Hydropower: Improving conditions for fish

Rehabilitation and environmental measures

This type of long-term measure for fish is often carried out in connection with modernising old power plants. One example is the upgrade of the power plants at Røssåga in Nordland County. Nedre Røssåga power plant was commissioned in 1955 and Øvre Røssåga in 1961. When the power plants were built, the level of environmental awareness was much less than it is today. Many also probably thought that fewer salmon in the river was a small price to pay for having electricity in the home.

"In the district of Helgeland, where the Røssåga power plants were built, only about half of the population had electricity in their homes, and the electricity that was available was rationed," says Bjørn Grane, environmental coordinator in Statkraft Region North.

"The construction of power plants supplied people with electricity for their washing machines, refrigerators, lighting and heating. In addition, the power plants laid the foundation for jobs, such as the ironworks in Mo i Rana and the aluminium plant in Mosjøen. The power plants improved people’s standard of living. It is important to understand this history to know why environmental protection was not a high priority at the time," he says.

Both power plants in Røssåga underwent extensive modernisation in 2016, and Statkraft made a significant effort to repair the environmental damage from the original development – partially to meet government requirements, but much also on its own initiative.

"Awareness of the power plants' environmental impact has become much greater, in the population in general and in Statkraft. We have also gained more knowledge about what we can do to correct negative environmental impacts," says Grane.

The modernisation at Røssåga increased production from the power plants and led to better conditions for all life in the river, not least for salmon and sea trout.

"An important measure was to move the power plant outlet 600 metres upstream in the river. This meant that the watercourse regained a long stretch with much higher water flow and significantly better spawning and rearing habitats for fish," says Grane.

"We have also installed rock structures that distribute the water flow and reduce the water velocity from the outlet," he adds.

Gene bank for salmon

In connection with the plants at Røssåga, Statkraft, in collaboration with the Norwegian Environment Directorate, manages a gene bank to preserve the genetic material of five different strains of wild salmon. The gene bank has agreements with several angling associations whereby members catch adult spawning salmon and harvest roe and milt from the fish.

"This gene bank, along with a couple of others, is absolutely crucial for protecting the Norwegian wild salmon stocks. Among other things, the gene banks make it possible to re-establish a salmon stock in a watercourse infected with the salmon parasite gyrodactylus salaris," says Grane.

"The parasite has to be removed with chemicals that kill all life, so without the gene bank, the salmon stock in the river would have been wiped out. "

New environmental requirements in Sweden

Hydropower is also important in Sweden, even though it accounts for a smaller share of energy production there than in Norway. Unlike Norway, Sweden does not have the large waterfalls with the high heights of fall needed for high-pressure power plants, so Swedish hydropower is largely based on run-of-river power plants situated in the large rivers.

There can often be 10–20 power plants along a river, which makes it very challenging to maintain the fish population in the watercourse. In the Lagan River, Statkraft has organised the transport of eel fry and adult eels past the power plants to give the endangered European eel a chance to survive. However, such measures are uncommon.

"Swedish hydropower has 'perpetual' licences, which has made it difficult to set new environmental requirements for the power plants," says Angela Odelberg, environmental coordinator in Statkraft Sweden.

"Many power producers have taken a number of voluntary measures in the form of stocking and trap and transport, but these are compensatory measures. The EU Water Framework Directive will set new and stricter requirements for more permanent solutions for hydropower. By 2023, we will propose measures in the first rivers where Statkraft has power plants, so a lot of attention is now being devoted to acquiring knowledge and conducting surveys to determine the most suitable measures."

Life in Ljungan

Statkraft is conducting such a survey on the Ljungan River, a 400-kilometre-long river that stretches from the Sylan mountain range on the border with Norway and across Sweden before draining into the Baltic Sea at Sundsvall. Fifteen major hydropower plants are located along the river. Five of them are operated by Statkraft, including the Viforsen power plant, which is the last before the river flows into the Baltic Sea.

Ljungan has a natural salmon population that is important to maintain, and in 2014 a research project began to survey the riverbed conditions in the last 20-kilometer-long stretch out to sea.

"Since this project started, we have acquired a great deal of knowledge about how our operations affect the environment and how we can improve the spawning and rearing conditions for salmon through habitat improvement measures, among other things," says Odelberg.

"The question is whether measures such as this are sufficient to meet the new environmental requirements from the EU. Do we need to build more waterways and fish ladders past the power plants? Do we need to release more water from the reservoirs? How extensive do the measures need to be to meet the environmental requirements that are coming? And how will this affect production?"

"The current debate in Sweden is about how we can make hydropower more environmentally friendly without severely affecting production. We want good conditions for salmon, trout and eel in our rivers. At the same time, the need for clean, renewable energy is increasing. I hope we can achieve both," she concludes.