Volunteers restore dried-up river in Kuusamo after buying power plant
Saturday 25th July 2026 on 07:00 in
Finland
A dried-up branch of the Kuusinkijoki river in Kuusamo, Piilijoki, has been restored to flow for the first time in 70 years, with early research showing migrating trout have returned to the waterway, Yle reports.
Camera monitoring by the Natural Resources Institute Finland (Luke) detected ten trout in the first summer following restoration, with nine of the ten being wild-born. The largest measured 74 cm, while even the smallest exceeded 50 cm.
Researcher Raisa Nikula said the first trout appeared on camera in late August last year, with more sightings in the following weeks. The fish, part of the Oulanka (Koutajoki) river system, travel to Russia’s Pääjärvi to feed and grow before returning to spawn in their native waters.
The restoration was carried out by the Kuusinkijoki kuntoon association, which purchased the Myllykoski hydropower plant from Koskienergia Oy for nearly €4 million four years ago. Funding came from private donations, local associations, a €300,000 contribution from Kuusamo municipality, and a €2 million state grant. After decommissioning the plant, the group reconnected Piilijoki’s natural channel to the Kuusinkijoki, bypassing the dam.
Nikula noted that Piilijoki has also become a popular passage for other fish species. While the river currently attracts trout as a migration route, future years will reveal whether they and other species, such as grayling, will spawn there.
The project may inspire similar efforts elsewhere in Finland. In Siikajoki, plans are underway to remove the Pöyrynkoski dam by 2028, aiming to restore migratory fish populations like salmon, sea trout, whitefish, and burbot, as well as over 100 km of new spawning grounds.
Luke’s monitoring uses a tunnel camera, typically employed in fish ladders, to track fish movements. This summer’s surveillance began on 12 June, with hundreds of roach and dozens of perch already recorded. Last autumn, a sudden influx of grayling was observed when water temperatures dropped to 16°C.