Five Vaal Dam sluice gates opened as water levels surge; Bloemhof outflows ramped up

The Department of Water and Sanitation (DWS) has opened five sluice gates at the Vaal Dam to manage rapidly rising water levels following persistent rains across Gauteng, Mpumalanga and other parts of the country.

The gates were opened in hourly intervals between 10am and 1pm on Monday, increasing outflows from 60 cubic metres per second (m³/s) to approximately 700 m³/s.

The department's Spokesperson Dr Mandla Mathebula said at Bloemhof Dam, outflows were also increased significantly from 60 m³/s to 250 m³/s at 10 am, and then to 400 m³/s at about 2pm as the system continues to absorb heavy inflows from upstream.

Mathebula said by Monday morning, Vaal Dam was sitting at 108.47% capacity, while Bloemhof was at 99.81%.

The department has warned that the increased releases may lead to localised flooding downstream, particularly along the Vaal River where low-lying areas and infrastructure along the floodplain could be impacted.

“Those residing in the riparian areas of the Vaal River are also urged to be alert and remove valuable equipment, movable infrastructure, and livestock as river levels may continue to rise,” Mathebula said.

Communities in the Vaal Triangle, Parys and surrounding riparian areas have been urged to stay alert, move equipment and livestock to higher ground, and take precautions as water levels rise. Farmers with pumps and infrastructure close to the river have also been advised to take protective measures.

Mathebula said as part of the dam safety protocols, sluice gates are opened for controlled water releases when dam levels rise sharply and to prevent the water resource infrastructure from failing, as it may lead to a dam bursting and causing a disaster of unimaginable magnitude.

He said the Department implements these necessary controlled water releases at the dams as part of dam safety precautions to safeguard the infrastructure and to protect human life.

The department said it will continue to monitor inflows at both Vaal and Bloemhof dams as rains persist.