Knypersley Reservoir is a canal feeder reservoir near Biddulph in Staffordshire. The reservoir was built in 1827 to supply water to the Caldon Canal, along with two others at Stanley Pool and Rudyard Lake. It is the only reservoir along the course of the River Trent, but as all of the inlets are unnamed, it is only downstream of the dam that the river formally becomes known as the Head of Trent.