Complex reservoir remediation projects in North Wales: contractor’s perspective

Overview

Impounding reservoirs are an important part of our national infrastructure and are subject to the provisions of the Reservoirs Act 1975. This legislation requires reservoir owners to act on all safety requirements made by the Inspecting Engineer (Qualified Civil Engineer) following a statutory reservoir inspection. Failure to do so could result in a serious event, leading to severe flooding.

The presentation will discuss the complex construction challenges faced by the contractor undertaking legally binding requirements made by the Inspecting Engineer on existing assets built between 1890 – 1976. The presentation will focus on the following areas:

• Llyn Celyn - large diameter valve replacement within a constrained area.
• Llyn Brenig – the engineering challenges of installing new bulkhead and gate installations fifty meters below  reservoir top water level.
• Pendinas Reservoir - the safe installation of siphon pipework in challenging environments.
• Cae Llwyd Spillway – delivering to tight timescales through challenging weather conditions.