Jyväskylä restores Tourujoki to create fish habitats

Jyväskylä has completed an eight-million-euro restoration of the Tourujoki river, creating natural-style rapids and habitats for migratory fish along a one-kilometre stretch, Yle reports.

The river runs through the city centre and was once polluted by untreated wastewater from a paper mill, which flowed into Lake Päijänne. The water sometimes contained sulphuric acid. Local resident Eero Väisänen recalls that its colour changed depending on what kind of paper the mill was producing.

The restoration was prepared over ten years. Work began in spring 2024, including the construction of a 300-metre natural channel made entirely of stone in the Kangas area. The river now also has pools where fish can rest and spawn, while a new bottom weir at its northern end regulates water levels in upstream lakes.

The project aims to bring migratory fish back to the river, particularly the critically endangered lake trout. The city is monitoring fish movements, water levels and flows. The restored rapids are mainly intended for conservation and recreation: fishing restrictions are in place or planned, and the steep water makes activities such as kayaking unsuitable.

Yle journalist and presenter Mikko “Peltsi” Peltola will host the river’s opening celebration on Saturday. He said the city now has impressive rapids to be proud of, while noting that it remains to be seen whether the fish will accept the habitat people have built for them.