From WIKI: Ladybower Reservoir was built between 1935 and 1943 by the Derwent Valley Water Board to supplement the other two reservoirs in supplying the water needs of the East Midlands. It took a further two years - until 1945 - to fill. The dam differs from the Howden Reservoir and Derwent Reservoir in that it is a clay-cored earth embankment, and not a solid masonry dam. The dam wall was built by Richard Baillie and Sons, a Scottish company. Consulting Engineers were G H Hill and Sons of Manchester.
Max. depth 135 ft (41 m)
Water volume 27,800,000 m3