Joburg Water said all towers and some tanks were empty at the Eikenhof booster pumping station.
This system is mostly affected by the closure and is responsible for providing water in the Greater Randburg and Roodepoort areas.
While work is progressing in Soweto, South Johannesburg and Lanesia, the Ekeinhof booster pumping station is affected, the reservoir and towers in Soweto still have capacity.
The Linacea and south of Johannesburg reservoirs were low until emptying on Wednesday and the system will take up to 10 days to recover.
Joburg Water provides static tanks in critical areas, including hospitals, clinics, municipal offices, schools and police stations.
There are also water tankers roaming through the affected suburbs. We thank the residents who answered the call to stock up on water before closing. Residents are also encouraged to keep their taps turned off as a forgotten open tap can lead to flooding or at least waste of water when the supply is restored.