Thirlmere Aqueduct

The aqueduct was built to carry approximately 55,000,000 imperial gallons (250,000 m3) per day of water from Thirlmere Reservoir to Manchester.

In 1874 John Frederick Bateman advised Manchester Corporation that the increasing demand for water, then averaging 18,000,000 imperial gallons (82,000 m3) per day, would soon exhaust the available supply from Longdendale.

His first recommendation was to source water from Ullswater, but it was eventually decided to seek powers to acquire Thirlmere and build a dam there.

[citation needed] The dam at Thirlmere 54°33′41″N 3°04′05″W / 54.5615°N 3.0680°W / 54.5615; -3.0680 rises 64 feet (20 m) above the old stream bed, and the reservoir when full has a surface area of 814 acres (3.29 km2), and a holding capacity of 8,235,000,000 imperial gallons (37,440,000 m3) above the level to which water may be drawn (540 O.D.)

There are 37 miles (59.5 km)[3] of cut and cover, made up of concrete horseshoe-shaped sections 12 inches (300 mm) thick.