hall2d wednesday 09h15 - valerie naidoo

Water Sector Overview

Moving towards a Water Sensitive Society

Valerie NaidooWater Research Commission

NCPC / DTi Industrial Efficiency ConferenceICC Durban 2015

22nd July 2015

DriversPopulation

Growth • Coverage (water, energy, food)

Industrialization /Development

• Consumption of resources• Improved wealth• Deterioration of environment

Urbanization• Densification• To centralize or decentralize?• New solutions

Limitation on Natural

resources

• Water (quantity and quality)• Food• Energy

Changes to natural

environment

• Droughts• Floods• Shortages• Scarcity• Temperature changes

United Nations (Dept of Economic and Social Affairs) : World Urbanization Prospects, the 2011 Revision

Urban Population (% and agglomerations by size class) – 2011 Highest Urbanizing countries in the world (7/10 are in

Africa)

Climate Change is being taken seriously in SA unlike ………

May 2, 2023 File name 4

Predictions : Drier western half of the country and wetter more variable weather in the eastern half

PO

LIC

Y

IMP

LEM

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5

CURRENT CONTEXTWater In SA

May 2, 2023

Legislative Environment

Legislationo Water Act

o Common resource to all

o No ownership but right to use

o Unity of water cycle and interdependence of its elements

o Water Services Acto Mandated to Local

Government

Principles1. Achieve equitable access for all2. Achieve sustainable use (ie some for

all, forever)3. Achieve efficient and effective use

(i.e. optimum social and economic benefits)

4. Priority to basic human needs and ecological sustainability (ecological reserve)

5. Water is viewed first as a common good

6. Water is also viewed as an economic good

Broad spectrum of actors in water management: DWS ; Waterboards; Local government (WSI), CMA’s

Physical EnvironmentMean Annual Precipitation (460 – 495 mm)

RAINFALL DISTRIBUTION

SEASONAL DISTRIBUTION RAINFALL

EVAPORATION RATES mm/annum

Management Environment: Dams and Interbasin Transfers

DWA, 2004South Africa has 794 large dams which can store up to 32 billion

m3/annum

Energy Intensive System Models

Planning Environment :Water Quantity

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WR2005 = 49 000 Mm3 (surface water) 98% allocated (77%)

Groundwater = 10 000 Mm3 (or 7 500 Mm3 under

drought conditions) (9%) Indirect Reuse = 30 to 60%

return flows (14%)

WR2012

Water Use in SA

15DWS Water Sector Overview Report, 2013

Planning Environment : Supply vs Demand

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2023-05-02 17

Based on rising population, economic growth projections, scarcity of resources as well as current use and efficiency levels, South Africa will demand 17 percent

more water than exists by 2030.The net deficit between supply and demand could grow to between 2.7—3.8

billion m3

Summary of water quality issues by geographical area in South Africa (Source: CSIR 2010)

So what do we know!

Global Risk Assessment (WEF)…..900 leaders

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The Mix (Supply Side)

Water Supply Settlements

Surface

Groundwater

Stormwater

Rainwater

Wastewater

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Aquifer recharge

Minewater

Seawater

greywater

Transfers

Ecological Reserve

Cost vs Value of Water

Urban water management transition states (Brown et al., 2009) (Developed World)

Socio-political

Framework for Water Sensitive Settlements in RSA, “Two histories, one future” (Developing World)

Socio-political and economic reality

Armitage et al, 2014 – adapted from Brown

Research

City/village/town/settlement

Surface waterRainwaterStormwaterGroundwaterBrackish waterSea waterWastewaterGreywaterMine water

The water balance

streamflows

Ecological infrastructure

Built infrastructure

ModelsTrans-disciplinary approachLevel of CertaintyScenariosTechnologiesDemonstrationsImpact analysis

Reduced island heat effect

Storage

Fit for purpose

Source and yieldTechnologiesSetting correct water quality objectives

Sustainable Urban Drainage in Cities

Sustainable Urban Drainage in Cities

Sustainable Urban Drainage in Cities

Sustainable Urban Drainage in Cities

9 South African Cities End use modelling Data - Property and

HH data ; Local area specific climate date

Looked at RWH, GWH, WED, on site leakage reduction ; Water demand variations

% water savings of 50% - with combinations

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Cape T

own

Maunga

ng

Buffalo

City

Nelson

Man

dela

Metrop

ole

City of

Tshwan

e

Ekurha

leni

Msunduz

i

eThe

kwini

Johan

nesbu

rg0.0

10.0

20.0

30.0

40.0

50.0

60.0

14.0 15.1

19.115.4 14.7

17.2 16.1

20.9

15.5

25.8

29.826.0

16.2

28.7 28.6

23.9 25.0 25.9

47.250.4 51.6 51.2 51.4 50.1 49.6 50.8

47.6

RWH GWH Combinations

% w

ater

save

d

May 2, 2023 File name 29

integration

(from WRC Project ; K5/2071)

A Water Wise Society – “enlightened”

The Water Sector 2025 – Institutional Landscape – WRC TT514-11

With any crisis comes opportunities for innovation and change.

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ThankYou