Entwistle Dam was designed by Thomas Ashworth, a local land surveyor, overseen by Jesse Hartley, the Liverpool Docks 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 in 1832 to regulate the supply of water in Bradshaw Brook for water power for the finishing textiles.
