Ladybower Reservoir

Ladybower Dam was built by the Derwent Valley Water Board between 1935 and 1943, an incredible achievement at any time, let along during a world war.

Unlike its two cousins in the Upper Derwent reservoirs group, the dam is not of solid masonry, but is an embankment of over a million tons of earth, with a core of 100,000 tons of puddled clay. The dam wall contains as much concrete as the core does clay. The upstream face, looking towards the Ashopton and Ladybower viaducts, is faced in stone.

When full the reservoir holds 6.1 billion gallons of water. It was formally opened by King George VI on 25 September 1945, having taken two years to fill. Two fully enclosed overflows of bellmouth form and 80 feet in diameter, like giant plugholes, carry overflow down to valve houses at the foot of the dam and thence into the River Derwent.