors were all locked with a 4-digit pin

code that was retained by the researchers for study period to ensure that settings were not

changed. The monitor does not control the shower in any way. Instead, its purpose is to help

families reduce water and energy costs by providing the information necessary for them to

shower efficiently. Ultimately, the participants have the choice of getting out of the shower

when the beeping occurs or to simply ignore it and continue showering. Specifically, the device

aims to educate families on sensible water consumption by empowering the consumer with real-

time information rather than constructing a military type environment.

Following the implementation of the shower monitors water end use data was collected over a

two week period in winter 2009, following the same process described above for the baseline

GCWSEU study. Analysed and verified trace analysis files for the pre- and post- shower

monitor retrofit were converted to database files whereby all shower events could be listed and

categorised based on event duration (based on event start and end time), volume or flow rate.

Relative and cumulative frequency distributions for sub-sample shower event characteristics

were then established along with as their associated mean, median and standard deviation

values. This data analysis process enabled shower event comparisons to be conducted pre- and

post- installation of the shower monitor. The baseline water consumption end use results, with a

particular focus on shower end use is presented in the next section, followed by the comparative

assessment pre- and post- implementation of the shower monitor.


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8.5 Baseline Water Consumption End Use Analysis

The break down of end use water consumption for the sampled households in the Gold Coast

(N=151) for winter 2008 is presented in Figure 8-2. Readers should again note that recycled

water is not currently supplied to the dual reticulated region as the treatment plant was not

commissioned. Thus, potable water was being supplied to appropriate end uses (i.e. toilet and

outdoor taps) which in the future (i.e. late 2009), will be supplied by recycled water. Due to this

fact, the cost for this water is the same as potable (i.e. no reduced pricing) and the water

restriction level remains constant between the regions. Moreover, no awareness campaign was

launched to encourage the uptake of recycled water in the dual reticulated region. Considering

this current situation and the limited variance between the applicable end uses of single and dual

reticulated households, the two datasets was treated as one sample for the purpose of this

present study (Willis et al., 2009a). Once recycled water is commissioned, it is expected that

there will be a clear distinction between the single and dual reticulated households,

predominately due to higher irrigation use within the latter sample.

Irrigation (Total)18.6 L/p/d

12%


1%


19%


13%

Dishwasher2.2 L/p/d

1%

Bathtub6.5 L/p/d

4%

Tap27.0 L/p/d

17%

Shower49.7 L/p/d

33%

Figure 8-2 Sample end use break down: winter pre-retrofit (n=151)

According to Figure 8-2, the average baseline consumption for the sampled Gold Coast

households (n=151) was 157.2 litres per person per day (L/p/d). The highest end use was

showering, with each person consuming almost 50 litres of water a day or 33% of total use.

Clothes’ washing was the next highest end use at 30 L/p/d or 19% of total consumption. Tap

use, toilet flushing and irrigation follow with end use percentages of 17%, 13% and 12%,

respectively. Bath use, dishwashing and leaks make up a small component of water end use with


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percentages ranging from 1% to 4%. Many of the prior mentioned end use studies show

irrigation consuming a higher proportion of the total household water consumption, especially

in summer months. The Gold Coast is located in a region experiencing a humid subtropical

climate, where irrigation consumption is generally lower in the wet summer months than other

seasons. Moreover, the study was conducted just after a period of drought where irrigation was

severely restricted; after this drought there was a culture shift whereby brown grass was

accepted in dry periods.

Figure 8-3 demonstrates the descending order distribution of the end use water consumption

break down for each of the measured 151 households. It also shows the proportion of sampled

households within each of the Queensland Water Commission (QWC) restriction regime

categories, upon which the Gold Coast Local Government Area (Capati et al.) must conform

(i.e. Target 140: Extreme Level; Target 170: High Level; Target 200: Medium Level; and

Target 230: Permanent Water Conservation Measures). The average total consumption of

sampled households in the study and distribution are representative of the Gold Coast at the

time of study.

Figure 8-3 Sample household end use distribution: winter pre-retrofit (n=151)

Whilst there were no restrictions at the time on the Gold Coast, almost half of the research

population (46%) consumed less than 140.0 L/p/d. Water consumption is highly varied between

individual households. The highest per capita use equated to 390.0 L/p/d whilst the lowest use

was as small as 38.4 L/p/d. This substantial difference between the highest and lowest per capita

consumption volumes demonstrates that a representative spread of water users is present in this

research sample. Figure 8-3 illustrates that shower end use in many households is the major

contributor to the total water consumption level. The extracted water end use distribution of this

specific activity is presented in Figure 8-4.

0.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

450.00

Household ID

Lit

res

/Pe

rso

n/D

ay

Leak (Total)

Irrigation (Total)

Toilet (Total)

Bathtub

Dishwasher

Tap

Shower

Clothes Washer

Queensland Water Commission Target Ranges (140, 170, 200 and 230)>230 L/p/d 201 - 230 L/p/d 171 - 200 L/p/d 141 - 170 L/p/d >140 L/p/d

21 homes(14%)

13 homes(9%)

20 homes(13%)

27 homes(18%)

70 homes(46%)


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Figure 8-4 Sample shower end use distribution: winter pre-retrofit (n=151)

Figure 8-4 shows that 13% of the sampled households consumed 30% of the total volume of

water utilised for showering purposes. This highlighted sub-sample (13%) constitutes a non-

linear shower use pattern as opposed to the remaining research population (87%) which shows a

reasonably linear rate of change in consumption. The distribution of shower use, as illustrated in

the Figure 8-4 insert, demonstrates that half of the population used less than 40 L/p/d of water

for showering which is equivalent to a 5 minute shower at 8L/min. For the remaining categories,

37% of households use between 41 to 80 L/p/d with the high user group (13%) consuming on

average more than 80 L/p/d in the shower. The high level of shower end use consumption and

its variability identified in the baseline study instigated the design for the shower monitor

intervention study described in the next section.

8.6 Visual Display Monitors Influencing Shower End Use Events

As described in the research method, the categorised shower end use event features were

compiled into a database for both the pre- and post- shower monitor implementation. Three of

the shower event features, namely, event duration, volume and flow rate, were summarised in a

clustered relative and cumulative frequency distribution histogram. Moreover, the mean and

median values for these features pre- and post- implementation of the shower monitor were

determined and compared. It should be specially noted that changes in flow rates before and

after shower monitor retrofits were of concern since the study sought to understand whether

households would reduce flow rates to maximise their shower duration before an alarm

sounded. As mentioned previously, readers should note that the fixed 40L volume is a function

of flow rate and duration and the device compensates for variation in these variables. The

0.00

50.00

100.00

150.00

200.00

250.00

Household ID

Lit

res

/Pe

rso

n/D

ay

(L

/p/d

ay

)

Daily Per Capita Distribution: Shower

10%

40%

19% 19%

13%

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

<20 21-40 41-60 61-80 >80

L/p/d

Re

lati

ve

Fre

qu

en

cy

(%

)




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following sections provide the results and discussion relating to changes in shower duration,

volumes and flow rates, respectively.

8.6.1 Influence on shower duration

The change in the relative and cumulative frequency distribution for shower event durations is

illustrated in Figure 8-5. The figure illustrates that post installation there is a much higher

frequency of shower event durations between 1-7 minutes. It appears that many of the 7-15

minute shower events have moved into these lower interval categories. Given that the shower

monitor was locked to beep after 40L with approximate shower duration of 5 minutes it seems

that many home owners still shower for a minute or two after the beeping commences. The data

shows that households that were originally water conscious have further reduced their

consumption with a significant increase in showers in the 1-4 minute intervals. Whilst the

frequency of shower events greater than 10 minutes has more than halved from 14% to 6.4%,

the results indicate that some residents still continue to have excessively long showers even with

a visual display and alarm present.

Nonetheless, as indicated in the inset of Figure 8-5, the mean shower duration reduced from

7.19 to 5.86 minutes, which equates to a saving of 1 minute and 20 seconds (i.e. 1.34 minutes)

or 18.6%. An independent sample t-test for equality of means was undertaken to test the

significance of mean differences (Table 1). Independent rather than paired sample t-tests were

undertaken since the total number of shower events in the sub-sampled households’ pre- and

post- retrofit was obviously different and were treated as two samples. According to Levene’s

test for equality of means the samples were treated as having unequal variances. The

independent unequal variance sample two-tailed t-test resulted in a very high t-value of 6.62 (p

< 0.0005) indicating significant mean value differences. The lower difference between the

median shower event durations (i.e. 50 seconds) indicates that the long tail of high duration

events increased mean values. This fact is reinforced by the samples standard deviation being

very high (i.e. 4.49 minutes pre-retrofit and 3.55 minutes post-retrofit), however, noticeably

reduced post retrofit of the shower monitor. In summary, the shower monitor reduced the time

spent in the shower, but not to the extent expected with the device alarming at 5 minutes based

on the set 8L/min flow rate. Residents may have decided to reduce their typical shower flow

rate to yield a longer event duration (i.e. reducing flow rate below 8L/min will increase duration

beyond 5 minutes before alarm sounds); this will be explored later.


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Figure 8-5 Sample pre- and post- monitor retrofit shower event duration frequency distribution

8.6.2 Influence on shower volumes

Figure 8-6 details the relative and cumulative frequency of shower event volumes pre- and post-

implementation of the shower monitor. The figure illustrates that even prior to the

implementation of the shower monitor, 39.9% of the shower event volumes were less than 40L

increasing to 59.3% after the implementation of the shower monitor. It appears that shower

users already practicing water conservation went even further in reducing shower volumes as

many of the 30-40 L events probably reverted to the 10-20 L or 20-30 L intervals. Another

interesting characteristic of the histogram is the reduction in shower events in the 60-100 L

range post-retrofit but the slight increase in the 40-50 L interval. It appears that a reasonable

proportion of residents that previously showered within the 50-100 L range now responded

within a minute or so of the alarm and finished their shower. Unfortunately, even after the

shower monitor retrofit 4.5% of the shower event volumes were greater than 100 L. Again, it is

evident that some residents having very high consumption shower events were not perturbed by

the shower display and alarming device. As indicated in the inset of Figure 8-6, the mean

shower event volume decreased from 57.37 L to 41.97 L after the shower monitor retrofit. This

resulted in a saving of 15.40 L per shower event or 27%. An independent sample t-test for

equality of means was undertaken to test the significance of mean differences (see Table 8-1).

0

5

10

15

20

0-1

1-2

2-3

3-4

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5-6

6-7

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8-9

9-10

10-1

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Duration event clusters (minutes)

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40

60

80

100

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freq

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y (%

)

Pre-Retrofit R.F

Post-Retrofit R.F

Pre-Retrofit C.F

Post-Retrofit C.F

Duration pre retrofit:Mean = 7.19 minsMedian = 6.00 minsDuration post retrofit:Mean = 5.86 minsMedian = 5.17 mins

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Table 8-1 Independent sample t-test for equality of means

Event description

Variance assumption

Levene's test for equality

of variances

t-test for equality of means

95% confidence

interval of the

difference

F Sig. t df Mean

(pre-retrofit) Mean

(post- retrofit)

Mean difference

(pre- vs. post)

Sig.

(2-tailed)

Std. error

difference Lower Upper

Assumed 27.14

.000 6.70 1631 7.19 5.86 1.34 .000 .200 .95 1.73 Duration (Giurco et al.) Not assumed 6.62 1469 7.19 5.86 1.34 .000 .202 .94 1.73

Assumed 39.34

.000 9.11 1632 57.37 41.97 15.40 .000 1.691 12.08 18.72 Volume (L)

Not assumed 8.93 1338 57.37 41.97 15.40 .000 1.724 12.02 18.78

Assumed 14.98

.000 5.82 1632 9.98 8.98 1.00 .000 .171 .66 1.33 Flow rate (L/min)

Not assumed 5.78 1556 9.98 8.98 1.00 .000 .172 .66 1.33

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According to Levene’s test for equality of means the samples were treated as having unequal

variances. The independent unequal variance sample two-tailed t-test resulted in a very high t-

value of 8.93 (p < 0.0005) indicating significant mean value differences. Of note also is that the

median shower event fell below the 40 L target after the implementation of the shower monitor

(i.e. 36.38 L). The improvement in shower event volumes is reinforced by the significant drop

in standard deviation from 40.36 L to 27.33 L per event (i.e. 13.03 L reduction). The results for

shower event volumes indicate that the shower monitor had a good degree of impact on

reducing shower water consumption to a mean value close to the targeted 40 L; this is a

promising result considering that the tail of high volume showers evident in the relative

frequency distribution histogram (Figure 8-6).

Figure 8-6 Sample pre- and post- monitor retrofit shower event volume frequency distribution

8.6.3 Influence on shower flow rates

Figure 8-7 details the shower event flow rate relative and cumulative frequency distribution for

the sampled households. Cumulative flow rate frequency distributions between 0-8 minutes

increased from 40.7 to 52% indicating that some residents were aware that reduced flow rates

would increase their shower duration before the visual display monitor alarmed. In general, the

relative frequency distribution histogram provides some evidence that residents have slightly

lessened flow rates from their baseline. Exactly 1 L/min or 10.2% was reduced from the mean

flow rate post shower monitor implementation (i.e. 9.78 to 8.78 L/min) and a slightly lower

reduction in the median flow rate was evident. An independent sample t-test for equality of

means was undertaken to test the significance of mean differences (see Table 8-1). According to

0

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15

20

25

0-10

10-2

0

20-3

0

30-4

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40-5

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60-7

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70-8

0

80-9

0

90-1

00

100-

110

110-

120

120-

130

130-

140

140-

150

Mor

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Volume event clusters (litres)

Rel

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(%)

0

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40

60

80

100

Cum

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freq

uenc

y (%

)

Pre-Retrofit R.F

Post-Retrofit R.F

Pre-Retrofit C.F

Post-Retrofit C.F

Volume pre retrofit:Mean = 57.37 LitresMedian = 46.38 LitresVolume post retrofit:Mean = 41.97 LitresMedian = 36.38 Litres


- 196 -

Levene’s test for equality of means the samples were treated as having unequal variances. The

independent unequal variance sample two-tailed t-test resulted in a very high t-value of 5.78 (p

< 0.0005) indicating significant mean value differences. In summary, the relative frequency

distribution provides an indicator that some residents understood how the device worked and

reduced their flow rates in order to extend shower duration. Additionally, the mean as well as

median flow rates are still above the targeted 8 L/min strived for but have nonetheless reduced

along with variance. The following section provides a discussion on the water and energy

savings, monetary savings and payback period, and non-monetary benefits, derived from the

implemented shower monitoring device.

Figure 8-7 Sample pre- and post- monitor retrofit shower event flow rate frequency distribution

8.7 Resource Conservation and Financial Modelling

8.7.1 Water and energy conservation

As determined in this study the shower monitor interventions reduced the sub-samples shower

event volume by 15.40 L or 27%. Based on the Gold Coast end use study sample (N=151) as

well as the post-implementation sub-sample end use data, the average number of shower events

per household per day was determined to be 2.65. Therefore, given the 15.40 L saving per

shower event and mean 2.65 shower events per household per day, a daily 40.85 litres per

household per day (L/hh/d) or 14.91 kilolitres per household per annum (kL/hh/a) saving can be

achieved. There are approximately 200,000 occupied dwellings in Gold Coast City.

Conservatively estimating that 50% of the determined water savings are achieved in the cities

dwelling stock due to a range of factors (e.g. household size, etc.), a total citywide annual

0

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15

20

25

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1-2

2-3

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Mor

eEvent flow rate (litres/minute)

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(%)

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40

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80

100

Cum

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freq

uenc

y (%

)

Pre-Retrofit R.F

Post-Retrofit R.F

Pre-Retrofit C.F

Post-Retrofit C.F

Flow rate pre retrofit:Mean = 9.98 Litres/minMedian = 8.74 Litres/minFlow rate post retrofit:Mean = 8.98 Litres/minMedian = 7.90 Litres/min


- 197 -

saving of 1.5 GL or 3% of total city consumption was determined. Put simply, water saved

through the installation of the alarming shower monitoring devices could fill 600 Olympic sized

swimming pools annually.

In addition to water savings, the energy cost associated with hot water often utilised for

showering is high. DeOreo and Mayer (2001) determined that 73.1% of shower end use water

consumption is hot water, heated through electric, gas, solar or combination fuel source hot

water systems. Therefore, 10.90kL (i.e. 14.91 kL/hh/a × 0.731) of hot water is saved annually

through the shower monitor device. The Specific Heat Capacity value for water is 4.187

kilojoules per litre (kJ/L). This means that 4.187 kJ/L of energy is required to raise the

temperature of one litre of water (1 kg mass) by one degree Celsius at standard temperature and

pressure. The ability of any of the heating systems to deliver this heat energy is governed by its

efficiency. If a system requires twice as much energy to what can be extracted in the form of hot

water then the system has an efficiency of 50%. Systems range in efficiency from close to 50%

for some gas systems to 99% for instantaneous gas. Based on the energy efficiency of heating

systems, Specific Heat Capacity, 10.90kL saving in hot water, and heating to increase the water

temperature by 45 degrees Celsius, total energy saved ranged from: (a) 665 Mega joules per

household per annum (MJ/hh/a) for a heat pump with electric backup system; to (b) 825-

1027MJ/hh/a for solar with electric/gas backup system; to (c) 2074-2738 MJ/hh/a for an electric

system; to (d) 2600-3541 MJ/hh/a for gas systems. In the sub-sample of households

participating in the end use study, the majority of households had traditional electric hot water

storage systems but there were still a few with other system types such as solar and heat pump.

