Selset Dam Upstream Face Upgrade
location
Co. Durham
The Challenge
The exposed upstream face of Selset Dam had been subject to decades of weathering and wave impact. While earlier improvements had stabilised the upper slope, the lower section remained vulnerable to storm damage.
The challenge was to safely deliver repairs on a steep 13-metre slope along the dam’s 650-metre length, while maintaining access and stability throughout the works. The site’s location and limited working area demanded a precise and efficient approach to materials delivery and installation.
The Solution
To stabilise the upstream face, voids beneath the existing stone pitching were first filled with 10mm aggregate to improve support and prevent further displacement. A 175mm thick layer of Open Stone Asphalt (OSA) was then placed across the slope to create a resilient, weatherproof surface capable of withstanding future storm impacts.
In total, approximately 8,600m² of OSA was laid across the dam face. Exposed edges were finished with a mastic seal to protect against water ingress and maintain durability.
How We Delivered
A temporary access road was constructed along the toe of the upstream face, enabling safe and efficient movement of materials and plant. Works were sequenced carefully to minimise load stress on the slope and ensure consistent compaction and finish quality across the full 650-metre length.
The project was completed over six weeks, with quality control and inspection carried out at each stage to confirm compliance with design standards and material specifications. The fast turnaround minimised disruption to dam operations while achieving a robust and lasting upgrade.
Community & Environment
Environmental management was central to the works, given the dam’s importance to local water supply. All activities were carried out under strict controls to prevent contamination or disturbance to the reservoir. Material use and access planning were optimised to minimise environmental footprint and protect the surrounding landscape.
Community impact was limited, with proactive scheduling and communication ensuring that reservoir operations and public access were unaffected throughout the project.
The Outcome
The completed works successfully restored the structural integrity of the Selset Dam’s upstream face, delivering a proven and durable solution to mitigate storm-related damage. The new OSA surface provides long-term protection with minimal maintenance requirements, safeguarding the dam’s continued operation and ensuring resilience against future weather events.
