Fortum will study the implementation of a by-pass solution to enable fish to migrate upstream from the Seitenoikea hydropower plant, located on the border of the Ristijärvi and Hyrynsalmi municipalities. The aim of the by-pass solution is to strengthen the natural cycle of endangered lake trout on the Hyrynsalmi route, which is part of the Oulujoki river system.
“The preliminary planning for the project will start this autumn. In 2023 we will conduct a by-pass solution feasibility study in which we will assess all the by-pass solution alternatives and determine which of them would be best for the conditions at the Seitenoikea power plant. Participation by the local stakeholders is a key factor in the project,” says Fortum’s Environmental Manager Katri Hämäläinen.
Based on the feasibility study, the general planning of the by-pass solution will start, and then the permits needed for its construction will be applied for. The timetable for implementing the project will be clarified as the planning progresses.
Natural cycle with Fishheart, by-pass solution and habitat restorations
The by-pass solution is part of a set of measures Fortum is implementing on the Hyrynsalmi route, which the National Fish Passage Strategy has identified as the only key site in the Oulujoki river system. The set of measures also includes, e.g., the hydraulic Fishheart fishway taken into use in 2021 at the Leppikoski hydropower plant downstream from Seitenoikea.
“The by-pass solution will enable lake trout to migrate upstream from Lake Oulujärvi to the area upstream from Leppikoski power plant as well as upstream from Seitenoikea power plant. Located upstream from the Seitenoikea is a 40-hectare area with potential habitats and breeding grounds important for the life cycle of trout,” Hämäläinen says.
The measures aiming to strengthen the life cycle of lake trout also include the planned habitat restorations and stocking of juvenile lake trout in the tributaries upstream from Seitenoikea. The stocking and the restorations aim to strengthen the fish population that imprints to the river.
Fortum is committed to advancing biodiversity through voluntary measures. The long-term goal on the Hyrynsalmi route is the natural reproduction of lake trout.