The incentivised solar panel rebate programs offered by the government may have had some

influence on the uptake of solar systems. Based on the heating system stock in each of the

respective sub-sample households and the calculated energy savings due to reduced hot water

consumption, an average annual energy saving per household was determined as 2168 MJ/hh/a

or 602 kilowatt hours per household per annum (kWh/hh/a). The Gold Coast citywide

consumption of energy in 2005 was 7.1 petajoules (PJ) increasing at an annual rate of 5.73%

(Australian Bureau of Agricultural and Resource Economics (ABARE), 2006). Based on this

base year energy use and the annual growth in power consumption, the 2009 energy use was

estimated at 8.9 PJ. As above, conservatively estimating that 50% of the determined water

savings are achieved in the cities 200,000 dwelling stock, due to a range of factors (e.g.

household size, etc.), a total citywide annual associated energy saving of 0.22 PJ or 2.4% of

total city energy consumption was determined.

8.7.2 Monetary savings and capital pay-back

Based on the study sample, water and energy pricing information specific to Gold Coast City,

and other economic indicators, a range of variables were extracted in order to model the life


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cycle monetary savings resulting from the shower monitor device and the payback period. It

should be noted that both water and energy savings have been modelled as these are the two

direct monetary benefits evident from reduced shower water consumption. Moreover, the

modelling is based on the situational context of Gold Coast City, Australia, where the study was

conducted.

The variables applied to model monetary savings and capital pay-back are as follows. Annual

water savings derived from this study were determined as 14.91 kL/hh/a as determined above.

Gold Coast Water currently (2009/2010) charges a water consumption rate of A$2.24/kL

(US$2.00/kL; 1AUD=0.8904USD; 25/2/2010) which equates to an annual monetary saving of

A$33.40 (US$29.74) associated with the shower monitor. A water price inflation rate of 10%

was chosen for the increase in the water consumption charge as the cost of water in Gold Coast

City, and across most of Australia, has been raising excessively over the last five years due to

widespread drought forcing government to invest heavily in water supply infrastructure

investments (e.g. desalination plants, dams, pipelines, etc.).

Electricity prices for Gold Coast City domestic consumers are currently A$0.18843/kW

(US$0.16778/kW) and A$0.11319/kW (US$0.10079/kW) for peak and off-peak rates,

respectively (2009/2010 rates). Gas prices are A$0.02046/MJ (US$0.01822/MJ) for small

volume users decreasing to A$0.01760/MJ (US$0.01567/MJ) for higher volume users

(2009/2010 rates). Given the energy savings presented above for the different heating source

systems in the sub-sample and base year energy tariffs in Gold Coast City, the costs to heat

water ranged from A$1.74/kL (US$1.55/kL) for a solar system with gas boost to A$7.90/kL

(US$7.03/kL) for an off-peak electric storage system. Based on the costs to heat each kilolitre of

water for each respective heating system in each sampled household and the 10.90kL of hot

water saved, an annual average energy saving for the base year (2009/2010) was calculated as

A$62.78/hh/a (US$55.90/hh/a). Similarly to water, energy cost inflation has increased at a rate

in excess of 10% per annum over the last five years and is expected to continue due to costs

associated with the governments’ climate change policies. Thus, an energy inflation rate of 10%

was again selected for discounted cash flow modelling.

Therefore the base year combined water and energy savings determined in this study was

A$96.18/hh/a (US$85.64/hh/a) (water cost savings = A$33.40/hh/a and energy cost savings =

A$62.78/hh/a). With respect to the capital cost of the shower monitor device and associated

installation costs, the average number of shower monitors installed in households was 1.3 at a

purchase price of A$75 (US$66.78) per device. Installation of the device could be easily

undertaken by the home occupier but for this study a professional plumber was employed

costing A$66 (US$58.77) per household, regardless of number of monitors installed. This


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equated to an average total capital outlay of A$163.50 (US$145.58) per household to yield the

mean 14.91 kL/hh/a water saving. There are no ongoing operational costs for the device as their

battery life is around 10 years which was considered the usable life of the device.

The payback period is the time it takes for the cumulative water and energy savings to cover the

capital investment of the shower monitor. A discount rate of 3% has been applied which

indicates a general cost of money in the Australian context. Considering the capital investment

cost, first year water and energy savings determined, water and energy price inflation as well as

the discount factor, the payback period for the herein mentioned alarming visual display shower

monitoring device was determined as 1.65 years. Moreover, over a 10 year life cycle period, the

annualised return of investment from conservation savings generated by the capital cost of the

shower monitor equates to 23.3%. This attractive payback period and annualised return provide

strong evidence that alarming visual display devices in the shower represent an attractive

investment.

In addition to the monetary savings listed above there are a number of non-monetary benefits

associated with resource consumption feedback devices such as the shower monitor discussed

herein. These are discussed briefly in the next section.

8.7.3 Wider non-monetary benefits

The modelled financial benefits and payback period for the alarming visual display monitor are

substantial enough to justify their implementation across all of the urban centres in Australia as

well as other urban settlements where water and energy resources are no longer secure and are

rapidly increasing in price. In addition to the monetary benefits for householders for installing

the device, there are a range of other non-monetary benefits for greater society. Firstly, reduced

water and energy requirements of an existing population could enable the deferment of both

water and energy supply infrastructure (e.g. dams, pipeline duplications, power plants,

desalination plants, etc.). Reductions in demand for such infrastructure will lessen the current

inflationary pressures on prices. Lessened water consumption also means lower energy costs

associated with urban water storage, production and distribution (e.g. pumping, water quality

processing, desalination, etc.).

Another benefit of particular mention in the current century is climate change adaptation.

Centralised water supply systems and the predominant non-renewable sources of power for

heating water create substantial carbon emissions which need to be reduced to limit climate

change impacts. Finally, and most importantly, the business management philosophy ‘that if

can’t measure it, you can’t manage it’ has transferable relevance to resource consumption in a

resource constrained world. Resource consumption awareness devices such as the one evaluated


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in this study assist resource users to take ownership of their usage and individually tackle their

own and/or society driven conservation goals; ultimately helping to reduce the ecological

footprint of the built environment.

8.8 Conclusions and Futures Directions

This paper presented findings from the GCWSEU study, namely, the evaluation of the influence

of alarming visual display devices on shower end use durations, volumes and flow rates.

Moreover, water and energy conservation modelling was conducted to ascertain monetary

benefits as well as the payback period of such devices. Broader non-monetary benefits were also

explored. The study determined that the shower visual display monitors instigated significant

water and energy savings and have a respectable payback period of less than two years. The

study provides empirical evidence to support the widespread implementation of alarming visual

display shower monitors, and also provides a methodology to explore the effect of a range of

other water and energy end use monitors. Through providing households with dynamically

updated visual displays on a range of behaviourally influenced water and energy appliances and

fixtures, residents will be better informed of their consumption rates and thus feel empowered to

reasonably limit and/or maintain control over their resource consumption.

This study also illustrated that smart water metering is vital for understanding water end uses,

particularly for understanding the characteristics of shower end use events. Future research

directions associated with this component of the research program, include: (1) to examine the

change in shower water conservation practices with time (i.e. longitudinal study); (2) conduct

interviews with residents participating in the study to explore how they responded to the device;

(3) examine the effect of visual display monitors and/or alarming devices on other domestic end

use events (e.g. tap fixtures); (4) evaluate shower event water temperature relative and

cumulative frequency distributions to better model heating requirements; (5) directly monitor

water heating power consumption associated with shower end use events; and (6) further model

water and energy conservation with a greater sample across different Australian urban centres.

Future research associated with the GCWSEU study is also discussed as follows. Firstly,

research is currently underway to examine the predictive power of descriptive (i.e. education

level, income, etc.), infrastructure (i.e. stock survey) and qualitative variables (i.e. attitudes,

perceptions, etc.) on water end use in domestic households. Secondly, recycled water will be

commissioned and supplied to residents in the Pimpama Coomera region of Gold Coast City in

late 2009, and a summer end use data collection phase (December-February 2009) will be

undertaken to establish the uptake of recycled water at the end use level. This, combined with

previous end use data, will provide ‘before and after’ end use results of the implementation of


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recycled water. This data will assist in verifying end use assumptions made in the planning

phases of the Pimpama Coomera development. Thirdly, the impact of education or awareness as

a demand management measure will also be tested within the study. Residents participating in

the research will be provided with their unique end use data as well as targeted suggestions for

reducing high end uses within their homes. This study seeks to establish if water consumption

behaviours alter as a result of the provided information.

Another component of the research program is the establishment of diurnal patterns for both

single and dual reticulated households in the Gold Coast. Dual reticulated households will have

two separate diurnal patterns for both potable and recycled water demand. Such diurnal patterns

will be determined at an end use level, thus providing a comprehensive understanding of water

consumption at a given time, which provides indications on how to affect peak loading to the

urban water system. The above stated components of the research program will culminate in the

development of a comprehensive domestic end use model for the Gold Coast as well as

evidence that supports, or otherwise, the effect of WDM measures (principally dual reticulation

and awareness/education initiatives) for conserving previous precious potable water supplies.

Such models and findings could be adapted for both national and international applications and

policy formulation.

8.9 References

Abrahamse W., Steg L., Vlek C. & Rothengatter T. (2007) The effect of tailored information, goal setting, and tailored feedback on household energy use, energy-related behaviors, and behavioral antecedents. Journal of Environmental Psychology, Vol 27:4, pp. 265-276.

Arroyo E., Bonanni L. & Selker T. (2005) Waterbot: exploring feedback and persuasive techniques at the sink. In: Proceedings of the SIGCHI 2005 conference on human factors in computing systems. Portland, pp. 631-639.

Australian Bureau of Agricultural and Resource Economics (Australian Bureau of Agricultural and Resource Economics (ABARE)). (2006) Australian energy consumption by industry, 1974–75 to 2004–05, June. Canberra.

Bechtel RB., Corral-Verdugo V. & Pinheiro JQ. (1999) Environmental belief systems: United States, Brazil, and Mexico. Journal of Crosscultural Psychology, Vol 30, pp. 122–128.

Birrell B., Rapson V. & Smith F. (2005) Impact of Demographic Change and Urban Consolidation on Domestic Water Use. Melbourne: Water Services Association of Australia Inc.

Britton T., Cole G., Stewart R. & Wisker D. (2008) Remote diagnosis of leakage in residential households. Water, Vol 35:6, pp. 89-93.

Chambers VK., Creasey JD., Glennie, EB., Kowalski M. & Marshallsay D. (2005) Increasing the value of domestic water use data for demand management - summary report. Wiltshire: WRc plc.


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Commonwealth Scientific and Industrial Research Organisation (CSIRO). (2007) Climate Change in Australia: Technical Report 2007. Melbourne: CSIRO.

Corral-Verdugo., Bechtel R. & Fraijo-Sing B. (2003) Environmental beliefs and water conservation: An empirical study. Environmental Psychology, Vol 23, pp. 247–257.

Darby S. (2006) The Effectiveness of Feedback on Energy Consumption. Environmental Change Institute, University of Oxford.

DeOreo WB. & Mayer PW. (2001) The End Uses of Hot Water in Single Family Homes from Flow Trace Analysis: Aquacraft Inc. Report, http://www.aquacraft.com.

Dobson JK. & Griffin JD. (1992) Conservation Effect of immediate electricity cost feedback on residential consumption behaviour. In: Proceedings of the 7th ACEEE Summer Study on Energy Efficiency in Buildings. Washington, DC, pp. 33-35.

Fischer C. (2008) Feedback on household electricity consumption: a tool for saving energy? Energy Efficiency, Vol 1:1, pp. 79-104.

Hauber-Davis G. & Idris E. (2006) Smart water metering. Water, Vol 33:3, pp. 56-59.

Hearn B. (1998) Benchmarking water use on farm: if you don’t measure it, you can’t manage it. In: Proceedings of the 9th Australian Cotton Conference. Gold Coast; 1998. pp. 519-529.

Idris E. (2006) Smart metering: a significant component of integrated water conservation system. In: Proceedings of the 1st Australian Young Water Professionals Conference. Sydney: International Water Association.

Inman D, Jeffrey P. (2006) A review of residential water conservation tool performance and influences on implementation effectiveness. Urban Water Journal, Vol 3:3, pp. 127 - 143.

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Kenney D., Goemans C., Klein R, Lowrey J. & Reidy K. (2008) Residential water demand management: lessons from Aurora, Colorado. Journal of the American Water Resources Association. Vol 44:1, pp. 192-207.

Mayer P., DeOreo W., Towler E., Martien L. & Lewis D. (2004) Tampa Water Department residential water conservation study: The impacts of high efficiency plumbing fixture retrofits in single-family homes. Tampa: Aquacraft, Inc Water Engineering and Management.

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McClelland L. & Cook S. (1979-1980) Energy conservation effects of continuous in-home feedback in all-electric homes. Journal of Environmental Systems, Vol 9:2, pp. 169-173.

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Taverner Research. (2005) Survey of Household Water Attitudes. Surry Hills: Taverner Research.

Turner A., White S., Beatty K. & Gregory A. (2005) Results of the largest residential demand management program in Australia. Sydney: Institute for Sustainable Futures, University of Technology.

Ueno T., Inada R., Saeki O. & Tsuji K. (2005) Effectiveness of displaying energy consumption data in residential houses: analysis on how the residents respond. In: Proceedings of the 2005 summer study of the European Council for an energy efficient economy. Stockholm: ECEEE, pp. 1289-1299.

Ueno T., Sano F., Saeki O. & Tsuji K. (2006) Effectiveness of an energy-consumption information system on energy savings in residential houses based on monitored data. Applied Energy, Vol 83:2, pp. 166-183.

Waisbord S. (1999) Family Tree of Theories, Methodologies and Strategies in Development Communications. Report prepared for The Rockefeller Foundation. New York.

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Webb T. (2007) Towards Sustainable Water Futures in Western Sydney. In the pipeline: a symposium -new directions in cultural research on water. Sydney: University of Western Sydney.

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Chapter 9

Pimpama-Coomera dual reticulation end use study: pre-commission baseline,

context and post-commission end use prediction


Journal of Water Science and Technology: Water Supply (2010) Vol 10:3, pp. 302-314, DOI:

10.2166/ws.2010.104.

9.1 Abstract

The Gold Coast Water Pimpama Coomera dual reticulation schemes’ recycled water supply will

be online in late 2009. In an attempt to achieve better estimates on both potable and likely

recycled water end uses within this region, this paper presents a predictive model that utilises a

range of input parameters, including: current use in the Gold Coast and the Pimpama Coomera

regions at both a bulk billing and end use level; recycled water use at other dual reticulated

schemes; and questionnaire survey of residents water source preferences for outdoor uses. Prior

to the commissioning of recycled water, potable water is supplied through the recycled water

pipelines. Water end use consumption analysis from the recycled water smart meter indicates

that this supply source currently provides 20% of total household use with the majority of use

being for toilet flushing. However, a range of factors have attributed to this low baseline level

with evidence collected in this study indicating that higher recycled water consumption rates

will occur once this supply line has been commissioned; largely due to the lower cost and fewer

restrictions placed on this water source for discretionary outdoor purposes. The weighted

amalgamation of a range of baseline adjustment factors assisted in the prediction of post-

commissioning end uses for the Pimpama Coomera dual reticulated region. The predictive

model indicated that recycled water end uses would account for 53 litres per person per day or

30.6% of total household consumption. The paper concludes with a brief overview of Phase 2 of

the study which aims to compare actual post-commission end uses with the baseline situation

and prediction, as well as the development of a robust end use model for dual reticulated

regions.

Chapter 9: Pimpama-Coomera dual reticulation end use study: pre-commission baseline, context and post-commission end use prediction

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9.2 Australian Dual Reticulated Communities

Long lasting droughts in various regions, increasing populations and demand on fresh or potable

water has driven the need, especially in Australia, to increase the reuse, recycling and

purification of water. The Australian National Water Initiative encourages water conservation

and the reuse of wastewater and stormwater (COAG, 2009). Hurlimann and McKay (2006a)

state that the focus of water reuse in Australia is through the application of dual reticulated

water supply in new developments. Recycling or reclaiming water for reuse in specified end

uses is well accepted as an effective and sustainable measure of water conservation (Anderson,

1996; Marks and Zadoroznyj, 2005; Po et al., 2005). Recycled water in dual reticulated regions

is generally supplied for toilet flushing and outdoor uses with the exception of filling pools and

spas (Gold Coast Water, 2004; Marks and Zadoroznyj, 2005; Kidson et al., 2006). Nationwide,

residential water restrictions which limit outdoor use exemplify that external water use is

considered nonessential (Syme et al., 2004) even though regions such as Perth have recorded up

to 54% of total household consumption externally (Loh and Coghlan, 2003). Nancarrow et al.

(2002) carried out a longitudinal study to determine attitudes to water restrictions with

respondents indicating that they were supportive of regular low level restrictions (i.e. watering

2-3 days per week over summer) but not those of a permanent and highly restrictive nature (i.e.

no external water use or bucket use only for long periods). The implementation of recycled

water through dual reticulation gives households the freedom to irrigate externally and to enjoy

the benefits of their outdoor space.

