 Raw water, from the River Thames, is pumped 2.7 km through a 54 inch (1.34 m) diameter pipeline from the pump house at Walton Water Works adjacent to the Knight reservoir.The reservoir can also be filled by gravity from the Bessborough and Knight reservoirs.The reservoir allows some settlement of suspended solids; biological cleaning through exposure to sunlight; and provides a buffer storage volume to maintain capacity at times of low flow in the river.