HS2 has completed a major environmental milestone in Warwickshire with the 749-metre realignment of the River Cole, marking the most significant natural river enhancement on the entire high-speed rail project.
The re-naturalisation near Coleshill supports the construction of the Birmingham Spur of the Delta Junction, one of HS2’s most complex engineering zones. The project, designed by Mott MacDonald SYSTRA Design Joint Venture and delivered by Balfour Beatty VINCI, integrates ecological restoration with infrastructure development.
The new river section features meandering bends, asymmetrical cross-sections, and strategic planting to create resilient habitats and improve biodiversity. Native vegetation, biodegradable matting, and coir pallets help stabilise the riverbanks and support aquatic life, including fish and invertebrates.
The project also includes public green spaces, footpaths, observation areas, and Japanese-style stepping stones, inspired by the site’s Edwardian history as a boating lake. These features will be accessible once the area reopens, forming part of HS2’s Green Corridor – a network of climate-resilient habitats and recreational spaces.
Head of Environment for Main Works Civils at HS2, Simon Casey, commented:
“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.”
Extensive hydraulic modelling ensured the realignment would not increase flood risk, with new flood storage areas and relief culverts integrated into the design. The reuse of natural river gravels also reduced carbon emissions and preserved the river’s ecological integrity.
The project involved a multi-disciplinary team of engineers, ecologists, landscape designers, and local stakeholders, including the Environment Agency, Warwickshire County Council, and North Warwickshire Borough Council. Community input helped shape the design of pathways and public spaces to ensure better connectivity and long-term value.
With the river realignment now complete, construction continues on the surrounding embankments and two River Cole viaducts, due for completion later this year.
Image credit: HS2 Ltd
Video credit: HS2 Ltd
