title slide an investigation funded through the innovative water strategies division of the texas...

Title SlideTitle Slide

An investigation funded through theAn investigation funded through the

INNOVATIVE WATER STRATEGIES INNOVATIVE WATER STRATEGIES

Division of the Division of the

Texas Water Development BoardTexas Water Development Board

11

Research TeamResearch Team Meredith Blount Miller – Meadows Center Stacy Bray – Meadows Center David Venhuizen, P.E. – Venhuizen Water

Works Karen Ford – White Hat Creative

22

““Building-scaleBuilding-scale”” Systems Systems

Independent rainwater Independent rainwater harvesting system for each harvesting system for each

buildingbuilding

THETHE strategy for all buildings: strategy for all buildings:

not an optionnot an option

33

Collective O&M and Collective O&M and ASSURED backup supply ASSURED backup supply

systemsystem

44

Study Focus: Texas Hill Study Focus: Texas Hill CountryCountry

Photo Courtesy of Hill Country Alliance- 2012 Calendar Contest 55

Water Supply OptionsWater Supply Options

Private well Private well on each loton each lot

Community well Community well and water and water

systemsystem

66


Connect to area-wide water systemConnect to area-wide water system

77

Water Supply OptionsWater Supply OptionsRegional pipelinesRegional pipelines

88


Rainwater HarvestingRainwater Harvesting!!!!

99

Why is a Why is a development-wide development-wide

rainwater harvesting rainwater harvesting SYSTEMSYSTEM

a good option?a good option?

1111

Rainwater Harvesting isRainwater Harvesting is

MORE EFFICIENTMORE EFFICIENT

1212

83% of rainfall onto the 83% of rainfall onto the Barton Springs watershed Barton Springs watershed

was lost to was lost to evapotranspiration, and evapotranspiration, and

never made it to a reservoir never made it to a reservoir or aquifer.or aquifer.

1313


MORE EFFICIENTMORE EFFICIENT

1414

Rainwater HarvestingRainwater Harvesting

““FITSFITS”” IN THE HILL COUNTRY IN THE HILL COUNTRY

1515


REDUCES UP FRONT COSTREDUCES UP FRONT COST

Developers should like this a Developers should like this a lot!lot!

1616


REDUCES FISCAL RISKREDUCES FISCAL RISK

Developers should like this a Developers should like this a lot!lot!

1717


UNDER THE USERS’ CONTROLUNDER THE USERS’ CONTROL

1818


MORE RELIABLEMORE RELIABLE

1919


MORE SUSTAINABLEMORE SUSTAINABLE

2020

Roof-harvested rainwater isRoof-harvested rainwater is

BETTER WATERBETTER WATER

2121

Water from wells and reservoirs is DEGRADED Water from wells and reservoirs is DEGRADED from quality of the original rainwater.from quality of the original rainwater.

2222


USES LESS ENERGYUSES LESS ENERGY

2323

Many reasons to consider Many reasons to consider building-scale RWH!building-scale RWH!

2424

Overview of Project Overview of Project ActivitiesActivities

Yield-demand modelingYield-demand modeling Backup supply optionsBackup supply options Regulation and governanceRegulation and governance Building design issuesBuilding design issues Cost effective analysisCost effective analysis MarketabilityMarketability SustainabilitySustainability Outreach/disseminationOutreach/dissemination

2525

The Modeling ProcessThe Modeling Process Simulate rainwater collection and use in Simulate rainwater collection and use in

househouse Shows Shows ““right sizeright size”” of RWH facilities of RWH facilities ““Right sizeRight size”” = size required for long-term = size required for long-term

sustainabilitysustainability Determined by backup supply requirementsDetermined by backup supply requirements ASSURED backup supply = RELIABILITYASSURED backup supply = RELIABILITY

