Dam impressive: Vaal reaches record winter levels for first time in over 11 years

The Vaal Dam has reached its highest water levels during the winter and autumn periods in more than 11 years, defying typical seasonal patterns that usually see reservoir capacity decline during the colder months.

Currently sitting at 107.69%, the dam’s winter performance represents an exceptional achievement given that water levels typically drop during this time of year due to reduced rainfall and continued water demands.

The reservoir has been consistently hovering around 107% throughout June, maintaining levels that would be remarkable for any season, but are particularly striking for winter.

According to data from The Reservoir, a water resource information centre serving the catchment management forums of the Upper Vaal water management area, this winter’s performance surpasses all comparable periods over the past 11 years, when the dam has traditionally operated at significantly lower capacities during the colder months.

Vaal Dam breaking seasonal patterns

The dam’s current winter levels represent a dramatic departure from historical seasonal trends.

Winter months have historically been challenging periods for the Vaal Dam, with reduced inflows and continued water extraction typically resulting in declining reservoir levels.

During previous June periods, the dam has recorded significantly lower levels, including:

• 39.83% in 2016,
• 48.10% in 2020, and
• 55.79% in 2024.

Even in stronger years, winter levels have rarely exceeded 100%, making the current 107.69% an outstanding achievement for the season.

The data shows that while the dam has reached above 90% capacity in several years, including:

• 2023 at 95.70%,
• 2021 at 97.90%,
• 2018 at 101.74%,
• 2017 at 98.63%, and
• 2014 at 94.80%, none of these previous winter performances match the sustained high levels being experienced this year.

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Vaal Dam recent peak and stabilisation

The exceptional levels follow an even more dramatic peak earlier this year when the dam reached 120% in April, prompting flood warnings.

The levels saw a decrease with reduced rainfall, with the last recent high percentage being 114% at the beginning of May.

A continued decrease in levels saw the reservoir record 108% around 14th May, before settling into its current winter pattern of sustained high levels, around 107%.

Flood warnings along the Vaal Dam have subsided as water levels stabilised from their peak earlier this month, bringing relief to residents who had endured weeks of uncertainty during the wet period that preceded the winter months.

ALSO READ: ‘Life is back to normal’: Flood warnings subside with Vaal Dam levels

Current dam levels

According to The Reservoir’s latest measurements, the dam is maintaining inflows of 74.8 cubic metres per second (m³/s) and controlled outflows of 16.8m³/s.

Meanwhile, the associated Vaal Barrage downstream is operating at a level of 7.5 metres with outflows of 20.2m³/s, while water temperatures have been recorded at 13.7°C.

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