Benson Weir replacement - walkway opening 1 April 2026

The footpath over Benson Weir unfortunately needed to be closed in November 2022 due to increasing safety concerns resulting from the accelerated weakening of the overall structure. It has been affected in recent years by the impact of floating objects against the deteriorated steelwork.

Our project team developed a business case during 2023 to secure the funding to progress the design and construction work. Technical designs for the new weir were completed in January 2024, and construction started in June 2024.

Creating the new weir

This significant project needed to be delivered over a 2-year period due to its scale and complexity. Periods of high flows during the construction work increased the complexity and duration of this project as our contractor used floating pontoons to position all of their cranes and equipment.

We prioritised the replacement of the weir gates to enable our operational staff to be able to continue managing River Thames flows throughout the project. Our contractor then focused on the creation of a new structure that allows many fish and eel species to pass easily though the weir structure. This fish / eel pass will help to improve the overall biodiversity of the non-tidal Thames and is something that we aim to achieve with every major weir refurbishment.

We have also improved the weir guarding system that reduces the likelihood of objects hitting the new weir during periods of increased river flow.

Our contractor has substantially completed the weir replacement works, and the weir walkway will re-open at 9am on 1 April 2026. The improved walkway over the weir has an increased width of 1.5m, compared to the previous 0.9m. This will allow more Thames Path users to walk over the weir freely and also allows for our operational staff to adjust the weir gates when needed without obstructing walkers.

For more detail please visit this section. or email enquiries_thm@environment-agency.gov.uk