2626

Rainwater Harvesting Rainwater Harvesting ModelModel

Average rainfall models inadequateAverage rainfall models inadequate Weather is not averageWeather is not average Multi-year modelMulti-year model Through wet and dry cyclesThrough wet and dry cycles Used 25-year model, 1987-2011Used 25-year model, 1987-2011 Covers the Covers the ““critical periodcritical period””

2727

Courtesy of John W. Nielsen-Gammon

Professor and Texas State Climatologist

Department of Atmospheric Sciences

28282828

Lowest 12-month rainfall Lowest 12-month rainfall totalstotals

1987-20111987-2011

29292929

Right-Size for OutlierRight-Size for Outlier 2010-2011 drought controls 2010-2011 drought controls ““right-right-

sizingsizing”” Outlier Outlier Very infrequent Very infrequent Right-sized for any future conditionsRight-sized for any future conditions Reliable and sustainableReliable and sustainable

3030

31313131

32323232

RoofprintRoofprintRoof area off of which rainwater is collectedRoof area off of which rainwater is collected

3434

Roofprint is the plan Roofprint is the plan area of the ROOF, all area of the ROOF, all

the roof, NOT the the roof, NOT the HOUSE areaHOUSE area

3535

Interior Water UseInterior Water Use

3636

Interior Usage Rate for Interior Usage Rate for RWHRWH

35 gpcd – presumed by RWH designers35 gpcd – presumed by RWH designers Is this reasonable?Is this reasonable?

100 gpcd – 100 gpcd – ““StandardStandard”” rate for rate for ““conventionalconventional”” water system planning water system planning

This is NOT residential INTERIOR water useThis is NOT residential INTERIOR water use

gpcd = gallons per capita (person) per daygpcd = gallons per capita (person) per day

3737

Water usage used for design Water usage used for design of on-site wastewater of on-site wastewater

systemssystems 60 gpcd with 60 gpcd with ““conservingconserving”” fixtures fixtures Actual water use observed to be Actual water use observed to be

~50 gpcd~50 gpcd

3838

Fixture/Use Unit Demand Usage Rate Water Use (gpcd)

Toilets 1.5 gal/flush 4 flush/person/day 6.0

Showers 1.9 gal/min. 4.8 min/person/day 9.1

Washing machine 42 gal/load 0.3 load/person/day 12.6

Dishwasher 8.5 gal/load 0.17 load/person/day 1.4

Faucets estimated estimated 8.5

Baths 50 gal/bath 0.14 bath/person/day 7.0

Total Water Use = 44.6

Household Water Usage Rates with Latest State-of-the-Art FixturesAWWA Study, circa 1990

3939

Total Water Use Average Daily Average Daily WaterY ear (gallons) Water Use (gpd) Use per Person (gpcd)

2003 32,457 88.9 22.2

2004 34,361 93.9 23.5

2005 33,840 92.7 23.2

2006 32,007 87.7 21.9

2007 35,529 97.3 24.3

2008 34,482 94.2 23.6

2009 38,544 105.6 26.4

2010 41,118 112.7 28.2

2011 36,174 99.1 24.8

9-year avg. 35,390 96.9 24.2

Rainwater Harvesting System Water Use History4-Person Household, 2 Adults, 2 Children

4040

Usage Rates in RWH Usage Rates in RWH ModelModel

50 gpcd – 50 gpcd – ““defaultdefault”” rate rate 45 gpcd and 40 gpcd – better demand control45 gpcd and 40 gpcd – better demand control

4141

Modeled Household Modeled Household OccupanciesOccupancies

2-person occupancy2-person occupancy ““Empty-nestersEmpty-nesters””/seniors/seniors

4-person occupancy4-person occupancy ““StandardStandard”” 3-bedroom house, likely 3-bedroom house, likely

the bulk of the bulk of ““normalnormal”” subdivision subdivision marketmarket

4242

Irrigation Water UseIrrigation Water Use

4343

Wastewater Reuse for Wastewater Reuse for IrrigationIrrigation

4444

Modeling Results SummaryModeling Results Summary

4646

Example Example Modeling ResultsModeling Results

4747

Dripping SpringsDripping Springs

Interior Usage OnlyInterior Usage OnlyRoofprintRoofprint 4,500 4,500 sq. ft.sq. ft.

