Roads operator funds salmon baffles under the A38 in Devon

Oak baffles installed in the culvert underneath the A38.

In time for the autumn migration season for salmon, National Highways has funded a £168,000 improvement scheme to modify a culvert under the A38 near Newton Abbot.

The culvert carries the River Lemon under the dual carriageway but following studies by the Environment Agency and environmental charity Westcountry Rivers Trust, it was found that fish were unable to navigate the culvert to reach their traditional spawning grounds.

The firm (formerly Highways England) funded the trust to carry out work to install dedicated and specially designed fish passes – making it possible for fish to swim upstream during their October to May spawning season – and local specialist fish pass designers, Fishtek Consulting, were brought in to design the most appropriate solution.

Mark Fox, National Highways’ Head of Scheme Delivery for the South West, said the project “will help support aquatic biodiversity at a location close to the A38”.

He said the work involved modifying a structure originally provided during the construction of the road.

The firm said the scheme has involved some low cost, low maintenance solutions – the installation of large oak baffles and the creation of small pools – to help bigger fish and eels to navigate the sloped culvert and for smaller fish to swim up in sections.

And it also includes measures to reduce the speed of the flowing water, making it easier for more fish to move upstream, as well as multiple depths and surfaces to give a wider variety of species the capability of passing through the culvert.

Further work is seemingly planned in the years ahead, including with the nearby Ashburn Check Weirs. Olivia Cresswell, Westcountry River Trust’s Aquatic Team Leader, said: “Historically, the River Lemon has struggled to achieve good status, with ecological discontinuity due to barriers to fish migration a main issue.

“We were delighted to work together with Fishtek Consulting to scope, design, assess and solve this significant barrier to fish and eel migration on the River Lemon, and using our collective specialist knowledge and experience, we and our partners were passionate to deliver this scheme that is right on our doorstep.”

Installed baffles will help the flow of water, and to the right, a special pass of ‘eel tiles’ to help eels swim upstream.

Environment Agency Project Manager James Cooper added: “The River Lemon is currently failing its Water Framework Directive objectives, with barriers to fish migration considered to be one of the key pressures facing migratory fish populations in the catchment.

“This project provides a vital contribution towards unblocking the whole river for migratory fish and eels, and it supports ongoing work being carried out by the Environment Agency and other partners to tackle all of the significant barriers to fish migration on the River Lemon, which will significantly improve the status of fish populations.”

National Highways manages four designated funds, allocated by the Government, to deliver benefits above and beyond building, maintaining and operating England’s strategic roads.

From protecting the environment and enhancing the landscape around roads, to improving safety, reducing congestion, and supporting communities, the aim is to make a positive difference to people’s lives.

For more information on National Highways’ designated funds, click here.