Ladybower Reservoir

Infobox lake
lake_name = Ladybower Reservoir
image_lake = Ladybower_Viaduct.jpg
caption_lake = The Ladybower Viaduct which carries the A6013 road to Bamford
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location = Upper Derwent Valley, Derbyshire
coords = coord|53|23|N|1|43|W|region:GB_type:waterbody_source:GNS-enwiki|display=inline,title
type = reservoir
inflow = River Ashop
outflow =
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basin_countries = United Kingdom
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Ladybower Reservoir is a large Y-shaped reservoir, the lowest of three in the Upper Derwent Valley in Derbyshire, England. The River Ashop flows into the reservoir from the west; the River Derwent flows south, initially through Howden Reservoir, then Derwent Reservoir, and finally through Ladybower Reservoir. Its longest dimension is just over 3 miles, and at the time of construction it was the largest reservoir in Britain.

The water is used primarily for river control and to compensate for the water retained by the upper two dams, but water can also be fed into the drinking water system, however this is unusual as the water must be pumped to treatment works rather than using gravity flow like in the other two reservoirs, increasing costs. The drinking water is treated at Bamford water treatment works by Severn Trent Water. Treated water flows down the 28 mile long Derwent Valley Aqueduct to a covered service reservoir at Ambergate to supply clean water to the cities of Derby and Leicester in the East Midlands of England. The aqueduct passes through the park of Chatsworth House on its way south. The Path of the aquaeduct is marked by a series of distinctive valve houses built of stone & Domed steel access chambers.

The building of the reservoir resulted in the 'drowning' of the villages of Ashopton and Derwent (including Derwent Woodlands church and Derwent Hall). The buildings in Ashopton were demolished before the reservoir was filled, but much of the structure of Derwent village was still visible during a dry summer some fourteen years later, especially the church clock tower. This has since been dismantled.

The area is now a popular tourist location, with the Fairholmes visitors' centre located at the northern tip of Ladybower.

Design and construction

Ladybower was built between 1935 and 1943, and took a further two years to fill (1945). The Dam differs from the other two as it is a clay cored earth embankment, and not a solid masonry dam, as the others. Below the Dam is a cut off trench 180 ft deep and 6 ft wide filled with concrete, stretching into the hills each side 500ft, to stop water leaking round the dam. The building of the dam wall was undertaken by the Scottish company of Richard Baillie and Sons. The two viaducts, Ashopton and Ladybower, needed to carry the trunk roads over the reservoir, were built by the London firm of Holloways, using a steel frame clad in concrete. Both firms encountered mounting problems when the Second World War broke out in 1939 making labour and raw materials scarce. This extended the proposed build time, but was carried on due to the strategic importance of maintaining supplies. The opening ceremony for the reservoir was carried out on Tuesday September 25, 1945 by King George VI accompanied by Queen Elizabeth.

During the 1990s the wall was raised and strengthened to reduce the risk of 'over-topping' in a major flood. The Original dam wall contains 100,000 tons of concrete, over One Million tons of earth and 100,000 tons of clay for the core. The Upstream face being stone faced. Materials were brought in via the Derwent Valley Water Boards own branch line to the site and their sidings off the main line in the Hope Valley.

The dam's design is peculiar in having two totally enclosed bellmouth overflows (locally named the 'plugholes') at the side of the wall. These are stone and of 80 ft Dia. with outlets of 15 ft dia. that each discharge via its own valve house at the base of the dam. The overflows originally had walkways around them but they were dismantled many years ago.

Gallery

External links

* [http://www.peakdistrict-nationalpark.info/studyArea/factsheets/09.html Peak District National Park Factsheet]
* [http://www.bbc.co.uk/insideout/eastmidlands/series4/east_midlands_reservoirs.shtml BBC Inside Out: Sunken villages]
* [http://simscience.org/cracks/dambusters.html Dam Busters Filmclips]