The Department of Water and Sanitation has taken decisive action in response to the significant rise in water levels at the Vaal Dam, which has prompted the opening of four additional sluice gates. This latest measure, announced on Friday, brings the total number of sluice gates currently open to ten, as the department seeks to mitigate potential flooding risks caused by heavy inflows from upper catchments.
Water outflows were increased at Bloemhof Dam from 2800 cubic metres per second (m3/s) to 3000 m3/s at 17:00 on Friday, to manage the inflows coming in the dam from upper catchments.
By midday on Friday, the Vaal and the Bloemhof Dam were sitting at 119.68% and 111.87% respectively.
“These adjustments are necessary to manage the continuous rising inflows and safe operation of the Vaal and Bloemhof Dams.
With more inflows anticipated into the dams, especially the downstream Bloemhof Dam, outflows may potentially be increased again on Saturday,” said the department spokesperson, Wisani Mavasa.
Furthermore, Mavasa said, 2 sluice gates were open, one at 3 metres, the second gate at 1.0 m at the Grootdraai Dam, while the storage level was at 110.08% on Friday morning.
Meanwhile, in the Orange River, the Gariep and the Vanderkloof Dams are sitting at 108.25% and 106.09% respectively and are 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 should continue to avoid the flooded areas as the river catchment remains oversaturated,” warned Mavasa.
The department said as part of the dam safety protocols, sluice gates are opened 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.
