Prepare for long season of drought, and some floods, too

South Africa should brace for more extreme weather conditions - prolonged periods of drought followed by intense flooding.

This is the warning from experts at the World Water Summit, which took place in Durban this week. Because of these extremes, the country needed to invest in more detailed and accurate long-term forecasting to prevent disaster situations.

The recent drought - which is easing countrywide except in the Western Cape, where dam levels are dangerously low - was caused by El Niño weather patterns, which result in below-average rainfall. But as this makes way for the anticipated La Niña phenomenon, which normally brings increased rainfall and possible flooding, experts say South Africa should be ready for any eventuality.

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Dr Asmerom Baraki of the Council for Scientific and Industrial Research said that, due to climate change, Southern Africa might see more of these extreme situations.

"We have more of a tendency of dry conditions in the region and this is how most of the models are projected at this stage. This means that South Africa will probably receive a rapid increase of extreme events," he said.

One of these extremes, according to Roland Schulze, professor of hydrology at the University of KwaZulu-Natal, is that extended drought periods will hit the Lesotho Highlands and parts of KwaZulu-Natal. This could have devastating effects on Gauteng, as Lesotho, in particular, is the "water tower" of the province.

Schulze said the multibillion-rand Lesotho Highlands Water Project - which supplies as much as 40% of Gauteng's water - will receive less rain, according to climate-change projections. This will leave the province facing similar restrictions as seen in the past year.

"Gauteng [is] the economic heartland of the country. We need to be careful to understand what is happening there."

The Water and Sanitation Department said last year that South Africa would be in "big trouble" without water from the landlocked country.

Schulze said the country needed a very detailed weather forecasting system, not just seasonal forecasts, to deal with extreme events.

"Our extreme events are, on one hand, floods, [so] we need to know what happens tomorrow.

"We also need to be worried about the drought. Droughts are a creeping phenomenon. You don't know you are in a drought until you're actually in it. That's the problem," said Schulze.

mthethwab@sundaytimes.co.za