Desalination on largescale viable

Janine Myburgh, president of the Cape Chamber of Commerce and Industry

The policy of taking water from the agricultural areas of the country and flushing it down city toilets is unsustainable, especially in coastal areas.

The chamber made this point in a letter to the Department of Water and Sanitation which is developing a master plan for the future.

There is convincing evidence that the desalination of seawater on an appropriate scale is now both viable and necessary in coastal towns.

One of the proposals made to the Cape Town City Council was to build a large desalination plant to produce about 250 million litres of water a day, about 30% of Cape Town’s needs, in a normal year. When this desalinated water is blended with 70% dam water the result will be an increase in tariffs of just 6.54%.

The offer is in line with the highly successful process used by the Department of Energy to attract independent power producers. In terms of this process, the desalinating company would design, finance, build, operate and maintain the plant in return for the City’s commitment to purchase the daily water output for an extended period of about 20 years.

The increased cost of desalinated water could also be offset by the lower cost of recycled water, especially for industry.

The use of desalinated water in coastal regions will mean more water should be available for agriculture and food production. Agriculture has made considerable progress in using water more productively.

Drip and micro irrigation systems as well as tunnels and shade cloth have produced bigger harvests with less water.

Agriculture deserves more water to enable more and better food production which will, in turn, create more jobs and export earnings.

The recycling and reuse of water must be increased to get maximum value from our water resources. In Cape Town, for instance, only 6% of water is recycled in a normal year. The other 94% is discharged into the sea, most of it treated to a safe and acceptable standard.

This is one of the important lessons to take from the drought in the Western Cape and we believe the time has come to set recycling targets for all cities and towns and to increase these targets as progress is made.

We believe increased water reuse should be a fundamental part of any future water and sanitation plan.