THE water pressure for areas of BB4, which includes Haslingden and Rawtenstall, is low, United Utilities said.
A water company spokesman said low water pressure levels were reported at 2.40am.
The spokesman said: "We’re currently investigating an issue in your area which may mean you have no water or it’s coming out your tap as a trickle.
"We’re sorry for the inconvenience and hope to have your taps flowing again very soon.
"We’ll provide further updates when we know more about what is causing the problem.
"To keep your taps flowing while our network engineers continue to search for the leak, we’ll be delivering water to you from a different area which may mean your water pressure is lower than normal.
"If you spot any water leaks in your road or street, please let us know by calling 0345 672 3723."