Environmental work is part of responsible hydropower production

Hydropower plays an important role in our journey towards a cleaner world. Solutions that are tailored to each water system to secure biodiversity are key in responsible hydropower operations.


Fortum has 13 hydropower plants in Finland and 140 in Sweden. We use these plants to generate electricity from flowing water without carbon dioxide emissions. Hydropower is clearly the biggest renewable energy source in the Nordic countries. Easy to store and regulate, hydropower can be deployed quickly and enables the addition of weather-dependent solar and wind power in electricity generation.

Our hydropower plants were built mainly in the 1950s and 1960s. Their construction altered the water systems and their natural conditions. However, the environmental impacts of hydropower are local and are well known to us.  

The damming and regulating of water changes the living conditions in the water system. The loss of flowing water locations reduces the spawning areas for migratory fish. Fish species and plants that thrive in slowly flowing waters often naturalise in reservoirs. Thus new types of fauna and flora emerge in the area. The recreational use of the water system also changes when the flow of water is slowed. We have long engaged in close collaboration with municipalities, including in the River Oulujoki region, to diversify recreational use of the river areas – for instance, to make boating easier in the water system. Regulating the water flow, in turn, helps with flood prevention.

As a responsible producer of hydropower, we are committed to securing biodiversity in water systems that are harnessed for hydropower production. For example, to improve the habitats of migratory fish, we are committed to reducing the environmental impacts of hydropower production through actions in line with permit obligations and through proactive, voluntary projects.

Concrete actions to secure biodiversity

Adverse impacts on the fishing industry are offset with obligations, often involving the restocking of fish, as prescribed by authorities. Every year we restock a total of a couple of million whitefish, zander, trout and salmon smolts in harnessed rivers and lakes. We raise the fish at our own and our contracted partners’ fish farms in Finland and Sweden. A good example of the success of restocking is the restoration of the zander population in the River Oulujoki. Through restocking, we have participated in successfully restoring Lake Oulujärvi’s naturally reproducing zander population that had virtually disappeared in the 1980s.

But we want to do more than just fulfil regulatory obligations

In addition to permit obligations, we are actively and successfully reducing the environmental impacts of our electricity production through voluntary collaboration with residents, municipalities, authorities, and fishery and partner cooperatives along the rivers.

Revitalisation of migratory fish populations is of interest to us and to several stakeholder groups, such as recreational fishermen, fishing rights holders, municipalities along the river, the fishing industry and environmental authorities. Good local collaboration plays a key role in reconciling the different needs of all these groups.

In 2017 we invested a total of 3.7 million euros in environmental work in Finland and Sweden. Voluntary projects accounted for more than 0.6 million euros of this.

Unlike in Finland and Sweden, elsewhere in the world it isn’t very common for hydropower producers to strengthen and revitalise migratory fish populations in large constructed rivers. So globally there are no patent solutions for revitalising fish populations that have disappeared over the decades. Every water system is unique. Therefore also the solutions securing the natural biodiversity must be tailored to each water system, something that we do successfully both in Finland and Sweden.

Environmental projects in hydropower

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