Well maintained gardens and outdoor areas are understood to provide a range of benefits,

including: serving to facilitate human relationships (Bhatti and Church, 2000); physiological

and recreational benefits (Kaplan and Kaplan, 1990; Syme et al., 2004); provision a sense of

place (Sime, 1993); and they also demonstrate a reflection or extension of residents homes

(Bhatti, 1999). Research such as this encourages the application of dual reticulated schemes as

they remove the constraint of water restrictions and allow householders to enjoy and maintain

their outdoor living space to their liking, not to mention the benefits of reusing a once

considered ‘waste’ form of water. The reuse of waste water through centralised dual reticulation

schemes like that in Pimpama Coomera has a range of environmental advantages. These include

reducing the quantum of effluent disposal, improving the receiving water quality through

reducing the pollutants discharged into downstream water systems, and a reduced draw on the

water extracted from the fresh water system. On the downside, these schemes can be energy

intensive due to the energy required for the recycled water treatment processes, as well as the

additional pump energy required to distribute two water supply sources to the household

(Anderson, 2003; White and Turner, 2003). Overall, the provision of recycled water for

appropriate end uses is considered to be beneficial due to the diversification of supply sources


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of water for customers, the reuse of waste water and for minimising the impact of water

restrictions on the community.

In Australia, numerous residential developments adopting dual reticulation have been

implemented. Some of the more prominent schemes include Mawson Lakes (Adelaide), New

Haven Village (Adelaide), Rouse Hill (Sydney Water), Aurora (Melbourne), Marriott Waters

(Melbourne) and Pimpama Coomera (Gold Coast). Table 9-1 presents an overview of the

nation’s current dual reticulation schemes and estimates/actual savings from recycled water

implementation.

Table 9-1 Summary of dual reticulated schemes in Australia

Scheme Description Recycled water end uses

Predicted/actual potable water savings

Rouse Hill, Sydney (Sydney Water, 2008)

Online 2001 Will serve up to 36,000 homes Centralised supply system


Predicted = 40% Actual = 35-40% reduction on total demand

Mawson Lakes, Adelaide (Hurlimann and McKay, 2006b)

Online 2005 Will serve up to 3500 homes


Prediction = 50% of householder’s water demand (265 kL/year)

New Haven Village, Adelaide (Fearnley et al., 2004)

65 homes Toilet & Outdoor uses

Prediction = 30-40% Actual = 50%

Aurora (VicUrban), Melbourne (Baldwin, 2008)

8,500 lots Development onsite collection & reuse


Prediction = Up to 45% (recycled water & conservation)

Pimpama Coomera, SEQ (Gold Coast Water, 2004)

Online end 2009 Will serve up to 45,000 homes Centralised supply system


Prediction = 35-45%

Marriott Waters, Melbourne (Victorian Government, 2009)

Online February 2009 Currently 100 homes On completion 1000 homes Dual reticulated development supply


Prediction = Up to 40%

Table 9-1 demonstrates that recycled water is well utilised in dual reticulated regions and that

predictions of uptake have been similar to those measured for mature schemes. Residents of

Rouse Hill use between 35-40% of their total household water consumption through recycled

water (Kidson et al., 2006; Sydney Water, 2008). Residents in New Haven Village in Adelaide

are using up to 50% of their total water consumption as recycled water (Fearnley et al., 2004).

Numerous dual reticulation schemes have been planned but measurements of the potable and

recycled water end use consumption have not yet been made or published. This study

investigates the end uses of the Pimpama Coomera (PC) scheme located in the Gold Coast,

Queensland with particular focus on the recycled water consumption component and break

down.


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9.3 Pimpama-Coomera Dual Reticulation Scheme

The Pimpama-Coomera Waterfuture (PCWF) Master Plan was developed to ensure sustainable

water consumption in the Gold Coast’s growing urban corridor. As observed in Table 1, PC is a

residential dual reticulated region with centralised distribution. In this region, recycled water

will be utilised for toilet flushing, outdoor watering, external maintenance (i.e. washing cars,

fountains) and fire fighting but is not permitted for the filling of pools or spas (Gold Coast

Water, 2004).

Currently recycled water is not flowing through the in-ground infrastructure; instead potable

water is supplying both lines for approximately 3832 homes. Being potable, this water is the

same quality, same cost and has the same level of restrictions as other potable water and at the

time of data collection, the campaign promoting the supply and encouragement of use of

recycled water had not yet been launched. In the future, the recycled water will be a low cost

and high quality Class A+5 supply. In 2004, Gold Coast Water (2004) originally estimated that

between 35-45% of total household water consumption can be replaced by recycled water, it

should be noted that total residential consumption was also higher than current consumption

rates, hence 35% was the revised estimate. The use of recycled water will reduce the demand on

current potable water supplies, decrease the volume of treated wastewater being released to the

environment and promotes the utilisation and reuse of a valuable resource (Gold Coast Water,

2004).

Recycled water will be supplied to residents in the PC region by the end of 2009. It is envisaged

that the recycled water uptake will be on par with initial targets. However, actual uptake and use

of recycled water especially for outdoor use can vary depending on restriction levels, social

values, climate, price of recycled water, land size, garden area and household perceptions and

attitudes towards water conservation (Syme et al., 2004; Dolnicar and Schafer, 2006)

This paper presents an investigation undertaken to examine the pre-commissioning level of both

the potable and recycled water use in PC and to predict future consumption levels once the

recycled water system has been commissioned. A discussion on the greater PC Dual

Reticulation End Use Study and objectives of this first phase of the research is presented below.

5 Class A+ recycled water is the highest quality of recycled water for non-drinking purposes in Queensland. Full details of

water quality guidelines for Class A+ and other recycled water schemes are published by the Department of Environment and

Resource Management (DERM) in the Water Quality Guidelines for Recycled Water Schemes and can be viewed at:

http://www.derm.qld.gov.au/water/regulation/recycling/pdf/water_quality_guidelines.pdf Standards of quality for Class A+

recycled water can also be viewed in Section 18AE, Schedule 3C of the Public Health Regulation 2005:

http://www.legislation.qld.gov.au/LEGISLTN/CURRENT/P/PubHealR05.pdf


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9.4 Pimpama-Coomera Dual Reticulation End Use Study

The PC Dual Reticulation End Use Study is a key component of the Gold Coast Watersaver End

Use Project. The objectives of the study are as follows:

Determine the recycled water pre-commissioning end uses for a statistically significant

sample of PC households;

Survey households participating in the end use study to determine attitudes, preferences

and behaviours with respect to recycled water; and

Predict the uptake of recycled water end uses and compare against actual end use break

downs post-commissioning.

This paper presents the results from Phase 1 of this study which includes: (1) the pre-

commissioning end uses for the sampled households; (2) create an end use adjustment

possibility distribution for each of the factors influencing the uptake of recycled water for

irrigation/outdoor purposes; and (3) the formulation of a post-commissioning prediction on end

uses within both the potable and recycled lines, with a particular focus on the estimated uptake

of recycled water for irrigation purposes. To achieve an accurate prediction on future recycled

water uptake, a range of information was analysed including both bulk and end use water

consumption levels, questionnaire surveys on water source preferences, and prior literature on

recycled water schemes, to name a few.

The approach taken to achieve the stated objectives for Phase 1 of the study was as follows:

1. Recruit a statistically significant sample of households (n=113) from the PC region and

undertake meter replacement to high resolution meters (Actaris CTS-5) to both the

potable and recycled lines to the household, which are capable of projecting 72.5 pulses

per litre;

2. Recruit a single reticulated control group (n=38) from a suburb with similar

demographics and volumetric consumption to PC and install high resolution meters;

3. Install data loggers (DataCell D-CZ21020) to record from both the potable and recycled

lines at the 10 second intervals necessary for end use analysis;

4. Undertake household stock inventory water audits with each household in the sample to

solicit demographics, a record of the water using fixtures and fittings within each home

(stock survey) and to establish unique water use behaviours of all residents within each

household i.e. approximate day/time and duration of water use activities such as

showers, baths, clothes washing, irrigation, etc. Stock inventory data cross referenced

with water audit stock survey data provided by the Australian Government Water


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Efficiency and Labelling Standards (WELS)6 Scheme database to obtain water use

consumption rates for fixtures such as washing machines, dishwashers, shower roses

and taps;

5. Conduct questionnaire survey with households to obtain detailed descriptive

information such as household resident age, family income, education level, etc.

Moreover, a range of questions sought to determine their likely uptake of recycled water

and their preference for predominant water sources available post-commissioning of

recycled water (i.e. potable, rain water tank, recycled water);

6. Conduct end use analysis graphically using Aquacraft’s Trace Wizard© software. A

quality assurance process to ensure accurate end use pattern matching was followed,

which included the following aspects: (a) utilising stock survey data, water use

behaviour survey data and household descriptive data to develop a unique template for

each household; (b) manual review and checking of each end use event over the two

week period by the analyst; and (c) independent checking of the categorised end use

data by a senior analyst. These steps provided the research team with greater confidence

in end use output files used for subsequent data analysis and results;

7. Compile end use water consumption summary for each household which serves as the

pre-commissioning end use data set; and

8. Utilise recycled water pre-commissioning end use data and baseline/end use adjustment

factor possibility distributions to make a prediction on the most likely recycled water

end use levels.

The pre-commissioning end uses and predicted post-commissioning end uses will serve as a

baseline against which actual post-commissioning water end use data can be compared.

9.5 Baseline Situation: Recycled Water Pre-Commissioning End Uses

Summaries of billed residential water meter consumption were obtained to establish average

potable consumption in single reticulated households on the Gold Coast and average potable

and recycled water consumption in the dual reticulated households in the PC region. The data

indicated that PC residents are currently consuming approximately 15% less total water than

other residents in the Gold Coast. This has not been the case in other dual reticulated regions

with Rouse Hill residents on average consuming 11% more water (potable and recycled) than

other Sydney residents when recycled water was being supplied to the region (Kidson et al.,

2006). Water consumption from the recycled water line currently accounts for 20% of PC

residents total water consumption. When comparing just potable water consumption, PC

6 WELS Scheme database available at: http://www.environment.gov.au/wels_public/


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residents are actually consuming 32% less than other Gold Coast residents. Rouse Hill

residents’ potable water consumption is 28% less than those in Sydney (Kidson et al., 2006).

To aid in the later provided prediction of potable and recycled water consumption within this

region, an understanding of where recycled water is used within the property is required.

Determining the percentage or volume of water use for toilet and irrigation requires examination

at the end use water consumption level (Turner, 2005). End use water consumption data was

obtained from a total of 113 dual reticulated households in the PC region and a control group of

38 single reticulated households in a comparable suburb on the Gold Coast. Figure 9-1 and

Figure 9-2 detail the end use break down in the single reticulated control group households, and

dual reticulated PC households, respectively.

Figure 9-1 and Figure 9-2 demonstrate that the uptake of water from the recycled water line in

PC is currently 20% of total water consumption for the monitored households (toilet and

irrigation recycled) which is also supported by bulk water meter readings. As noted, recycled

water is not currently supplied through the recycled water pipes; potable water is the current

source. Use of water for flushing toilets should not change when the recycled water is flowing

as lower cost or minimal restrictions should not alter the behaviour of toilet flushing. Figure 9-1

and Figure 9-2 also demonstrate that toilet volumes and percentages are similar between the PC

region and control group. The end use which will alter when recycled water is online will be

irrigation or outdoor use. Currently PC residents only use 6% of their total water consumption

from the recycled water line for outdoor uses (see Table 9-2). Even when considering that a

proportion (i.e. 50%) of the outdoor potable tap fixture use (10 litres per person per day

(L/p/day) or 6%) will transfer to recycled water the total irrigation volume still only amounts to

Figure 9-2 Dual reticulated (n=113) Gold Coast end use water consumption break

down (winter 2008)

Figure 9-1 Single reticulated (n=38) Gold Coast end use water consumption break

down (winter 2008)

Clothes Washer

26.8 L/p/d17.5%

Shower55.4 L/p/d

36.2%

Tap30.1 L/p/d

19.6%

Dishwasher1.8 L/p/d

1.2%

Bathtub3.2 L/p/d

2.1%


12.6%


9.1%

Leak (Pot)2.7 L/p/d

1.8%


Clothes Washer

31.1 L/p/d19.6%

Shower47.7 L/p/d

30.1%Tap

26.0 L/p/d16.4%

Dishwasher2.4 L/p/d

1.5%

Bathtub7.6 L/p/d

4.8%


13.7%


6.3%


6.4%

Leak (Pot)1.2 L/p/d

0.7%

Leak (Rec)0.7 L/p/d

0.4%



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9.6% of total consumption (23.7% total). When the recycled water line is commissioned, it is

expected that this percentage will increase significantly from its current level. The following

section details the approach taken to approximate dual reticulation end uses; focused on the

uptake of recycled water for outdoor uses such as irrigation.

9.6 Predicting Recycled Water Post-commissioning End Uses

9.6.1 Predictive analysis approach and input factors

The majority of end uses established in the pre-commissioning data read conducted in winter of

2008 should remain constant. This includes toilet use, which is supplied by recycled water, as

this is not a discretionary use and will only be marginally if at all affected by the introduction of

recycled water. Therefore the predictive analysis conducted herein is focused on outdoor uses,

specifically the uptake of recycled water for irrigation and other outdoor purposes. To assist

with the prediction on outdoor use changes due to the commissioning of the recycled water line

in the region in mid 2009, the following factors have been considered:

Baseline end uses established from winter 2008 logging period and initial adjustments;

Predicted and actual recycled water use in other dual reticulated regions;

End use studies conducted elsewhere and irrigations’ contribution to total consumption;

Influence of restrictions on outdoor water use and changes to behavioural norms;

Outdoor water use activities source preference matrix created from survey responses

received by sampled households;

Influence of recycled water pricing;

Influence of climate, lot size and recycled water marketing campaign; and

Other factors affecting general outdoor use and uptake of recycled water.

The influences of these factors are discussed below as well as predicted post-commissioning

end uses.

9.6.2 Establishing baseline end use situational context

Table 9-2 displays the water end use percentage break down and relevant volumetric

consumption for residents in the PC region. A minor adjustment to this original end use break

down has been made, with 50% of potable irrigation water use being transferred to recycled

irrigation (Table 9-2). The lower cost of the recycled water and the encouragement to utilise this

cheaper and sustainable supply source will instigate this change. Some potable irrigation will

still occur for the filling of pools and spas.


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Table 9-2 assumes no increase in overall water consumption or change in behaviour. In fact,

prior research has established that indoor water consumption is not generally affected by

weather conditions (Gato, 2006). This has lead to researchers deducting winter use from

summer use to determine outdoor seasonal uses (Kidson et al., 2006). Hence, it is reasonable to

assume that indoor consumption in PC will remain relatively similar and the adjustments should

be made to irrigation.

With the transfer of half of the potable irrigation to the recycled water supply, Table 9-2 shows

that baseline recycled water consumption will increase from 20.6% to 23.7%. Leakage for the

recycled water supply has been retained at current levels as almost all leakage, as identified

graphically in the trace analysis, in the recycled water line is related with toilet refill. It should

be noted that other small volumes of leakage are also present within potable household

consumption from taps, showers and other devices as demonstrated in Figure 9-1 and Figure

9-2.

Table 9-2 PC baseline end use situational context

End Uses Volume (L/p/day) Percent (%) Potable End Uses Leak 1.2 0.8% Clothes Washer 31.1 19.6% Shower 47.7 30.1% Tap 26 16.4% Dishwasher 2.4 1.5% Bath 7.6 4.8% Irrigation 5.0 3.2%

TOTAL POTABLE 121 76.3% Recycled End Uses Leak 0.7 0.4% Toilet 21.7 13.7% Irrigation 15.2 9.6%

TOTAL RECYCLED 37.6 23.7% TOTAL VOLUME 158.6 100%

9.6.3 Influence of irrigation end use measurements conducted elsewhere

Loh and Coghlan (2003) in Perth found that irrigation can account for up to 54% or 180 L/p/d of

total end use while Roberts (2005) in Melbourne recorded up to 25% of total consumption or

57.5 L/p/d being outdoors. Heinrich (2007) in New Zealand recorded 22% or 44.2 L/p/d of

external use in summer and in winter on the Gold Coast the average outdoor consumption was

just 12% or 18.6 L/p/d. This figure is low as data was recorded during winter and over the

logging period unseasonably high rainfall occurred. Maidment et al. (1985) has previously

determined that rainfall can instigate a sudden drop in seasonal use. The Perth study was

conducted in early 2000 when domestic water was not generally valued in Australia. The 2005

Melbourne study of 57.5 L/p/day or 25% is more reflective of average unrestricted irrigation


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use. Whilst this irrigation volume is much higher than the current average consumption on the

Gold Coast, it is expected that the supply of discounted and minimally restricted recycled water

could potentially boost use to similar levels found in Melbourne.

9.6.4 Influence of water restriction levels and changes

Gato (2006, pp 112) established that with the absence of garden watering, brought on by the

implementation of outdoor water restrictions, Melbourne’s average winter consumption was

‘34% lower (758 against 503 L/household/d) than the summer consumption of the same year

(2004)’ while the ‘per capita consumption incurred a reduction of 35% (260 verse 168 L/p/d)’.

Investigations were undertaken to establish the impact of outdoor water restrictions on the Gold

Coast (see Table 9-3).

Table 9-3 Influence of water restriction levels on billed water meter consumption in the Gold Coast

(ML/d)

Year

Population Growth (from Priority Infrastructure Plan estimates)

Level 1 Odd/Even days. Sprinkler & pool top up allowed

Level 2 Odd/Even days with sprinkler ban. Hose allowed

Level 3 Hose/sprinkler ban. Odd/Even bucket watering

Level 4 Odd/Even hand held buckets during designated time

Level 5 Odd/Even hand held buckets for garden during designated time only. Target 140L/p/d

Level 6 Level 5 & further business & high residential users targeted. Target 140L/p/d

0% 13% 14% 18% 24% 30% 2004/05 177.0 153.9 151.6 144.7 134.6 123.0 2005/06 2.24% 181.0 157.3 155.0 148.0 137.6 125.8 2006/07 3.07% 186.5 162.1 158.5 151.3 141.8 129.6 2007/08 3.07% 192.2 167.1 163.3 155.9 146.2 134.0 2008/09 3.07% 198.1 172.3 168.3 160.7 150.7 137.7 2009/10 3.07% 204.2 177.5 173.5 165.7 155.3 142.0 2010/11 3.07% 210.5 183.0 178.8 170.8 160.1 146.3

Table 9-3 demonstrates that water restrictions reduced potable water consumption in the Gold

Coast by as much as 30%. This figure is on-par with that reported in Melbourne.

