The Vaal Dam has reached an alarming 109% capacity as of 10:00 AM on April 6, 2025, prompting authorities to open the fifth sluice gate at the Vaal River to manage the overflow. With water surging out at a staggering 581,000 litres per second, low-lying communities downstream, including those near the Bloemhof Dam, are now on high alert as officials issue urgent evacuation warnings.
Heavy rainfall over the past few days has pushed the dam beyond its limits, raising concerns about potential flooding in several areas. The Department of Water and Sanitation confirmed that the fifth gate was opened today, just 24 hours after the fourth gate was activated on Saturday, April 5, 2025. This rapid response comes as the Vaal Dam’s water levels spiked from 107.8% to 109% in a matter of days, driven by relentless inflows from upstream rivers.
Wisani Mavasa, spokesperson for the department, explained the situation in an interview earlier today. “We had to open the fifth sluice gate this morning due to the rapid rise of inflows into the Vaal Dam,” Mavasa said. “The water is flowing downstream and will reach the Vaal Barrage in about six hours. Communities in low-lying areas near the barrage and along the riverbanks need to evacuate immediately to avoid being caught in flood lines.”
The Vaal Dam, a critical water source for Gauteng and surrounding provinces, has been under strain following weeks of above-average rainfall across the region. The decision to open additional gates aims to relieve pressure on the dam’s infrastructure while managing the risk of uncontrolled spillage.
The cascading effects of the Vaal Dam’s overflow are already being felt further downstream. The Bloemhof Dam, located along the Vaal River in the North West province, is currently sitting at 106% capacity and rising. Authorities are working tirelessly to keep its levels in check, but Mavasa warned that the situation remains fluid—quite literally. “This water is flowing fast, and it’s heading towards Bloemhof Dam at a rapid pace,” she noted. “We’re doing our best to manage it, but with water coming through so quickly, it’s a challenge to keep levels below 100%.”
Residents in low-lying areas near the Vaal River and its tributaries, particularly around Bloemhof, have been urged to evacuate as a precaution. Floodwaters could reach homes within 100 metres of the riverbanks, placing hundreds of households at risk.
Johannesburg’s Emergency Services are closely monitoring the situation, with teams deployed to assess vulnerable areas across the city and its surrounds. The heavy rains that filled the Vaal Dam beyond its 100% capacity have also left low-lying suburbs on edge. Authorities are calling on residents to stay vigilant and avoid crossing flooded roads or bridges. “We’re keeping a close eye on the low-lying areas,” an Emergency Services official stated. “Our priority is to ensure communities stay safe. We urge everyone to follow evacuation orders and take this seriously.”
The City of Johannesburg has activated its disaster management protocols, with emergency hotlines available for residents needing assistance. The combination of overflowing dams and saturated ground has heightened fears of flash flooding, particularly in informal settlements and flood-prone zones.
The Vaal Dam’s overflow is a direct result of persistent rainfall across Gauteng, Mpumalanga, and the Free State over the past few weeks. Weather experts report that the region has experienced one of its wettest seasons in years, with rivers and tributaries feeding into the dam at unprecedented rates. This has left water management officials with little choice but to release excess water in controlled bursts.
Historically, the Vaal Dam has exceeded 100% capacity during extreme weather events, with notable overflows recorded in 1996 and 2011. However, the current situation—combined with the Bloemhof Dam’s near-critical levels—marks a rare and concerning escalation.
With flood warnings in place, authorities have shared practical advice for those in affected areas:
- Evacuate Early: If you live in a low-lying area near the Vaal River or Bloemhof Dam, move to higher ground immediately.
- Avoid Waterways: Stay clear of rivers, streams, and flooded roads to prevent being swept away.
- Stay Informed: Monitor local radio, TV, and online updates for the latest alerts.
- Prepare an Emergency Kit: Include essentials like food, water, clothing, and medication in case of prolonged displacement.
Mavasa emphasised the urgency of the situation: “If you’re within 100 metres of the river or in a flood line, you need to act now. Don’t wait for the water to arrive.”
As the situation develops, the Department of Water and Sanitation is urging residents to heed evacuation orders and prepare for potential flooding. The combination of heavy rainfall and the Vaal Dam’s overflow presents significant risks, and authorities are committed to ensuring the safety of residents in affected areas.
