Southampton water outage to last until the weekend, firm says
The firm said the problem was caused by a "technical issue" at its Testwood Water Supply Works, resulting into low pressure or a loss of water supply.
It added that bottled water stations were being set up and it was continuing to deliver them to customers on its priority list.
The first station opened at Places Leisure Centre - formerly Fleming Park - in Passfield Avenue, Eastleigh.
Southern Water said tankers were pumping water directly into the network to help reduce the impact.
Three of them had been dedicated to Southampton General Hospital, which is also being affected.
The lack of water also caused more than 20 schools to shut, including North Baddesley Infant School and Halterworth in the Test Valley, and The New Forest Academy, Cadland Primary School and Wildground in the New Forest and Mountbatten school Romsey.
Southern Water said it had contacted all of them.