Determining how residents’ behaviour will alter in PC when moving from five years under

varying levels of water restriction to basically non-restricted outdoor water use is difficult and

little research is available on the topic. It is assumed that behaviours will remain reasonably

constant with water consumption increasing over time to align with the permanent water

conservation targets stipulated in the South East Queensland Water Strategy (i.e. Target 200).

The fact that residents in Rouse Hill are consuming more water than residents in other regions

of Sydney (Kidson et al., 2006) supports the premise that outdoor consumption will increase

over time as has been the case in other dual reticulated regions.


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9.6.5 Influence of customer water source preferences

In determining which event water is used for externally, end use data is limited as it only

demonstrates the summation of all external use as one. Individual events can be seen in Trace

Wizard© but determining whether an event is watering the lawn or garden, or housing down the

driveway can not be done without the use of diaries. To obtain practical volumes of water used

for such outdoor purposes, a literature search as well as a questionnaire survey investigation was

carried out. Loh and Coghlan (2003) with the Water Corporation of Western Australia found

that the majority of outdoor water consumption was used on the lawn and garden with the

remaining volume used for filling swimming pools.

Prior research which focused on correlating total household water consumption with garden

based attitudes has resulted in inconsistent outcomes (Syme et al., 2004). Gato (2006, pp. 98)

established that in Melbourne, in February 2004, that the average volume of a garden watering

event was 202L (n=1468), with an average duration of 17 minutes and events occurred on

average 3 times a week. A quantitative attitudinal survey was undertaken to assist in

establishing which water source PC residents prefer to use for various high use outdoor

activities; the results are presented in Table 9-4. Respondents were requested to rank their

preferred water source, with 1 being the most preferred and 3 being the least preferred water

source (i.e. PW: Potable Water; RW: Recycled Water; and RWT: Rain Water Tank) for the

listed activities.

Table 9-4 PC respondent perceptions on preferred source for outdoor activities (n=70)

Activity Recycled Water

Rain Water Tank

Potable Water

Ranked Preference Percentage (%)

Watering the Pot Plants

2 1 3 RWT = 50.0%; RW = 40.0%; PW = 10.0%

Watering the Garden 2 1 3 RWT = 51.4%; RW = 45.7%; PW = 2.9%

Watering the Lawn 1 2 3 RW = 50.0%; RWT = 40.0%; PW = 5.7% Do not do = 4.3%

Cleaning Hard Surfaces

1 2 3 RW = 62.9%; RWT = 30%; PW = 2.8%; Do not do = 4.3%

Washing the Car 1 2 3 RW = 44.3%; RWT = 42.8%; PW = 10% Do not do = 2.9%

Washing the House 1 2 3 RW = 47.1%; RWT = 38.6%; PW = 8.6% Do not do = 5.7%

Table 9-4 shows that for the majority of outdoor high volume uses, PC residents would prefer to

use recycled water. Interestingly, respondent’s preferred rain water tanks for watering pot plants

and the garden. Although this is the case, only 21 of the 70 respondent households actually has a

rainwater tank on their property with the average size of a RWT in the dual reticulated region

being 3000L with only two of these RWTs plumbed into homes, one to a cold kitchen tap

(gravity fed) and the other for cold laundry use (pump fed). Hence a significant proportion of


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residents will in fact use recycled water as that is the only available water source alternative to

potable. Those with RWTs have the option of utilising either rain water or recycled water (RWT

is the preference for watering pot plants and the garden but not other outdoor uses such as

watering the lawn) although in dryer months, when irrigation demand is at its highest, these

small capacity RWTs are likely to have emptied and hence recycled water will need to be

utilised for all outdoor watering activities.

Customer surveys (n=70) also revealed that 62% of residents have stated they will increase their

recycled water consumption while 30.5% predict they will continue to use the same amount of

recycled water and 5.1% will reduce their recycled water use once recycled line water comes

online. For potable water consumption levels, 58% expect to use the same amount of water,

37% will reduce their water and 5% expect to increase their water consumption. For those

households with RWTs, 20.3% state they will reduce tank water consumption, 52.5% will use

the same amount of tank water and 27.2% expect to increase RWT use when recycled water

comes online. These perceived water source behaviour changes demonstrate a preference to

increase recycled water consumption, reduce or maintain potable water consumption, and to

reduce or maintain RWT consumption (72.8%), with only a quarter indicating they may

increase their RWT use if water is available.

9.6.6 Influence of recycled water pricing

Various opinions have been published on the effect of price on water consumption. While it was

initially thought that pricing water per unit, and hence payment for what water consumers use,

would be an effective demand management option (Inman and Jeffrey, 2006), research has

demonstrated that is only the case for some instances and in most cases water demand is price

inelastic (Espey et al., 1997; Renwick and Archibald, 1998). Thomas and Syme (1988) provided

evidence that external use was likely to be substantially more sensitive to price changes than

indoor use. Hence, external use may be one consumption use that possesses price elasticity

therefore the price of recycled water is likely to affect the consumption rate in PC. Hurlimann

(2008, pp. 4) reported that community members of Mawson Lakes have experienced a

‘significant increase in the perceived value of recycled water’ with 269 survey respondents

expressing that the cost of recycled water should increase to AUD$0.89/kL in 2007 in

comparison to AUD$0.49/kL in 2005 and AUD$0.46 in 2004. This demonstrates a willingness

to pay more for the product and recognition of its value. The cost of recycled water in the Gold

Coast was established through community consultation and market research undertaken by the

Gold Coast Waterfuture Product and Pricing Advisory Committee. The current cost, in the

09/10 financial year, is AUD$1.34/kL or 60% of the potable water price which is

AUD$2.24/kL. Recycled water is charged at a considerably lower rate than that of potable water


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and hence it is assumed that the use of recycled water rather than potable water outdoors will

occur.

9.6.7 Influence of climate

Hoffmann et al. (2006, pp. 347) has illustrated that there is a strong influence on residential

water consumption from the weather ‘particularly summer months and the number of rainy

days’. End use consumption data collected in the Gold Coast over a winter period with higher

than average rainfall very likely contributed to the low baseline value for irrigation related water

consumption. The uptake of recycled water in the Gold Coast will be intrinsically affected by

the climate with hot dry periods resulting in higher outdoor water consumption while cooler or

rain periods will reduce outdoor water consumption. Higher uptake rates will be experienced in

PC if drought conditions occur but if weather conditions of higher rainfall continue, as has been

seen over first part of 2009, outdoor water consumption may not increase substantially

immediately following commissioning.

9.6.8 Influence of lot size

Mayer and DeOreo (1999) established that in America larger lot sizes consumed more water

through irrigating although residential behaviour of watering lawns is quite predominant. In PC

it is assumed that lot size will have a slight effect on outdoor irrigation although it is believed

that garden size and plant type will have more impact that lot size. The average lot size in the

PC region is 662m2, maximum lot size is 15,000m2 and minimum size is 208m2.

9.6.9 Influence of recycled water awareness campaign

An awareness campaign will be launched to PC residents prior to recycled water coming online.

This campaign has the potential to affect the rate of uptake of recycled water in the region.

Generally public education or awareness is targeted to reduce water consumption and it has

been shown to be successful (Nieswaidomy, 1992). Encouraging the increase of recycled water

in the PC region will have varying outcomes on uptake volumes of the product. Similar

campaigns would have been launched in other dual reticulated regions although they have not

specifically been measured hence it is difficult to predict the impact of such a campaign. Overall

it is predicted that an awareness campaign will increase recycled water use in PC as residents

will understand that the product is available and is a cheaper source of water, thus leading to an

increase in consumption.


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9.7 Predicting Post-commissioning Dual Reticulation End Uses

9.7.1 Possibility theory underpinning prediction model

There are a number of mathematical techniques that are commonly applied for predictive

assessments, including probability theory, Monte Carlo simulation, sensitivity analysis and

possibility/fuzzy set theory. This study adopted the latter possibility/fuzzy set theory approach

due to the inherent fuzziness of future predictions of water use for a new supply source (i.e. A+

recycled water) in a new context (e.g. Gold Coast, Queensland, Australia). Probability theory is

not suitable for this application as it relies on historical data sets to accurately predict future

scenarios. Given that there are a limited number of dual reticulation water supply schemes in

Australia, limited availability of recycled water use in these existing communities, and that the

climatic conditions of each region has a significant bearing on recycled water take-up, this

intrinsic uncertainty does not fit the axiomatic basis of probability theory. This is simply due to

the uncertainty of recycled water uptake estimates being usually caused by the inherent

fuzziness of the parameter estimate rather than randomness (Choobineh and Behrens, 1992).

Similarly, Monte Carlo simulation and sensitivity analysis require historical data in the form of

probability distributions to provide meaningful predictions on future water use scenarios. A

technique to alleviate the shortcomings of these traditional techniques in this uncertain context

is to apply possibility theory where the user needs only to determine a range (lower and upper

least likely boundary) and most likely value for each parameter contributing to the estimate.

Practitioner and research literature was examined to create a range for each examined factor and

expert intuition was applied to ascertain the most likely value within that range. Therefore,

possibility theory is superior to other techniques where qualitative judgements dominate the

prediction process (Altunkaynak et al., 2005).

Another issue to address in the predictive assessment was the interdependent nature of

influencing factors and the relative contribution of each factor to the final estimate (see Table

5). Structural Equation Modelling (SEM) is the ideal technique that handles both the direct and

indirect effects of multiple factors on independent variables (Stewart, 2007). However, given

the lack of empirical data to build such a statistically powerful model, a more simplistic

weighted contribution assessment by an expert panel was employed. Nonetheless, this simple

weighted average model avoids double counting and ensures that those factors that were

perceived to have a greater influence on the final estimate contribute greater to the final

weighted average.

9.7.2 Prediction model application

As mentioned, any increase in recycled water consumption in PC is likely to occur through

irrigation use. Other end uses are likely to remain the same as the baseline end use measurement


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(see Table 9-2). Each of the above listed factors which are noted to potentially influence

recycled water utilisation for irrigation purposes (i.e. outdoor uses) have been allocated a lower

least likely, most likely and upper least likely possibility distribution established from the above

mentioned discussion (see Table 9-5). Factor A considers the percentage of recycled water use

in mature dual reticulation schemes removing 14% for toilet flushing. Factor B utilises the

lowest and highest irrigation percentages as found in other end use studies. Factor C was

established using Gold Coast Water (GCW) restriction data with a 30% increase with no

restrictions and 13% increase if restrictions on sprinklers were introduced. Factor D utilises

survey data on customer water source preferences received from PC residents participating in

the end use study. Factor E presents the influence of the potable comparative price of recycled

water. Factor F was established by considering low to extreme irrigation events during summer

months. Finally, Factor G conservatively estimates the influence of the awareness campaign on

uptake.

The values serve as an adjustment to the baseline measured end use irrigation volume or total

consumption level on a litre per person per day (L/p/day) basis. Influence factor weightings

were determined by an expert panel. The weighted summation of the adjusted baseline value

resulted in a possibility distribution for recycled water irrigation as: (1) lower least likely value

= 25.6L/p/day; (2) most likely value = 30.6L/p/day; and (3) upper least likely value =

41.8L/p/day.

Table 9-5 Recycled water for irrigation purposes influencing factors and weighted possibility distribution

Factor ID (i)

Influencing Factor Description

Adjustment Method Lower Value

Most Likely Value

Upper Value

Influence Weight (wi)

A Other dual reticulated recycled water uptakes

% of total end use1 21% 26% 36% 25%

B Prior end use irrigation break down

% of total end use1 22% 30% 54% 15%

C Relaxed water restrictions

% increase on baseline2 13% 20% 30% 10%

D Customer water source preferences

% increase on baseline2 30% 40% 50% 15%

E Price of recycled water % increase on baseline2 20% 30% 40% 15% F Climate affects % increase on baseline2 20% 30% 40% 10% G Awareness campaign % increase on baseline2 20% 25% 30% 10%

Notes: 1Total volumetric consumption = 170L/p/day; 2Baseline recycled water irrigation established as 15.2L/p/day

As per Table 9-6, the most likely recycled water uptake for irrigation in PC is estimated to be

30.6 L/p/d thereby resulting in total recycled water use (i.e. toilets, irrigation and leakage)

equating to 30.5%. The predicted increase in recycled water consumption takes the current total

per capita consumption from 158.6 to 174 L/p/day. Lower and upper estimates result in recycled

water utilisation being 28.4% and 34.7% of total water consumption on a per capita basis,


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respectively. Establishment of actual recycled water end uses will be established in the second

phase of the PC dual reticulated end use study.

Table 9-6 PC recycled water post-commissioning end use prediction

End Use Break Down Most Likely End Uses Lower End Uses Upper End Uses

End Uses Volume

(L/p/day) Percent

(%) Volume

(L/p/day) Percent

(%) Volume

(L/p/day) Percent

(%) Potable End Uses

Leak 1.2 0.7% 1.2 0.7% 1.2 0.6% Clothes Washer 31.1 17.9% 31.1 18.4% 31.1 16.8% Shower 47.7 27.4% 47.7 28.2% 47.7 25.8% Tap 26 14.9% 26 15.4% 26 14.0% Dishwasher 2.4 1.4% 2.4 1.4% 2.4 1.3% Bath 7.6 4.4% 7.6 4.5% 7.6 4.1% Irrigation 5.0 2.9% 5.0 3.0% 5.0 2.7%

TOTAL POTABLE 121 69.5% 121 71.6% 121 65.3% Recycled End Uses Leak 0.7 0.4% 0.7 0.4% 0.7 0.4% Toilet 21.7 12.5% 21.7 12.8% 21.7 11.7% Irrigation 30.6 17.6% 25.6 15.1% 41.8 22.6% TOTAL RECYCLED 53 30.5% 48 28.4% 64.2 34.7%

TOTAL VOLUME 174 100% 169 100% 185.2 100%

9.8 Future Research: Post-commissioning Comparative Analysis

The end use predictions determined in this Phase will be assessed in Phase 2 of the PC Dual

Reticulated End Use Study. Phase 2 of the research involves the collection of end use water

consumption data in summer (December 2009 to February 2010) after recycled water is

supplied to PC. The collection and analysis of recycled water end use data will allow actual

quantification of recycled water consumption in PC. Real consumption data will be compared

with the predicted uptake presented in this paper.

9.9 Conclusion

Several dual reticulated schemes are online in Australia with recycled water uptake rates

between 35-50% recorded. The PCWF Master Plan predicted that 35-45% of total water

consumption in the PC dual reticulated region will be recycled water. Billing data determined

that PC residents are currently consuming 20% of their total water through the recycled water

meter (potable water being the current source) and end use investigations determined that in

winter 2008, 14% of that use is occurring through toilet flushing while only 6% is being used

externally as irrigation. Expectedly, current consumption is currently 15% lower than the initial

minimum targets. Recycled water outdoor events will, over time, meet or exceed the current

shortfall. Exploration into residential water restrictions on the Gold Coast revealed that full

outdoor water restrictions (Level 6) lead to a 30% reduction in total water consumption.


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Questionnaire surveys of PC residents (n=70) determined that recycled water was the preferred

source for most outdoor activities and 62% of those respondents believed that they would

increase their recycled water use once it was online. The effect of these influencing factors

along with climate, pricing, the awareness campaign and the change from restricted to un-

restricted use for recycled water and their potential influence on the actual uptake of recycled

water were encapsulated in a predictive model. This model resulted in a most likely prediction

that recycled water uptake will increase to around 30% in the PC region within the first year.

GCW will continue investigating the actual uptake of recycled water in the PC region through

Phase 2 of the PC Dual Reticulated End Use Study.

9.10 References

Altunkaynak, A., Ozger, M. & Cakmakci, M. (2005) Water consumption prediction of Istanbul city by using fuzzy logic approach. Water Resources Management, 19(5): 641-654.




Bhatti, M. (1999) The meanings of gardens in an age of risk. In: T. Chapman, J. Hocky (Eds), Ideal Homes? Social Change and Domestic Life. Routledge, London, pp. 181-193.

Bhatti, M. & Church, A. (2000) I never promised you a rose garden: gender, leisure and home-making. Leisure Studies, 19: 183-197.

Choobineh, F. & Behrens, A. (1992) Use of interval mathematics and possibility distribution in economic analysis. Journal of Operational Research Society, 43(9): 907-918.








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Hoffmann, M., Worthington, A. & Higgs, H. (2006) Urban water demand with fixed volumetric charging in a large municipality: the case of Brisbane, Australia. The Australian Journal of Agricultural and Resource Economics, Vol:50, pp. 347-359.


Hurlimann, A. C. (2008) Community Attitudes to Recycled Water Use: an Urban Australian Case Study Part 2. Salisbury, SA, CRC for Water Quality and Treatment Project No. 201307.



Kaplan, R. & Kaplan, S. (1990) Restorative experience: The healing power of nearby nature. In: Francis, M, Hestor, R.t (Eds), The Meaning of Gardens. MIT Press, Cambridge, pp. 238-243.



Maidment, D. R., Miaou, S. P. & Crawford, M. M. (1985) Transfer Function Models of Daily Urban Water Use. Water Resources Research, 21(4): 425-432. Apr. 1985a.









