timeline item
Here is the information we have
on the item you selected
This entry was funded by
More like this
sign up for our newsletter
© 2018 Engineering Timelines
engineering timelines
explore ... how   explore ... why   explore ... where   explore ... who  
home  •  NEWS  •  search  •  FAQs  •  references  •  about  •  sponsors + links
Scar House Dam
Middlesmoor, Nidderdale, North Yorkshire, UK
associated engineer
Lewis Mitchell
date  5th October 1921 - 1933
era  Modern  |  category  Dam/Reservoir  |  reference  SE065769
ICE reference number  HEW 2033
Scar House Dam, then the tallest in Britain, was the last of three dams built on the River Nidd to impound water to supply the North Yorkshire city of Bradford. In an early form of social engineering, workers and their families were accommodated in a purpose-built village on the site, the remains of which are still visible.
The Nidd Valley water scheme still supplies most of Bradford's water and is located in a designated Area of Outstanding Natural Beauty. The earliest of the dams is Gouthwaite (1893-1900), 13km down the river valley from Scar House Dam. Its eastern half is a 17.1m high concrete and masonry structure but its western half is an embankment. The reservoir is now a nature reserve.
The second is Angram (1904-16), just 1.6km upstream of Scar House. It was designed by Bradford City Council's water engineer James Watson — Lewis Mitchell's predecessor. The masonry faced dam is 44.8m high with a concrete and stone core.
Mitchell used a similar design at Scar House Dam, which has a crest length of 480.1m and a 51.5km long gravity aqueduct connecting the reservoir to Bradford. It was built using direct labour — a popular approach to dam construction at the time — and contains 413,000 cubic metres of concrete and masonry. Stone for both dams was quarried on site.
The then Lord Mayor of Bradford, Lieutenant Colonel Anthony Gadie, started the excavation on 5th October 1921. He also placed the first batch of concrete at the base of the dam on the 5th June 1925.
The dam's crest road is 52.3m above the original river bed level. To ensure a sound foundation on the limestone bedrock, the soft overburden was removed to a depth of up to 12.2m at the river and less at the ends. Then a concrete cut-off trench 1.8m wide, 556.3m long and between 18.3m and 75.3m deep was sunk. It took more than three years to excavate the foundations using steam-powered machines, hand drilling and blasting.
A pair of cable (Blondin) cranes linked by steel ropes was used to move concrete and stone across the valley using buckets on a pulley system. The crane support struts can still be seen in the hillside. Men and materials travelled up and down on a gravity railway — as one carriage came down it pulled another back up.
The overflow is an apron spillway consisting of 10 arched-over sections with a central draw-off tower on the upstream side of the dam. Runoff in a valley to the south is intercepted by an 8.8km long contour conduit and conveyed into the reservoir via a 1.65km long tunnel. The reservoir contains some 10 million cubic meters of water.
The Scar House village was built in 1922 and had electricity and running water. It had living accommodation for 1,250 people, a school, a hospital, a concert hall, a gymnasium, a canteen, a fish shop and a cinema. Most of these were dismantled when the work was completed, though the concrete foundations remain along with the cinema projection booth and the canteen — now Darley Village Hall.
The dam was completed in 1933 and the reservoir in 1936. The scheme cost more than £2m and was known initially as "Gadie's Folly" until it maintained the city’s water supply during a two-year drought.
The dam is open to walkers and accessible by car along a road built on the line of the former private railway that was constructed between the London & North Eastern Railway terminus at Lofthouse and the Angram site to serve the dams.
Architect (reservoir): William Illingworth
Research: ECPK
"Scar House Reservoir's History" available at http://www.nidderdaleaonb.org.uk
reference sources   CEH North

Scar House Dam