Dozens of homes had their water service disrupted after workmen damaged a pipe in Fulwood.
Workmen struck the pipe at around 9.15am at the roadworks on Eastway, just beyond the junction with the A6 Garstang Road.
They had been working on widening a section of Eastway to allow for the addition of new street lighting and a toucan and puffin crossing ahead of the construction of a new Aldi store and Costa drive-thru later in the year.
Water service was interrupted for two hours until tankers arrived at 11.30am to pump water back into the affected network.
Engineers are now on site to repair the damaged pipe but the water company warned that it might be 11.30pm until the supply is fully functional.
A United Utilities spokeswoman said: “A third party has damaged the water main on Eastway.
"We were first made aware of it at about 9.30am this morning. It cut off water supplies to some of the houses in the immediate area.
“Our engineers managed to isolate the damaged pipe to stop the water.
"We have sent some of our water tankers up to the area to pump water into the local network and supply the affected homes.
"The tankers got the water back on at about 11.30am and they will continue to keep those properties supplied until the water main is fixed later today.
"We thank residents for their patience in the meantime.”
Workmen have been on site since Monday, January 7 as work continues on widening a stretch of Eastway in Fulwood to serve a new mini-retail park at its junction with Oliver’s Place.