Cistern capacityCistern capacity 35,00035,000 gallons gallons

OccupancyOccupancy 4 4 persons persons

Water usage rateWater usage rate 5050 gpcd gpcd

Backup supply requirementsBackup supply requirements1996 1996 2,000 gallons 2,000 gallons

2008 2008 4,000 gallons 4,000 gallons

2009 2009 14,00014,000 gallons gallons

2011 2011 18,00018,000 gallons gallons

Total = Total = 38,000 gallons38,000 gallons4848


Interior Usage OnlyInterior Usage OnlyRoofprintRoofprint 4,500 sq. ft. 4,500 sq. ft.


OccupancyOccupancy 4 persons 4 persons

Water usage rateWater usage rate 45 gpcd45 gpcd

Backup supply requirementsBackup supply requirements2009 2009 4,000 gallons 4,000 gallons

2011 2011 10,00010,000 gallons gallons

Total = Total = 14,000 gallons14,000 gallons

4949


Interior Usage OnlyInterior Usage OnlyRoofprintRoofprint 4,500 sq. ft. 4,500 sq. ft.

Cistern capacityCistern capacity 35,000 gallons35,000 gallons


Water usage rateWater usage rate 40 gpcd40 gpcd

Backup supply requirementsBackup supply requirements2011 2011 2,0002,000 gallons gallons

Total = Total = 2,000 gallons2,000 gallons

5050


Interior + Irrigation UsageInterior + Irrigation UsageWITHOUT wastewater reuseWITHOUT wastewater reuse

RoofprintRoofprint 4,5004,500 sq. ft. sq. ft.



Interior usage rateInterior usage rate 50 gpcd 50 gpcd

Irrigated area Irrigated area 2,4002,400 sq. ft. sq. ft.

Backup water supply required in Backup water supply required in 13 years13 years

Max. yr. = Max. yr. = 58,00058,000 gallons in 2011 gallons in 2011

22ndnd most = most = 40,00040,000 gallons in 1996 gallons in 1996

33rdrd most = most = 38,00038,000 gallons in 2008 gallons in 2008

Total over 25 years = Total over 25 years = 268,000268,000 gallons gallons

5151


Interior + Irrigation UsageInterior + Irrigation UsageWITHOUT wastewater reuse, larger systemWITHOUT wastewater reuse, larger system

RoofprintRoofprint 7,0007,000 sq. ft. sq. ft.





Backup supply requirementsBackup supply requirements

2009 2009 6,000 gallons 6,000 gallons

2011 2011 28,00028,000 gallons gallons



Interior + Irrigation UsageInterior + Irrigation UsageWITH wastewater reuseWITH wastewater reuseRoofprint Roofprint 4,500 sq. ft.4,500 sq. ft.

Cistern capacityCistern capacity 35,000 gallons35,000 gallons




Backup supply requirementsBackup supply requirements

19961996 2,000 gallons 2,000 gallons

2008 2008 6,000 gallons 6,000 gallons

2009 2009 14,00014,000 gallons gallons

2011 2011 22,00022,000 gallons gallons




5454

Options for Backup Supply Options for Backup Supply SystemSystem

A private well for each A private well for each buildingbuilding

Community well, Community well, ““minimaminimall”” distribution system distribution system

Community well + Community well + tanker truck tanker truck

deliverydelivery

Connection to Connection to existing PWS existing PWS

systemsystem

Tanker truck delivery Tanker truck delivery from potable water from potable water

supplysupply

5555

Tanker TrucksTanker TrucksSupplied by Public Water Supplied by Public Water

SystemSystem Likely to be predominant methodLikely to be predominant method Favored by developers – no up front Favored by developers – no up front

costscosts Regulatory issues – requirement for Regulatory issues – requirement for

ASSURED supply?ASSURED supply? How formalized?How formalized? What will it cost to set up?What will it cost to set up?