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Sime, J. (1993) What makes a house a home: the garden? In: Bulos, M, Teymur, N (Eds), Housing: Design, Research, Education. Aldershot, Averbury, pp. 239-254.

Stewart, R. A. (2007) IT enhanced project information management in construction: pathways to improved performance and strategic competitiveness. Automation in Construction, 16: 511-517.







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Chapter 10

Residential potable and recycled water end uses in a dual reticulated supply system


Journal of Desalination (2011): Vol 272:1-3, pp. 201-211, DOI: 10.1016/j.desal.2011.01.022.

10.1 Abstract

The need to understand, model and predict urban water consumption is paramount, particularly

with urban densities increasing throughout the world. Specifically, it is vital to determine

potable water savings, daily demand patterns and actual end use water consumption experienced

in diversified water supply schemes in order to verify planning estimates and justify the future

application of such schemes. This paper details the results of a mixed methods (quantitative and

qualitative) end use investigation, pre- and post-commissioning of recycled water, in a dual

reticulated supply scheme in the master planned Pimpama Coomera region, Gold Coast,

Australia. Recycled water, supplied for irrigation and toilet flushing, accounted for 59.1 L/p/d or

32.2% of total consumption post-commissioning, with irrigation being 28.9 L/p/d or 15.7%.

Furthermore, developed end use diurnal patterns demonstrate the unique daily demand

consumption within the region and significant reductions in peak potable water demand when

compared with single reticulated supply areas. The paper concludes with discussions of

implications for better informed water services infrastructure planning activities.

10.2 Integrated Urban Water Resources Management

The provision of a secure supply of water for increasing populations in climate challenged

regions is a critical issue. Australia is the world’s driest inhabited continent with unpredictable

rainfall patterns, hence the significant focus on conserving and sustainably managing the

nation’s already finite water supplies (Birrell et al., 2005; Commonwealth of Australia, 2008c).

Queensland, an eastern state of Australia, has become increasingly hotter and drier, with trends

indicating reduced rainfall of up to 50mm annually (Anderson, 1996; Commonwealth of

Australia, 2010). This reduced rainfall trend is occurring over concentrated urban centres, where

much of the nation’s population resides, resulting in rainfall-dependent eastern Australian cities

and towns having water supplies fall to record low levels over the past ten years

(Commonwealth of Australia, 2008a; ABS, 2010). Traditionally, the supply of water for cities


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and towns placed a heavy reliance on dams, weirs or rivers but changing weather patterns and

the growing urban population’s water demands have necessitated a new approach (Barlow,

2009). Hence, Australia is now focussed on the development, planning and implementation of

new water demand reduction initiatives to meet short-term water supply deficiencies and to

manage long-term demand, together with supply augmentations including desalination (Turner

et al., 2005; Webb, 2007; Barlow, 2009).

Integrated sustainable water resources planning and management has become a key driver of a

raft of measures required to ensure future water demands are satisfied (WSAA, 2008). This

sustainable water resources planning and management method involves the introduction and

application of alternate supply options (such as desalination or recycling), water demand

management measures (efficient devices, water restrictions and price controls) and source

substitution initiatives (rainwater tanks, stormwater or recycled water), for a sustainable and

secure source of water for future populations (Mitchell, 2006). The application of demand

management and source substitution initiatives is widespread throughout the nation. However,

the effective potable end use water savings which can be achieved by these measures is assumed

or predicted and in almost all cases, and often remains unverified after application (Turner and

White, 2006; Turner et al., 2007b). The verification of effective water savings related to such

initiatives is vital for the improvement of water services planning; for the accurate forecasting of

water supply and demand and for strengthening the knowledge and application of such

sustainable water management initiatives for the future (WSAA, 2003; WSAA, 2008).

10.2.1 Water services planning

Urban water demand forecasting used for the planning of water services infrastructure has been

carried out for decades with consistent improvement occurring with the invention of new data

collection techniques, analysis and modelling technologies. Predicting urban water demand

requires an understanding of historical water services records, projected changes in demand

patterns and system performance (DNRM, 2005). Water demand modelling elements, as

detailed by WSAA (2003), include diurnal patterns, end use water consumption, peaking factors

(maximum day, mean day maximum month and maximum hour), fire fighting parameters,

system losses, non-revenue water and pressure parameters. These and other climatic,

demographic and consumer influences are detailed in Figure 10-1. Figure 10-1 illustrates the

influence of climate, water usage practices, water use equipment, demographics and land use,

the water supply system and source substitution on water demand. While all elements presented

in Figure A.1 are required for urban water forecasting, it is well documented that all too often

‘demand forecasting studies have relied on projections of historical metered data without

considering end uses’ or by adopting end use data from different locations or countries (WSAA,

2003, pp. 6). Because household water consumption differs between countries, locations and

Chapter 10: Residential potable and recycled water end uses in a dual reticulated supply system

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populations, it is paramount that location specific end use data is utilised for local demand

forecasting (Turner et al., 2005; Inman and Jeffrey, 2006).

Figure 10-1 Factors that influence demand (White and Turner (2003) & WSAA (2008))

Giurco et al. (2008a) state that end use water consumption data is also required for the

determination of actual potable water savings of alternative supply sources and water demand

management initiatives. End use data assists in refining and validating the design assumption

parameters that influence the planning of water services infrastructure (Gato, 2006). The advent

of high resolution water meters and loggers along with affordable wireless communication

technologies has enabled the dynamic, accurate measurement and data transfer of end use water

consumption information (Stewart et al., 2010).

10.2.2 Water end use and diurnal patterns

Water end use studies provide data to assist in the determination of when, where and how

residents consume water in the home (White, 2001; Giurco et al., 2008a). End use studies also

offer ‘significant opportunities for providers to improve water service delivery and long term

planning’ through the provision of detailed consumption data utilised for water demand

predictions (Giurco et al., 2008a, pp. 1). The collection of end use data also assists with

verification of other demand forecast factors including diurnal patterns and peaking factors like

maximum day, mean day maximum month and maximum hour. Diurnal patterns demonstrate

the demand or consumption across a day in hourly intervals. This pattern varies depending on

the population, weather, the time of year, the day of the week (i.e. weekday versus weekends),

season and residential consumption characteristics (Zhou et al., 2002). In Australia, end use


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water consumption studies have been undertaken in Perth and Melbourne, and most recently,

the herein described investigation on the Gold Coast. Studies have been done in the USA and

New Zealand. In Queensland, numerous bulk supplied diurnal patterns have been determined

for forecasting total residential urban water use. However, end use water consumption and end

use diurnal patterns for Queensland and for the Gold Coast are not available. Table 10-1 details

some of the more significant end use studies completed.

Table 10-1 Summary of findings from other water end use studies

Author Study title Country Region No. homes

Avg. consumption (L/p/day)

End use or additional factors investigated

Willis et al. (2009b)

Gold Coast Watersaver End Use Study

Australia Gold Coast 151 Winter: Indoor = 138.6 Outdoor = 18.6

End use only to date

Mead (2008)

Investigation of Domestic End Use

Australia Toowoomba 10 Indoor & outdoor = 122

End use & diurnal patterns

Heinrich (2007)

Water End Use and Efficiency Project (WEEP)

New Zealand

Kapiti Coast 12 Indoor & outdoor = 184.2 Summer: 203.9 Winter: 168.1

End use & bulk diurnal patterns

Roberts (2005)

REUMS Australia Yarra Valley, Melbourne

100 Indoor = 169 Outdoor = extra 20% = 34


Mayer et al. (2004)

Tampa Water Department Residential Water Conservation Study


Tampa 26 Pre retrofit = 752.9 Post retrofit = 403.9 (indoor & outdoor)

End use and retrofitting

Loh and Coghlan (2003)

Domestic Water Use Study

Australia Perth 124 & 120

Indoor = 155 Outdoor = extra 54% = 83.7

End use & bulk diurnal patterns

AWWA (1999)

Residential End Uses of Water (REUW)


12 regions 1188 Indoor = 262.3 Indoor & outdoor = 650.3


Loh and Coghlan (2003) undertook the first national end use investigation in Perth, Australia

which detailed diurnal patterns from a total consumption level based on income, no end use

diurnal patterns were published. The variability between indoor and outdoor consumption

recorded in earlier end use studies is particularly prevalent when comparing Perth and

Toowoomba (Table 10-1). Outdoor consumption in Australian studies ranged from 18.6 litres

per person per day (L/p/d) in winter in the Gold Coast, 34 L/p/d Melbourne and 83.7 L/p/d in

Perth. Indoor consumption also varied, with the Perth study recording 155 L/p/d, the Melbourne

study 169 L/p/d, the Gold Coast study 138.6 L/p/d and the Toowoomba study recording just 122

L/p/d. Roberts (2005) end use investigation covering Yarra Valley in Melbourne also detailed

end use water consumption diurnal patterns for winter and summer use. In Roberts (2005)

winter study, end usage peaked between 7 and 8am (9.1% of total use), mostly due to

showering, and between 6 to 7pm (6.9% of total use) due to a range of end uses in the home.

Summer morning end use peaked between 7 and 8 am (8.3% of total use) while the evening


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peak occurred between to 9 to 10pm (10.3% of total use) due to significant irrigation usage

(Roberts, 2005). While Mead’s (2008) Toowoomba end use study was only from a small

sample, end use diurnal patterns were detailed. Mead’s (2008) highest peak occurred between 7

to 8am in the morning at 38 litres per household per day (L/H/d) with the evening peak

occurring between 5 to 6 pm (32 L/H/d). Shower usage was the highest end use contributor in

both morning and evening peaks. Weekend data showed flatter and longer peak periods in the

morning, with similar patterns for the evening. Clothes washing was an influential end use

peaking factor on the weekends (Mead, 2008). The variability described between indoor,

outdoor and diurnal consumption patterns determined through earlier end use studies prompted

Giurco (2008a) and WSAA (2003) to encourage more research in this field. End use

investigations into the effective water savings attributed to demand management and source

substitution initiatives are required (Giurco et al., 2008b; WSAA, 2008).

The use of recycled water for specified end uses is well accepted as an effective and sustainable

measure of water conservation and other schemes have been implemented throughout Australia

(Anderson, 1996; Marks and Zadoroznyj, 2005; Po et al., 2005). The six schemes currently

present throughout the nation include Rouse Hill (Sydney), Mawson Lakes (Adelaide), New

Haven Village (Adelaide), Aurora (Melbourne), Marriott Waters (Melbourne) and the herein

described Pimpama Coomera scheme (Gold Coast) (Willis et al., 2010a). All these schemes

supply recycled water for toilet flushing and irrigation. These schemes were all premised on

modelled predictions of end use and total potable water savings which could result from the

application of dual reticulated recycled water. Predicted water savings ranged from 30–50% of

the households’ total demand (Fearnley et al., 2004; Hurlimann and McKay, 2006a). Bulk

supplied data have been recorded at Rouse Hill and New Haven Village with savings between

35–50% found respectively (Fearnley et al., 2004; Sydney Water, 2008). Actual potable water

savings for the other dual reticulated schemes are yet to be published. To date, no data have

been published internationally on the actual water end use sourced from domestic potable and

recycled service pipes within dual reticulated regions, nor has there been any verification of

modelled end use diurnal demand patterns for these unique supply areas. Such field-collected

end use data are necessary to improve forecasting, water services planning and to strengthen the

application of similar schemes.

10.2.3 Gold Coast’s Pimpama Coomera dual reticulation scheme

Gold Coast City is one of South East Queensland’s major urban growth areas with the

population predicted to grow from the current 0.5 million to 2.5 million people by 2056 (Po et

al., 2005). This population expansion would trigger water consumption increases from the 2007

consumption of 185 megalitres per day (ML/d) (≈ 48.87 mega gallons (US) per day) to 466

ML/d by 2056 (≈ 123.1 mega gallons (US) per day) (GCW & GCCC, 2007). With residents


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consuming 75% of the city’s total yearly water supply in 2008/09, considerable focus has been

placed on reducing and managing residential water consumption in the city as well as

reclaiming water and sourcing through desalination (capacity of Tugun Desalination Plant 125

ML/d).

The PCWF Master Plan is the blueprint for sustainable integrated urban water management, for

the Pimpama Coomera region of the Gold Coast, which is largely undeveloped and one of the

fastest growing residential areas in Australia (Po et al., 2005). It stipulates the provision of

sustainable water sources for a projected 150,000 people in 2056 (Pimpama Coomera region

only) through the inclusion of dual reticulated recycled water, water conservation through water

demand management (WDM) measures, rainwater tanks, stormwater management and smart

sewers. The PCWF Master Plan region is Australia’s first centralised dual reticulation

distribution scheme for recycled water, providing Class A+ recycled water for approved end

uses, which include toilet flushing and external irrigation (with the exception of filling pools

and spas). Class A+ recycled water is the highest quality of recycled water for non-drinking

purposes in the State of Queensland, Australia. It was predicted that between 30 to 40% of

traditional communities’ existing consumption could be substituted by recycled water. The

introduction of rainwater tanks and water conservation measures would also reduce total potable

water consumed in the PCWF Master Plan region (GCW, 2004).

The Pimpama Coomera (PC) End Use Study is a component of the wider Gold Coast

Watersaver End Use (GCWSEU) Study which commenced in 2007 (Willis et al., 2009b). The

GCWSEU study was developed to investigate end use water consumption on the Gold Coast.

Other objectives include establishing the effective end use savings attributed to dual reticulation

and water demand management initiatives such as efficient and resource consumption

awareness devices (Willis et al., 2010b). To date, there have been no end use investigations on

dual reticulated recycled water schemes. Hence, the PC End Use Study was focused on

establishing the end use water consumption, pre- and post-recycled water commissioning, and

to determine savings attributed to a dual reticulated recycled water supply scheme (Willis et al.,

2010a). The end use evaluation of a dual reticulated region is the first of its kind, both nationally

and internationally.

The pre-commissioning Phase 1 component of the study was completed in 2009. The objectives

of this phase as detailed by Willis et al. (2010a) included:

Determine the recycled water pre-commissioning end uses for a statistically significant

sample of PC households;

Survey households participating in the end use study to determine demographics,

attitudes, preferences and behaviours with respect to recycled water; and


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Predict the uptake of recycled water end uses and compare against actual end use break

downs post-commissioning.

Recycled water in the PC region is supplied through a separate recycled water pipeline for toilet

flushing and irrigation; leakage also occurs on this line. Phase 1 of the PC End Use Study

determined that toilet flushing behaviours would remain relatively similar but that irrigation

would alter depending on a variety of factors such as water restrictions, recycled water pricing,

climate and awareness campaigns. Phase 1 resulted in the development of a predictive uptake

model of recycled water for the PC area based on these influencing factors. The predictive

model calculated that the most likely total recycled water consumption post-commissioning

would be 53 litres per person per day (L/p/d) or 30.5% of total household consumption. Of this,

toilet usage was 21.7 L/p/d, leakage was 0.7 L/p/d and irrigation was 30.6 L/p/d. The lower least

likely estimates were 48 L/p/d or 28.4% with irrigation being 25.6 L/p/d and leakage and toilet

usage remaining the same as the most likely estimate. The upper least likely estimate was 64.2

L/p/d or 34.7% recycled water use with 42.8 L/p/d for irrigation consumption and leakage and

toilet usage remaining the same as the most likely estimate (Willis et al., 2010a). In December

2009, recycled water was supplied to the PC area. This triggered the commencement of Phase 2

of the PC End Use Study, namely the measurement of post-commissioning end use water

consumption in the PC area. This paper details the results of Phase 2 of the PC End Use Study.

10.3 Objectives and Scope of the Paper

The objectives of Phase 2 of the PC End Use Study are:

Determine the end uses for a statistically significant sample of PC households post-

commissioning of recycled water using quantitative and qualitative data sources and

analysis techniques;

Compare dual (potable and recycled supply) and single (potable only) reticulated water

supply schemes;

Undertake a comparison of measured recycled water consumption post- commissioning

of recycled water in the PC region against the PC dual reticulation demand forecast

model developed in Phase 1 of this study; and

Develop a tool and investigate average daily diurnal demand patterns at an end use level

for the PC dual reticulated region and the single reticulated control group.

This paper presents the results for the above stated objectives for Phase 2 of the study. To

achieve the above stated objectives, a variety of collected quantitative and qualitative data sets

and analysis techniques/tools were utilised including seasonal climatic data, bulk supply data,

water end use data, qualitative water audits, questionnaire surveys and an end use diurnal


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pattern software tool. The method carried out to satisfy the objectives of Phase 2 of the study

are summarised below:

1. Revalidate data collected through Phase 1 questionnaire survey, which obtained detailed

descriptive information such as household occupants, resident age, family income,

ownership status and education level;

2. Obtain seasonal climatic data and bulk supplied water consumption data for potable and

recycled water for the duration of the study;

3. Utilise the sample of recruited households in the single and dual reticulated PC region

from Phase 1 of the study to obtain actual end use water consumption from both the

potable and recycled water lines. This data was collected utilising high resolution

Actaris CTS-5 water meters (0.014 L/pulse) recording to DataCell D-CZ21020 data

loggers at 10 second intervals;

4. Conduct end use analysis procedure using collected high resolution flow data inputted

into Aquacraft’s Trace Wizard© software, with the categorisation process aided by

household stock inventory, qualitative household behaviour and descriptive data

solicited from households sampled. The end use analysis quality assurance procedure

detailed by Willis et al. (2010a) was adhered to, which included the use of qualitative

water consumption behaviour data to identify and categorise water flow traces. Such

qualitative information is critical for ensuring that flow trace data is accurately

disaggregated into a registry of water end use events;

5. Compile the end use water consumption summaries for each household, which served

as the post-commissioning end use data set;

6. Revisit the Phase 1 recycled water prediction model to compare the differences in actual

post-commissioning end use consumption in the PC dual reticulated region.

