Thirlmere Aqueduct
The Thirlmere Aqueduct is a 95.9-mile-long (154.3-kilometre-long) pioneering section of water supply system built by the Manchester Corporation Water Works between 1890 and 1925. Often incorrectly thought of as one of the longest tunnels in the world, the aqueduct's tunnel section is not continuous.
The aqueduct was built to carry approximately 55,000,000 imperial gallons (250,000 m3) per day of water from Thirlmere Reservoir to Manchester. The construction of the reservoir and aqueduct was authorised by the Manchester Waterworks Act of Parliament. The first phase was completed in 1897 and, for the pipeline sections, subsequent phases were completed in 1925. The first water to arrive in Manchester from the Lake District was marked with an official ceremony on 13 October 1894.
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. In the face of local opposition the project received Royal Assent in 1879. Under this act Manchester was granted priority of right to 25 imperial gallons (110 L) per person per day. A pumping station was built at Heaton Park Reservoir in 1954–1955 incorporating a large relief by Mitzi Cunliffe signed and dated 1955. The building materials and the reliefs are all symbolic of the achievement in bringing water from the Lake District to Manchester. The building was given grade II listing in 1988.
This tunnelled section under Dunmail Raise was dug by two teams mining towards each other. The two tunnel sections joined within 20 cm of centre.
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