Weir Removal – Acorn Bank, Cumbria, National Trust & Ebsford Environmental

As the principal contractor, we successfully delivered the sensitive in-river removal and naturalisation of the failing weir on Crowdundle Beck, working in close partnership with Ebsford Environmental and the National Trust as part of the Acorn Bank Weirs Project.

This landmark project, the culmination of years of planning and collaboration, involved the full removal of the redundant weir structure and its replacement with a nature-based boulder cascade. The solution was carefully designed to maintain water supply to the historic Acorn Bank Watermill, while significantly improving habitat connectivity and ecological conditions in one of Cumbria’s most ecologically valuable river systems.

Key Elements of the Works

Full removal of the deteriorating weir structure on Crowdundle Beck.
Installation of a natural boulder cascade over a 45m river reach using:
Over 800 tonnes of locally sourced gravel, cobbles, and boulders.
A carefully engineered sequence of cascades and pools designed to:
Improve fish passage upstream.
Provide resting, hiding, and spawning habitats for species such as Atlantic salmon, brown trout, and the White-clawed crayfish – the UK’s only native freshwater crayfish.

Environmental & Heritage Oversight

Throughout the project, our team worked under the supervision of both a qualified ecologist and an archaeologist to:

Safeguard the surrounding river environment.
Ensure that any archaeological finds were properly recorded and preserved.
Avoid disturbance to protected species and designated habitats during construction.

Outcome & Benefits

Improved river connectivity and biodiversity.
Enhanced upstream habitat availability for key aquatic species.
Long-term protection of Acorn Bank’s historical watermill infrastructure.
Delivery of a sustainable and low-impact alternative to hard-engineered weirs

Funding & Partnerships

This project was funded through the UK Government’s Species Survival Fund, developed by Defra and its Arm’s-Length Bodies. It is being delivered by The National Lottery Heritage Fund, in partnership with Natural England and the Environment Agency.