Vaal River system flood alert issued as more sluice gates opened

WITH the opening of the fifth sluice gate at the Vaal Dam, the Vaal River System has officially entered flood stage. Authorities have issued a flood alert and are urging communities along the riverbanks — from the Upper Vaal region down to Bloemhof Dam and beyond — to remain vigilant as continued rainfall is expected to keep river levels rising.

While dam managers have assured the public that the situation is being closely monitored and effectively managed, the volume of water being released is beginning to overwhelm tributaries and low-lying areas. The gradual rise in water levels means that sections of the Vaal River will burst their banks, causing localised flooding, particularly in areas prone to water backing up from tributaries.

Current Dam Levels and Flows:

Grootdraai Dam:

Level: 101.66%

Outflow: 176 m³/s

Sluice gates: One sluice is still open as per the latest update.

Vaal Dam:

Level: 109.53%

Fifth sluice gate has been opened

Inflow: 1121.73 m³/s

Outflow: 601.50 m³/s

Vaal Barrage:

River Height: 7.52 meters

Gates Open: 11 total, 2 gates fully opened, 8 gates opened at 27”, 1 gate at 18”

Outflow: 1027 m³/s

Bloemhof Dam:

Level: 104.39%

Current Outflow: 996.79 m³/s

Planned Increase: Outflow to be increased to 1400 m³/s by 16:00

Impact downstream could escalate if rains persist

The cumulative pressure building through the river system is of concern, particularly if more sluice gates are opened in response to continued rainfall. While the current outflows are being managed to mitigate sudden surges, the system is nearing capacity. Should the rains persist over the next few days, as forecasted, further gate openings may become necessary — significantly increasing the flow into downstream areas and potentially triggering widespread flooding in floodplains and agricultural zones.

Public Safety Advisory

Authorities are stressing there is no need for panic. “This is not a tsunami,” said a spokesperson from the Department of Water and Sanitation. “We have experienced flooding of this nature before, and it is being well managed. But we do urge everyone near rivers and flood-prone areas to take precautions.”

Residents are advised to:

• Avoid crossing low-lying bridges or flooded roads.
• Monitor local alerts and social media updates for changes in flood risk.
• Ensure valuable items are kept above potential flood lines in case of rapidly rising waters.
• Prepare for possible evacuations in extreme cases, especially in informal settlements or river-adjacent areas.

Communities are also encouraged to keep an eye on their neighbours, particularly the elderly and those who may need help in the event of flooding.

What Happens If More Gates Are Opened?

If rainfall continues and more gates are opened at the Vaal Dam, the impact will ripple downstream. This could mean:

• Significant rises in the Vaal River water level as it passes through Parys, Vanderbijlpark, Sasolburg, and Christiana.
• Increased pressure on the Bloemhof Dam, which is already over 104% full and expecting a major rise in inflow later today.
• Strain on local infrastructure, such as bridges, roads, and irrigation systems, which may be damaged or submerged.
• Delays in emergency response due to flooded access routes.

The knock-on effects could even be felt along the Orange River system, depending on the volume of water passed through Bloemhof and into the downstream channels.

A Call for Calm and Community Spirit

Despite the potential severity of the situation, officials are calling for calm and cooperation. “Be safe and be kind,” reads the closing line of the official alert — a reminder that in times like these, the strength of a community can make all the difference.

Stay tuned to official weather channels, municipal alerts, and emergency services for real-time updates.

If you live near a river, stay informed — and stay dry.