Water has been restored to parts of northern Johannesburg, after some suburbs’ taps were dry since Tuesday.
Areas that had been affected by the outage include Bryanston, Epsom Downs, Palmlands, Douglasdale, Fourways, Lonehill and Magaliessig, and surrounds.
Some schools in those areas were closed on Thursday because of the water cuts.
Johannesburg Water spokesperson Isaac Dhludhlu told News24 on Thursday that water should have been restored to most areas by Thursday afternoon, with the possible exception of some high-lying areas.
Dhludhlu said the outage was caused by the failure of a pressure-reducing valve at the reservoir. "We have decided to replace three valves over the next seven days.
"We are starting work this evening at 20:00 and will be working through the night."
Dhludhlu said work was being carried out at night to reduce the impact on households.
"By the time people wake up the next morning, there will be water," Dhludhlu said.
"We will be able to run two pumps, instead of three, while replacing the faulty valve.
"By Friday next week, we should have completed all of them."
Dhludhlu said water interruptions during repairs should be minimal and intermittent.
As a precaution, water tanks were still available in the affected areas.
Last month, a substation that provides electricity to the Rand Water infrastructure that pumps water to approximately 40% of Johannesburg, as well as parts of the West Rand and Rustenburg, caught fire in an apparent act of sabotage. Water supply to many suburbs was interrupted.
City Power spokesperson Isaac Mangena told News24 at the time that the damage was so severe that, under normal circumstances, it would have taken at least 72 hours to repair.
Supply was however restored within 32 hours.