The water from Thirlmere goes to Manchester through a tunnel that needs no pump - the water flows due to gravity alone. However, there are points where the gradient of the tunnel takes it above ground level. One such point is Greenhead Gill at Grasmere so they had to build two bridges to take the aqueduct out of tunnels and above ground. This included a change in direction. There is a brilliant film about the project that includes a visit to the site to be found on the Institution of Civil Engineers website https://www.ice.org.uk/what-is-civil-engineering/what-do-civil-engineers-do/thirlmere-aqueduct-and-reservoir
