HS2 has announced the successful completion of a major river realignment in Warwickshire, a 749-metre project that marks the most significant re-naturalisation of a river on the entire project. The work on the River Cole near Coleshill was designed to enhance biodiversity, improve climate resilience, and create new green spaces for the community.
The project, delivered by HS2’s construction partner Balfour Beatty VINCI and designed by the Mott MacDonald SYSTRA Design Joint Venture, involved creating more meander bends and enhancing habitats both in and along the river. This was necessary to facilitate the construction of the Birmingham Spur of the Delta Junction, a complex section of the HS2 route that required two new viaducts and a series of embankments.
Following the completion of excavation work in 2024, temporary dams were removed to allow the water to flow into the new section of the river. The team has since been monitoring the new watercourse to ensure it is establishing itself as intended.
In addition to the environmental benefits, the design incorporates new recreational spaces and pathways inspired by the area’s historical use as a boating lake. When the area is reopened to the public, communities will be able to enjoy grassed embankments, footpaths, observation areas, and Japanese-style stepping stones. This forms part of HS2’s wider Green Corridor programme, which aims to create a network of bigger, better-connected, and climate-resilient habitats.
Simon Casey, HS2 Ltd’s Head of Environment for Main Works Civils, said: “As climate change continues to pose challenges, HS2 aims to create solutions that successfully integrate climate resilient infrastructure, environmental preservation and positive community benefit. The holistic approach to this River Cole realignment is a shining example of this and it’s incredibly exciting to see what the team has achieved. It is part of our wider Green Corridor programme and will create a valuable learning legacy for the civil engineering profession, providing a replicable model for future projects.”
The design of the new river section includes natural features like riverbank planting, ponds, and wet grasslands to support the rich variety of species already present and encourage new ones. The reuse of natural river gravels from the floodplain for the new riverbed also helped to reduce carbon emissions.
Ian Johnson, Project Director at Mott MacDonald SYSTRA Design Joint Venture, said: “The River Cole realignment incorporates nature-based solutions, ecological enhancements, infrastructure resilience and environmental conservation which ensures the long-term sustainability of the local ecosystem. The multi-stage channel design with varied asymmetric cross-sections and increased meander bends creates a more natural river environment and more diverse habitat features, which enhances ecological resilience and promotes biodiversity in the area. The design not only improves flood resilience and natural river processes, it also contributes to the overall health of the river ecosystem, reduces carbon during construction, and creates public spaces for people to enjoy.”
With the river realignment now complete, the Balfour Beatty VINCI team will focus on finishing the surrounding embankments and viaducts. The two River Cole viaducts are expected to be completed later this year.
