Homes across south Wolverhampton and Sedgley either had no water or low pressure as a result of a power issue affecting a water pumping station.
Severn Trent, responsible for the supply in Wolverhampton, and South Staffs Water, responsible for Sedgley, apologised to those affected at 8pm and said engineers were working to get water back flowing.
The problem was said to have been sold by 9.30pm.
An update from Severn Trent said: "Customers living in the WV2 and WV4 area of Wolverhampton may be experiencing poor pressure this evening due to a power failure.
"We're sorry for any inconvenience caused and we expect to have this issue resolved as soon as possible."
While South Staffs Water said: "We are aware that there is a problem in the Sedgley area, causing low pressure or loss of water supply.
"This is due to power dips in the area that have affected our pumping station, our engineers are on site.
"We're sorry about this and we’re working to fix it as quickly as possible.
"We apologise for any inconvenience and ask you for your patience while we deal with the situation."
Earlier in the day parts of Kingswinford were without water due to a broken water booster pump.