Background

The River Severn is the longest river in Britain, flowing approximately 220 miles from mid Wales through Shropshire, Worcestershire and Gloucestershire before discharging into the Bristol Channel. Historically, the construction of weirs and navigation locks along the river helped manage low summer flows and winter flooding, but significantly restricted the movement of migratory fish species.

At Bevere Weir in Worcestershire, a major ecological project was delivered as part of the Unlocking the Severn programme. The aim was to restore fish passage on this stretch of the river by constructing a new bypass channel fish pass, allowing species such as twaite shad, salmon and eel to migrate upstream to spawning grounds for the first time in more than 170 years.

The challenge

The construction of a 100 metre long bypass channel required careful integration with the existing riverbank and surrounding landscape.

Key challenges included:

  • Supporting gently sloped ramps within the fish pass to create suitable swimming conditions
  • Preventing erosion of riverbanks adjacent to the new channel
  • Delivering a solution quickly to reduce risk from river levels and weather
  • Ensuring the finished structure blended sympathetically into a natural riverside environment

Any retaining solution needed to provide robust engineering performance while supporting the project’s wider biodiversity objectives.

The solution

To support the side slopes of the fish pass channel and control erosion, a bespoke retaining wall solution was developed using the Redi Rock™ Ledgestone modular wall system.

The Ledgestone blocks were selected because they combine:

  • A deep, natural stone appearance suitable for sensitive environmental settings
  • High mass concrete units (approximately 1 tonne per block)
  • Dry laid, interlocking construction enabling rapid installation
  • Proven structural performance for earth retention

Marshalls’ Redi Rock™ team supported the scheme through a full design service, providing engineering input from planning through to construction to ensure the wall met both technical and environmental requirements

The outcome

Despite delays caused by Covid 19 restrictions and adverse weather, the completed scheme has been positively received by all stakeholders, including the Environment Agency, Canal & River Trust, Severn Rivers Trust and Natural England.

Key outcomes include:

  • Effective erosion control supporting the new fish pass channel
  • Rapid construction with reduced on site risk
  • A sympathetic finish that integrates with the river landscape
  • Restored river connectivity supporting fish migration and biodiversity

The Bevere Weir project demonstrates how bespoke modular retaining solutions can play a critical role in delivering environmentally sensitive river engineering schemes that balance flood management, ecology and buildability.