South Africa. The City of Cape Town has saved millions of Rands following the installation of water pressure management systems which reduce water pressure during off-peak periods.
The city became the first major city in the world to implement a large scale, pressure management project in 2001.
The project was introduced in Khayelitsha, specifically to reduce leakage during off-peak periods.
Water wastage in Khayelitsha was reduced by approximately 1000 cubic metres per hour, the installation, which has been fully operational for six years continues to save the city’s nine million cubic metres per annum, approximately R30 million.
The city is currently installing the third largest water pressure system in Mitchells Plain, a large area which is relatively flat and low-lying and experiences high water pressures during off-peak periods.
City’s Water and Sanitation Director, Sipho Mosai said that the installation will cost about R6 million with the savings expected to provide a pay-back period of less than a year.
“This installation will also help to prolong the life of the water reticulation system and will protect household plumbing fittings,” said Mr Mosai.
He said further benefits from the proposed installation will be reduced sewage flow from the area and a reduction in burst pipes which, in turn will provide a more reliable water supply to all residents.
Mr Mosai warned that during the construction phase there could be disruptions to the water supply in Mitchells Plain as it nears completion but assured the residents that the city will be doing everything in its power to reduce this to a minimum.
“There will be a definite disruption for a day or two in mid-June as the system is cut-in, it would be wise to store a container of water for emergencies during this time and a bottle or two in the fridge for drinking purposes,” Mr Mosai advises.
The pressure management is complicated and often misunderstood since it involves reducing the pressure of water supplied to consumers during off-peak periods.
He said that such pressure reduction should not be seen as a reduction in the level of service to the consumer, but rather an improvement.
“In recent years, there has been a growing awareness of the problems associated with water being supplied to the public at high pressure, as this has the potential to stress the pipes conveying the water.
“This is most prevalent at night when consumers are asleep and very few are using water and most leakages and new pipe bursts occur between 8pm and 6 am,” Mr Mosai said.
He further explained that reducing the water pressure during this period will in turn reduce the leakage, reduce the occurrence of new pipe bursts and help to prolong the life of the household plumbing systems.
Mitchells Plain residents should be aware that several tests will be carried out before mid-June to test whether the entire Mitchells Plain system can be shut down for the cut-in.
“These shut downs will most probably be carried out overnight during off-peak water use.
“Construction of further smaller-scale pressure management projects is in progress in Lwandle, Delft and Fisantekraal, the Atlantis project is now in the implementation phase with commissioning imminent,” Mr Mosai said.
By: Gabi Khumalo