Higher than normal water consumption coupled with below average dam levels, have resulted in restrictions applied in three Gauteng metros.
City of Johannesburg, Tshwane and Ekurhuleni were hit with a "reduced flow" from Friday morning, said Rand Water spokesperson Justice Mohale.
"These reductions are as a consequence of higher than normal demand resulting in average storage capacity dropping below 60%," said spokesperson Justice Mohale.
Mohale said some reservoirs including Brakfontein, Klipfontein and Hartebeeshoek are "currently below safe operating levels".
"Rand Water's operating philosophy is to maintain reservoir storage levels between 60% and 80% for equitable distribution which is why we are taking the measure of reducing the flow.
"This is being implemented to assist with the recovery of these reservoir levels while managing high water consumption within the above mentioned metros," said Mohale.
He said consumers have been asked to use water sparingly.