Vaal Dam: A fifth sluice gate has been opened this morning at the Vaal Dam to manage water levels, which have increased overnight as a result of the ongoing rainfall in the Vaal River catchment. This action comes approximately 24 hours after the Department of Water and Sanitation (DWS) opened the fourth sluice gate at the dam.
According to South African Government News Agency, water storage levels at the Vaal Dam stood at 107.82% on Saturday, but as of this morning, the levels have risen to 109.39%. Consequently, the outflows at the dam will increase from 550 cubic metres per second (m³/s) to just under 700 m³/s, while the inflows into the dam are currently at 1,000 m³/s.
Bloemhof Dam has also experienced a rise in storage levels, increasing from yesterday’s 103.23% to 106.91% this morning. Water releases at Bloemhof Dam will be staggered incrementally, moving from the current 1,000 m³/s to 1,100 m³/s at 10 am, 1,200 m³/s at 12 pm, 1,300 m³/s at 2 pm, and the final increase at 4 pm to 1,400 m³/s.
The increased outflows from the Vaal Dam are expected to reach the barrage in about six hours and Bloemhof Dam within three to four days, potentially resulting in rising water levels in both the dam and the river, leading to overtopping of the riverbanks.
Due to the increased water releases by the five sluice gates, there might be a possible overflow at the riverbanks downstream, which could affect infrastructure built in lower-lying areas.
At Grootdraai Dam, located in Mpumalanga in the Upper Vaal River Catchment, upstream of Vaal Dam, one sluice gate remains open at 2.5 metres to facilitate water releases. Currently, the dam is at 102.41%.
The department is implementing these necessary controlled water releases as part of dam safety precautions to safeguard infrastructure and ensure full storage capacity after the rainfall season. Through various platforms, the department continuously shares hydrology reports and updates with recommendations to send early warning systems and activate evacuation plans in case of flooding.