Around 50,000 properties in Glasgow and Paisley are having problems with their water supply.
Scottish Water is in the process of trying to restore normal supplies after reports of stoppages, low pressure and discoloured water. The cause is yet unknown.
The affected postcode areas are G41, G42, G53, G52, G41, PA1, PA2, PA3 and PA4.
A Scottish Water spokesman said: "We are in the process of restoring normal supplies. The situation is improving."