Department of Water and Sanitation (DWS) says the five sluice gates remain opened at the Vaal Dam, while outflows at Bloemhof Dam are to be increased to manage rising water levels.
“Since the opening of the fifth sluice gate [on Sunday] morning due to the heavy inflows into the Vaal Dam, the Department of Water and Sanitation will keep all the five sluice gates opened and there will be no changes in the dam’s outflow…
“However, should there be increased inflows into the Vaal Dam, it may result in additional gates being opened. The DWS will continue to monitor Vaal Dam and effect changes on the outflow as and when necessary,” the department said in a statement on Monday.
The department reported that the water storage level at the Vaal Dam was at 111.11% on Monday morning, rising from Sunday’s 109.3% full supply capacity.
This is due to the continuous high inflow of water at 1002.25 mᵌ/s from the upper catchment.
The Bloemhof Dam storage level has also increased from 107% on Sunday to 112.08% full supply capacity on Monday morning.
As a result, the department said water releases at the dam will be increased at different times on Monday and will be staggered from the current 1 400 m3/s to 1 550 m³/s at 12pm to 1 700 m³/s at 2pm, and the last increase will be 1 850 m³/s at 4pm.
Possible overtopping of riverbanks downstream
The department warned that the current controlled water releases by the five sluice gates may lead to possible overtopping of riverbanks downstream, and this will affect infrastructure built in lower-lying areas within the 1 in 100-year floodline.
“People living within the floodline of the Vaal River downstream of the Vaal Dam and the Bloemhof Dam should evacuate and move to a safe area and remove valuable equipment, movable infrastructure and livestock,” the department said.
One sluice gate remains open at Grootdraai Dam
One sluice gate remains open at Grootdraai Dam in Mpumalanga in the Upper Vaal River Catchment, upstream of the Vaal Dam, to enable water releases.
On Monday morning, the dam recorded 102% full supply capacity.
The department reiterated that these necessary controlled water releases at the dams are being implemented, as part of dam safety precautions to safeguard the infrastructure and protect human life.
“The DWS is continuously monitoring the water levels in the Vaal River System. Through various platforms, the department continuously shares hydrology reports and provides regular updates regarding the water levels in the dams, with recommendations in order to provide early warnings in case of flooding.”
