The risk of flooding along the Vaal and Orange Rivers is extremely high, as more rain is expected in the catchment.
The Department of Water and Sanitation, said on Thursday, both controlled and uncontrolled water releases at 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.
The Department also said evacuations are in place and residents are urged to avoid flooded zones.
Two more sluice gates were opened and the third, on Wednesday, around 4pm, to manage water outflows, which paced at 461.090 cubic metres per second (m3/s).
Water level in the Vaal Dam is at 111.64% full, necessitating the opening of the fifth sluice gate.
The Department said it expects inflow into the Bloemhof Dam, to be around 1 390 m3/s on Thursday morning.
Water outflow was 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.
Similarly, one sluice gate was opened at the Grootdraai Dam, when its storage capacity exceeded 100% full, amounting to about 105.71%, with inflow of 141.72 m³/s.
The Department said the Gariep & Vanderkloof Dams are spilling over at 107.13% and 105.3% respectively.
Picture: Department of Water and Sanitation