Removal of the Acksjö Dam

In August 2017 the Acksjö dam was torn out in Hagfors Municipality, Sweden. The aim was to increase the possibility for trout migration, as well as to improve conditions of life for several species. The project was financed by the Fortum Environmental Fund (Bra Miljöval). It was a collaboration between different parties, not least the river Klarälven water council.



The Acksjö dam was located in the lake mouth of Acksjön lake where the lake outfall in the river Acksjö is situated. The dam was owned by Fortum, and it had been operating as a water storage dam for the hydropower plants in river Klarälven. The Acksjö river is a tributary to river Klarälven and has been affected by many human activities. The greatest impact comes from former logging when the river was cleared from rocks and stones to enable smoother transportation of the logs. In Sweden’s near future the need of flexibility in the energy system will be crucial. In order to  meet the needs of renewable and CO2-free energy production, water reservoirs are needed. When reviewing the Acksjö dam, the contribution to flexibility from this dam deemed to be low. Instead, by tearing it out,  we could implement a suitable environmental measure in the area as it has mitigation possibilities.


When the project is finalized the area will hopefully reach good ecological status and conditions for several species will have improved. As part of the project, a follow up will be carried out to investigate how the ecosystem has changed due to the measures.


As a first part of the implementation, Fortum removed the gates in the outlet to lower the water level in the lake in early 2017. Later, in August 2017, removal of the dam in full was underway. When the project was finalized no damming parts of the dam remained that will lift the water level and the water will be free flowing.

In addition to tearing out the dam there will also be biotope restorations in the river, which will be carried out by the County of Värmland. They will restore damage caused by the log driving period, e.g. by adding gravel and larger stones to improve spawning areas in the river.

Cooperation partners and stakeholders

The project is done in a broad cooperation. In addition to Fortum and the County Administration in Värmland, a number of land owners and non-profit organisations such as Klarälven’s water council, snow scooter club, fishing interest and the village community in Bergsäng, have been involved.

Low emissions

Environmental projects

At Fortum we actively implement environmental projects within hydropower.

Read more about environmental projects
Climate and resources

Environmental approach

Read about our environmental approach within hydropower

Read more about environmental approach