Matt Carroll, project officer from the South Cumbria Rivers Trust, shares about the removal.


Crosthwaite is a small village situated in South Cumbria within the Lake District National Park. In the village lie two fields that form the site of this deculverting project. The aim of the project was to create brand new freshwater and riparian habitat by opening up a culverted beck. This beck has remained in darkness under the surface since the 1800’s, constrained by large rocks and slate. Due to its age, the culvert was failing in numerous places along its length, causing high flow events to burst through and spread gravels onto the surrounding fields.

Historically many miles of culvert were installed throughout the lake district. This was mostly done to improve agricultural efficiency by increasing areas of land available for cultivation and livestock and for small scale mill schemes. Unfortunately, many of these culverts are now failing due to difficulty/lack of maintenance, resulting in blockages, often seen as water emerging on the surface of the field. This causes surface water runoff leading to:

  • Water logging the soils for extended periods of time causing soil compaction.
  • Widespread surface erosion within the field parcel and ripping out vegetation/crop.
  • Surface flows carry away important soil reserves upon which all agriculture is based.
  • Expensive fertilisers applied to the land may be removed as water washes the nutrients away wasting money and time.

Problems of culvert blockage and lack of maintenance resulting in surface flow also have implications on rivers and lakes downstream:

  • Compacted areas of the field reducing water infiltration leading to higher river flows and flooding downstream.
  • Surface sediment and soil runoff ends up in the rivers and lakes downstream. This can block river gravels by filling in the spaces between the stones, causing fish eggs to die through lack of oxygen as they are buried beneath the surface of the gravel.
  • Fertilisers, slurry or muck that have been washed off as a result of surface flow can result in excess nutrients within the rivers and lakes, changing the important chemical balance of the water.


Deculverting of watercourses has many environmental benefits, including:

  • Reduction in flood flows and sediment runoff reaching water courses downstream, improving conditions for fish eggs and invertebrates.
  • An open water course now accessible to wildlife, fish and birds.
  • Creation of natural habitat along areas which were previously unavailable.
  • Linking up new stretches of salmon and trout breeding and spawning grounds which were previously unreachable due to the presence of a culvert.

By opening the beck, allowing a natural flow regime and natural processes to take over, it is hoped that the beck in Crosthwaite will be colonised by aquatic plants, insects and fish species.

Fully opened channel in the lower field.

Alongside the deculverting, the project also aims to provide a private educational resource to the pupils of Crosthwaite Church of England Primary School. An educational pond with dipping platform is being introduced to allow the pupils to learn more about the freshwater environment and species that call it home. Alongside the opened beck, a private path is being created through both fields to allow the school children access to the local church. The only route beforehand was along the busy main road through the centre of Crosthwaite village.

The Works

Work started in late November 2018, and quickly the new beck was uncovered. Usually in-river working is not permitted by the Environment Agency during the winter months due to spawning salmonids. For this project we were granted permission to complete the works as long as we had strict silt and pollution prevention controls in place. This permission was granted because the culvert prevented the migration of salmonid species up this tributary and therefore the risk was limited.”


The Crosthwaite Culvert in Northern England was possible through the donation of 10.000 Euros. By opening the stream, it is hoped that it will be colonised by aquatic plants, insects and fish species. They are also installing an educational freshwater pond where local, young students can come learn about the freshwater environment and species. This is an amazing project and ambition that would not have been possible without the generosity of the people who are investing in the rewilding of our future.


Images and video provided by South Cumbria Rivers Trust

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