Habitat restoration in river Vuoksi

To strengthen the stream fish populations in the river Vuoksi in eastern Finland, we have restored parts of the river by improving spawning and breeding areas for trout and grayling.


The river Vuoksi has an abundant local grayling population. Lake salmon, lake trout and vendace come down to the river from lake Saimaa. The trout population is supported with regular fish stockings.

Fortum has two hydropower plants along the river Vuoksi, Imatra and Tainionkoski. Due to the damming of the river, rapid sections and their characteristic habitats have mostly vanished. These stream habitats are important spawning and breeding areas for trout and grayling.

Project description

The river restoration project started with defining suitable habitats for grayling, trout and salmon by modelling the Finnish part of the Vuoksi river with Fortum's habitat modelling tool. With modelling and field surveys, areas for spawning and breeding ground restoration were found.

Three areas between the power plants of Imatra and Tainionkoski were restored to create habitats for fish and other species. Specifically, the bottom of the river bank was reshaped and gravel and stones were added to make the bottom more natural and more suitable for spawning and shelter for young fish. Habitat restorations continue on the Finnish side of the Vuoksi river.

Cooperation partners and stakeholders

The Vuoksi river habitat restorations are a joint project between Fortum, the municipality of Imatra and environmental authorities.