7. Develop a diurnal pattern tool using ‘Borland C Builder’, which is a Microsoft (MS)

Windows ‘Multiple Document Interface’ (MDI) compliant software. The ‘Diurnal’

program processes MS-Access data files produced by the auxiliary Trace Wizard©

software with variable time series intervals ranging from hourly to five minute intervals;

and

8. Undertake analysis using the ‘Diurnal’ tool for the collaboration of end use water

consumption data across required time intervals for daily use.

For a comprehensive explanation of the methods undertaken to complete the GCWSEU study,

readers are referred to Willis et al., (2009b), Willis et al., (2010a) and Willis et al., (2010b). The

results of the above described method are detailed below.


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10.4 Pimpama Coomera End Use Water Consumption Study

10.4.1 Pre-Commissioning of recycled water to Pimpama Coomera region

Phase 1 of the PC End Use Study identified factors reported to influence the uptake of recycled

water. Climate was predicted to have the most significant impact on irrigation hence, an

overview of climatic variables including rainfall and temperature and coinciding bulk recorded

supply were summarised to establish appropriate periods to monitor end use water consumption

post-commissioning (Figure 10-2).

0

5

10

15

20

25

30

35

0

100

200

300

400

500

600

Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun

Ra

infa

ll (m

m)

/ B

ulk

Re

s. (

L/p

/d)

Te

mp

era

ture

(°C

)

Month

Average Max Temperature and Rainfall

2008/09 Rainfall (mm) 2009/10 Rainfall (mm)

2009/10 Bulk Res. Supply GC City (L/p/d) 2008/09 Bulk Res. Supply GC City (L/p/d)

2008/09 Max Temp (°C) 2009/10 Max Temp (°C)

Figure 10-2 Rainfall and maximum temperature with bulk recorded supply for Gold Coast City over the

duration of the Gold Coast Watersaver End Use study July 2008 – June 2010

Climatic trends shown in Figure 10-2 follow sub-tropical patterns of high temperature and

rainfall throughout summer and lower temperatures and rainfall in winter. Figure 10-2 illustrates

that the first pre-commissioning data collection period in winter 2008, occurred within an un-

seasonally high rainfall period (Phase 1). This is reflected in both the city wide bulk supply and

end use data being the lowest recorded over the study period. The summer pre-commissioning

data log occurred in December 2008 when the Gold Coast city was under Queensland Water

Commission (QWC) medium level restrictions of Target 200 L/p/d. November 2008

experienced extreme rainfall of 440.6mm. This was the third highest rainfall month recorded on

the Gold Coast between 2001 and 2010. December 2008 also experienced high rainfall volumes

of 123.8mm. Understandably, bulk supplied residential consumption in December was low at

176.9 L/p/d, with monthly consumption increasing to 196.3 L/p/d in January 2009. The total


- 232 -

pre-commissioning end use water consumption in the dual and single reticulated regions,

recorded in summer 2008/09, is detailed in Figure 10-3. Single reticulated region use is

presented in Figure 10-3a, the dual reticulated region potable and recycled combined supply in

Figure 10-3b while, Figure 10-3c and d present the dual reticulated regions potable and recycled

supply lines separately.

Figure 10-3 Pre-commissioning end use water consumption data (summer 08/09)

The average summer pre-commission end use water consumption across the single and dual

reticulated regions was recorded as 146.9 L/p/d (n=127). Total consumption for the single

reticulated region was 158.4 L/p/d (Figure 10-3a) while the dual reticulated region was 9%

lower at 143.5 L/p/d (Figure 10-3b). The end use consumption volumes were relatively similar

but just slightly lower in the dual reticulated region for shower, clothes washer, tap, toilet and


76.2%

Irrigation (Rec)6.2 L/p/d21.5%

Leak (Rec)0.7 L/p/d

2.3%

Clothes Washer

29.7 L/p/d25.8%

Shower45.6 L/p/d

39.8%

Tap26.3 L/p/d

22.9%

Dishwasher2.2 L/p/d

1.9%

Bathtub2.6 L/p/d

2.3%


6.1%

Leak (Pot)1.4 L/p/d

1.2%

Clothes Washer

29.7 L/p/d20.7%

Shower45.6 L/p/d

31.8%

Tap26.3 L/p/d

18.3%

Dishwasher2.2 L/p/d

1.5%

Bathtub2.6 L/p/d

1.8%


15.3%


4.8%


4.3%

Leak (Pot)1.4 L/p/d

1.0%

Leak (Rec)0.7 L/p/d

0.5%Clothes Washer

28.3 L/p/d17.9%

Shower51.1 L/p/d

32.3%Tap28.6 L/p/d

18.1%

Dishwasher2.1 L/p/d

1.3%

Bathtub1.4 L/p/d

0.9%


13.4%


8.0%

Leak (Pot)13.0 L/p/d

8.2%

Total: 158.4 L/p/d Total: 143.5 L/p/d


a. Daily per capita consumption summer pre (L/p/d):

Single Reticulated (n=29)

b. Daily per capita consumption summer pre (L/p/d):

Dual Reticulated (n=98)

d. Daily per capita consumption summer pre (L/p/d):

Dual Reticulated (Recycled line only) (n=98)

c. Daily per capita consumption summer pre (L/p/d):

Dual Reticulated (Potable line only) (n=98)


- 233 -

dishwasher. In this data logging period, total irrigation consumption in the dual reticulated

region was practically equal with the single reticulated region being 13.1 L/p/d (potable +

recycled Figure 10-3b) or 9%, while the single reticulated region was 12.7 L/p/d or 8 (Figure

10-3a). In PC, irrigation on the recycled water line was just slightly lower than the potable water

line, being 6.2 L/p/d for recycled versus 6.9 L/p/d for potable. This may be due to the lack of

community awareness programs encouraging the use of recycled for irrigation in the dual

reticulated region. Recycled line toilet use accounted for 21.9 L/p/d while leakage was 0.7 L/p/d

(Figure 10-3d). In the summer pre-commissioning phase, recycled water consumption

accounted for 28.8 L/p/d or 20% of total end use in the dual reticulated region. Overall, other

end uses (shower, clothes washer, tap, toilet etc.) were very similar in volumetric consumption

across both regions. Clothes washer is slightly lower in the single reticulated region while

shower consumption is slightly higher, compared to the dual reticulated region. Bathtub usage is

higher in the dual than the single reticulated region (2.6 versus 1.4 L/p/d) due to young children

occupation. Leakage is also significantly higher in the single reticulated region (13.0 versus 2.0

L/p/d) due to two single reticulated homes experiencing week long leakage during the

monitoring period. This leakage volume is the reason for higher weekly average consumption in

the single reticulated region. Overall, the total volumetric consumption in the single and dual

reticulated regions was low due to high rainfall during the summer pre-commissioning data

collection period.

10.4.2 Post-Commissioning of recycled water to Pimpama Coomera region

As of the 1st of December 2009, recycled water was supplied to the PC region, which triggered

data collection for the summer post-commissioning period (i.e. Phase 2). The commissioning of

recycled water was launched with an extensive awareness campaign promoting its supply and

encouraging the use of recycled water in PC. Post-commissioning end use water consumption

data was sampled over the summer 2009/10 season, identified as December 2009 to the

beginning of March 2010. Two week data sets were taken from dissected samples over the

season to account for seasonal affects (predominately rainfall) on irrigation usage. In total, the

dual and single reticulated sample size was n=100 and n=34, respectively. During the post-

commissioning collection periods, Gold Coast City was on QWC’s permanent water

conservation target level of 200 L/p/d. Figure 10-2 shows that the end use water consumption

data collection period in December 2009, occurred when city wide bulk supplied water peaked

to its highest level (224.36 L/p/d), while February and March 2010 had reduced bulk values due

to lower temperatures and higher rainfall in these months (Figure 10-2). Understandably, the

irrigation end use category is the most variable and difficult to sample reliably. The strategy to

collect end use data from a portion of households over the season serves to provide a mean

irrigation volume for the sample in the season, but readers should note that irrigation end use

values have much higher variance around the mean than indoor end uses. Figure 10-4 illustrates


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the end use water consumption, post-commissioning of recycled water, in the single and dual

reticulated regions. Single reticulated region use is presented in Figure 10-4a, the dual

reticulated region potable and recycled combined supply in Figure 10-4b while, Figure 10-4c

and d detail the dual reticulated potable and recycled supply lines separately.

Figure 10-4 Post-commissioning end use water consumption data (summer 09/10)

As discussed, the overall total water consumption increase from pre-commissioning in 2008 to

post-commissioning 2010 data was due; to high rainfall in the 2008 logging periods, the capture

of a record high consumption period in December 2009 and a gradual increase in total

consumption across the study due to relaxed water restrictions and water conservation

messages. Recycled water consumption post-commissioning in the PC region saw a significant

increase of recycled water for irrigation purposes. Weather conditions during the post-


46.6%


48.9%

Leak (Rec)2.7 L/p/d

4.5%Clothes Washer

28.9 L/p/d23.2%

Shower43.3 L/p/d

34.8%

Tap28.0 L/p/d

22.5%

Dishwasher2.2 L/p/d

1.8%

Bathtub2.6 L/p/d

2.1%


15.0%

Leak (Pot)0.8 L/p/d

0.7%

Clothes Washer

28.9 L/p/d15.8%

Shower43.3 L/p/d

23.6%

Tap28.0 L/p/d

15.2%

Dishwasher2.2 L/p/d

1.2%

Bathtub2.6 L/p/d

1.4%


15.0%


10.2%


15.7%

Leak (Pot)0.8 L/p/d

0.4%Leak (Rec)2.7 L/p/d

1.5%

Clothes Washer

36.9 L/p/d21.5%

Shower52.7 L/p/d

30.6%

Tap33.3 L/p/d

19.4%

Dishwasher1.4 L/p/d

0.8%

Bathtub1.6 L/p/d

1.0%


13.5%


12.7%

Leak (Pot)1.0 L/p/d

0.6%



a. Daily per capita consumption summer post (L/p/d):

Single Reticulated (n=34)

b. Daily per capita consumption summer post (L/p/d):

Dual Reticulated (n=100)

d. Daily per capita consumption summer post (L/p/d):

Dual Reticulated (Recycled line only) (n=100)

c. Daily per capita consumption summer post (L/p/d):

Dual Reticulated (Potable line only) (n=100)


- 235 -

commissioning period were generally dryer than those experienced in the pre-commissioning

phase albeit both a high and low rainfall and consumption period of water use were captured.

The average consumption post-commissioning of recycled water to the PC region was 183.6

L/p/d (Figure 10-4b), a significant increase on pre-commissioning consumption of 143.5 L/p/d

(Figure 10-3b). Total consumption post-commissioning (183.6 L/p/d) consisted of 59.1 L/p/d or

32.2% being consumed on the recycled water line and 124.5 L/p/d or 67.8% consumed on the

potable line (Figure 10-4b). Recycled water irrigation was 28.9 L/p/d and potable irrigation was

18.7 L/p/d, both significantly higher than that recorded pre-commissioning. Recycled line toilet

use and leakage were at 27.5 L/p/d and 2.7 L/p/d respectively (Figure 10-4d), which is higher

than recorded pre-commissioning. Other end uses remained similar to those experienced pre-

commissioning with shower and clothes washer accounting for 43.3 and 28.9 L/p/d respectively

(Figure 10-4c). Overall, the major change in end use water consumption post-commissioning

was in irrigation, with other end uses remaining similar pre-and post-commissioning of recycled

water to the PC region.

Figure 10-4a demonstrates that the single reticulated regions end use data varies somewhat from

the dual reticulated region (Figure 10-4b). Firstly, total consumption is only 171.9 L/p/d, which

was 11.7 L/p/d or 6% less than the dual reticulated region. Irrigation in the single reticulated

region was 21.9 L/p/d which was similar to that recorded in PC on the potable line (18.7 L/p/d).

Clothes’ washing was slightly higher in the single reticulated region (36.9 versus 28.9 L/p/d)

with shower usage also higher (52.7 versus 43.3 L/p/d). Toilet usage was lower in the single

reticulated region being 23.1 L/p/d compared with 27.5 L/p/d in PC. Tap, dishwasher and

potable leakage were similar with bath use remaining higher in PC as has been the trend

throughout the study duration. As a note to readers, toilet end use demand averages reported

herein are more reliable and transferable to other schemes than irrigation. Irrigation end use

demand averages can fluctuate from season to season and year to year due to localised climatic

conditions (e.g. high rainfall summer reduces demand substantially) and are also less

transferable to other regions with different climatic conditions.

10.4.3 Comparison of Phase 1 prediction with Phase 2 data

When comparing the results of Phase 2 of the PC End Use study (summer post-commissioning

end use) with the recycled water uptake predicted in Phase 1 of the study (pre-commissioning

prediction based on winter 2008 data) the actual recycled water end use falls between the most

likely estimate, 53 L/p/d or 30.5% and the upper estimate of 64.2 L/p/d or 34.7% (Willis et al.,

2010a). The Phase 2 summer post-commissioning total recycled water usage was 59.1 L/p/d or

32.2% of total household end use (Figure 10-4d and b). Post-commissioning recycled water

consumption included irrigation 28.9 L/p/d, toilet 27.5 L/p/d and leakage 2.7 L/p/d. The pre-

commissioning most likely end use estimates from Phase 1, included irrigation of 30.6 L/p/d,


- 236 -

toilet 21.7 L/p/d and leakage 0.7 L/p/d. As seen in Figure 10-4, a difference in post-

commissioning end use was predicted for irrigation due to a likely change in demand instigated

by the presence of recycled water, while toilets and leakage consumption was not altered. The

pre-commissioning upper end use estimates included increased irrigation usage of 41.8 L/p/d.

When comparing recycled water end uses pre- and post-commissioning, recorded irrigation of

28.9 L/p/d (post-commissioning) was very close to the most likely estimate of 30.6 L/p/d. The

variation between the most likely prediction and actual post-commissioning end use is due to

the increase in toilet and leakage use. This demonstrates that the indicators and methodology

used to predict recycled water irrigation uptake post-commissioning was relatively accurate and

provides rigour to the utilisation of this predictive model for recycled irrigation uptake. While,

the differences between the Phase 1 recycled water uptake prediction and the Phase 2 actual

recycled water consumption are not dramatically different, this variation does support the need

to undertake data collection to verify predictions and assumptions. This data also allows for the

strengthening and validation of the Phase 1 PC End Use Study recycled water uptake prediction

model. Some alteration will need to be made to the predictive model to include an increase in

consumption for both toilet and leakage coinciding with an increase in average daily demand.

10.5 Compilation of end use average hourly diurnal patterns

10.5.1 Developed end use diurnal pattern software tool

A software tool was developed to assimilate data files containing household end use water

consumption events into patterns of average hourly use. The software was designed to read

water usage events from analysed end use data files (interchangeable Trace Wizard/MS-Access)

and collate the individual fixture use events into hourly usage periods across a day. The

tabulated data can be grouped within user selected time periods, from hourly (24 graph points)

through to five minute intervals (288 graph data points). This function enables the display of

data to the resolution detail required within an average day 24 hour period. The software can

collate single and/or multiple files as indicated by the user, in order to explore the determination

of water usage from particular regions, suburbs or homes with a particular socioeconomic status

or varying occupancy. The software outputs compiled data in the form of a spreadsheet and/or

graph. As further elaborated below, end use diurnal patterns, which are premised on actual high

resolution smart metering data for a particular region, provide essential information for a range

of infrastructure planning functions.

10.5.2 Diurnal patterns of consumption

Average hourly water consumption patterns demonstrate daily water demand and peak usage

throughout the day. Diurnal patterns were determined for both the single and dual reticulated


- 237 -

regions for total household consumption along with the dual reticulated potable and recycled

supply lines only (Figure 10-5).

