Niki Moore
Ilembe, the fastest-growing area on the east coast of South Africa, has embarked on a pilot project to raise water supplies that features the sale of salt extracted from a desalination plant and the establishment of a shrimp-breeding farm.
The municipality of 560 000 residents, centred on KwaDkuza north of Durban, has approved a desalination plant that will supply as much as half a million litres of fresh water a day, recycling the salt for sale. Wind turbines may be used to save on power bills.
The $6.1 million (R59m) project was initiated because the east coast has such a low water table that boreholes are usually unfeasible. The area has short, fast-flowing seasonal rivers that affect the reliability of water and a dispersed rural population that makes infrastructure expensive.
Ilembe, like much of the nation, is looking for a long-term, self-sustaining water solution. The Treasury’s 2012 Budget Review says South Africa will start running out of water 13 years from now without better management. On current projections, South Africa’s water demand will outstrip available supply by 2025 to 2030, according to the document.
“We have a 35-year master plan for water,” Ilembe municipal manager Mike Newton said. With a rate of growth of 5.7 percent, a 70 percent rural population, climate change and proximity to the sea, desalination is “an attractive emergency back-up in case we run out”, Newton added.
Using technology already in place in the southern Cape, the project will build a portable desalination plant at Blythedale, a resort north of Durban.
It will combine techniques to create a blueprint for two larger proposed desalination plants on the north and south coasts of KwaZulu-Natal to provide water for the province.
The supply will be drawn from the dunes via a borehole instead of the sea to tap waters already partly desalinated.
With reverse osmosis being used in the project, the potable supply will be remineralised as desalinated water is acidic.
Phase one of the project will cost R11m including specialised equipment, with the second phase commercialising the salt.
Part of the brine would be supplied to aquaculturalists to breed salt-water shrimp, and the rest would be dried for sale.
A projected output is a ton of salt a day.
The salt-water shrimp project is already linked up with the Ocean Basket chain of seafood restaurants, which started an aquaculture company, and it is envisaged that the salt-drying project will be done in conjunction with community projects.
Phase three of the project is to find alternative energy supplies for the plant using vertical axis wind turbines or hydrogen separation.
The goal is to make each plant self sustaining.
All three phases will cost R60m, amortised by selling water over the 30-year lifespan of the plant. This desalination project is an experimental prototype for two larger planned desalination plants for KwaZulu-Natal, one for the north coast and another for the south coast. – Bloomberg