Water crisis threatens as invasive plants overrun Vaalkop Dam

North West dam is the main source of water for drinking, agriculture and industry, but officials have been 'ignoring' the problem since 2017

- Sheree Bega

Hartbeespoort Dam on steroids". That's how landowners around the Vaalkop Dam in the North West have described the dam's heavy infestation with the invasive alien aquatic plants, water hyacinth and common salvinia.

These water weeds are now smothering 100% of the Vaalkop Dam - a crucial water source for the Bojanala and Waterberg districts - and it's become a "desperate situation", according to Martin Frere, a board member of Bushwillow Estate on the dam.

This week, the Vaalkop Dam Alien Vegetation Action Group, which comprises Bushwillow Estate, Finfoot Lodge and Mziki Nature Reserve, warned that the structure is at risk of ecological and economic collapse.

Situated about 60km northwest of the polluted Hartbeespoort Dam, Vaalkop is considerably less well-known. Although it is about half the size of Hartbeespoort Dam, it is the primary source of drinking, agricultural, and industrial water for the North West, supplying towns such as Rustenburg, Swartruggens and Thabazimbi, the Sun City resort and the platinum mining belt with potable water.

A major distinction is that Hartbeespoort Dam is primarily used for irrigation downstream, Frere noted. In contrast, Vaalkop Dam has a huge water treatment plant, run by Magalies Water.

“Its capacity is 270 million litres a day so the water used from that dam is predominantly potable water ... It’s a really significant water resource for the province. If Magalies Water had to stop abstraction, the consequences would be devastating,” he said.

Despite the dam’s importance, authorities have largely ignored its plight, the Vaalkop Dam Alien Vegetation Action Group said.

The first little islands of water hyacinth, the world’s worst aquatic weed, were first detected in the system in October 2017. The invasion was immediately reported to the then-department of forestry, fisheries and the environment and then to the department of water and sanitation in 2018.