Turton and Entwistle Reservoir is a water reservoir in the village of Edgworth,

Lancashire Lancashire ( , ; abbreviated ''Lancs'') is a ceremonial county in North West England. It is bordered by Cumbria to the north, North Yorkshire and West Yorkshire to the east, Greater Manchester and Merseyside to the south, and the Irish Sea to ...

, England. The reservoir's existence is due to the Entwistle Dam. When constructed in 1832 the Entwistle Dam was the highest in Britain; it rises 108 feet from the base. The reservoir contains almost 750 thousand

imperial gallon The gallon is a unit of measurement, unit of volume in British imperial units and United States customary units. The imperial gallon (imp gal) is defined as , and is or was used in the United Kingdom and its former colonies, including Ireland ...

s (roughly 3,400,000 litres) and, with the

Wayoh Reservoir Wayoh Reservoir is a water reservoir in the town of Edgworth, Lancashire, England. It was completed on 28 April 1876 to supply water to Bolton Bolton ( , locally ) is a town in Greater Manchester in England. In the foothills of the West P ...

just below, satisfies around 50% of

Bolton Bolton ( , locally ) is a town in Greater Manchester in England. In the foothills of the West Pennine Moors, Bolton is between Manchester, Blackburn, Wigan, Bury, Greater Manchester, Bury and Salford. It is surrounded by several towns and vill ...

's need for drinking water. Entwistle Dam was designed by Thomas Ashworth, a local land surveyor, overseen by

Jesse Hartley Jesse Hartley (21 December 1780 – 24 August 1860) was an English Civil Engineer and Superintendent of the Concerns of the Dock Estate in Liverpool, England between 1824 and 1860. Hartley's career Despite having no experience building docks, ...

, the

Liverpool Docks The Port of Liverpool is the enclosed Dock (maritime), dock system that runs from Brunswick Dock in Liverpool to Seaforth Dock, Seaforth, Merseyside, Seaforth, on the east side of the River Mersey and the Great Float, Birkenhead Docks betwee ...

engineer. Other works were by Joseph Jackson, an engineer and surveyor from Bolton. It was built for the Commissioners of the Turton and Entwistle Reservoir, a group of local mill owners who obtained an enabling act of Parliament, the ( 2 & 3 Will. 4. c. xxiv) to regulate the supply of water in Bradshaw Brook for water power for the finishing textiles. Records suggest it was built entirely of puddle clay with no distinct core. Earth dams usually have a waterproof cutoff under their earthworks designed to stop seepage under the dam but it is doubtful whether there was any such a cutoff at Entwistle. The reservoir has a rock-cut outlet tunnel driven through the valley side rather than a culvert or pipeline and a siphon draw-off pipe. The dam is 108 ft high and 110 metres long at the crest. The present overflow channel and valve tower were added by the Bolton Corporation Water Works who took over the reservoir in 1864.

References

{{authority control Drinking water reservoirs in England Buildings and structures in Blackburn with Darwen Reservoirs in Lancashire