The
Howden Reservoir is a Y-shaped
reservoir, top one of the three in the
Upper Derwent Valley, England. The western half of the reservoir lies in
Derbyshire, whereas the eastern half is in
Sheffield, South Yorkshire. The county border runs through the middle of the reservoir, following the original path of the
River Derwent. The longest arm is around 1.25 miles (2 km) in length. The reservoir is bounded at the southern end by Howden Dam; below this, the
River Derwent flows immediately into
Derwent Reservoir and subsequently the
Ladybower Reservoir. Other tributaries include the
River Westend, Howden Clough and Linch Clough.