Vaal Dam at 97%, could it reach 100% milestone by the weekend?

The Vaal Dam is rapidly approaching its maximum storage capacity, with water levels standing at an impressive 97.73% as of Wednesday.

This has raised hopes that the reservoir could reach the 100% milestone by the weekend.

The dam has a full storage capacity of 2.561 billion cubic metres.

Its current water levels depict a strikingly strong comeback compared to the beginning of the year when it plummeted to below 30%.

Dramatic rise in Vaal Dam water levels

On Friday, the dam was just over 90% capacity, sitting at 90.3%, but recent heavy rains have dramatically transformed the water landscape.

Midvaal councillor Pieter Swart highlighted the remarkable progression.

“The Vaal Dam reached a storage level of 94.17% on 3 March 2025, as shown in the daily flow data for March 3 to 9, 2025, a significant increase from the 25% recorded on New Year’s Day.”

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Vaal Dam technical details reveal promising trends

Current hydrological data paint an optimistic picture.

The Reservoir, a Water Resource Information Centre for the Catchment Management Forums of the Upper Vaal Water Management Area, revealed that the Vaal is experiencing a substantial inflow of 481.4 cubic metres per second. The outflow remains relatively modest at 16.8 cubic metres per second.

Meanwhile, Vaal Barrage levels are currently at 7.6 metres, with an outflow of 89.8 cubic metres per second and a water temperature of 23.2 degrees Celsius.

“An inflow of 398.0 m³/s was recorded on 3 March, with a steady discharge rate of 16.8 m³/s from the dam and a constant Vaal Barrage discharge of 10.1 m³/s throughout the week,” Swart elaborated.

The reservoir’s consistent water level increases suggest that the dam could potentially reach its full 100% capacity by the weekend.

Earlier Reservoir reports from Tuesday, showed the dam at 96.12%, with an inflow of 439.0 cubic metres per second and an outflow of 16.8 cubic metres per second.

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Vaal Dam sluice gates on standby

Water and Sanitation Minister Pemmy Majodina recently assured that the Vaal Dam’s sluice gates are up to standard.

She said the department would warn communities nearby if water needed to be released from the dam to maintain a safe level.

This is a precautionary measure to prevent overflow, which she said could lead to disaster.

Although the dam has been checked and is safe, residents downstream need to be informed when water is released to avoid panic.

“Already in December, we prepared the communities to say it takes three days for released water to go to the Vaal Dam and to come to Gauteng. So, people were just watching because we cannot risk the lives of our people. Water can be a good thing, but it can be very dangerous,” Majodina said.

The department of water and sanitation has also provided crucial insights into the dam’s capabilities.

“The Vaal Dam operates with a full supply level of 100%, but it has a flood absorption capacity of 26%, meaning it can accommodate water levels up to 126% before posing a significant structural or operational risk,” the department explained.

As a precautionary measure, they aim to keep the dam’s level below 103% to ensure optimal peak inflow attenuation.

The department employs comprehensive monitoring systems, including real-time flow gauging stations, South African Weather Service rainfall forecasts, and advanced hydrological modeling tools.

ALSO READ: Will the Vaal Dam overflow? Here’s what will happen if it reaches 100% capacity

Expert insights on potential overflow

Contrary to public concerns about overflow, officials have emphasised that the Vaal Dam is designed to manage high water levels safely.

Swart clarified, “The Vaal Dam doesn’t ‘overflow’ in the way some other dams will do. It makes use of sluice gates to release water in a controlled manner, once the dam reaches 100%.”

Water expert Carin Bosman reinforced this point, saying that the term “overflow risk” is technically misplaced.

“The dam is designed to overflow so there is no risk associated with the overflow. The risk of overflow is not a risk. The dam is designed to overflow,” Bosman stated.

She explained that overflow events typically occur “towards the middle end of March, beginning of April, and that’s the dams designed to handle overflow”.

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