Figure 10-5 Average hourly diurnal pattern profile: single and dual reticulated regions

Figure 10-5 illustrates the variation in daily water demand between the single and dual

reticulated regions. While total daily consumption was slightly higher in the dual reticulated

region, the single reticulated regions maximum peak was greater than that seen in the dual

reticulated region. Interestingly, the morning peak in the single reticulated region inclines

sharply to just above 22 litres per hour per person per day (L/h/p/d) between 8 am and 9am

(Figure 10-5), while the dual reticulated morning peak (total supply) rises more gradually to

reach a peak of just 16 L/h/p/d at 8am (Figure 10-5). This trend is reversed in the evening, with

the dual reticulated region peaking at 19 L/h/p/d at 7pm (total supply), while the single

reticulated evening peak is much more gradual reaching 12 L/h/p/d at 6pm. The diurnal pattern

for the single reticulated region is similar to the trend determined by Mead (2008) but differs to

that found by Roberts (2005). The apparent variations in diurnal characteristics and peak

demand between the supply regions (Figure 10-5) illustrate the impact of varying socio-

demographics and behaviours between the sample groups. When comparing the single

reticulated region with the dual reticulated regions potable supply the morning peak ranges from

22 L/h/p/d to just 12 L/h/p/d while the evening peak flows are both at 12 L/h/p/d. This

significant reduction in potable peak morning flow demonstrates the variation in potable

demand that can exist between single and dual reticulated supply regions. To further explore the

apparent differences in diurnal pattern between traditional single reticulated and dual reticulated

regions, end use diurnal patterns were examined.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Single Reticulation Total 0.68 0.50 0.53 0.83 0.96 2.81 8.64 21.52 21.86 13.51 10.26 8.18 9.50 8.02 7.50 8.00 10.90 12.48 10.29 7.73 9.02 6.11 3.98 2.15

Dual Reticulation Total 1.23 2.63 2.56 2.04 2.04 7.04 12.01 15.80 12.89 12.43 11.81 8.09 6.59 6.79 8.73 7.04 13.54 17.57 18.96 18.27 10.22 8.22 5.89 2.76

Dual Reticulation (Potable line only) 0.60 0.96 0.87 0.42 0.99 4.05 8.54 11.96 10.07 9.97 8.13 6.11 4.85 4.60 6.99 5.24 8.18 12.23 11.59 8.42 7.29 5.11 3.94 1.67

Dual Reticulation (Recycled line only) 0.63 1.67 1.69 1.63 1.05 2.99 3.47 3.84 2.81 2.46 3.68 1.98 1.74 2.20 1.74 1.80 5.36 5.34 7.38 9.86 2.93 3.11 1.95 1.09

0

2

4

6

8

10

12

14

16

18

20

22

24

Ave

rag

e d

aily

diu

rnal

co

nsu

mp

tion

(L/h

/p/d

)

Hour

Single Reticulation Total

Dual Reticulation Total

Dual Reticulation (Potable line only)

Dual Reticulation (Recycled line only)


- 238 -

10.5.3 End use diurnal patterns of consumption

Daily end use consumption patterns allow for the determination of water use events that

contribute to peak demands. Figure 10-6 present the diurnal patterns of the single reticulated

region (Figure 10-6a), dual reticulated region potable and recycled combined supply (Figure

10-6b), dual reticulated potable only (Figure 10-6c) and dual reticulated recycled line only

(Figure 10-6d). Figure 10-6a demonstrates that in the single reticulated region the largest peak

occurred between 8 and 9am with another small peak at 1pm and an evening peak at 6pm. The

sharp morning peak is predominantly due to showering and clothes washing. All other

household end uses are also higher in this morning peak with the exception of leakage.

Irrigation use appears to peak earlier in the morning than other end uses demonstrating an

alignment with current water restrictions and awareness messages that encourage outdoor

watering in early morning and late afternoon. Evening irrigation occurred between 5 to 7pm.

Leakage remains relatively consistent while dishwasher use occurred in the morning, after lunch

and after dinner. Bath use peaked in the morning while, tap use was at its highest between 8 to

9am and 6 to 8pm. Toilet flushing was highest in the morning and relatively consistent

throughout the day. Clothes washer use peaked in the morning between 7 and 9am and dropped

drastically after 10pm. In the single reticulated region shower use is the primary contributor to

the morning peak while, evening peak usage was due to irrigation and shower end use.

The end use pattern of daily demand for the PC dual reticulated region total (Figure 10-6b)

exhibited distinctive differences when compared with the single reticulated region (Figure

10-6a). Figure 10-6b illustrates the morning peak at 8am, with another small peak at 3pm, while

the greatest evening peak occurred between 6 to 8pm. Leakage is much lower in the dual

reticulated region generally present during the waking hours of the day. Dishwasher use peaks

in the morning and evenings. Bath use peaks in the evenings, while tap usage had similar peaks

in the morning and evenings with consistent use throughout the day. In PC (Figure 10-6b),

showering is the highest morning end use, as seen in the single reticulated region (Figure

10-6a). Showering peaks at 8am and between 6 to 7pm in the evening. Clothes washer use also

contributes to the morning peak between 8am to 10am, slightly later than the single reticulated

region. Irrigation on the potable line peaks at 3pm and again between 6 to 7pm.

- 239 -

a. Diurnal consumption: Single reticulated region (potable line only) b. Diurnal consumption: Dual reticulated region (combined potable + recycled)

d. Diurnal consumption: Dual reticulated region (Recycled line only)

c. Diurnal consumption: Dual reticulated region (Potable line only) c. Diurnal consumption: Dual reticulated region (Potable line only)

Figure 10-6 End use hourly diurnal pattern profile: single and dual reticulated regions

- 240 -

Figure 10-6 End use hourly diurnal pattern profile: single and dual reticulated regions

On the recycled water supply line (Figure 10-6b), leakage is highest between 10am and 12pm

and remains relatively consistent across the rest of the day. Toilet use with recycled water is

relatively even across the waking hours of the day with a slight peak in the morning and

evening. Recycled water irrigation is higher between 2 to 4am and inclines sharply in the

evening between 6 to 8pm (Figure 10-6b). Irrigation on the recycled line is the primary

contributor of the high evening peak; shower use is the highest contributor to the morning peak

(Figure 10-6b).

10.5.4 Variation in peaks between single and dual reticulated supply schemes

Dual supply regions introduce two separate reticulated supply sources to reduce the average

daily and peak demand on potable supply systems as experienced in single reticulated regions.

Figure 10-6c and d present the diurnal demand experienced in the dual reticulated system on the

potable and recycled water pipelines, respectively. When comparing the single reticulated

regions diurnal demand (Figure 10-6a) with the dual reticulated regions potable diurnal demand

(Figure 10-6c) a significant reduction in peak morning demand is apparent while, the evening

demand remains relatively similar. The recycled water supply pipeline removes toilet flushing,

some irrigation and leakage in both the morning and evening peaks. The recycled water supply

reduces the peak morning demand by 4 L/h/p/d and the evening peak by 10 L/h/p/d in the dual

reticulated region when looking at the combined potable and recycled water supply (Figure

10-6b). This is a significant saving when considering the sizing of water supply infrastructure

for peak demands. The use of recycled water for clothes washing (occurring in some dual

reticulated regions in Australia) has the potential to reduce the peak morning demand by an

additional 4 L/h/p/d. While, the diurnal patterns of demand do differ between the single and

dual reticulated supply regions, the introduction of a recycled water supply network does reduce

the average daily demand and peak demands when compared with traditional single reticulated

supply. Understanding end use daily patterns of demand has significant application and

implication for sustainable urban water planning and management.

10.6 Conclusions, Implications and Future Directions

The results from this end use investigation provide much needed data for the verification of end

use water consumption and daily demand patterns in single and dual reticulated water supply

regions. This is a unique world first investigation predicting and measuring actual end use water

consumption in a dual reticulated water supply region. The recycled water uptake, post-

commissioning (Phase 2), was higher than initially predicted pre-commissioning (Phase 1)

primarily due to increases in toilet and leakage consumption. The predictive model focussed on

post-commissioning increases of irrigation which, resulted in the predicted versus actual


- 241 -

recycled irrigation end use being very close. Post-commissioning of recycled water in the PC

region resulted in this supply providing 59.1 L/p/d or 32.2% of total daily consumption. Of this,

irrigation on the recycled water line was 28.9 L/p/d or 15.7% of total daily consumption

compared to the predicted most likely uptake of 30.6 L/p/d. Understanding the baseline recycled

water consumption, and the variation in irrigation and other end uses through high and low

demand periods from climatic conditions, provides data to assist in predicting and modelling

yearly demand and supply for potable and recycled water infrastructure in dual reticulated

regions. This also applies to single reticulated regions.

Validating the daily diurnal patterns for both single and dual reticulated regions demonstrates

maximum and average demands in these supply schemes and identifies the end uses which

attribute to peaks. Such data is invaluable for modelling and forecasting demand and supply and

for verification of assumptions in desired standards of service and other water services

infrastructure planning documentation. The end use diurnal patterns determined for the PC

region provides support for the implementation of dual reticulated supply schemes as they can

provide significant reductions in peak demands on potable water infrastructure. The potable

water demand peaked at 12 L/p/h/d in the dual reticulated region compared with 22 L/p/h/d in

the single reticulated region. Such significant reductions in peak demand would allow for

reductions in pipe sizing and treatment volumes of potable water for this region.

The collected end use data from the PC End Use Study will inform the sizing of infrastructure,

can assist in delaying infrastructure upgrades and also validating and directing water treatment

and pumping requirements of potable and recycled water to regions in the Gold Coast,

Australia. Understanding recycled water demand also allows for accurate forecasting of

recycled water discharges for the environment. The data also provides verification of the

assumptions made in the PCWF Master Plan for recycled and potable water consumption and

savings. Data can also be used to inform the development of demand management messages to

offset peak usage periods i.e. encouraging showering in later hours of the day when possible and

to encourage PC residents to use recycled water almost exclusively for external irrigation.

Overall, the results from this study support the application of dual reticulated schemes through

significant reductions in peak demand on potable water supply infrastructure and by the

reduction of average potable water demand by 59.1 L/p/d or 32.2%. The diurnal patterns of

daily demand differ extensively between the single and dual reticulated regions demonstrating

the unique consumption patterns in these alternative supply schemes. Information gathered

through this study will assist in the refinement of predictions and assumptions for both end use

and diurnal demands for single and dual reticulated regions water infrastructure planning. It will

allow for accurate forecasting and modelling resulting in informed decision making for water


- 242 -

infrastructure sizing and upgrades and future supply and demand requirements in the Gold

Coast.

10.7 References






Commonwealth of Australia (2008a) Drought. online article, available at http://www.bom.gov.au/lam/climate/levelthree/c20thc/drought.htm Accessed 20/03/08. Bureau of Meteorology.






GCW (2004) Pimpama Coomera Waterfuture Master Plan March 2004. Gold Coast, Gold Coast Water and Gold Coast City Council.




- 243 -



Hurlimann, A. & McKay, J. (2006) Urban Australians using recycled water for domestic non-potable use—An evaluation of the attributes price, saltiness, colour and odour using conjoint analysis. Journal of Environmental Management, Vol: 83, pp. 93-104.












Turner, A., White, S., Kazaglis, A. & Simard, S. (2007) Have we achieved the savings? The importance of evaluations when implementing demand management. Water Science and Technology: Water Supply, Vol 7:5-6, pp. 203-210.




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Willis, R., Stewart, R. & Emmonds, S. (2010a) Pimpama-Coomera dual reticulation end use study: pre-commission baseline, context and post-commission end use prediction. IWA Water, Science and Technology: Water Supply, Vol 10:3, pp. 302-314, DOI: 10.2166/ws.2010.104.

Willis, R., Stewart, R., Panuwatwanich, K., Capati, B. & Giurco, D. (2009) Gold Coast Domestic Water End Use Study. Journal of Australian Water Association Vol 36:6, pp. 79-85.

Willis, R. M., Stewart, R. A., Panuwatwanich, K., Jones, S. & Kyrakides, A. (2010b) Alarming visual display monitors affecting shower end use water and energy conservation in Australian residential households. Journal of Resources, Conservation and Recycling, Vol 54:12, pp. 1117-1127, doi:10.1016/j.resconrec.2010.03.004.



Zhou, S. L., McMahon, T. A., Walton, A. & Lewis, J. (2002) Forecasting operational demand for an urban water supply zone. Journal of Hydrology, 259, 189-202.

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Chapter 11

Conclusions, Contributions and Implications

Presented in this final chapter, is a summary of the key findings of this research. The

contributions and limitations of the research are detailed along with recommendations for future

research directions. The chapter begins with Section 11.1, which reiterates research objectives

and highlights the key outcomes which satisfied these objectives. Section 11.2 identifies the

theoretical and practical contributions made by this study. The limitations of the research and

suggestions for future study in the urban water management field are presented in Section 11.3.

Section 11.4 concludes the chapter and thesis discourse.

11.1 Research Objectives and Outcomes

The principle objectives of this research were: (1) to investigate end use water consumption

breakdowns in detached residential households; (2) to determine the potable water savings

attributed to water demand management initiatives and dual reticulated recycled water schemes

and; (3) to assess the relationship between consumer attitudes and end use consumption. More

specifically, it aimed to establish residential end uses in both traditional single reticulated

households and non-traditional dual reticulated households and to ascertain diurnal patterns for

both of these supply types in the context of the Gold Coast, Australia. Water demand

management initiatives investigated included water efficient devices and resource consumption

awareness devices. Socio-demographic factors were also examined to determine those that

significantly affected end use water consumption. Moreover, the link between attitudes and

residential end use water consumption was verified. These components culminated in the

development of a comprehensive domestic end use database for the Gold Coast as well as

evidence that supports the influence of water demand management and source substitution

measures, for conserving precious potable water supplies. To achieve the vast array of

objectives, a number of research activities were carried out. A summary of these research

activities and their associated outcomes are presented in Figure 11-1.


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PUBLICATION








consumption






Australia



Pub

Pub

Pub

Pub

Pub

Pub



Figure 11-1 illustrates the three phased approach undertaken to achieve the research objectives

and the outcomes of each phase/stage, predominantly in the form of a refereed journal

publication. Further detail on each phase and respective stages are presented below.

Chapter 11: Conclusions, Contributions and Implications

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11.1.1 Knowledge acquisition

To establish a robust framework for the research, existing literature including research

publications, academic and industry reports were critically reviewed, as presented in Chapter 2

and within the introductory section of Chapters 5 through to 10. This review focused

predominantly on the development, implementation and measurement of water demand

management and dual reticulated recycled water source substitution, as well as advanced water

monitoring technologies and the measurement of end use water consumption. This literary

investigation determined the need to measure the effectiveness of water demand management

initiatives and dual reticulated recycled water supply schemes at an end use level. The

establishment of wider research objectives allowed for the formation of paper-specific

objectives and research questions to address some of the gaps identified in this phase of the

research. Two distinct phases emerged being, water end use with demand management, and dual

reticulated recycled water schemes.

11.1.2 Water end use and demand management

Phase 2 of the research investigation (Figure 3-3 and Figure 11-1) involved the adoption of

numerous research methods to investigate potable end use water consumption and the end use

water savings attributed to various water demand management initiatives. Primarily, this phase

included: establishing an understanding of residential end use study design; determining

appropriate technology for end use data collection; verifying the sample size, research region

and recruitment approach; determining the end use consumption monitoring process and data

acquisition approach; developing water stock audits and interview questions and undertaking

these with each participant in the study to validate stock and end use water consumption

behaviour in households; undertaking analysis of end use water consumption data;

development, application and analysis of a questionnaire survey to establish socio-

demographics and attitudinal perceptions surrounding water related issues; and, the recruitment,

delivery and analysis of a water demand management educational shower monitor for a sub-

sample of the research participants.

Detailed research approaches undertaken to carry out these activities are discussed in Chapters

5, 6, 7 and 8 along with the results of analysis. Chapter 5 presented the initial findings from the

Gold Coast Watersaver End Use Study based on data collected in winter 2008. This end use

data collection period occurred just a few months after drought breaking rainfall, hence

residents were generally consuming at a low level for irrigation. The chapter detailed the end

use monitoring approach along with the specifics of the project schedule for the study duration.

The average end use water consumption was recorded at 157.2 L/p/d with shower, clothes

washer and tap use dominating household end use. Irrigation was measured at 18.6 L/p/d or


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11.8% of total end use; this low use was attributed to moderate rainfall during the data

collection period and a shift in culture towards reduced garden irrigation. The end use water

consumption on average, was lower than that found in any earlier national and pacific end use

studies. A section questioning the use of volumetric or percentages for end use water

consumption modelling and forecasting argued for the use of volumetric consumption due to the

similarities and differences seen between the current and earlier end use studies. The

investigation determined that end use water consumption varied significantly between

individual households with the highest per person consumption recorded at 390 L/p/d and the

lowest at 38.4 L/p/d. It was also found that a small percentage of homes were responsible for a

large percentage of total recorded consumption for both showering and irrigation, triggering the

need to identify and effectively manage such homes water consumption. Comparative

assessment utilising basic demographic information determined that households in the higher

socioeconomic regions consumed more water per capita than those in lower socioeconomic

regions.

Chapter 6 presented the results of a mixed methods investigation into the relationship between

winter 2008 end use water consumption and socio-demographic factors. Moreover, the actual

end use water consumption savings attributed to water efficient devices was examined and pay-

back periods for water efficient shower heads, clothes washers and rainwater tanks (RWTs) was

determined. For this investigation, end use water consumption data, questionnaire survey data,

water audit and water behaviour interview data was utilised. The use of these multiple data

sources enabled validation of end use consumption and behaviours within households and

allowed for the analysis of various socio-demographic variables and the influence of water

efficient devices. It was found that socio-demographic factors such as household income,

household resident typologies, lot size and RWT ownership influenced relevant end uses. An

interesting finding was that actual water savings associated with the installation of water

efficient devices (e.g. washing machine, shower rose restrictors etc.) was higher than reported in

previous investigations with this phenomenon hypothesised to be due to the extremely low

average water consumption measured. Financial payback periods were determined with results

indicating the payback period of showerheads to be less than half a year, clothes washers to be

6.5 years and rainwater tanks to be 21 years. The payback period of RWTs at 21 years was high

due to the low consumption experienced for irrigation; further investigation on the payback

period of RWTs was recommended.

Chapter 7 presents the results of an investigation into understanding the relationship between

end use water consumption and environmental and water conservation attitudes. Again, a mixed

method design was adopted to carryout this investigation. A thorough critique of literature

occurred to develop the theoretical background pertinent to the development of environmental


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and water conservation attitudinal constructs. Propositions were developed and tested through a

mixed methods research approach. End use water consumption data, questionnaire survey data,

water audit and behaviour interview data were analysed using a number of statistical methods

(e.g. ANOVA, cluster analysis etc.) to achieve stated objectives. This resulted in the

determination of two constructs to measure attitudes of concern for the environment and water

conservation awareness and practice. Statistical analysis verified that resident’s fell either

within a moderate to high concern (MHC) level for environmental and water conservation

practice or a very high concern (VHC) level for the two attitudinal constructs. End use water

consumption was established for the entire research sample with a total use of 152.3 L/p/d.

