SA may face 'monster floods'

2005-09-09 10:40

Johannesburg - In many areas of South Africa, floodwaters have the potential to build up to monstrous proportions and wreak havoc along their path, Mondi Wetlands Project manager David Lindley said on Thursday.

Stressing that Hurricane Katrina was a wake-up call for decision-makers around the world, he said South Africa had seen similar environmental degradation to what had contributed to the destruction of New Orleans.

This had been a factor when the tropical cyclones Eline struck South Africa in 2000 and Demoina in 1994.

Lindley warned that floodwaters in South Africa often no longer had anywhere safe to flow.

"They cannot sink into the ground or be held in marshes; so they have the potential to build up to monstrous proportions and wreak havoc along their path."

The project is a programme of the Wildlife and Environment Society of SA and the Worldwide Fund for Nature, specialising in the wise use and rehabilitation of wetlands.

Lindley singled out wetlands in Mpumalanga and coastal forests in KwaZulu-Natal being tilled for agriculture and overgrazing in Limpopo as activities that would contribute to such uncontrolled flooding.

Added to this were overgrazing in Limpopo and the creation of trout dams in wetlands at Dullstroom.

In cities, the canalised Liesbeek River in Cape Town flooded recently and Johannesburg's Jukskei did so repeatedly.

'Take care of nature's safety valves'

"Look at the state of many of our urban rivers nowadays - there is little natural grass or indigenous tree cover along the banks any more to stabilise them," said Lindley.

"Stormwater slices off great chunks of river bank as it ploughs through, creating large, straight channels that encourage even greater water speeds, which drown people and livestock, carry off homes and flush away bridges.

"These days, most of Gauteng is paved so water doesn't soak into the ground anymore. Instead, it runs off in great volumes and at great speeds into stormwater drains and then into rivers."

Lindley said the increased severity of floods and droughts due to global warming meant people should take even more care of nature's safety valves.

These safety valves were grasslands and wetlands, he said.

"In nature, river banks are protected from flood erosion by either indigenous grasses or riverine forests.

"Rivers do not occur in isolation but are part of intricate wetland systems consisting of grassland 'sponges' in catchment areas, marshes, reedbeds, floodplains and river banks."

He warned that people "had been running roughshod over nature and she's coming back to bite us".

"If the world continues on its current course-massively altering the natural world and further increasing fossil fuel consumption, future generations may face a chain of disasters.

"These could make Katrina-scale catastrophes a common feature of life in the 21st century."

- SAPA