Interesting report, covered in the Guardian

At least 239 barriers, including dams and weirs, were removed across 17 countries in Europe in 2021, in a record-breaking year for dam removals across the continent.

Spain led the way, with 108 structures taken out of the country’s rivers. “Our efforts to expand dam removals across Europe are gathering speed,” said Pao Fernández Garrido, project manager for the World Fish Migration Foundation, who helped produce Dam Removal Europe’s annual report.

“An increasing number of governments, NGOs, companies and communities are understanding the importance of halting and reversing nature loss, and buying into the fact that dam removal is a river-restoration tool that boosts biodiversity and enhances climate resilience. We’re also seeing lessons being learned from previous dam removals, new countries kickstarting removals, and new funds, including crowdfunding.”

More than 1m barriers are estimated to exist on Europe’s rivers, with many built more than a century ago. At least 150,000 are old, obsolete barriers that serve no economic purpose.

Dams, weirs and other river obstacles block fish migration routes, often leading to the loss of breeding areas and reduced numbers of species such as salmon, sturgeon, trout and eel, which affects the wider biodiversity of ecosystems, including species ranging from eagles to otters. Free-flowing rivers also transport sediments and nutrients.