Investigation on the unique end use water consumption for the MHC and VHC residential

groups determined that the VHC residents consumed significantly less water in total (128.2

L/p/d) than the MHC group of residents (169.0 L/p/d). At an end use level, VHC residents

consumed significantly less water in discretionary end uses of shower, clothes washer, tap and

irrigation when compared with the MHC residents. These results provide support for the

hypothesis that a very high level of concern for the environment and water conservation resulted

in lower water consumption across discretionary end uses. The residents within the VHC group

had a higher representation of families with slightly higher incomes, albeit this difference was

not significant.

Chapter 8 details the design and results from an investigation into the shower end use water

consumption savings attributed to an alarming visual display monitor. This investigation was

carried out to ascertain the effectiveness of an advanced resource conservation water demand

management technology on the highest end use consumption activity in residential households.

Again, a mixed methods design was adopted with both pre- and post-intervention end use water

consumption data recorded to establish the water savings attributed to the shower monitoring

device. The alarming visual display shower monitor was installed in 44 households from the

wider research sample with pre-and post-intervention data analysed through t-tests. The

reduction in average shower duration was found to be significant along with a decrease in the

rate of higher duration showers. The volume of showers was also significantly reduced post-

intervention with the median shower event falling below the stipulated 40 L per shower target.

The flow rate of showers with the alarming monitor was also significantly reduced. Resource

conservation and financial modelling determined that the payback period for the alarming

shower monitor device would be 1.65 years based on conservative cumulative water and energy

savings. Wider non-monetary benefits were also explored. This chapter concluded the water end

use and demand management phase of the study. Phase 3 focused on the dual reticulated

recycled water element of the research; details on this final research phase are presented below.


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11.1.3 Dual reticulated recycled water

Phase 3 involved the adoption of methods and analysis techniques to investigate the potable end

use water consumption savings attributed to the supply of recycled water to dual reticulated

residential households in the Pimpama Coomera (PC) region (Chapter 3). Primarily, this phase

included: the development, application and verification of a predictive recycled water uptake

model, pre-commissioning of recycled water to the PC region; measuring end use water

consumption in the PC region post-commissioning of recycled water; validating end use water

consumption in the PC region for both recycled and potable water; and developing a tool to

ascertain diurnal consumption patterns for dual and single reticulated regions. Two papers

containing pertinent literature, methods, data and results, are detailed in Chapters 9 and 10.

Chapter 9 presents the pre-commissioning end use water consumption recorded in the PC region

and details the construction of a model to predict the recycled water uptake in the PC region

post-commissioning. An overview of other residential dual reticulated recycled water regions is

discussed along with predicted and recorded bulk supplied consumption attributed to these

schemes. The literature review established that there was no end use water consumption data

recorded for residential dual reticulated recycled water supply schemes. Full detail on the

Pimpama-Coomera Dual Reticulation End Use study was presented including an overview of

the PCWF Master Plan. The mixed methods approach utilised throughout the study was adopted

to determine baseline end use water consumption data pre-commissioning. Literature and uptake

recorded in other dual reticulated regions were considered to assist in predicting potential post-

commissioning recycled water consumption. Some of the influencing parameters were: level of

water restriction, influence of customer water source preferences, price of recycled and potable

water, climatic parameters, lot sizes and the presence of a recycled water uptake awareness

campaign. The most likely predicted uptake of recycled water was determined to be 53 L/p/d or

30.5% of total end use water consumption (i.e. 30.5% A+ recycled supply and 69.5% potable

supply).

Chapter 10 deliberates the actual end use water consumption measured post-commissioning of

recycled water to the dual reticulated region of PC. Details of the pre-commissioning prediction

of recycled water uptake and the objectives of the PC Dual Reticulated End Use study are

revisited. Additional data from the summer pre-commissioning phase was presented. Again, a

mixed method research approach was followed to measure and analyse end use water

consumption post-commissioning with comparisons between the single reticulated control

group and the dual reticulated group made. Overall, it was found that post-commissioning end

use water consumption on the recycled water line was 59.1 L/p/d or 32.2% of total end use

consumption. This recorded recycled water end use consumption was slightly higher in the post-

commissioning data collection phases primarily due to increases in toilet and leakage


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consumption. This measured used was very close to that predicted in Chapter 9. The developed

‘Diurnal’ software enabled the compilation, analysis and presentation of end use diurnal pattern

apportionment for both single and dual reticulated regions. Diurnal patterns of use in the dual

reticulated recycled water supply region were very different to those seen in the single

reticulated region. Overall, the supply of recycled water to the dual reticulated region almost

halved the peak hour potable demand when compared to the single reticulated region.

Discussion on the application of empirically determined dual reticulated end uses and diurnal

patterns of consumption for infrastructure planning concluded this chapter.

11.2 Study Contributions

Water demand management initiatives and source substitution measures have been developed

and implemented throughout Australia and world. While the planning and application of such

water security options is widespread, the measurement and verification of the actual water

savings attributed to such initiatives is limited. Furthermore, end use investigations to verify the

potable water savings resulting from the introduction of residential dual reticulated recycled

water has not been reported in national or international literature. With this in mind, the herein

described research was carried out with a view to collect actual end use water consumption data

to support these empirical investigations. Contributions to the existing body of knowledge along

with implications for the urban water planning and management field are outlined in the

following sections.

11.2.1 Contributions to existing body of knowledge

Undeniably, the integrated water resource management field is well developed with

methodologies and application well documented. However, the measurement and validation of

the total and end use water consumption savings attributed with the application of water demand

management and source substitution measures is limited. Such end use data is necessary to

validate water resource planning and modelling assumptions. Moreover, no statistically

significant end use study has occurred in Queensland nor has an investigation into the

effectiveness of water efficient devices and the influence of socio-demographics on

consumption. An understanding of the relationship and influence of residential attitudes on

internal end use water consumption categories was another link missing within the reported

literature. Additionally, no investigation revealing an end use consumption breakdown for dual

reticulated recycled water schemes could be sourced in worldwide literature.

This study utilised a mixed method research approach to investigate the above mentioned

research gaps. The approach enabled the determination of end use water consumption for single

and dual reticulated households in the Gold Coast, along with the measurement of end use water


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consumption savings related to water efficient devices, educational prompt devices, positive

environmental and water conservation attitudes and the application of dual reticulation for

residential use. Specific contributions to the current body of knowledge are elaborated:

The research provided water consumption volumes and percentages for all residential

end uses within both single and dual reticulated regions for the Gold Coast City. Data

collected covered winter and summer seasons, for pre- and post-commissioning of

recycled water. End use studies with greater scope and frequency are highly encouraged

and required (Giurco et al., 2008a; Schlarfrig, 2008). The acquisition of such data is

important for daily demand forecasting and in the refinement of the planning and

management of water demand and supply for the Gold Coast and other regions across

Australia (Gato, 2006). Internal end use consumption volumes remained similar

throughout the research duration while irrigation altered dramatically with climatic

variables. The use of volumetric consumption for forecasting and planning was reported

as preferential to the use of traditional percentages.

Empirical end use water consumption data was ascertained for water efficient

showerheads and clothes washers. Only one other investigation of this nature has been

reported in Australia (Roberts, 2005) with results differing substantially due to higher

total consumption in the 2005 study and the ongoing advances in water efficiency

technologies. Payback periods for water efficient showerheads and clothes washers

were less than half a year and 6.5 years respectively. The variation in end use irrigation

consumption between those households with or without rainwater tanks was also

examined with statistically significant savings reported albeit payback periods being

high.

The influence of environmental and water conservation attitudes on end use water

consumption was established. While, the connection betweens attitudes and water

consumption behaviour had previously been established, an empirical study revealing

actual end use consumption data to measure attitudes, had not been carried out

(Nancarrow et al., 1996; Hassell and Cary, 2007). Attitudes of very high concern for the

environment and water conservation were found to significantly reduce total and

discretionary end use water consumption volumes. Residents with moderate concern for

the environment and water conservation consumed significantly more total and

discretionary end use water than those with very high concern. The results from this

investigation support the ongoing communication of demand management awareness

messages to influence positive environmental and water conservation attitudes, which

will in turn, result in reduced water consumption.

The study determined that showering was one of the highest end uses within homes;

hence methods to reduce this behaviourally influenced end use were researched. An

investigation into the potential end use water savings of a resource consumption display


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monitor which prompts users to end a shower a set volume of water used was a first of

its kind reported in the literature. The introduction of this resource awareness device

resulted in significant reductions in shower duration, volume and flow rates. The

payback period for the awareness device calculated from water and energy savings to

the household was just 1.65 years. This investigation promotes the merits of introducing

self awareness devices within homes to assist in reducing resource consumption,

ultimately helping to reduce urban ecological footprints.

There are numerous residential dual reticulated recycled water supply schemes within

Australia with each scheme being premised on engineering estimates of recycled water

uptake using a range of assumptions. No end use water consumption investigation has

been undertaken in a residential dual reticulated recycled water supply region (WSAA,

2002). End use data was captured both pre- and post-commissioning of recycled water

to the sampled households in the PC region, a smaller sample within a traditional single

reticulated region was also retained as the control group. Pre-commissioning data was

combined with influencing factors determined from literature to establish a predictive

model for the uptake of recycled water in the PC region. Monitored post-commissioning

recycled end use water consumption was slightly higher than that predicted with toilet,

leakage and irrigation increasing slightly due to the lack of water

restriction/conservation messages and climatic factors. Diurnal patterns for both dual

and single reticulated residential supply systems were determined at an end use level

with average daily demand patterns differing significantly between the two supply

schemes. The single reticulated region demonstrated trends seen previously for these

traditional schemes with the highest peak in the morning and another smaller peak in

the evening. The dual reticulated region had a much lower potable supply morning

peak, inclining more gradually when compared to the single reticulated region.

Moreover, the evening peak was higher than the morning peak with the key contributor

being recycled irrigation consumption. The variation in hourly end use demand seen in

the PC dual reticulated region, when compared to a single reticulated region supports

the need to undertake end use water consumption analysis to improve forecasting

estimates for these diversified supply schemes.

11.2.2 Implications for water planning and management

Along with an array of theoretical contributions, this study provides numerous practical

applications for the water planning and management industry. Almost all data that was

collected, analysed and complied throughout this research journey can be utilised to improve

water services planning, modelling and forecasting, as well as to support water demand

management and source substitution as effective urban water resources management initiatives.

Particular implications to the water planning and management industry are as follows:


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End use water consumption data acquired from the Gold Coast region can be used to

update and verify planning and modelling assumptions utilised in documentation, such

as the desired standards of service, and for accurate modelling of water use and waste

water discharges. The obtainment of actual diurnal patterns of consumption is also

essential for the verification of, and use in, planning documentation. This data is also

extremely useful for understanding the elements and factors that influence residential

demand hence assisting to improve residential demand forecasting.

Validation of real end use water savings and payback periods attributed to water

efficient devices, rainwater tanks and resource consumption display shower monitor

devices provides evidence to strengthen the application of water demand management

initiatives. The results from this study significantly support the introduction and use of

water efficient showerheads and clothes washers and promotes the application of

resource awareness devices to reduce end use and total household water consumption.

Moreover, results provide water demand management professionals with an

understanding on where educational programs should be targeted to obtain the highest

effective household water savings. Findings also support the continuation of awareness

and education programs to instil sustainable water consumption and environmental

attitudes. Learning’s are applicable for consumption reduction for other resources i.e.

energy, waste or materials and for use across commercial and industrial sectors.

Analysing consumption in a dual reticulated recycled water region provided world first

data on end uses and diurnal patterns in these unique source substitution areas. End use

data determined that, as predicted, toilet and leakage remains relatively consistent

throughout the year, while irrigation is strongly impacted by climatic conditions and the

promotion of recycled water uptake. Total potable water consumption was reduced by

37.2% through the introduction of recycled water. Diurnal patterns showed that the peak

hour demand on the potable water supply system is almost halved through the supply of

recycled water. The acquisition of such data is invaluable for water services planning,

and the forecasting and modelling of supply and demand within water supply regions.

Furthermore, such data assists in the verification of urban water planning assumptions

such as those presented in the desired standards of service reports.

11.3 Study Limitations and Future Research Directions

This study included a variety of methods, numerous rigorous analysis procedures and produced

an array of theoretical and practical results for immediate application. Despite this, there were

several limitations identified. These limitations together with recommendations for future

research directions are as follows:


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The study investigated residential end use water consumption in single detached

households on the Gold Coast. Additional monitoring of dual lot dwellings, townhouses

and units could be carried out to compare with indoor end uses found in single detached

dwellings. Further end use research throughout other regions in Queensland is

recommended. Such a study is underway, with the Urban Water Security Alliance

commissioning an SEQ wide study to investigate differences in location specific end

use consumption.

Due to the delay in the commissioning of recycled water to the PC region, the winter

end use data log was not carried out. End use water consumption data collection and

analysis in the winter period will assist to further verify low and high use seasons.

Collection of end use data over a longitudinal basis in line with climatic trends will also

assist in verifying the exact impact of climate on end use consumption in the Gold

Coast.

Additional investigations on the long term effectiveness of the educational shower

monitor prompt devices are necessary to determine if water savings would continue in

the long term. The use of a larger sample size would also assist in verifying results and

determining appropriate shower volumes for different demographic subsets. The

application of questionnaires or interviews to better understand perceptions of the

device and its affect on behaviour change would provide interesting outcomes for

sustainable consumption behaviour theory. Furthermore, the monitoring of energy use

attributed to end use water consumption in the home would verify and strengthen the

predictions on energy savings and subsequently the payback period of such devices.

Measuring and understanding the energy savings related to water demand management

initiatives will promote the uptake of these measures. The water energy nexus is an area

which requires significant applied research attention, especially with the need to move

towards sustainable resource consumption.

The development of a knowledge base containing sustainable urban water management

information to inform the most appropriate initiatives to implement for both short and

long term water security would greatly assist water management in Australia. National

policy formulation would result from the development of such a platform.

11.4 Closure

An explanatory mixed method research design was carried out to determine end use water

consumption data for single and dual reticulated, Gold Coast single detached residential

households. More specifically, the study determined the potable water savings attributed to

water demand management initiatives including efficient and resource consumption awareness

prompt devices; the relationship between environmental and water conservation awareness


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attitudes on end use water consumption; and the end use consumption in a dual reticulated

supply region pre- and post-commissioning of recycled water. An introduction, overarching

literature review, research method and situational context explanation is presented in the first

four chapters of the dissertation. These chapters form the foundation for the research.

This dissertation is predominantly composed of peer-reviewed papers related to the various

research objectives contained within the two distinct phases of the project namely, water end

use and demand management; and dual reticulated recycled water end uses. Chapters five

through to ten are reformatted journal manuscripts (published, accepted or submitted) which

include their own background, literature review, research method, data analysis, results and

discussion. Finally, this dissertation concluded with a summary of the research contributions,

implications and limitations as well as proposed recommendations for future research in the

sustainable urban water management field.

11.5 References






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Appendices

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Appendix A Demographic Investigation of Gold Coast

Regions


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Community Profile - http://203.84.234.220/Profile/GoldCoast/Default.aspx?id=292

Parkwood/Arundel - consider uni students

Ashmore/Benowa - consider older population and more people owning their homes)

Molendinar – consider govt owner properties and couples with older kids

Carrara – has significantly lower income

Mudgeeraba – slightly lower income and more people purchasing but not significant

Pimpama – Coomera

More people per household than average

More renters than people purchasing

Appendices

- 273 -

High incomes / High households of parents with young kids

Skewed towards younger population - parents with young kids

Unusual that there is a proportion of high incomes combined with a high proportion of renters. Possible

that people are renting in Pimpama Coomera until they build or buy elsewhere. Or maybe new generation

is investing their money elsewhere (other than in their own homes)???


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Parkwood – Arundel (compared to Pimpama Coomera)

More people per household

Slightly people purchasing than renting

Slightly lower income

Appendices

- 275 -

More people aged 12-24, maybe due to uni being close by

Ashmore – Benowa (compared to Pimpama Coomera)

Slightly less people per household More people purchasing/owning than renting

Lower income More one parent families

Older population


- 276 -

Molendinar (compared to Pimpama Coomera)

Slightly more people per household

Similar pattern in purchasing vs. renting but higher level of Govt. owned properties

Lower income / Couples with older children

Appendices

- 277 -

Older kids – higher proportion of 12 to 24 yr olds.

Carrara – Merrimac (compared to Pimpama Coomera)

Slightly less people per household / Similar pattern of renting vs. purchasing


- 278 -

Lower income / Less number of couples with kids

Similar

Mudgeeraba (compared to Pimpama Coomera)

Slightly more people per household / More people purchasing then renting

Appendices

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Lower income / Similar

Similar

Helensvale


- 280 -

Elanora

Edens Landing – Holmview

Appendices

- 281 -

Oxenford – Maudsland


- 282 -

Appendix B Participant recruitment letter

Appendices

- 283 -


- 284 -

Appendix C Frequently asked questions

Appendices

- 285 -


- 286 -

Appendices

- 287 -


- 288 -

Appendix D Participant consent form

Appendices

- 289 -


- 290 -

Appendix E Water audit and interview

Appendices

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- 292 -

Appendices

- 293 -


- 294 -

Appendices

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- 296 -

Appendix F Questionnaire Survey

Appendices

- 297 -


- 298 -

Appendices

- 299 -


- 300 -

Appendices

- 301 -


- 302 -

Appendices

- 303 -


- 304 -

Appendices

- 305 -


- 306 -

Appendices

- 307 -

Appendix G Letter for questionnaire survey