Description: A large section of Derwent Village and all of Ashopton Village now lie underneath Ladybower Reservoir. By the beginning of the 20th century, populations of the industrial towns in North Derbyshire, Sheffield, Nottingham, Derby and Leicester, had greatly increased, and with this growth came the need for more water. It was recognised that the upper Derwent Valley in North Derbyshire would be ideal for water storage to satisfy this need. The valley was deep and long, surrounded by gritstone edges with narrow points for dam building, and had high rainfall. Royal Assent for the reservoirs was granted in 1899. The Derwent Valley Water Board was set up and Gothic style dams were built to contain the waters and the first two dams, Howden and Derwent, which were constructed between 1901 and 1916. It was at this time that Birchinlee (Tin Town) was constructed in the valley to house the workers. The village was dismantled on completion of the dams but the old village site can still be seen alongside the Derwent Reservoir just to the north of Fairholmes Visitor Centre. Later, construction of the Ladybower Dam began (in 1935) and continued throughout the years of World War 2.
This project involved the flooding of the villages of Derwent and Ashopton despite much controversy. Despite protests the dam went ahead and was finished in 1943, though the reservoir took a further two years to fill (at the time this was the largest reservoir in Britain). Graves in the churchyard at Derwent had to be exhumed and the bodies taken for reburial at Bamford. The church tower had been left intact and reappeared eerily above the waters in 1947 when the water level was low. The Packhorse Bridge at Derwent was moved stone by stone, and rebuilt at Slippery Stones, at the head of Howden reservoir, since it had a preservation order on it. In 1943 the Ladybower Dam was used for practice runs by the 617 Dambusters Squadron of Lancaster Bombers. It was officially opened on 25 September 1945 by the King.