Thames Water - Alderbrook to Lambs Wood trunk main

Background

As part of our ongoing partnership with Thames Water, the Clancy team was brought in to deliver a new 5km trunk main that stretches from the Alderbrook reservoir to Lambs Wood reservoir in Surrey.

This is in order to balance the water capacity between the two reservoirs, which supply local communities south of Guildford. The new trunk main will help to build further resilience across the Guildford area and meet future demand for water as the population grows and new housing is built in the region.

Solution

Leveraging our experience in the sector, we determined that the most effective way to install the trunk main was using a combination of open cut and trenchless techniques with 30 per cent of the project being delivered using horizontal directional drilling (HDD) to reduce disruption and speed up delivery times. As part of this, we collaborated with Thames Water’s project and operational team to amalgamate trenchless solutions, while also gaining design approvals to utilise EZ valves to maintain pipe integrity and reduce disruption to the water supply.

Engagement on the project was key when building the pipeline through local environments and communities. Approximately 50 per cent of the proposed site was on public highways, while the rest was on private property which included the Alderbrook Estate and the Cranleigh showgrounds. The latter is a frequently-used site for community events throughout the year, including triathlons, along with car and agricultural shows. This meant that close collaboration with stakeholders and Surrey County Council was needed to ensure that we could operate in the middle of the site, while still keeping it open for recreational use.

The Clancy team also effectively worked with other third-parties to guarantee the project went smoothly and safely. This project required constructing around other critical assets including gas lines, so careful risk management was necessary to keep health & safety the top priority.

Ecological conservation was also a key concern. Our team identified badger sites in the area and liaised with Natural England to ensure that these habitats were protected. We also collaborated with the College of Arboriculturists to redesign our route to avoid impacting mature oak trees in the area.

Benefit

The project is still ongoing, but it is hitting all targets in terms of timings and milestones. The eventual result will improve the consistency and reliability of water supplies, ensuring that the network adapts to changing weather patterns, and customer demand.

Clancy’s work has supported Thames Water in improving the resilience of its water supply. It’s a project that we are proud to be a part of and one which has already been recognised for our hard work – winning Thames Water’s Project Pride Gold Award – in acknowledgement of our site safety and performance.