Tankers are being delivered to Brixton, Greenside, Coronationville and other suburbs.
The City of Johannesburg says water towers in some high lying areas are completely empty.
Consumers are still urged to abide by control measures as the situation intensifies.
Joburg Water's Hilgard Matthews says, “We have dispatched water tankers in Brixton, in Coronationville at the Rahima Moosa Mother and Child Hospital and at the Helen Joseph Hospital. We’re going to call in another tanker at Helen Joseph Hospital.”
Gauteng Health MEC Qedani Mahlangu says both hospitals are without water, and all non-emergency operations will be postponed until a consistent flow of water is restored.