Water, water everywhere – but not a drop to drink

The document examines desalination as a potential water source for Cape Town, noting that while it provides a rainfall-independent supply, it is often the most expensive option and carries significant energy and environmental costs. It details existing small-scale plants in South African municipalities and warns against over-investing in large-scale facilities based on experiences in Australia.

• Desalination is generally the most expensive water source for cities, costing between two to four times more than other options globally. In Cape Town, smaller short-term desalination is the most costly at R34 to R44 per kilolitre, compared to raw surface water at R1 to R4 per kilolitre.
• The process is energy-intensive, requiring between 2 and 12kWh of electricity per 1,000 litres depending on the method used (reverse osmosis, vapour compression, or membrane distillation). Because South Africa relies heavily on coal-fired power, this energy use contributes to greenhouse gas emissions that fuel the droughts desalination is meant to mitigate.
• Desalination poses environmental risks to marine life, as intake points can capture small organisms like plankton and fish larvae, and the resulting concentrated brine—containing biocides and antifouling chemicals—is toxic when disposed of back into the sea.
• South Africa utilizes desalination in various capacities: mines use it for polluted mine water and acid mine drainage, and several municipalities (including Mossel Bay, Knysna, Bitou, Ndlambe, and Cederberg) operate or have developed small-to-medium scale plants, though some remain on standby or non-operational due to costs or development status.
• Cape Town has four small-scale desalination projects planned at the Waterfront, Cape Town harbour, Monwabisi, and Strandfontein. The document warns against over-investment, citing Australia, where $10 billion AUD was spent on six plants that became prohibitively expensive once cheaper water policy reforms and efficiency measures were implemented.

APA

WWF South Africa (n.d.). Water, water everywhere – but not a drop to drink. https://www.wwf.org.za:443/bucket_list/?24281/wednesday-water-file-07

Chicago

WWF South Africa. Water, water everywhere – but not a drop to drink. n.d. https://www.wwf.org.za:443/bucket_list/?24281/wednesday-water-file-07.

Wikipedia

{{cite report |author=WWF South Africa |title=Water, water everywhere – but not a drop to drink |url=https://www.wwf.org.za:443/bucket_list/?24281/wednesday-water-file-07 |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{wwfsouthafricandwater, author = {{WWF South Africa}}, title = {{Water, water everywhere – but not a drop to drink}}, institution = {WWF South Africa}, url = {https://www.wwf.org.za:443/bucket_list/?24281/wednesday-water-file-07}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }