Nearly 150 years after it was built for a paper mill, work has begun to demolish a 3-meter-high dam in Cumbria as part of national efforts to improve biodiversity by allowing fish and invertebrates to move more freely along the rivers of the United Kingdom.
The Bowston Weir is located on the other side of the Kent River, a site of special scientific interest of international importance, where white-clawed prawns and freshwater pearl mussels, as well as the crowfoot of water, an oxygenating aquatic plant. But the river is in poor condition due to human interference over the centuries.
Pete Evoy, director of South Cumbria Rivers Trust, said: “Removing the Bowston Dam will help renaturalize this section of the Kent River, improve navigation for migratory species, reduce flood risks for residents. and will provide a net biodiversity gain of 44%.
“We look forward to seeing more fish, eels, invertebrates and other species,” he said. “It will be the first dam retreat into the Kent River, but hopefully it won’t be the last.”
One of Kent’s 14 hurdles, the 25-meter-wide dam was built in 1874 to control the flow of water that fed Bowston Mill, which made cloth and ropes for the paper industry. The mill closed in the 1960s and was demolished but the dam was left in place.
It is estimated that there are between 50 and 60,000 dams, dams and sewers in UK rivers, less than half of which are mapped, including barriers built for industry, agriculture and flood defenses. Many are now obsolete, but they continue to block rivers, harming ecosystems.
Bowston is the removal of the largest river barrier planned for the UK this year. Funded by the European Agricultural Fund for Rural Development, it is expected to take up to three months.
It took years to remove the Bowston weir to get approval. Photography: courtesy of Ebbsford Environmental
“The Cumbria River Restoration Strategy aims to eliminate as many disused dams as possible and restore the natural connectivity of our rivers,” said Oliver Southgate, director of the Agency’s Cumbria River Restoration Program. of the Environment.
“The Bowston Dam is one of the largest in the Kent Basin. Although the dam already has steps for fish, completely removing the barrier will allow all fish species better access to spawning water. up and will help restore natural processes in this part of the river, benefiting people and wildlife. “
Reaching the Bowston weir disposal point was a long and challenging process, said Evoy, who began by reaching the agreement of the weir owners, James Cropper, who continues to make paper today.
“We got approval to move towards elimination in 2020, after years of discussions. Local residents expressed a lot of disapproval, due to concern about the perceived flood risk, the riverside property and concern that disposal would affect local biodiversity.
“The application had to go to a planning committee,” he said, “and it was finally approved in February 2022, five years after the initial feasibility report.”
Last year was a record for the elimination of dams in Europe, with at least 239 dams, dams and other barriers dismantled in 17 countries, including a dam that has blocked Norway’s Tromsa River for more than 100 years. The recently launched Open Rivers program will invest € 42.5 million (£ 36.5 million) over the next six years in removing river barriers across Europe.
But conservationists and river experts are concerned about the slow pace of action in the UK and the lack of introduction of promised legislation. “We are frustrated by the current situation,” Evoy said. “Most of these structures were built many years ago; they did not take into account the environmental impacts they would have.
“In the era of a climate and ecological crisis, weir withdrawals should be part of a nationally supported plan to undo the damage they have caused to our rivers.”
Spain removed 108 barriers from rivers in 2021, largely due to legislation requiring the owner to pay for their removal once they have stopped using them. This type of legislation is considered vital to the hope of restoring the UK’s rivers. The Environment Agency noted recent improvements to fish passes through England’s rivers, including the Severn and Tyne. But it could not provide a timetable for new legislation on the removal of river barriers.
“Successive governments have been promising legislation to liberate and restore rivers across the UK for more than two decades, but so far they have failed to do so,” said Barry Bendall, chief operating officer of Rivers Trust. “With the considerable decline in our aquatic biodiversity, we urgently need to restore freely flowing rivers.
“But without legislation, there is very little imperative for owners of these barriers to do something about it, so obsolete landfills across the UK will remain in place for generations to come.”
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