Butterley Reservoir and dam
Butterley, north of Ripley, Derbeyshire, UK
date 1793 - 1795
era Georgian |
category Dam/Reservoir |
ICE reference number HEW 1615
Butterley Reservoir is the largest of three lagoons built to service the Cromford Canal, a 23.5km waterway through eastern Derbyshire. The reservoir is retained by an earth dam with a clay core ó an early example of this type of structure. A rail line on a stone causeway bisects the lake. No longer a canal feed, it is a popular location for freshwater anglers.
Cromford Canal, built 1789-94 by William Jessop (1745-1814), runs 23.5km east and south from Cromford to the Erewash Canal at Langley Mill, with a 3.6km northern branch to Pinxton. A feature of Jessop's canal engineering is his careful provision of sufficient water supply, and Cromford Canal was no exception. It was fed by Butterley Reservoir and the smaller lakes at Codnor Park Reservoir (SK431515) and Butterley Park Reservoir, north of the eastern portal (SK421513) of Butterley Tunnel. Butterley Park Reservoir was dismantled in 1935: the dam was breached and the water let through a concrete spillway into the canal summit pound.
Butterley Reservoir was created by damming the Hartshay Brook. It covers 12.1 hectares, containing an estimated 283 million litres of water, or enough to fill 2,800 locks. Its dam, on the south west side of the reservoir, is built on high ground between the valleys of the Rivers Erewash and Amber.
Butterley Dam, Jessopís earliest, is an earth dam with a puddled clay core. It is about 275m long and 137m wide at base, a crest width of 5m or more, and stands 1.2 - 3.4m above the present water level. The visible side slopes are 2.5 to 1 downstream and 1.25 to 1 upstream.
A spillway outlet (SK397518) is situated at the north west end of the dam, and a flight of steps on the downstream face near its south east end led to a valve chamber (SK398516) inside the dam. A stopcock let water from the reservoir discharge directly into a shaft to the Cromford Canal, flowing through Butterley Tunnel. At this point, the tunnel soffit is 15.2m below the reservoirís water level (some 9m below ground).
In 1814, the height of the dam was increased to raise the water level by 910mm. A similar exercise was undertaken in 1845, and the dam is now some 8.5m high, though the original ground level has been obscured by spoil tipping.
In 1875, the Midland Railway took their Ambergate to Pye Bridge line west to east across the centre of the reservoir. The rail tracks were carried on a 238m long timber trestle viaduct with 22 equal spans of 9.1m. The viaduct was replaced, probably in the 1930s, when the London, Midland & Scottish Railway constructed the stone causeway that exists today.
The tunnel under the reservoir partially collapsed in 1900, and canal traffic ceased in 1944. The railway over the reservoir closed in 1948, but the stretch between Hammersmith and Pye Bridge has been restored by Midland Railway Butterley (established 1973), which operates steam trains on the line.
The reservoir itself is a fishing amenity as well as being a source of water for fire fighting. In 2009, British Waterways and Derbyshire County Council carried out a programme of works including valve restoration, a new retaining wall, flood protection, refurbishment of the footpath along the dam, and improved safety and visitor facilities.
Resident engineer: Benjamin Outram
Contractor: direct labour