Removal of Dovecliff weir restores river health

15 Oct 2021 09:17 AM

The £2.5 million project to remove the Dovecliff weir at Egginton, South Derbyshire is now complete following a 24-month programme of works.

• River Dove opened up for the first time in almost 900 years
• Completion of the biggest weir removal project in the country
• Improvements for the passage of fish, improved biodiversity and other environmental gains in the River Dove catchment

The £2.5 million project to remove the Dovecliff weir at Egginton, South Derbyshire - the biggest weir removal project in the country - is now complete following a 24-month programme of works.

For the first time in almost 900 years, over 550 kilometres of watercourse have been opened up for the free passage of fish of the River Dove and its tributaries. Dovecliff weir was the first barrier to fish migration along the River Dove and, in combination with other completed fish passage projects, its removal now enables all fish species to access their spawning grounds.

Along with improving passage for fish, removing the weir benefits water quality, public safety and welfare, wider floodplain biodiversity and boosts the local economy by attracting more visits by anglers to the area.

Christopher Grzesiok, Fisheries Biologist at the Environment Agency said:

Rivers are dynamic ecosystems which provide many benefits to both people and wildlife. Over the centuries, rivers have been impacted by industry and urban growth, affecting how they function. Building weirs, such as this one at Dovecliff, have broken the dynamic function of rivers, resulting in a loss of ecological diversity and river function.

By removing the weir, we will improve biodiversity and fish passage through the entire Dove catchment. It will also improve the habitat for fish to spawn and grow as it creates a more natural river environment, without the impact of human-made barriers.

We’re already seeing the benefits upstream of the site with the formation of gravel bars and improved habitat for invertebrates, spawning fish and other wildlife.

Paul Herickx, Project Executive at the Environment Agency said:

The weir, which dates back to the 1200s, was structurally assessed in 2016 and sections were found to be in a poor condition. The weir no longer served a functional purpose and, as it would continue to have been costly to repair and maintain, its removal was the best solution.

We have overcome a number of significant challenges, including the global pandemic, one of the wettest winters on record and some of the highest flood flows ever recorded in the area to finally complete this unique project.

Whilst there have been significant construction challenges to safely remove the structure, seeing the River Dove flow freely for the first time in almost a millennia and knowing that its natural processes are now rebalancing makes all the team’s efforts worthwhile.

The final stage of the project will be the landscaping to replant native trees and shrubs in place of those that were removed to enable the works to take place. This will be carried out in late autumn 2021 in line with the planting season.

Background

• For further information about the Dovecliff weir removal project visit: https://consult.environment-agency.gov.uk/west-midlands/removal-of-dove-cliff-weir/.
• During the works, a temporary channel was created to divert the river and allow the weir to be removed in a dry working area. This was for ease of works, to minimise the risk of silt being disturbed and entering the river uncontrolled, and to allow archaeologists to safely record the structure. Fish used the temporary channel to freely move up and downstream, this was also the first time coarse fish and salmon could pass the weir. The temporary channel has now been backfilled and is being turned into a wildflower meadow to increase biodiversity.
• An ancient wooden river structure was also discovered during the works. Early indications are that it is medieval and it is under investigation by archaeologists.
• Weirs were historically designed and installed to control water and at that time the environmental impacts of their installation weren’t fully considered or understood.  It was later discovered that they altered natural functions of rivers and their connection with the floodplain, impacting on water quality and adversely affecting aquatic ecology and the wider surrounding environment.
• Fish and invertebrate species greatly benefit from weir removal as weirs act as barriers to their movement. Weir removal benefits all aspects of aquatic ecology, including recovery of the riverbed and banks, and development of a more diverse habitat.  A greater diversity of fish and invertebrate species is documented both up and downstream following weir removal.