SYSTRA-designed River Cole realignment completed on HS2

The 749-metre realignment of the River Cole near Coleshill in Warwickshire is the most significant scheme of its kind on the project, and was needed as part of the Delta Junction works, where two new viaducts and a series of railway embankments are being constructed.

The re-naturalisation will improve the existing river environment by creating more meander bends and enhancing habitats in the river and along its banks to maximise biodiversity, and has also seen the creation of new public green spaces and paths alongside the river to enhance community access.

The realignment was designed by the Mott MacDonald SYSTRA DJV and delivered by ecologists and engineers working for HS2’s construction partner Balfour Beatty VINCI (BBV). In consultation with external stakeholders, including the Environment Agency, the team has created a holistic nature-based design which goes beyond the standard environmental mitigation measures.

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 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.

Ian Johnson, Project Director, Mott MacDonald SYSTRA Design Joint Venture

“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.”

“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.

A multi-disciplinary team has been involved in this complex project, including river engineers, geomorphologists, hydraulic modellers, engineers, agrotechnicians, landscape designers, architects and ecologists. With construction of the river realignment now complete, the teams will focus on completing the surrounding embankments and viaducts.

During the development of the design in this area, HS2 Ltd, Balfour Beatty VINCI, and the Mott MacDonald SYSTRA DJV worked closely with the Environment Agency, local community, Independent Design Panel, Warwickshire County Council and North Warwickshire Borough Council.  

The community has been particularly involved in ideas for high-quality pathways for better connectivity, with the design aiming to revive the area’s recreational aspect through the development of public green spaces and paths alongside the river.  

Excavation works were completed in 2024 and temporary dams were then removed, allowing the water to flow into the new river section. The two River Cole viaducts, which span the river, are due to be completed later this year.

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