Hall2D Wednesday 09h15 - Valerie Naidoo
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Water Sector Overview Moving towards a Water Sensitive Society Valerie Naidoo Water Research Commission NCPC / DTi Industrial Efficiency Conference ICC Durban 2015 22 nd July 2015
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Transcript of 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
EN
TATI
ON
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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
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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.
May 2, 2023 31
ThankYou
