The Department and Water and Sanitation opened one sluice gate at the Vaal Dam on Thursday to increase outflows and manage dam water levels.

In a statement on Thursday, the department said one sluice gate of the Vaal Dam opened at 12pm, in order to increase releases, due to the increased water levels at the dam amid continuous rainfall.

The dam, which supplies most of Gauteng, is currently sitting at 106.14%.

The department said the increased outflows seek to keep the dam at 105%.

"The opened sluice gate is expected to release between 110 to 130 cubic metres per second (mᵌ/s) and will remain open over the long weekend and dam levels continue to be closely monitored to ensure that any further action is activated depending on the level of water in the dam.

"All outlet valves that were previously opened and were releasing 60.1 cubic metres per second (mᵌ/s) of water at the Vaal Dam, have now been closed because they do not have the required capacity to release the required volumes," the department said.

The department emphasised that the current water release by single sluice gate is within the safe operational limits and is not expected to lead to overtopping of riverbanks downstream.

"At Bloemhof Dam, outflows have also been increased to 250 mᵌ/s from 10 am today through the pipes and to allow for the extra flows that are expected from Vaal Dam in about three to four days and to keep the dam below 100%. Water levels at the dam are currently at 97.6%," the department said.

The department added it will continue to monitor the water levels at both the dams closely.