The water level of the Vaal dam has reached 98.99%, with the Department of Water and Sanitation (DWS), in line with its flood management plan, slowly releasing some water to ensure balance between the inflows and outflows at the dam.

About 61.2 cubic metres per second (mᵌ/s) is being released, using five of the dam’s eight valves for river releases, to ensure that the dam’s capacity stays within the range of 100% to 103% at the current inflow levels.

Normal day-to-day releases entail using two valves ranging from 16.8 mᵌ/s to 17.6 mᵌ/s to keep the natural flow in the river.

The DWS assured that the water flow is insignificant and will not make the river overtop the banks.

“According to hydrological monitoring and forecasting systems, the Vaal dam may reach 100% in the next few days as the torrent rainfall continues in the catchment, and increased releases may be required on both dams should the need arise to safeguard to prevent dam failures and major disasters,” the department said in a statement.

As part of the flood management plan, dam safety protocols are activated when dams breach the full capacity mark and overflow to prevent the infrastructure from failing, which may lead to a dam bursting and causing a disaster of unimaginable magnitude and also leave the areas it supplies without sources of water, the DWS explained.

The water level of the Bloemhof dam, located downstream of the Vaal river catchment, is currently at 100.94% and has an additional 16% flood absorption capacity.

Owing to increased river inflows from the upper catchments and recent rainfall in the Bloemhof catchment area, controlled outflow releases have also been activated at the dam and water is currently being released at 320 mᵌ/s through outlet pipes.

These releases are meant to facilitate the proper management of water levels and to keep the dam at or below its full supply capacity of 100%.

There are currently no sluice gates open at both dams.

Along the Vaal river and downstream the Vaal dam, water levels may rise as a result of inflows from Suikerboschrand, Klip and Rietspruit tributaries over the high flow period owing to the heavy rains in the catchments of these rivers.

“The DWS follows operating rules and procedures when releasing water from the dams . . . and will gradually implement the releases in line with the established flood management protocols in coordination with the National Disaster Management Centre, the Provincial Disaster Management Centres and affected local municipalities.”

Through various platforms, the department said it will continue to engage, and share hydrology reports and updates on a regular basis on the water levels in both dams, with recommendations to send early warning systems and activate evacuation plans in cases of flooding.

Stakeholders include the disaster management operations in the affected municipalities, local police services (police water wing), farmers and locals upstream and downstream along the Vaal river system.

The DWS continues to actively monitor inflow water levels at Vaal dam as torrential rains continue, to ensure that necessary precautions are in place in line with dam safety standards and hydrological monitoring systems to safeguard and maintain the integrity of the water resource infrastructure as well as reduce flood conditions while keeping the dam at full capacity.