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Water woes

Online since 5.03.2017 • Filed under Editor's Choice • From Issue 20 page(s) 15-17
Water woes

The Western Cape is in the middle of its most serious water shortage in decades and other provinces are not far behind. To Build put some questions to various of the key role players involved.


To Build asked Councillor Xanthea Limberg, Mayoral Committee (Mayco) member for Informal Settlements, Water and Waste Services and Energy at the City of Cape Town about water losses in the pipeline upstream of the consumer. ‘The City of Cape Town, which has more than 11 000km of water mains and associated infrastructure (reservoirs, pump stations, water meters, valves and hydrants), has established itself as a national leader in reducing water losses - as well as user demand - through its Water Conservation and Water Demand Management Programme,’ says Limberg.


‘Water losses, which includes losses through leaks and bursts, as well as water lost through meter tampering, general metering inaccuracies and administrative errors, for the overall systems have been reduced from around 25% in 2009 to below 15% according to the latest data,’ she adds. Limberg explained that this reduction in water loss is because of various interventions, including extensive water pipe replacements, extensive pressure management of the water supply system and improved response times. These interventions have also reduced the burst rate from 63,9 bursts per 100km of piping in the 2010/2011 financial year, to 31 bursts per 100km, saving millions of litres of water in the process.


While it is not possible to precisely delineate how much water was lost to theft and meter tampering issues as opposed to how much was lost to pipe bursts, estimates are that approximately 8,6% of total water fed into the City’s reticulation network is lost through leaks, bursts and to a much less significant degree, overflows on storage tanks.


National losses

The apparent optimism of the City of Cape Town’s Mayco member regarding losses of water through pipelines is not shared by many industry leaders, at least as far as the national picture is concerned. In stark contrast to Cape Town’s estimates of 8.6%, national water loss averages have been estimated to be as high as 25% in some  nstances, according to a recent Engineering News report quoting. South African Institute of Civil Engineering President, Dr Chris Herold.


The South African Plastic Pipe Manufacturers Association (SAPPMA) Chairman, Jan Venter, said in 2015 that pipelines lie at the heart of South Africa’s infrastructure and should be replaced before they fail. ‘The Water Research Commission completed a survey of 132 municipalities in South Africa a few months ago. Their findings revealed that water lost through leakage, incorrect metering and unauthorized consumption averaged around 37% of our country’s available water supply. This amounts to a financial loss of around R7.2 billion per year. Australia, another water-scarce country, loses less than 10%. South Africa simply cannot afford to continue losing so much treated water,” says Venter.


Materials of older buried water systems not known

Most South Africa’s pipelines were installed in the early 1950s and 1960s and were manufactured from our country’s existing pipelines made of cement, asbestos or steel. Although the exact materials used in the buried water systems in this country is not known, cast iron pipes were used from 1870- 1930, cement-lined cast iron from 1930-70, asbestos cement from 1950-70, ductile iron pipes from 1960 on and PVC from 1970 onwards.

‘The old cement and steel pipes that were installed do not have an economic lifespan of longer than 50 years. The fact that they have been corroded by now can be seen from all the water leaks that are springing up everywhere, as well as disrupted water supplies,’ says Venter.


‘Kilolitres of treated water is lost every year around the country as a result. If the local municipalities only spent the money allocated in their budgets to upgrade and replace old and failing water infrastructure, we would be able to save enough purified water to significantly reduce the impact and long-term effects of the below average rainfall,’ he adds.


Efforts recognised

Cape Town’s water management efforts have been recognised internationally when City of Cape Town’s Water Conservation and Water Demand Management Programme was announced as the winner in the Adaptation Implementation Category at the 2015 C40 Cities Awards in Paris.


Tightening up on steel

According to the Southern Africa Stainless Steel Development Association (SASSDA), the importance of tightening up South Africa’s water supply infrastructure comes into sharp focus when one considers statistics cited in a Timeslive.co.za report. This stated that up to 40% of Johannesburg’s water goes unaccounted for annually, costing the city R1.16 billion in the year (ending 30 June 2015). Of that about R851 million worth of water was lost to leaks. These high losses have been identified in part to the use of inferior or inappropriate metals in pipe joints and other fittings used by municipalities, including flanges, tee-pieces, reducers, and bolts and nuts all bearing short lifespans. This is further compounded by high pressure systems and high corrosion levels in South African soils and resultant challenges in leak detection.


‘There is high value potential in using stainless steel material for service piping and all fittings, predominately manufactured using grade 316 stainless steel in the service delivery of municipal water. This can potentially save millions of Rands currently lost in leakage and filtration costs as well as see a reduction in the usage of water per capita,’ says SASSDA Executive Director, John Tarboton.


Some winners

The Drakenstein Municipality in the Western Cape is just one of a handful of municipalities which has had the wisdom to ensure its water-wise future. When asked why his municipality is a frontrunner in the use of stainless steel applications, Drakenstein Municipality Senior Engineer: Water Services, Andre Kowaleski, who has 33 years’ experience as a technical official in the municipality says: ‘Since 2002 we have applied grade 316 stainless steel in all the metal we use in our underground network, or grade 304 in above-ground applications.


‘We also use stainless steel in all our refurbishments, including the recent refurbishment of the Meulwater Reservoir, Paarl Mountain and Van Blerk Reservoir in Wellington. This stems from the fact that when it comes to replacement maintenance, it would be unwise to put a pipe in the ground that has an operating life of between 50 and 100 years and then have to replace fittings, such as T-pieces and connection saddles that corrode and rust away, after just a few years. There’s no logic in that. You must use material with a life span of 50-100 years,’ he explains. ‘So even though the initial cost of stainless steel installations is considerably higher than other available materials, we are reaping the rewards of our long-term approach and currently have a 13.4% water loss figure, as compared to other municipalities’ average water loss of 39%. Our figure will only improve as we continue replacing inferior fittings over the years,’ he adds.


Inclusive approach needed

Food for thought indeed. While there is much blaming of the consumers for current water consumption levels at present (formal residential properties use 65% of the City of Cape Town’s water supply), municipalities should perhaps adopt less of the blame-and-complain approach and approach the problem at both ends, including their distribution infrastructures.

 

Sources

• Councillor Xanthea Limberg – City of Cape Town, www.capetown.gov.za/thinkwater

• Jan Venter - Southern African Plastic Pipe Manufacturer’s Association, www.sappma.co.za

• John Tarboton - Southern Africa Stainless Steel Development Association, www.sassda.co.za

Issue 20

Issue 20

March 2017

This article was featured on page 15-17 of
To Build Magazine Issue 20.

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