Cape Town ponders giant desalination project as resources dwindle
Cape Town, South Africa is nearing completion of its feasibility study for a 450 Ml/d desalination plant that could be built near Koeberg on South Africa's west coast within the next 10 years at a cost of some R14.9 billion (US$ 1.23 billion).The city anticipated it will need to expand its bulk water resources. If approved, the desalination plant will be the largest in the country, contributing 22% of the city's water supply.
City officials have emphasised that the plant was one of a number of options under consideration to deal with Cape Town's growing demand for water. Councillors in the utilities portfolio committee were reported to be concerned about the cost implications for users of desalination. Other options included direct potable reuse of wastewater and raising the walls of the Steenbras Dam.
Paul Rhode, of the water and sanitation department said the plant would have a significant impact on residents' water tariffs with annual running costs at R1.2 billion (US$ 100 million).
Construction in the initial 150 Ml/d first phase of the plant, would be R 9.2 billion (US$ 760 million). And it would cost an additional R 5.7 billion (US$ 470 million) to upscale the plant to 450 Ml/d before planning and design costs.
City councillor, Matthew Kempthorne, said the study showed the city was planning for its future. He said that as Koeberg power station - which is close to the proposed desalination plant site - is scheduled to close by 2023, the city could use its intake and outlet structures to shave R 3 billion (US$ 250 million) off the construction cost.
The city's director of water and sanitation, Peter Flower, said the project could eventually be the city's only option to meet the growing water demand.
Rhode said the proposed plant would reduce the city's reliance on surface water by more than 70% and improved technology would bring down its costs. He said the city would consider setting up a pilot plant in the next two years, with a limited capacity, to test the water quality.
He said the city was in discussions with South African nuclear power company, Eskom, about possibly setting up the pilot plant next to the Koeberg nuclear power plant.
Currently most of the city's water comes from surface water, and only 13% of its supply comes from within the municipal boundaries.