Howden Reservoir

Practice site for Operation Chastise

The Howden Reservoir is a reservoir at the northern end of the Derwent Valley, which lies partly in Derbyshire and partly in South Yorkshire in England. The reservoir has the shape of a "Y" and the longest arm is nearly 2 miles long. The border between the two counties runs through the middle of the lake along the course of the original river.

Construction of the dam was on 16 July 1901, the completion was in July 1912. Situated on the southern wall is a fully bricked dam, which is 36 m high and 330 m long.

The main tributary of the reservoir is the Derwent, smaller tributaries are the River Westend, Howden Clough and Linch Clough. The Derwent leaves the reservoir at the southern end and goes immediately into the Derwent Reservoir.