Alien plants threaten to guzzle a third of the water in Cape Town and PE, according to a state report
Invasive alien plants threaten up to 30% of the water supply in major cities in the Western and Eastern Cape, such as Cape Town and Port Elizabeth, according to a new government report.
The Status of Biological Invasions and their Management 2017, produced by the South African National Biodiversity Institute and the Centre for Invasion Biology at Stellenbosch University, estimates that currently invasive alien plants, such as pine and wattle trees, consume between 1,450- and 2,450-million m3 of surface runoff water each year.
For some context, 44 dams supply water to the Western Cape, with a maximum storage capacity of 1,870.4-million m3.
These invasive shrubs and trees invade the catchment areas, where rainwater naturally collects into rivers and dams. The report estimates that if the Western and Eastern Cape’s catchments are fully invaded, they will deliver 30% less water to the cities of Cape Town, George, Mossel Bay, Knysna, Plettenberg Bay, and Port Elizabeth.
Source: businessinsider.co.za