Manx Utilities has completed two major reservoir safety projects designed to strengthen dam resilience and secure a reliable water supply for the Isle of Man.

The Cringle Spillway Refurbishment finished on December 8, while a valve replacement programme at Clypse Reservoir has also concluded, with the reservoir now refilling under close operational monitoring.

At Cringle, the project team constructed a new concrete spillway channel, replaced an ageing raw water main and cleared the downstream stilling pond.

The works were delivered under budget and incorporated additional quality and safety measures during the final stages. Ecological safeguards were put in place throughout the scheme, ensuring protected orchids and fungi were preserved, and public access to the site was maintained.

The upgrade addresses the risk that the 80-year-old stone masonry spillway could be undermined during periods of heavy rainfall, potentially leading to dam erosion or subsidence.

A spokesperson from Manx Utilities said: ‘The upgrade mitigates the risk that the 80‑year‑old stone masonry spillway could be undermined during heavy rainfall—a failure that could lead to dam erosion or subsidence.

‘The improvement therefore safeguards communities and properties along the Silverburn River as far as Castletown Harbour.

‘In keeping with Cringle’s character, the project retained and reinstated the distinctive white quartz stone that capped the original spillway walls. The preserved quartz has been placed behind the new walls where required, linking the new structure with the site’s heritage.’

At Clypse Reservoir, two critical valves - one transferring water to Kerrowdhoo and another enabling controlled drainage - have been replaced.

A new pressure sensor providing real-time water level data has also been installed.

‘Manx Utilities worked closely with DEFA throughout these projects to ensure environmental best practice,’ the spokesperson added.

‘While draining Clypse was essential for safety, mitigation measures were taken to minimise ecological impact as far as possible.

‘Fish reintroduction will occur once water levels stabilise, under DEFA Fisheries guidance, to restore a healthy habitat.’