5656

Tanker TrucksTanker TrucksSupplied by Public Water Supplied by Public Water

SystemSystem Conditions of service for guaranteed supplyConditions of service for guaranteed supply Cost of guarantee?Cost of guarantee? Commercial hauler, or utility/HOA truckCommercial hauler, or utility/HOA truck Supply capacity, number of trucks availableSupply capacity, number of trucks available Regulatory statusRegulatory status Backup requirement must be very limitedBackup requirement must be very limited

5757

Tanker trucksTanker truckssupplied by a public water supplied by a public water system REQUIRE that you system REQUIRE that you hold backup supply to low hold backup supply to low

levels.levels.

5858

Tanker Truck System:Tanker Truck System:Capacity LimitationsCapacity Limitations

Development with 100 housesDevelopment with 100 houses 1 House = 1 Truck / 1 House = 1 Truck / MonthMonth1 House = 1 Truck / 1 House = 1 Truck / MonthMonth

= 100 Trips / Month= 100 Trips / Month= 100 Trips / Month= 100 Trips / Month5959

Tanker Truck System:Tanker Truck System:Capacity LimitationsCapacity Limitations

22 working days in a month100/22 = 4.5 truck trips per day

One tanker truck, full time

for one development!

22 working days in a month100/22 = 4.5 truck trips per day

One tanker truck, full time

for one development! 6060

Is the private sector ready Is the private sector ready for this kind of demand?for this kind of demand? Ability to meet intermittent demandAbility to meet intermittent demand Ability to expand fleet as number of Ability to expand fleet as number of

developments growsdevelopments grows Further investigation neededFurther investigation needed

6161



6262

TCEQ RegulationsTCEQ Regulations Regulatory status of development-Regulatory status of development-

wide RWH strategywide RWH strategy Rules under considerationRules under consideration Rules for backup supply strategiesRules for backup supply strategies Rule interpretations for RWH Rule interpretations for RWH

systems that systems that areare public water public water supply systemssupply systems

6363

Regulatory Status?Regulatory Status? Building-scale RWH systems currently unregulatedBuilding-scale RWH systems currently unregulated Would it be a Would it be a ““public water supply systempublic water supply system”” if: if:

Platted as THE water supply system the development?Platted as THE water supply system the development? Collective O&M of all RWH systems?Collective O&M of all RWH systems? Collective arrangements for backup supply?Collective arrangements for backup supply?

6464

Would this cause the Would this cause the TCEQ to consider TCEQ to consider

building-scale RWH a building-scale RWH a

“public water supply “public water supply system?”system?”

6565

Current understanding ofCurrent understanding ofTCEQTCEQ’’s positions position

Building-scale RWH system to remain Building-scale RWH system to remain unregulatedunregulated

Regulations being developed for RWH Regulations being developed for RWH systems with connection to public systems with connection to public water supply system on propertywater supply system on property

Regulatory status of tanker truck Regulatory status of tanker truck backup supply system needs backup supply system needs clarificationclarification

6666

Rule Interpretations for RWH Rule Interpretations for RWH that ARE Public Water Supply that ARE Public Water Supply

SystemsSystemsvillage centers, churches, community hallsvillage centers, churches, community halls

6767

Public Water Supply Public Water Supply SystemsSystems

Rule Interpretations for Rule Interpretations for RWHRWH

ChlorinationChlorination VSVS UV disinfection unit UV disinfection unit

6868

Are these practices Are these practices approved for building-scale approved for building-scale

systems?systems?

What would be the testing What would be the testing and reporting and reporting requirements?requirements?

Would they be affordable?Would they be affordable?6969

County-level GovernanceCounty-level GovernanceThrough Platting RequirementsThrough Platting Requirements

Rainwater Harvesting as Rainwater Harvesting as THE development-wide water SYSTEM – THE development-wide water SYSTEM –

what requirements would that generate?what requirements would that generate?

