When the Røssåga watercourse was developed in the 1950s, parts of the river were left dry and overgrown. Now the water is back, and the salmon.
Salmon anglers are very happy about the significantly improved living conditions for salmon in the Røssåga River. (Photo: Henrik Fredriksen/Korgen Camping)
The restoration of the Sjøforsen stretch of the Røssåga River in Hemnes Municipality in Nordland County has become a win-win situation. The water is flowing and the salmon have good spawning areas, without affecting power generation.
"When Nedre Røssåga power plant needed rehabilitation, Statkraft decided to build an additional power plant, New Nedre Røssåga," says Bjørn Grane, environmental coordinator in Statkraft.
"This is a good example of a rehabilitation of an old power plant providing opportunities to reduce negative environmental impact. For the original Røssåga development, the draining of Sjøforsen was undoubtedly one of the most controversial."
The 650-metre-long stretch of the river was originally an important spawning and living area for the salmon. After the hydropower development in the 1950s, water flow was greatly reduced. Vegetation and forest took over.
"The extensive restoration project has not only brought back the water and the salmon, we've also developed the area for hikers by building a trail and reopening overgrown areas. In addition, comprehensive measures have been taken to control flooding," says Grane.
Gry Elly Fordelsen is one of many who appreciate the rehabilitation of the river. She is the general manager and owner of Korgen Camping and a member of the Røssåga River Business Association.
"In this location we have hosted salmon fishing folk for almost 200 years, from the British 'Salmon Lords' who travelled here in the 1800s to today's camping tourists. The life in the river is absolutely crucial to us," she says.
Fordelsen gets positive feedback from her guests every day regarding the improvements.
"There've been some difficult years of construction work, but now it has become very nice. Every day we get compliments from anglers and other camping tourists, and the area has become very popular with locals too. The hiking trail and planting are a great finishing touch. The river has become very accessible. Now we are looking forward to the salmon fry growing to be nice and big. You have to have a long-term perspective, because it will take many years before we really see the results of the rehabilitation."
She praises Statkraft for the initiative and the work that has been done.
"Statkraft earns a lot from our river, so it's natural that the company contributes with environmental measures. At the same time, they deserve credit for what has been a major improvement, both visually and because of the monitoring being done by a fish biologist," says Fordelsen.
Bjørn Grane and the Statkraft team resurrected an old idea when the new power plant was being planned. By placing the new outlet right up under Sjøforsen they could direct water back to this stretch of the river. The outlet has been placed in a way that ensures acceptable water flow.
Freshwater biologist Øyvind Kanstad Hanssen was added to the project to ensure a design that would be beneficial for the salmon.
"There were several challenges related to the rehabilitation of the river. We had to provide enough water so that the fish didn't risk being stranded. At the same time it was important that the water speed did not get too high, being so close to the outlet from the power plant," says the biologist.
The solution was to divide the watercourse and create two zones for the water flow.
"We made a 'motorway' for the water on one side of the river and a 'sidewalk' for slower traffic on the other side. We slowed the water by laying out a number of groups of rocks, and built a threshold that helps reduce water speed. This threshold also ensures adequate water levels when production in the power plant varies. To create good spawning areas, we aerated the gravel in the river and removed sand and sludge. Good living areas for young fish were created by adding large amounts of rock."
The project has carried out several measurements of life in the river before and after the implementation of the environmental measures. The first fish biological studies in the river were carried out a few months after the New Nedre Røssåga power plant was commissioned in July 2016. Measurements showed that young salmon had already began using the new stretch of river.
"We saw the effect immediately," says Kanstad Hansen. "During a spawning survey in the autumn, 40 per cent of all spawning fish in the river were found in Sjøforsen, where before there were hardly any spawning fish or young fish."
He believes it is important that power companies take responsibility for the environment in regulated watercourses.
"As a society, we know more and consider other criteria than we did during the great hydropower developments in the 1950s and 1960s. Now we have the possibility to correct mistakes made in earlier times. Therefore I think this could be a model to be followed in other situations. The restoration was not mandated by the government authorities. Statkraft started and carried out the project on its own initiative," says the freshwater biologist.
Salmon fishing has a long tradition in the Røssåga River. In the mid-1800s the "Salmon Lords" came from England. Today both local anglers and visitors from Norway and abroad try their luck in the river. (Photo: Gry Elly Fordelsen/Korgen Camping)
The project has taken into account that unforeseen things can happen.
"We have built connections in the outlet tunnels between the old and new power plants that ensure safe water distribution to the newly restored section of the river regardless of the operating status of the power plants," says Statkraft’s environmental coordinator Bjørn Grane.
"Next year an automatic diversion valve will be installed with a capacity of 15 cubic metres per second which will deliver water to the river in the event of a shutdown of the power plants."
With increased water levels in the river it has also been important to prevent flood damage.
"Extensive safety measures have been implemented. Several major structures along the shoreline are in place. These are covered with natural stone to blend into the landscape," says Grane.
The restoration of Sjøforsen has clearly been an extensive process.
"Overall, this environmental measure is one of the largest of its kind in Norway. It's therefore very satisfying that the environmental conditions in Sjøforsen have changed from very bad to good. For Statkraft it's also extremely important that one of the biggest environmental challenges at Nedre Røssåga power plant has been significantly reduced. It is a good example of the fact that unwanted environmental conditions from previous power developments are largely reversible," says Grane.
Text: Jenny Bull Tuhus
Photo: Tine Poppe, Bjørn Grane, Korgen Camping
18. Sep. 2017
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