The rising dam levels resulting from heavy inflows into the Vaal Dam from the upstream catchment has necessitated the Department of Water and Sanitation (DWS) to activate more controlled water releases in the Vaal River System today. As such, two more sluice gates will be opened in a staggered manner at 10:00 and 16:00 respectively. The third sluice gate was opened yesterday at 16:00 to manage the water outflows which are now at 461.090 cubic metres per second (m3/s). As of this morning, Vaal Dam is at 111.64% of storage capacity. Therefore, by afternoon, five sluice gates will be open to manage the
water inflow of 1 332.51 m3/s coming from the upper catchment.
At Bloemhof Dam, water outflows are also being increased incrementally at different times from 800 m3/s to 1050 m3/s at 09:00; 1300 m3/s at 11:00; 1550 m3/s at 13:00; and to 1800 m3/s at 15:00. These adjustments are necessary to manage the continuous rising inflows and safe operation of the dam which is at 106.71% today. Inflows into the dam are estimated at 1 390 m3/s as of this morning. One sluice gate has now been opened at Grootdraai Dam, and the storage capacity is at 105.71%, with inflows of 141.72 m³/s. In the Orange River, the Gariep and the Vandekloof Dams are currently sitting at 107.13% and 105.3% respectively and overspilling. The controlled and uncontrolled water releases at all these dams will lead to overtopping of riverbanks downstream of the Orange and the Vaal Rivers, resulting in flooding of settlements that are in the lower-lying areas within the 1 in 100-year floodline.
People living within the floodline downstream of the Vaal and Bloemhof Dams and have had to evacuate and should continue to avoid the flooded areas as the river catchment remains oversaturated.
With more rainfall predicted in the Upper Vaal Catchment, the DWS will continue to monitor inflow water levels in the Integrated Vaal River System (IVRS) to ensure that necessary precautions are in place in line with dam safety standards and hydrological monitoring systems to safeguard infrastructure and attenuate any flood conditions. As part of the dam safety protocols, sluice gates are opened for controlled water releases when dams breach the full capacity mark, to prevent the water resource infrastructure from failing as it may lead to a dam bursting and causing a disaster of unimaginable magnitude. The Department implements these necessary controlled water releases at the dams as part of dam safety precautions to safeguard the infrastructure and protect human life.
