Bosley Reservoir which feeds the Macclesfield Canal will be drained to 10 percent of its capacity while the work takes place.
The 35 hectare reservoir holds 1,350 million litres of water – enough to fill 540 Olympic sized swimming pools.
Works, which began on 20 July will take 22 weeks and will include repairs to the Grade II listed ‘valve tunnel', improvement to access for inspection and maintenance teams, as well as visitors, and repairs to the face of the dam.
Magnificently engineered flight
The repairs will ensure the reservoir meets current flood risk guidelines and complies with the requirements of the Reservoirs Act. This includes the installation of two large pipes and underground chambers to allow us to drain the reservoir rapidly in the event of a major incident.
The canal was opened in 1831 and the reservoir feeds the magnificently engineered flight of 12 locks at Bosley which raises the canal by 118 feet.
Canal & River Trust senior project manager Richard Spencer said: “The CCTV survey of the cast iron draw-off pipe is critical to the project. Subject to the findings of this survey, further remedial action may be needed, including lining the pipe, to ensure its future integrity.
“The work being carried out will ensure that the reservoir meets the standards required by the Reservoirs Act and will be able to service the needs of the Macclesfield Canal and the Bosley locks for many years to come.
“The reservoir is a popular location for birdwatchers, walkers and anglers. The valve house and horseshoe arch bridge which carries the road across a stream at the eastern end of the dam are both Grade II listed buildings.
“We will endeavour to keep disruption to the public footpaths to a minimum while we carry out this essential work.”