Johnston said while the metro had reservoirs to supply water during interruptions, the reservoirs needed electricity to be prepared for outages.
“With load-shedding happening so frequently, the continuous flow of water is interrupted.
“This means reservoirs which are under significant pressure, such as high-lying reservoirs, may slowly have their water level lowered until they threaten to run dry.”
He said suburbs such as Laudium in Centurion and Waterkloof Ridge in the east of Pretoria were at risk of water shortages during long power outages.
“Even though we have asked residents to work to limit water usage, as we are in a water-scarce area and already at level 1 water restrictions, I want to ask residents to please be particularly mindful of this risk right now.”
Johannesburg Water spokesperson Puleng Mopeli said water supply problems were worsened by a recent heatwave in Gauteng, during which there was a high consumption of water.
“Though some of our critical infrastructure has been exempted from load-shedding, our towers are taking a strain.”
The water utility said its Hursthill reservoir in Johannesburg was critically low on Monday.
“Customers in higher-lying areas will experience low pressure to no water,” their statement read.
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