Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 16 February 2010
Desalination plants are not the answer to water supply problems in South Africa and many other parts of the world, and should not be seen as some kind of silver bullet.
The Department of Water Affairs spokes person Linda Page, who was quoted in Eleanor Momberg’s article ‘Sea may be solution to the water crisis” (Sunday Independent 31 January 2010), mentioned some of the advantages of desalinating water, but she had failed to mention any of the many negative impacts associated with this practice.
In 2007, WWF International released the report Making water: Desalination – option or distraction for a thirsty world? The report showed that some of the driest and thirstiest places in the world with large populations were turning to desalination. These include countries such as Australia, the Middle-East, Spain, India and China which have already made investments in this infrastructure and are using it to diversify their water supplies.
According to the report, desalinating sea water is an expensive, energy-intensive and greenhouse gas emitting way of accessing water. This practice has many negative impacts on the environment, some of which include brine build-up, the destruction of prized coastal areas and a resultant reduction of emphasis on the conservation of rivers and wetlands. Many of the areas of most intensive desalination activity also have a history of damaging natural water resources, particularly groundwater.
In a time where climate change is starting to cause notable effects on South Africa’s fresh water supply it seems ironic, at best, to address this symptom of climate change by adding to the cause (through a process which contributes large amounts of greenhouse gas emissions). Such “vicious circle” approaches make little sense.
Desalination, at best, is a short-term solution and nothing can replace the need for proper management of our freshwater ecosystems; through inter alia, the removal of alien plants, which are sucking up 3,300 million cubic metres of our precious water supply each year.
WWF believes that ensuring sustainable water sources begins with protecting natural assets such as rivers, floodplains, and wetlands. These natural systems purify and provide water as well as protecting against extreme or catastrophic events. Resource planning needs to come before large infrastructure planning.