Water securityDesalination: global examples show how Cape Town could up its game
Day zero is looming for Cape Town and a dedicated and efficient long-term solution to South Africa’s water woes must be found. The weather can’t be controlled and drought patterns for the region are set to worsen. It’s time to stop relying solely on rainfall and dam levels for clean water as a critical resource. South Africa boasts a coastline of over 2500 kilometers so it should be considering the oceans as an abundant water supply. Converting seawater to clean drinking water can be achieved by desalination, a proven technology that’s been used around the world. Desalination plants have dramatically increased in number and sophistication around the world due to membrane technology breakthroughs and energy saving equipment. Three global examples in Saudi Arabia, Spain, and Israel show that South Africa could increase water output in a timely and cost effective way.
Day zero is looming for Cape Town and a dedicated and efficient long-term solution to South Africa’s water woes must be found. The weather can’t be controlled and drought patterns for the region are set to worsen. It’s time to stop relying solely on rainfall and dam levels for clean water as a critical resource.
South Africa boasts a coastline of over 2500 kilometers so it should be considering the oceans as an abundant water supply. Converting seawater to clean drinking water can be achieved by desalination, a proven technology that’s been used around the world. Desalination involves removing the salinity (dissolved salts and minerals) from water. There are a number of ways of doing this, but the only process that ticks all the boxes in terms of catering for large volumes, environmental impact and cost, is reverse osmosis.
South Africa has around ten desalination plants dotted along the coast from Lambert’s Bay in the west to Richards Bay in the east. The output from each is quite small and caters only for households in the immediate vicinity.
Cape Town has started down the road of desalination. A temporary desalination plant is due to start producing 2000 cubic meters of water a day (going up to 7000 in phase 2) starting in March. The city will buy the water at a cost of around R30 per kiloliter. The contract is due to run for two years after which the equipment will be removed and the area rehabilitated.
But the city needs to develop far more ambitious plans. With a population of around four million people it needs a water output of around 500 000 cubic meters per day to supply each individual with roughly 100 liters. Desalination plants have dramatically increased in number and sophistication around the world due to membrane technology breakthroughs and energy saving equipment.
Three global examples in Saudi Arabia, Spain, and Israel show that South Africa could increase water output in a timely and cost effective way.
