Taps could run dry in suburbs in the Ekurhuleni and Tshwane metros after a power outage, believed to have been caused by vandalism, at a Rand Water booster station on Friday.

Although power was restored to the Mapleton booster station in the early hours of Sunday morning, the system could take up to a week to return to normal, Rand Water said.

"It is important to note that there will not be an immediate relief in the water supply system. The system will require a recovery period of up to one week to fully stabilise," it said in a statement.

"As we move forward, we will closely monitor the situation and provide regular updates to the public on any further developments."

According to the City of Tshwane, a City of Ekurhuleni substation supplies the booster station. The outage affected the Vlakfontein reservoir, which supplies the City of Tshwane.

The municipality said in its statement, "The cause of the power failure was investigated, and it was revealed to be vandalism. Repairs have since been accomplished and, in the meantime, the focus is towards the provision of water."

"While Rand Water is on course with restoration to their reservoirs and their bulk water system, residents are cautioned that there is no flow, particularly in Eersterust and Mamelodi," it added.

Due to the lack of flowing water, the Mooikloof, Grootfontein, Carina Street, and Garsfontein reservoirs are empty.

The City of Ekurhuleni urged consumers to use water sparingly while the system recovers.