The project
Overview
We were proud to support the construction of a major new spillway at Wales' largest reservoir, 300 m above sea level in Eryri National Park. Designed to handle a 1-in-10,000-year storm, the project needed precision and resilience in a remote, weather-exposed location.
Surveying and setting out
Our responsibilities included the detailed setting out of the 200 m spillway, which has both open channel and covered sections. More than 10,000 m³ of concrete were poured, and accurate survey control was critical throughout the build.
On a site like this, control has to hold up to weather, plant movement and months of construction, so every pour lands where the design says it should.
Enabling works
Around 70,000 m³ of material was excavated, stockpiled and reinstated as part of the enabling works. We also supported the safe installation and monitoring of approximately 1,000 temporary soil nails, which kept the slopes stable during construction.
Outcome
Despite the logistical and environmental challenges, we delivered reliable survey control, responsive monitoring and adaptable support. Our work was key to the safe, compliant and successful delivery of this critical flood-resilience infrastructure.
