This was highlighted in the Status Report on Biological Invasions in South Africa, which was released by the South African National Biodiversity Institute (Sanbi).
Sanbi director for Invasive Monitoring and Reporting Sebataolo Rahlao said invasive alien plants reduced surface water runoff from 1 500 to 2 500 million cubic metres a year. Primary catchments areas most affected were in the Western and Eastern Cape and in KwaZulu-Natal.
Rahlao said: “Because of their deep-root system, they take off water that would have been available for our access; they are essentially extracting from our water. We should be worried about it.”
He said the issue of invasive species was a historical one and not one that could be resolved overnight.