Ongoing rainfall across Central South Africa has led to controlled water releases from the Bloemhof and Vaal dams since March. While these releases have raised concerns among communities along the Vaal River—with some experiencing losses—experts stress that such measures are essential to safeguard infrastructure and manage flood risk.
According to Roelie van Reenen, supply chain executive at Beefmaster Group, Central South Africa’s extensive water network is designed not only to promote long-term water security but also to minimise damage during periods of excessive rainfall.
“The alternative to managing such situations through controlled water release can have devastating consequences. During flood periods, the volume of water coming down the system can equal two to three times the dam’s full capacity. The infrastructure simply cannot accommodate this without proper management, and so controlled water release becomes necessary,” says van Reenen.
To manage the significant inflows and protect communities downstream, authorities at the Bloemhof Dam recently released more than 1,2 billion cubic metres of water over five days. In the first period, around 777 million cubic metres of water were released at a peak rate of 3 000 cubic metres per second. Over the following days, an additional 432 million cubic metres were discharged at a slightly reduced rate of 2 500 cubic metres per second. Although levels remain high at both Bloemhof and Vaal dams, reports indicate that water levels are now subsiding.
“These are certainly uncomfortable times for farmers and other agricultural players in the area, but without this infrastructure and its careful management, we would face even more extreme impacts from both drought and flooding,” he explains. “We cannot allow our dams to run empty. Our dams help buffer against extremes—offering vital support for water security and flood control.”
What can farmers do to prepare for periods excess water
Van Reenen adds that it’s crucial for agricultural assets—such as irrigation systems, centre pivots, and buildings—to be constructed above designated flood lines to avoid potential damage during controlled releases.
“Authorities are handling the outflow from the dam effectively, as best as they can, especially since there are many people downstream who may be impacted,” he says.
Decisions to release water are made with multiple considerations in mind—including the likely impact on communities below the confluence of the Vaal and Orange rivers, and further along the Orange River. It can affect communities from Douglas in the Northern Cape to Oranjemund in Namibia.
Van Reenen urges agricultural stakeholders in the area to maintain perspective and avoid alarmism.
“There is a lot of misinformation out there, so it is important to look at the facts,” he says. “The current rain and dam levels have been at these levels many times before. The Bloemhof Dam was released at 3000 m³/s at its peak recently, while in previous flood situations this has been much more.”
Further data shows that over the last century, the probability of a major flood event occurring in any given 20-year period is around 18%, rising to 40% over a 50-year timeframe.
Authorities also issue advance notifications before opening sluice gates, giving communities sufficient time to prepare or evacuate flood-prone areas.
Function and management of Bloemhof Dam
Van Reenen notes that during challenging times, it’s helpful to remember the original intent of key infrastructure like the Bloemhof Dam. Primarily built to support the Hartswater Irrigation Scheme—which spans more than 30 000 hectares—the dam works in conjunction with the Vaalharts Barrage, completed in the 1930s near Warrenton, to sustain what became South Africa’s largest irrigation project.
By the 1950s, this network had transformed a semi-arid region into one of the country’s most productive farming areas, supplying water through over 1,280 kilometres of canals to crops like maize, lucerne, cotton, and groundnuts. In addition to its agricultural role, the dam has long played a critical part in flood management, regulating flows to protect downstream communities. While it cannot eliminate floods entirely, its design—including raised dam walls and controlled outflows—aims to mitigate the impact of extreme volumes of water, which currently exceed 2.5 million litres per second.
Van Reenen empathises with businesses and small communities along the river who are bearing the brunt of the current flooding.
“The river helps drive economies, as businesses and communities rely heavily on the river to sustain them. When the river is in flood, livelihoods are disrupted, businesses suffer, and everyday life becomes significantly harder. No one is visiting the areas because of the flooding and now is a peak tourist season given that it is Easter and public holidays. Everyone in the area is feeling the impact,” concludes van Reenen.
Key takeaway
“As a country we need to build more dams. With more dams, discharges and peaks can be managed more effectively. Importantly, water is an extremely valuable resource for food and job security, as well as economic drive in South Africa. An investment into more water storage in this country will reap benefits for current and future generations,” concludes van Reenen.
