- A fifth sluice gate has been opened at the Vaal Dam in South Africa to manage water levels, which have increased overnight because of the ongoing rainfall in the Vaal River catchment.
- This is in about 24 hours after the Department of Water and Sanitation (DWS) had opened the fourth sluice gate at the Vaal Dam.ย
- Water storage levels at the dam stood at 107.82% on Saturday but as of this morning, the levels have risen to 109.39%.ย
- The outflows at the dam will move from 550 cubic metres per second (mแต/s) to just under 700 mแต/s.
- The inflows into the dam are currently 1 000 m3/s.ย
Bloemhof Dam storage levels have also risen from yesterdayโs 103.23% to 106.91% this morning, and water releases will be staggered incrementally from the current 1 000 mแต/s to 1 100 mยณ/s at 10am; 1 200 mยณ/s at 12h00; 1 300 mยณ/s at 14h00, and the last increase at 16h00 to 1 400 m3/s.
The Vaal Dam is a key water source for Gauteng, supplying a significant portion of the province’s water needs, particularly for the cities of Johannesburg, Pretoria, and Ekurhuleni. South Africa’s Department of Water and Sanitation recently called on Gauteng municipalities to implement strick water restrictions where water demand cannot meet supply. Read moreย
The increased outflows from Vaal Dam are expected to reach the barrage in about six hours and Bloemhof Dam in three to four days, and will result in water levels rising in both the dam and the river, overtopping of the riverbanks.
Due to increased water releases by the five sluice gates, there might be a possible overflowing at the riverbanks downstream and this will affect infrastructure built in lower lying areas.
At Grootdraai Dam located in Mpumalanga in the Upper Vaal River Catchment, upstream of Vaal Dam, one sluice gate remains opened at 2.5 metres to enable the water releases. The dam is currently sitting at 102.41%.
The department is implementing these necessary controlled water releases at the dams as part of dam safety precautions to safeguard infrastructure and ensure that there is full storage capacity after the rainfall season.
The department, through various platforms, continuously shares hydrology reports and updates on a regular basis with recommendations in order to send early warning systems and activate evacuation plans in case of flooding.
Author: Bryan Groenendaal
