The project aims to re-establish connectivity in the upper Pjältån River through the demolition of two dams.
The Pjältån River is the second largest river in the county of Östergötland, in Sweden, and the most important for sea trout reproduction. It also holds significant potential as a growth habitat for European eel, once migratory barriers are removed.
The project will remove the dams at Sten övre, at the outlet of Lake Näknen, and Vekmangeln, at the outlet of Lake Lower Vekmangeln. The natural outlets of these lakes will be restored, enabling fish migration and re-establishing connectivity that has been lost for at least 150 years, along with natural lake level fluctuations.
| Project status | Completed |
|---|---|
| Project type | Dam removal: demolition |
| Country | Sweden |
| River | Pjältån |
| Removal date | Autumn 2025 |
| Km to be opened | 25 km |
| Focal species | Pike, perch, bream, roach, burbot, eel |
| Organisation | Municipality of Norrköping |
| Website | norrkoping.se |
The former uses of the river for timber floating and milling have long since ceased, leaving behind redundant infrastructure that continues to block natural river functions and fish migration. The project offers an opportunity to remove these obstacles and allow both historically lost and currently present species to return and thrive in the river system once again.
The primary goal is to restore connectivity that has been absent for over 150 years, allowing fish to access habitats upstream of the old dams. The demolition of the dams at Sten övre and Vekmangeln will enable fish migration from the lower river to upstream spawning and nursery habitats. It will also secure natural seasonal fluctuations in lake levels, benefitting both aquatic and riparian ecosystems.
The restoration will improve conditions for key species such as pike, perch, bream, roach, burbot and eel. These changes are expected to boost the ecological integrity of the Pjältån River and support long-term biodiversity recovery in the region.
Since 12 November 2025, fish have been able to reach even the smallest tributaries within the Pjältån river system, opening up migratory routes of around 25 km upstream from below Lake Näknen. As part of this project, two dams have been removed and natural-like lake outlets have been created. From both an aesthetic and hydraulic perspective, the project has been successful; however, 2026 will reveal which species migrate upstream and downstream within and between the lakes.
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