A year ago, the old dam of UPM's former paper mill Kaipola in Arvajankoski, Jämsä, was demolished as part of UPM's stream water programme. After the demolition, the rapid was restored, allowing the endangered lake-migrating brown trout to more easily ascend from Lake Päijänne to the Arvaja rapids. There are eight rapids along the approximately 19-kilometre-long route, of which Arvajankoski is the lowest.
Trout have been studied in the Arvaja rapids for a long time. Uninterrupted monitoring started in 1984 and spawning nests have been counted for approximately fifteen years. Funding from UPM's stream water programme now allows the research to continue. "Monitoring is extremely important in order to document the effects of projects such as the restoration of the Arvajankoski rapid," says biologist and fish expert Jukka Syrjänen from the Central Finland Water and Environment Association.
UPM's stream water programme aims to release or restore 500 kilometres of stream waters by 2030. With the restoration of Arvajankoski, a total of almost 60 kilometres of waterways in addition to the Arvaja rapids were freed for trout and other migratory fish, not to mention other stream species.
"The aim of our stream water programme is also to achieve impacts, not just kilometres," says Mikael Rytkönen, Environmental Manager at UPM Energy. "That is why I think it is important that we also contribute to funding research projects like this."