Work to replace two faulty valves at Clypse Reservoir is now under way after the reservoir was almost completely drained.
Manx Utilities confirmed that contractors began the replacement project on Monday, following several weeks of preparatory work to empty the reservoir. As a result, the footpaths around the Onchan reservoir have been closed to the public for safety reasons.
However, the nearby Kerrowdhoo Reservoir remains fully open for walkers and anglers.
A Manx Utilities spokesperson said: ‘While the contractor replaces the failed valves at the base of the dam, our staff will carry out ground maintenance along the overflow channel and support the contractor as needed.
‘For public and worker safety, paths around Clypse Reservoir will remain closed throughout the works, but Kerrowdhoo Reservoir remains open and access is unaffected.’
The work is expected to be completed by the end of October, although the reservoir will not be refilled until spring 2026.
Last month, Manx Utilities reported that a routine inspection had found one of the two critical valves at the reservoir had failed to operate. Further investigations revealed a fault in the submerged valving system and confirmed that both valves would need to be replaced.
Because the valves are located underwater, the reservoir had to be fully drained to allow access for the work.
When full, Clypse Reservoir holds about 2% of the Isle of Man’s total water reserves. As part of the project, water has been redirected to Kerrowdhoo Reservoir to ensure a safe working environment.
Manx Utilities said it has been working closely with the Department of Environment, Food and Agriculture’s Inland Fisheries team to protect the welfare of fish stocks during the draining process.