7070

County-level GovernanceCounty-level GovernanceThrough Platting Through Platting

RequirementsRequirements ““Water availabilityWater availability”” standards standards Water treatment standardsWater treatment standards Backup supply standardsBackup supply standards

7171

What does What does ““water water availabilityavailability””

require?require? ““Right-sizingRight-sizing”” of roofprint and of roofprint and

cisterncistern Backup supply system as Backup supply system as

determined by that system sizingdetermined by that system sizing

7272

Who sets the standards Who sets the standards for water availability?for water availability?

Commissioner’s Court?Commissioner’s Court? Developers?Developers?

7373

Outreach to County Outreach to County GovernmentsGovernments

““Chicken-or-eggChicken-or-egg”” conundrum conundrum Developers aren’t requesting plat approval Developers aren’t requesting plat approval

for this kind of water supply solution.for this kind of water supply solution. Therefore, no impetus for county Therefore, no impetus for county

governments to think through these matters.governments to think through these matters. Further outreach efforts are suggested:Further outreach efforts are suggested:

SurveysSurveys SeminarsSeminars Focus group workshopsFocus group workshops

7474



7575

“Right-Sized” RWH FacilitiesAt Each Modeling Location

2-Person Occupancy 4-Person OccupancyModeling Roofprint Cistern Size Roofprint Cistern SizeLocation (sq. ft.) (gallons) (sq. ft.) (gallons)

Austin

2,500

15,000

4,500

35,000

Blanco

2,500

15,000

4,500

35,000

Boerne

2,500

15,000

4,500

35,000

Burnet

2,500

15,000

4,500

30,000

Dripping Springs

2,500

15,000

4,500

35,000

Fredericksburg

3,000

20,000

5,000

40,000

Menard

3,000

20,000

5,500

40,000

San Marcos

2,500

15,000

4,500

30,000

Wimberley

2,500

15,000

4,500

30,000

7676

““Right-SizingRight-Sizing”” the theRoofprint and CisternRoofprint and Cistern

7777

The The ““Veranda StrategyVeranda Strategy””

Reduces solar Reduces solar load and air load and air conditioning conditioning requirementsrequirements

Creates outdoor Creates outdoor living spacesliving spaces

7878

Bladder-type cistern that could Bladder-type cistern that could be placed under the veranda be placed under the veranda

floorfloor

8080

Additional Roofprint with the Additional Roofprint with the ““Veranda StrategyVeranda Strategy””

8181

Need Hill Country RWH Need Hill Country RWH Vernacular DesignsVernacular Designs

Business opportunity for architects?Business opportunity for architects? Design competitionDesign competition Student design studio projectStudent design studio project

8282

““Chicken or Egg” AgainChicken or Egg” AgainDevelopers need house designs that could Developers need house designs that could implement rainwater harvesting systems.implement rainwater harvesting systems.

8383



8484

Cost Effectiveness ofCost Effectiveness ofRWH vs. Other StrategiesRWH vs. Other Strategies

Compare Compare globalglobal life-cycle costs life-cycle costs Other strategies to be evaluated:Other strategies to be evaluated:

8585

Cost items for Cost items for

Building-scale RWH StrategyBuilding-scale RWH Strategy First CostsFirst Costs

““ExtraExtra”” roofprint roofprint Collection/first flush hardwareCollection/first flush hardware CisternCistern Treatment systemTreatment system Disinfection systemDisinfection system Pump/pressurization systemPump/pressurization system

On-going CostsOn-going Costs Power costsPower costs O&M, equipment replacementO&M, equipment replacement Backup water costsBackup water costs

8686

Summary and ComparisonSummary and ComparisonCosts of Water Supply OptionsCosts of Water Supply Options

