Built as an emergency measure, the country's largest desalination plant will be operational by December 18.

The Knysna municipality, the department of water affairs and forestry and GrahamTek Systems signed the contracts for the project last week.

The plant, the technology for which was designed in South Africa, will be at Myoli Beach and will be fed by at least eight special boreholes or beach wells.

The waste brine produced by the plant will be injected into two beach wells from which it will dissipate into the sand and filter back into the ocean.

The water produced by the plant will cost less than R3 a kiloliter.

A 2.8km pipeline to the Blombosnek reservoir, into which the fresh water will be pumped, will be laid.

Ground-water consultant Etienne Mouton said the water situation in South Africa was "pretty bad".

"We are a low-rainfall country and our most obvious source for bulk water is dams and ground water, but this is not always possible," he said.

Desalination technology, which is fairly new to South Africa, is also used on Robben Island, and in the Eastern Cape coastal resort towns of Kenton-on-Sea and Bushman's River Mouth.

Rashid Khan, chief director of the Western Cape region of the department of water affairs and forestry, said: "Nowhere else in the country is desalination taking place on this scale".

Knysna councillor Andrew Finn said the town was leading the country in desalination technology.