Police are on the scene as part of Riversway has flooded near Preston Docks.
The junction with Pedders Lane is completely submerged following heavy rain, that has seen a weather warning put in place across Lancashire.
Workers on the scene reported the problem was caused by a blocked sewage pipe that was unable to cope with the amount of rain that fell.
And a flood warning has been issued for Leyland with the downpours expected to continue throughout Sunday.
Localised thunderstorms are forecast in the North West, with up to 40mm or rain set to fall in the space of an hour in the worst affected areas.