Remove tens of thousands of obsolete dams in Europe to bring rivers back to life, says new report
Dam Removal: A viable solution for the future of our European Rivers stresses that the density of dams, weirs and locks in Europe is far higher than previously suspected, with salmon, eel, sturgeon and other migratory fish encountering obstacles every kilometre on average. Previously, only dams higher than 10 metres were counted, but these represent less than 3 percent of all river barriers.
“Dams have played a critical role in Europe’s development but they have also contributed to the slow death of our rivers and the catastrophic decline in freshwater species,” said Stuart Orr, WWF Leader, Freshwater Practice. “Tens of thousands of small dams and barriers are no longer in use but they are still in place: blocking fish migrations, stopping the flow of sediment and nutrients, and undermining the value of rivers to people and nature.”
The report estimated that in France, Spain, Poland and the UK alone, there are up to 30,000 mainly small dams which are now obsolete. No comprehensive study currently exists on the total number of obsolete dams in Europe, but this figure is likely to be much higher.
While these barriers provide no benefits to communities, they still prevent rivers from flowing freely, contributing to the disappearance of freshwater species, particularly migratory fish that can no longer reach their spawning grounds. This also affects birds feeding on fish as well as many other animals.
The report calls for governments across Europe to start removing these redundant dams to help breathe life back into river systems and provide new opportunities for local economies. Dam removals will also enable Member States to meet their commitments under the EU Water Framework Directive (WFD), under which all countries must achieve good status for the majority of their water bodies, including rivers, lakes and wetlands, by 2027.
“Nature can recover remarkably fast when given the chance: dam removals in Europe have seen fish immediately returning to rivers for the first time in decades and existing species multiplying rapidly,” said Peter Gough from World Fish Migration Foundation, one of the authors of the report. “As the fish return so do the fish eating birds and a wealth of other species dependent on healthy river systems and wetlands and so do fishers and birdwatchers, giving rural areas a new lease of life”.
Dam removals have slowly started to pick up the pace in Europe, and the Water Framework Directive’s ambitious goals, timeline, and visionary approach to water management have been instrumental.
The report lists a series of case studies that illustrate the remarkably rapid impact of dam removals. In the Netherlands, after two weirs were removed from the ‘Boven Slinge’ stream in 2015, the number of fish species in the newly connected stretches increased by an average of 30 percent and the number of individual animals increased by 148 percent. In nearby Denmark, the removal of a dam on the Gudenå river saw trout numbers upstream rise from zero to 4-5 per m2. Meanwhile, the removal of the Maisons-Rouges dam in France in 1999 has resulted in a spectacular surge in fish numbers with sea lamprey numbers soaring from barely any to over 41,000 within eight years.
“Dam removal has proven to be a very eco-efficient and cost-effective measure to reach the objectives of the Water Framework Directive, which all member states have committed themselves to,” said Orr. “Dam removal is also significantly cheaper than maintaining aging, obsolete dams. Freeing rivers offers additional advantages from cleaning water naturally to boosting tourism numbers to restoring a river’s natural flood defences – critical in the age of climate change. It is a no brainer: removing redundant dams costs less and achieves more.”
The report’s launch comes ahead of the EU’s public consultation of the WFD, which is part of its standard review, and will be held later this year. While studies show that dam removal is a viable solution, there is an urgent need for all small and large dams in Europe to be mapped, including the priorities for dam removal. The report also calls for dam removals to be integrated into Member States’ River Basin Management Plans, for the involvement of local communities in dam removal, and alternatives to new dams to be seriously considered.