We have participated in the restoration of several locations along the river Vuoksi main channel, where 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. These stream habitats are important spawning and breeding areas for trout and graylings.
The Vuoksi river habitat restorations are a joint project between Fortum, the municipality of Imatra and environmental authorities. The 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.
River Vuoksi is a transboundary river system, with a total of four hydropower plants located in the upper part of the river. 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. With modelling and field surveys, we were able to identify several potential areas for spawning and breeding ground restoration.
In 2020 we worked on the environmental restoration of the Kokkasaari area, where a small islet, formed by dredging of rocks in the river, was re-shaped and gravel added to provide more underwater breeding and living habitat for fish.
The Imatra City Creek
The Imatra City Creek, an artificial creek nearby the Imatra hydropower plant, was built in 2014. The creek is about 1km long, with a head difference of about 24 m, and it provides a breeding and spawning area for local trout, as well as a recreational attraction in the middle of Imatra city.
The city creek has proven to be a success as a spawning and breeding habitat for local trout. The density of juvenile trout has been high. There are also perch and roaches living in the creek. The city creek is continuously studied by researchers who follow up on the development of the fish population and benthos in the artificially created creek.