Wimbleball reservoir on Exmoor is a concrete buttress construction which was completed in 1979.
The dam impounds water from the River Haddeo to form a reservoir with a net storage of 21,320 megalitres and a surface area of 150 hectares.
Wimbleball supplies Exeter and parts of East Devon by releasing water into the River Exe. This water is subsequently abstracted at Tiverton and Exeter.
Water is also supplied by pipeline to Wessex Water's Maundown Water Treatment Works. This arrangement was put in place at the time of construction.