Fortum is to implement a dam by-pass solution this year at the Leppikoski hydropower plant on the Hyrynsalmi route in the Oulujoki river system in Finland.
The company will utilise the hydraulic Fishheart fishway, which is a Finnish innovation enabling fish to migrate past obstacles.
Fortum’s goal is to strengthen the natural life cycle of lake trout in the vicinity of the Leppikoski hydropower plant, which is one of the top targets in the National Fishway Strategy. The targets on the Hyrynsalmi route, designated by the fishery authorities for restoration of fish migration, are the strategy’s only top targets in the Oulujoki river system. In order for the fishway to help strengthening migratory fish stocks, the migrating fish need habitats and breeding grounds.
The tributaries above Leppikoski power plant have some 26 hectares of potential habitats and breeding grounds necessary for the life cycle of the trout. In 2021 Fortum said it will improve habitats upstream from Leppikoski at Torvenkoski and Tolosenjoki. It will stock lake trout juveniles on the Hyrynsalmi route in an effort to imprint the trout to the river Emäjoki and thus strengthen the natural life cycle of the trout.
“We are committed to strengthening the migratory fish stocks, and we have long been carrying out various projects in the Oulujoki river system, such as habitat improvements and migratory fish transfers to spawning areas. The Leppikoski power plant environment is a densely built area and thus a challenge, but the structurally light Fishheart can be installed there. In addition, Fishheart can be installed quickly; in fact, the goal is for the Oulujärvi lake trout to have the possibility to migrate to the spawning areas upstream of the dam as early as next autumn,” said Fortum’s Environmental Manager?Susanna?Hyrkäs.
Fishheart has been used in a power plant environment at the Taivalkoski hydropower plant on the river Kemijoki and in Sweden. Because Fishheart is a floating, mobile system, its optimal positioning can be determined through testing and in this way improve the possibility for fish migration over the dam.
“We are excited for the opportunity to use Fishheart in a new location. The experiences gained through two summers of use on the river Kemijoki and in Sweden show that Fishheart is a functioning migrating solution for constructed rivers,” noted Fishheart Ltd’s Mika Sohlberg.
Fortum has discussed the Hyrynsalmi route fish migration solution with local stakeholders, including the respective fishing right owners' associations. Fishheart will be implemented in the water areas managed by the Paltamo I and Paltamo II associations.
“Mature lake trout migrate to the Leppikoski power plant every year. It’s great that we can start to help the fish migration and can figure out the actual amount of fish willing to migrate and the development of the number of migrating fish by using Fishheart. We are optimistic in working with Fortum to achieve the shared goal,” sids Raimo Kantola from the Paltamo I cooperative.
There have been observations of highly endangered freshwater pearl mussels on the Hyrynsalmi route. The trout is a necessary host fish for the mussel and strengthening the natural life cycle of lake trout could also revitalise the mussel population on the Hyrynsalmi route.