Vital water infrastructure across Gauteng and the Free State continues robust performance since March 2025, with major dams in the catchment area operating at or above optimal capacity.
The Vaal Dam, a critical component of South Africa’s water supply infrastructure, has maintained capacity above 100% since March 2025.
On Wednesday, the dam recorded 101% as the integrated Vaal River system continues to show robust water levels across multiple reservoirs, according to the latest data from The Reservoir, a water resource information centre for the catchment management forums of the Upper Vaal Water Management Area.
Compared to the same time last year — the week of 26 January 2025 — the Vaal Dam stood at 61%.
After months of low dam levels, the Vaal Dam began to rise rapidly between January and March due to heavy summer rains.
The current sustained performance marks approximately 10 months since 7 March 2025, when the dam reached 100%. Before this period, the dam had last recorded full capacity in 2023.
Barrage maintains stable operating levels
On Wednesday, the Vaal Dam maintained the same capacity as the previous day while managing inflows of 78.3 m3/s against outflows of 21.4 m3/s, with no gates currently open, The Reservoir reported.
The Vaal Barrage, which regulates water distribution downstream, maintained a level of 7.5 metres, an outflow of 10.1 m3/s, and a water temperature of 23.6 °C.
Recent daily measurements show the system’s stability, with the Vaal Dam registering 101% on Tuesday, with inflows of 79.8m3/s and identical outflows of 21.4m3/s with no sluice gates open.
On Monday, the dam stood at 100.88% with higher inflows of 82.7m3/s against the same controlled outflow.
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Upstream dams operating above capacity
The integrated system’s upstream dams are performing exceptionally well, with several exceeding their normal operating levels.
Grootdraai Dam, which feeds water down the Vaal River directly into the Vaal Dam, stands at 102.1%, according to The Reservoir’s measurements updated on Tuesday, 27 January 2026.
Sterkfontein Dam has reached 100.1% capacity. Water from this facility flows down the Nuwejaarspruit into the Wilge River, which subsequently feeds into the Vaal Dam.
The dam receives pumped transfers from Woodstock Dam, which itself operates at 98.4% capacity.
The Lesotho Highlands Water Project continues to contribute substantially to the system.
Mohale Dam in Lesotho recorded 101.8% capacity, with water being transferred via gravity-fed systems to Katse Dam.
Katse Dam stands at 97.4%, pumping water into the Liebenbergsvlei that flows into the Wilge River and ultimately into the Vaal Dam.
Bloemhof Dam, the major reservoir downstream from the Vaal Dam, recorded 96.5% capacity on Tuesday.
Water flowing from Bloemhof Dam continues down the Vaal River to the Douglas Weir before joining the Orange River system, completing the integrated water management network that serves multiple provinces and supports both urban and agricultural water demands across the region.
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