Workers abseil to carry out reservoir repairs

The work to remove vegetation across the wall face is carried out every five years

The first phase of maintenance work has begun at St Saviour's Reservoir this week, Guernsey Water has announced.

An abseil team was working across the 28m (92ft) wall face in stages to clear away built-up moss and vegetation, staff said.

The work would also see special attention given to construction joints where water ingress could do most damage, as well as the unblocking of drainage points, they added.

Geomarine civil engineer Johnathan White said it was one of the most "substantial maintenance jobs" in the island.

Mark Stonebridge has been repairing the structure's concrete archways

The second phase of the project would see a cantilevered platform built across the dam so a full survey of the walkway could be carried out, staff said.

Mark Stonebridge, who is carrying out concrete repairs to the underside of the bridge, said some parts have "bubbled and chipped away" due to "natural erosion".

He said the process of fixing it involved removing damaged layers and applying a special compound to seal it.

Guernsey Water said the works were essential to ensuring the structure, which holds about 25% of the island's stored water, remained in good condition.

Capital delivery manager Carl Falla said the walkway would be closed for the public's safety while the "intricate and time-consuming job" was carried out.

He added the works were critical to ensuring the site remains in "good condition and serves us for many generations to come".

The project is expected to be completed by October.

Construction of the dam began in 1939 and was completed in 1947.