8787



8888

Marketing Focus GroupMarketing Focus GroupThe marketing focus group included The marketing focus group included

members of the following interest members of the following interest groups:groups: Land developersLand developers HomebuildersHomebuilders ArchitectsArchitects Land planners and engineersLand planners and engineers Real estate brokersReal estate brokers Banker (home finance specialist)Banker (home finance specialist) Consumers (potential home buyers)Consumers (potential home buyers)

8989

What determines What determines

Marketability?Marketability?ASSURED backup supply ASSURED backup supply

availableavailable RWH-RWH-““friendlyfriendly”” house designshouse designs Regulatory Regulatory

clarityclarity

Cost Cost effectiveeffective

Readily available Readily available financingfinancing

9090

The BIG ONE – PerceptionThe BIG ONE – Perception

9191

““Conservation Ethic”Conservation Ethic”

9292

Will perception about Will perception about “deprivation” deter developers “deprivation” deter developers

from adopting RWH?from adopting RWH?

Education Key Factor for Education Key Factor for MarketabilityMarketability

Photo courtesy of ARCSA: http://www.arcsa.org/content.asp?contentid=194

9393



9494

Sustainability of Sustainability of DevelopmentDevelopment

““Development lives mainly on water falling on it.”Development lives mainly on water falling on it.”

9595

Long-Distance Water Long-Distance Water ImportationImportation

Photo courtesy of California Department of Water Resources

9696

““Conservation Development”Conservation Development”The Pattern Favored for the Hill The Pattern Favored for the Hill

CountryCountry

9797

Hydrologic SustainabilityHydrologic SustainabilityDoes RWH Does RWH ““robrob”” water from streams and aquifers? water from streams and aquifers?

World Birding Center Headquarters, photo courtesy Lake Flato Architects

9898

Hydrologic SustainabilityHydrologic Sustainability Strategy for analysis:Strategy for analysis:

Rainfall-runoff response of undeveloped siteRainfall-runoff response of undeveloped site Rainfall-runoff response of developed site, no RWHRainfall-runoff response of developed site, no RWH Rainfall-runoff response of developed site with RWHRainfall-runoff response of developed site with RWH

9999

Outcomes of Hydrologic Outcomes of Hydrologic ModelingModeling

Rainwater harvesting will NOT result in Rainwater harvesting will NOT result in decreased levels of runoff from the finished decreased levels of runoff from the finished development in comparison with the land in its development in comparison with the land in its ““rawraw”” state. state.

The addition of impervious cover other than The addition of impervious cover other than roofs – i.e., streets and driveways – and land roofs – i.e., streets and driveways – and land alterations – e.g., improved landscaping, alterations – e.g., improved landscaping, drainage structures – will result in a higher runoff drainage structures – will result in a higher runoff rate from all non-roof areas, more than making rate from all non-roof areas, more than making up for what is captured into rainwater cisterns.up for what is captured into rainwater cisterns.

100100

Hydrologic SustainabilityHydrologic Sustainability

101101

Hydrologic SustainabilityHydrologic SustainabilityRWH off rooftops in a development RWH off rooftops in a development

would would improveimprove the hydrological the hydrological integrity of the developed property.integrity of the developed property.

102102

For more information:For more information:

Texas Water Development BoardTexas Water Development Boardwww.twdb.texas.gov/innovativewater/rainwawww.twdb.texas.gov/innovativewater/rainwa

ter/ter/

Meadows Center for Water and the Meadows Center for Water and the EnvironmentEnvironment

Texas State UniversityTexas State Universitywww.rsihillcountrywater.org/rainwater-www.rsihillcountrywater.org/rainwater-

harvesting/harvesting/

David Venhuizen, P.E.David Venhuizen, P.E.venhuizen-ww.com

103103

title slide an investigation funded through the innovative water strategies division of the texas...

Documents

rainwater collection

original rainwater

roofharvested rainwater

development wide rainwater

large scale rainwater

water supply options

better water

areawide water system