Vaal Dam remains full despite falling inflows | The Citizen

While the dam remained at a high level, this marked a drop from the same week last year, when it stood at 106.7%, according to the Department of Water and Sanitation (DWS).

Vaal Dam’s storage opened the week at 100.63% on Monday, before decreasing to 100.38% on Tuesday, according to the weekly hydrological report compiled on behalf of Rand Water and DWS.

Storage decreased further to 100.35% on Wednesday, then rose slightly to 100.41% on Thursday, before dropping to 100% by Friday.

The weekly average storage was recorded at 100.35%, with a high of 100.63% and a low of 100%.

Inflow into the dam decreased every day of the week, the report showed.

Monday recorded an inflow of 43.7m³/s, which decreased to 39.3m³/s on Tuesday.

Inflow decreased again to 38 m3/s on Wednesday, before increasing slightly to 42.6m³/s on Thursday.

Friday recorded the lowest inflow of the week at 25.7m³/s, a sharp decrease from the previous day. The weekly average inflow stood at 37.9m³/s.

Discharge from Vaal Dam remained constant at 16.8m³/s every day from Monday to Friday, the data indicated. No sluice gates were opened on any day of the week.

The Vaal Barrage recorded a consistent level of 7.5 metres from Monday through Friday, according to the report.

Discharge at the barrage also remained unchanged throughout the week at 22.6m³/s.

Water temperature at the barrage increased from 12.6°C on Monday to 16.4°C on Tuesday.

It then decreased to 15.6°C on Wednesday, before rising again to 16.4°C on Thursday. Friday recorded a slight decrease to 16.2°C.

The report noted that not all abstraction and evaporation losses from Vaal Dam were reflected in the figures, and cautioned that weekend data remained unverified pending confirmation.