Listed Building record MDR4660 - River Weirs, Retaining Walls and Sluices, off Bridge Foot, Belper

River Weirs, retaining walls and sluices, off Bridge Foot, Belper, built c1796. The first two mills in Belper, the South Mill and the North Mill, were served by the water retained by Jedediah Strutt's first weir, a simple structure which spanned the river near the present day railway bridge. To power the West Mill, Strutt needed a new and very much larger weir. An outline of this structure appears on a plan of 1796, and building of the Horseshoe Weir began soon after. As the name suggests, the weir is of distinctive shape. It was modified and increased in height in 1819 and 1843 yet remains largely unaltered. The weir and its associated watercourses altered the river significantly. By 1820, some 5.8 hectares of water had been added to the Derwent immediately above Bridge Foot. Ree's Cyclopaedia, which was published serially between 1802 and 1820, described the mills at Belper as being '...on a scale and most complete we have ever seen, in their dams and their water works.' It is one of the outstanding engineering structures of the late 18th century. (1) Mill weir and sluices that were built in 1796-1797 to provide water for Belper Mills, though they have since been much modified. The present [2011] water power drives twin turbine generators housed in a low building south of the mill complex. The tail race passes in a culvert under the road and rejoins the river below the mill complex. The power generated is sold through the national grid. (2) The condition of the weir was assessed in 2016 by engineers determining the risk of unexpected collapse: 'All components of the weir and its adjacent structural elements are in a Fair or Good condition –except for the upstream slope of the central part of the weir and parts of the downstream slope (both to the right of the central sluice). The upstream part is in a ‘Very Poor’ condition and has already suffered failure of the facing blockwork over an approximately 4 square metre area. The downstream part is in ‘Poor’ condition and likely to fail in the near future. Without remedial action it can be expected that the area of failed blockwork will widen and there is a significant risk of a complete breach of the weir, especially during a large flood.' (3) From the National Heritage List for England: 'SK 3448 SW, 1/50; SK 3448 SE, 1/50 BRIDGE FOOT, Belper River Weirs, Retaining Walls and sluices to Belper River Weirs 05.02.66. II* The Horseshoe Weir became necessary when the West Mill was built in 1795. Thought to have been built 1796-1797. Impressive concave weir with associated sluices and retaining walls. Built by Jedidiah Strutt on a reef of gritstone to provide power for his mills using a network of water channels and water wheels to develop a total of 500 hp. To north of weir, sluices and floodgates with four segmental-headed ashlar arches supporting foot-walk for weirs. Additional sluices to channels under mills. Additional weir to west side of bridge. Stone caged retaining walls extending from both side of river bridge to weirs. Picturesque. Listing NGR: SK3454048170.' (4)