The Brief:
Stourton Castle Weir, located on the River Stour in Staffordshire, is a historic structure that has been part of the castle grounds for over 300 years. As a site of archaeological importance and an operational hydroelectric scheme, the weir could not be removed. However, it presented a significant barrier to the natural migration of fish and eels along this stretch of the river.
To address this ecological challenge while preserving the historic structure, the Environment Agency designed and funded a fish bypass channel. The project was administered by the Wildlife Trust, with JPR Environmental appointed as Principal Contractor to deliver the works.
The Solution:
JPR Environmental constructed a 220-metre meandering bypass channel designed to replicate the characteristics of a natural river, allowing fish and eels to safely navigate around the historic weir.
The works included the construction of a reinforced concrete inlet structure with a vehicle access bridge, an outlet structure formed using a Flex MSE vegetative wall system, and limestone riprap erosion protection at both the inlet and outlet. The new channel was excavated using 20-tonne excavators and lined with a bentonite clay geosynthetic liner before being covered with compacted subsoils.
To create a diverse and natural flow regime, the channel bed was lined with river cobbles, while large perturbation boulders were installed at regular intervals to generate varied water velocities, create resting areas and provide suitable spawning habitat for fish. Throughout the project, JPR worked closely with the Environment Agency, the Wildlife Trust and other stakeholders to resolve design challenges, including accommodating previously unidentified historic infrastructure within the castle grounds.
The Result:
The completed bypass channel now provides a sustainable route for fish and eel passage, significantly improving ecological connectivity on the River Stour while preserving the historic weir and its hydroelectric function.
Delivered on time and within budget, the project successfully balanced heritage conservation with environmental enhancement. The new channel has restored fish migration, increased habitat diversity and demonstrated how carefully designed engineering solutions can protect both our natural environment and historic assets.
