The warning follows increased controlled water releases from both dams due to dangerously high inflows in the oversaturated upper catchment.

Department spokesperson Wisane Mavasa confirmed that dam levels continue to rise sharply, requiring immediate action. “The rising dam levels, caused by the heavy inflow into the Vaal Dam, have necessitated the activation of additional controlled water releases in the Vaal River System.”

Amid rapidly rising water levels at the Vaal Dam due to heavy inflows from the upper catchments, the Department of Water and Sanitation (DWS) will open six sluice gates to manage the water inflow of 2056.50 cubic metres per second (m3/s) of water flowing into the dam… pic.twitter.com/y4Zgqya5u4

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Sluice gates at the Vaal Dam are being opened in phases. “The third sluice gate was opened yesterday at 16:00 to manage water outflows, currently at 461.09 m³/s. As of this morning, the dam is at 111.64% of storage capacity. By (Thursday) afternoon, five sluice gates will be open to manage an inflow of 1,332.51 m³/s,” Mavasa said.

The fifth gate opened at 14:30, and the sixth was set to open at 16:00.

At Bloemhof, similar measures are being taken. The outflow at the Bloemhof Dam was increased from 800 m³/s to 1,800 m³/s in hourly increments. As of Thursday morning, the dam was at 106.71% of capacity, with inflows reaching 1,390 m³/s.

District Municipality Fire and Disaster Management manager Herman Bezuidenhout urged affected communities to act swiftly. “Residents at Hoek and downstream to Bloemhof should consider evacuating, as roads will likely be cut off once the flow reaches 1,800 m³/s at 15:00,” he warned.

He also urged residents to take precautions. “Move electrical appliances to higher ground and switch off electricity before leaving. Others in nearby areas may be called on to assist if the situation worsens.”

Mavasa said one sluice gate has been opened at Grootdraai Dam, currently at 105.71% capacity, with inflows of 141.72 m³/s. The Gariep and Vanderkloof Dams on the Orange River are also overflowing, at 107.13% and 105.3% respectively.

“These controlled and uncontrolled releases will result in riverbanks overtopping along the Orange and Vaal Rivers, potentially flooding low-lying areas within the 1-in-100-year floodline,” Mavasa said. “Evacuation and avoidance of flood zones remain essential.”

With more rain expected in the Upper Vaal Catchment area, the DWS will continue to monitor the Integrated Vaal River System closely to ensure dam safety and mitigate flood risks.

OFM News/Kekeletso Mosebetsi cg