Elan Valley aqueduct resilience

Through development of an asset management plan for the Elan Valley aqueduct (EVA), which delivers clean water to over one million people, we helped Severn Trent secure future investment from Ofwat for this strategically important asset.

One of Severn Trent’s most important assets, the 119km-long Elan Valley Aqueduct was opened in 1904 and delivers fresh water to over a million people every day. After 100 years there was increasing risk of supply failure due to the condition of the assets, therefore strategic planning was needed to ensure the aqueduct would continue to safely provide water to customers, taking into account future needs and anticipated increase in demand.

We developed an asset management plan to analyse long term investment needs and options, which involved managing and undertaking physical condition surveys and asset performance health monitoring assessments during an annual shutdown period of only four days. We built a GIS risk model to collate and analyse data, carrying out hydraulic modelling to identify the flood risk from failures, and devised a defect coding system for condition surveys, for assets such as aqueducts and bridges, to facilitate deterioration and reliability analysis. This portfolio of information helped to inform asset investment decisions and the development of future shutdown and outage plans.

Our scope of work also included the use of our Linear Infrastructure Costing tool to quickly capture designs and enable fast, comparable, optimised costed solutions for areas at highest risk. We also delivered a library of hundreds of historic and operational documents accessed via an ArcReader map for use in the control room to support operational decision making and emergency response.