Vaal Dam remains over 101% full as inflows ease heading into August

The Vaal Dam wall is seen during a period of heavy rains, 3 January 2021. Picture: Michel Bega Weekly hydrological data from The Reservoir shows steady storage levels and rising barrage discharge as the Upper Vaal system settles after a volatile year. The Vaal Dam remained comfortably above full capacity through the week of 27 July to 31 July 2026, according to data released by The Reservoir, the Water Resource Information Centre for the Catchment Management Forums of the Upper Vaal Water Management Area.

The Reservoir noted that the figures were supplied on behalf of Rand Water and the Department of Water and Sanitation, and cautioned that not all abstraction and evaporation losses from the Vaal Dam were reflected in the reported data. Storage stood at 101.89% full on Monday, 27 July, before easing slightly to 101.76% on Tuesday and Wednesday and settling at 101.64% on both Thursday and Friday. According to The Reservoir’s weekly bulletin, the dam’s storage averaged 101.74% across the week, with a high of 101.89% and a low of 101.64%.

No figures were yet available for Saturday or Sunday at the time of publication, with those cells still marked as pending verification. Inflow into the Vaal Dam showed a gradual decline over the five reported days. Monday recorded an inflow of 43.5m³/s, the highest figure of the week, before dropping to 40.5m³/s on Tuesday and 39.7 m3/s on Wednesday.

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Thursday saw a slight uptick to 41.0m³/s, followed by a dip to 39.6m³/s on Friday, the lowest reading of the week. The weekly average inflow came to 40.8m³/s, based on figures supplied by The Reservoir on behalf of Rand Water and the Department of Water and Sanitation. Discharge from the Vaal Dam held steady at 16.9m³/s every day from Monday through Friday, giving a weekly maximum, minimum and average that were all identical at 16.9m³/s.

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