PREVENTATIVE INTERVENTIONS REGARDING
INVASIVE AQUATIC WEED IN THE VAAL RIVER BARRAGE RESERVOIR
The Vaal River Barrage Reservoir is not only a critical water source for numerous strategically important industries, but also a waterfront residential hub with rich tourism, sport and recreation offerings. It is home to South Africa’s most valuable inland waterfront properties -aptly named “Millionaire’s Mile” and “Millionaire’s Bend.”
In 2021 and 2022, early signs of the invasive aquatic plant Pistia stratiotes (commonly known as water lettuce) were observed by local residents and reported to the Authorities. Heavy rainfall and flooding in those years helped temporarily wash the infestations downstream. However, by late 2023 -with minimal rainfall - an alarming proliferation of the weed occurred, with water lettuce spreading exponentially within weeks.
In response - the local Vaal River community convened a critical meeting in January 2024. This marked the beginning of what would become a model case of successful intervention through public-private collaboration.
While the Department of Water and Sanitation (DWS) worked on securing the necessary General Authorisation (GA) and funding for an integrated management approach, the Vaal River community was granted interim permission to physically remove the infestation. Besides many river individual residents, residential estates, and boating clubs using every imaginable way of physically removing the IAP physically – it was mass extraction using pusher boats, curtains (ropes), and heavy equipment that made a significant difference.
All of this was entirely funded and driven by the local community.
By July 2024, over 400 hectares of invasive aquatic plants had been successfully removed, restoring navigability to the river.
At the same time, DWS finalised the GA and appointed Rand Water as the Implementing Agent for a three-year programme to manage IAP (Invasive Aquatic Plant) control, supported by an operational budget.
Since then, the project has evolved into a remarkable success story. Though water lettuce has since given way to water hyacinth (Pontederia crassipes), the Vaal River Barrage Reservoir remains open and usable - thanks to ongoing collaborative efforts. The Vaal River community, Rand Water, DWS, and the Centre for Biological Control now work hand-in-hand, meeting monthly as equals in a spirit of shared purpose. This coordinated, respectful partnership is rare in South Africa’s IAP landscape - and a powerful example of what is possible when communities and government unite.
The approach combines several authorised interventions - physical extraction, river curtaining, herbicide treatment, and biocontrol - guided by real-time data and shared expertise. This integrated strategy, coupled with a committed partnership across all parties, has led to outcomes not seen elsewhere in the country.
The community has since called for a similar collaborative model to be applied to tackling wastewater pollution - demonstrating the far-reaching potential of this kind of cooperation.
Included below are maps and charts from early 2025 that illustrate the tools used at the monthly meetings to manage the infestations. Through proactive measures such as early detection, targeted response, and regular monitoring, the ecological balance of the Vaal River is being safeguarded – and will be continued to be safe-guarded and its long-term sustainability preserved.
As of today, all curtains in the main river (including the Taaibos) have been removed -symbolising the return of full access for fishing, boating, golfing, residential enjoyment, and tourism. The river is once again a place for all to enjoy - thanks to a collective effort that sets a national benchmark for environmental action.
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