Science helping to fix SA's water woes

Thomas Hartleb, News24

Pretoria – Although South Africa will likely face water shortages in future, and the quality of the country’s water is getting worse, scientists are working on some innovative projects to reverse this.

In an apple orchard in the Western Cape, researchers are measuring exactly how much water the trees need to allow for more efficient water use, the Council for Scientific and Industrial Research (CSIR) hydrosciences researcher, Mark Gush, told reporters on Wednesday.

Sensors are used to measure evaporation from the orchard, and probes inserted into the trunks of the trees measure the rate at which water moves up from the roots.

While it was a labour and scientifically intensive approach, it has shown it is possible to save water, particularly at the end of the growing season.

Research is also being conducted to reduce food waste, which will help save the water that would have been used to grow the wasted food, Gush said.

"People in agriculture have done some incredibly innovative things, and we need to draw on those stories,” said Emma Archer van Garderen, CSIR chief researcher of integrated water assessments.

Rooibos now water-wise

One example was a rooibos tea co-operative. Rooibos is grown in a winter rainfall area and has currently had a very bad season.

The co-operative, with the help of a non-governmental organisation, brought in scientists and reduced its water use. It is now exporting its tea under a water-wise label.

"Farmers are incorporating concerns about water and soil conservation into marketing agricultural products."

There was, however, strong evidence of decreased water flow and water quality in the country, Van Garderen said. Climate change would further exacerbate South Africa’s major problems such as service delivery, the water and energy crunch, the burden of disease and land transformation.

"Everyone says there is a litany of bad news, but working with government we can look for were might the good news be, where the opportunities for innovation are."

The Olifants River catchment area in Mpumalanga is "one of the worst case scenarios", said James Dabrowski, CSIR senior researcher specialising in water quality and aquatic ecology.

The combination of agriculture, coal mining, and now the development of Eskom’s Kusile Power Station with its increase in human activity, are causing large-scale pollution of rivers in the province.

“It can’t get much worse than what it is,” he said of the catchment area.

Reduce river pollution

One proposal he has, to reduce river pollution from sources such as fertilisers, is to follow what is being done in places such as the UK and the US.

Land use in a catchment area is mapped. This information is overlaid with topographical and weather information, and combined with the location of waste water treatment plants.

The result is a map indicating the sources and extent of agricultural pollution. Each waste water treatment works can then determine the level of nutrients needed to filter out of the water.

“We do have quite a number of challenges, but there are solutions to these challenges,” Dabrowksi said.

However, the problem with this was the standard of the country’s waste water treatment works.

Harrison Pienaar, the CSIR’s competency area manager of water resources, said the crisis lies with how South Africa’s water is managed.

"At local government level there are serious challenges. We are not addressing inefficiencies," he said.

Source :