A dam that has blocked the Tromsa River in Norway for greater than 100 years was blown up with dynamite this week, releasing migratory routes for fish.

“It’s a giant step,” mentioned Tore Solbakken of Norwegian angling membership Gudbrandsdal Sportsfiskeforening, who has campaigned for 5 years to have the previous hydropower plant dam eliminated. “I’m very completely satisfied. It’s all about restoring wholesome rivers and fish populations.”

In-built 1916, the seven-metre excessive dam within the small city of Fåvang, in Innlandet, east Norway, has not been in use for greater than 50 years. The Tromsa is a tributary of the Lågen River, which feeds into Lake Mjøsa, Norway’s greatest lake. Campaigners say eradicating the dam will assist fish within the space thrive once more, together with grayling, burbot, Alpine bullhead and customary minnows. It’s hoped the principle beneficiary would be the lake-dwelling trout, which might weigh greater than 10kg and feeds in downstream lakes and the Lågen. Till now, the fish have solely been in a position to dwell and spawn within the decrease 950 metres earlier than the dam, whereas they are going to quickly have the ability to swim 10km upriver.

machinery and worker at dam removal site
Tore Solbakken and his native angling membership campaigned 5 years for the dam to be eliminated. {Photograph}: Rob Kleinjans

“A couple of years in the past, I watched the DamNation documentary and that impressed me to attempt to take away dams that aren’t in use any extra,” mentioned Solbakken. “Fish boundaries, hydropower dams, roadbuilding and the way in which we safe rivers towards flooding are all huge issues for large brown trout and different fish. You will need to handle all of the small rivers. If we do this, we will have a constructive future for our space.”

The dam’s destruction is a part of a pattern to take away the out of date boundaries that litter Europe’s waterways. In October, the Open Rivers Programme, a €42.5m challenge to supply grants to help the removing of small dams and the restoration of river circulate throughout Europe, was launched with the backing of the charitable fund Arcadia. Final month, the European Fee launched a guide for member states to establish boundaries that could possibly be eliminated to assist obtain the aim of restoring 25,000km of rivers to free-flowing by 2030.

“Dams in rivers block migration routes – the swimways – of fish,” mentioned Herman Wanningen, founding father of the World Fish Migration Basis and Dam Removal Europe. “Some fish species, reminiscent of Atlantic salmon, eels and sturgeon, journey 1000’s of kilometres to finish their lifecycle. Dams additionally impede vital sediment and nutrient transport, and drastically change the pure circulate of rivers. Breeding locations are misplaced.”

It’s estimated that there are no less than 1.2 million instream barriers in Europe and that they’re an element within the huge drop within the variety of migratory freshwater fish throughout the continent, with numbers declining by more than 90% between 1970 and 2016.

“Free-flowing rivers underpin a wealth of biodiversity,” Wanningen mentioned. “In addition they present meals for tons of of hundreds of thousands of individuals, as these rivers are lively and fish. Free-flowing rivers ship wealthy sediments, that are essential to agriculture and in addition mitigate the influence of floods and droughts. There’s a lot potential for free-flowing rivers in Europe.”

“Norway is a serious hydropower nation. Eradicating dams right here isn’t regular,” mentioned Solbakken. “Nevertheless it’s not controversial should you’re eradicating previous dams that aren’t in use, in rivers protected by rules towards new hydropower.”

machinery and workers at dam removal site
The dam was blown up with dynamite packed into holes alongside the construction. After the rubble is eliminated a group will begin work restoring the river. {Photograph}: Rob Kleinjans

The marketing campaign by Solbakken and the 120 members of the fishing membership resulted within the authorities agreeing to foot the invoice of three.4m kroner (£290,000) to take away the dam.

On Wednesday, the small group drilled 5 holes deep into the dam then packed 20kg of dynamite into every one. Blowing up dams is uncommon in Europe however was judged to be the most secure methodology on this case. “As deliberate, the dam cracked within the center and prime,” mentioned Solbakken. “The subsequent step is to make use of the excavator. It’s a large dam and it’ll take days to take away all of it. There’s nonetheless loads of work to do.”

The group will then set about restoring the river immediately forward of the dam website. “The Tromsa dam is in a steep canyon, so our problem is to construct up a nature-like step-pool cascade to allow the fish to swim upstream within the robust present,” mentioned Ulrich Pulg, a fish biologist and river restorations professional. “This challenge could have a number of one-metre steps. It is going to seem like white-water rapids throughout floods however huge lake-dwelling trout will make it.”

Different dams are earmarked for removing throughout Europe in 2022, together with in Spain, France and the UK. “Increasingly more river managers and NGOs are choosing up their instruments for excavations,” mentioned Wanningen. “Simply a few months in the past, three dams in Montenegro and one in Slovakia went down for the primary time within the historical past of those international locations. The European analysis challenge, Amber, which we participated in, has proven there are about 150,000 dams and weirs in Europe that haven’t any operate any extra and could be taken out with none drawback.

“Rivers are the veins of the Earth. We have to deal with them with care.”

Discover extra age of extinction coverage here, and observe biodiversity reporters Phoebe Weston and Patrick Greenfield on Twitter for all the newest information and options

Source link