Theewaterskloof Dam. Picture: Ayanda Ndamane/ANA Pictures

Cape Town - Experts have warned Cape authorities that it will take at least four years to build large-scale desalination plants and are not the answer to their prayers to avoid "Day Zero".

The City of Cape Town, however, will continue with its plans to build desalination plants, which are expected to be completed in March, 2018.

Dawid Bosman, senior manager at Trans-Caledon Tunnel Authority said desalination can change the industry and will secure the economic viability of the country. Bosman was speaking at a workshop presented by GIBB Engineering, which brought industry experts together to discuss solutions for the water crisis.

Bosman said countries like Australia have built massive desalination plants.

“The difference is that they knew what they wanted. The markets will punish you if they see that you are unsure of what type of plant it is that you want. The cheapest daily capital expenditure per cubic meter of desalinated water is about $200 (R2 823). 

"It can stretch to $3 500, but it should not reach that level. Capital expenditure should be between $800 and $1 400. 

"A desalination plant cannot be a quick fix for a drought."

Bosman said site selection is critical.

"A running plant attracts and develops local suppliers and a pool of skilled resources, diminishing the need for costly importers."

He said the country's water resources have over the years become even scarcer. Bosman added that the country's dams are extensively developed, but Western Cape dams remains isolated from the rest of the country's water supply network.

“Many other provinces can share water between each other. It happens fairly frequent and is easy, but in the Western Cape it is very difficult. We must start accepting that the days of cheap water is over.” 

Cape Town Mayor Patricia de Lille has said that the desalination plants will produce two million litres of water per day.

The City has budgeted just more than R3.3 billion for their water projects, but the cost of a desalination plant could be much more depending on its size.

[email protected]

Cape Argus