Integrated urban water management Experiences from Ethekweni Municipality, South

AfricaJay Bhagwan

Executive ManagerWater Research Commission

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Principles of IUWM

• IUWM means that in the planning and operation of urban water management, consideration should be given to the interaction and collective impact of water related processes* on issues such as human health, environmental protection, quality of receiving waters, water demand, affordability, land and water-based recreation, and stakeholder satisfaction. Individual processes should then be planned and managed in such a way that the collective impact be optimised as far as possible. – The difference between sustainable water management and integrated water

management is not always clear. – Essentially sustainability is the goal, and integrated management a strategy

for pursuing the goal

*Water-related processes in urban environments include potable water supply; sanitation (ranging from pit latrines to full water-borne sewerage and treatment); water reuse; environmental flows; water demand management; solid waste management; industrial water and waste management; urban drainage; water-based recreation; and environmental protection.

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Brief Statistics

• 3,6 million people• Area increased by 68% to 2297 sq km• 646 000 properties• Supply 908 Ml/day of water from 9

Treatment Works• Treat 500 Ml/d of Waste Water• 263 Water Reservoirs• 27 Waste Water Treatment Works• 7 000 km of sewer mains• 12 000km of water mains• 445 000 water connections• Combined annual expenditure of R4.3bn

(2010/11)• Municipal budget 2010/11 R23.5bn

A Municipality Of Contrasts

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Challenges• Poverty and job creation• Food security• Energy constraints• Migration• Growing informal areas• Water demand• Climate variability

OPPORTUNITY – RESOURCE - BENEFICIATION

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The institutional context

• It is rare to find an integrated approach to themanagement of water, sanitation, solid wastedisposal and storm water• In South Africa there is even fragmentation ata national, policy and regulatory level• The environment is socio-politically dominated• A difficult environment

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Illegal Connections

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BENEFICIATION STRATEGIES

• Non-revenue water management• Improving service levels• Re-use of treated effluent• Biodiesel from Microalgae• Deep row entrenchment of sludges• Sludge beneficiation through pelletisation• Mini and pico hydro• Water Reuse• Rainwater harvesting• Use of effluents in agriculture• Stormwater and drainage• AGROECOLOGY PROGRAMME

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Multiple levels of service

• Three levels– Regulated supply of

200kl per day (free basic)

– Semi – pressure– Full pressure

• Benefits– Reduce demand– Reduce peaks– Reduces pressure on

infrastructure

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NRW Plan– Reduce real losses

• AC Mains replacement• Active leak detection• Pressure reduction• Rezoning• Improving reservoir

integrity

– Reduce apparent losses• Illegal connection

rectification• Billing data integrity

improvements• Improve meter accuracy

• NRW by volume for 2006/2007 – 30.6%

• NRW by volume for 2009/2010 – 37.5%

• Target for June 2013 – 28% loss (R175m pa savings)

• Target for June 2018 – 25% loss (ILI 4.5)– 2% NRW reduction

per annum is realistic.

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Intervention for Reduction – Real Losses• Rezoning - New Pressure Standard -2.5bar –

6bar (225 designed /300 commissioned)• Advanced pressure management (optimising

existing + controllers) (57 sites)• Active prv Maintenance (2500 inspections)• GSM based failure detection devices on prv’s

(100)• Leak detection (7500km / 9000 leaks)• AC mains relay (incl rezoning + replace

connection pipes) (1800 km)• New Fault Manager software to assist with

analysis of faults data. Improve speed and quality of repairs.

• Reservoir overflows (incl response time)• Reservoir integrity (leaks)

Leakage control 14 600km

25 400 leaks

Replace AC Mains R550m

Pressure Reduction

48m to 40m in Umlazi (20% reduction in non-revenue water)

Install Meters 12 000 (Inanda, Umbumbulu, Folweni)

Bulk Meters 240 reservoirs

Non-Revenue WaterInterventions

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This program has realised savings of R310m in the past 3 financial years at EWS at a cost of R152.6m

Results

No.

Description Saving

1 Leak Detection R4,5m

2 Installation of 4 000 water meters in Inanda

R8,5m

3 Pressure Reduction R6,0m

4 Advanced pressure control on 10 sites R1,1m

5 Top 200 consumer meter programme R9,8m

6 Meter change out programme R4,4m

7 Informal area rectification R1,4m

Total R35,7m

Savings due to Interventions

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Water Reuse

• Direct industrial reuse of wastewater

• Commissioned in 2001• Treats 47.5 Ml/day of domestic

and industrial wastewater to a near potable standard

• Sales to industrial consumers for direct use in their processes

• Public Private Partnership eThekwini Water Services with Durban Water Recycling (Pty) Ltd

Advantages for the metro council (EWS)Delayed capital investment (marine outfall and potable supply infrastructure)•No capital investment for recycling plant•Long term revenue stream from a recycled water levy•Reduced cost of water services to Durban’s citizens•Reduces treated wastewater discharge by 10%

Advantages for the end-users (Mondi Paper and Sapref) 44% reduction in water tariff (2001) for Mondi•Likelihood that the price of recycled water will escalate at a lower rate than potable water•Enhanced security for water supply in times of drought

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Benefits

• At operational capacity (47.5 Ml/d) the reclamation plant meets 7% of the city’s current potable water demand

• The potable water that was previously drawn by industrial consumers is available for redistribution to previously disadvantaged, peri-urban communities without the need to invest in major bulk water supply and treatment infrastructure. Used to extend supply to up to 220 000 household in the greater Durban area.

• Reduce demand on the resource. Thus the project serves to scientifically protect and ensure the sustainable development of the existing available water resources of the city.

• EWS treats 470 Ml/d of wastewater. Of this volume, approximately 200 Ml/d is discharged to sea as screened and degritted wastewater.

• The reclamation project reduces the city’s total treated wastewater discharge by 10% and reduces the partially treated load on the marine environment by up to 24% (v/v).

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Energy

• Mainly linked to reducing carbon footprint through the use of renewable energy

• 10Mw of hydro generating capacity planned

• Pico hydro generating on reservoir inlets planned – estimated 30 Mw

• Constructed a large scale raceway to grow algae and harvest for biofuel and biomass production.

• Deep row entrenchment of sludges

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METHANE TO ELECTRICITY

• 28 wastewater treatment works (WWTW)

• which treat over 460 ML/day of sewage, producing

• the equivalent of 100 tons of sludge per day

• 10 operate anaerobic digesters• and it is the aim of the EWS to

convert the methane• produced at the larger of these

WWTWs into electricity. • Approximately 50% of the power

used by the works can be supplied by the methane

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LaDePa sludge pelletisation

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Benefits

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AGROECOLOGY PROGRAMME • earthworks and landscaping to

capture water run-off in the soil to secure water for the crops beyond the rainy season and prevent soil erosion;

• planting of perennial crops and food trees that hold eThekwini’s steep slopes in place while providing a diversity of foods into the future

• the use of appropriate renewable technologies to augment the water supply to gardens.

• helping growers with training and basic infrastructure

• 3000 gardens (equating to 60,000 job opportunities)

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Thank You