Residents living in parts of Clitheroe, Dunsop Bridge, Whalley and Billington are without water this morning (Friday).
Due to a water leak, householders, especially in the Clitheroe and Dunsop Bridge areas, have been experiencing no water or very poor pressure since this morning.
Engineers from United Utilities have been dispatched to fix the leak.
A spokesman for United Utilities said: "You may have noticed that the water is coming out of your tap slower than usual or may have gone off altogether. We have found a technical fault on our water mains network in your area, due to a power cut, which is causing the problem with your water supply.
"Our engineers are looking into this and we are working hard to get this problem sorted as quickly as we can. We're sorry for the trouble this may be causing and thank you for your patience."