TRIWA LIFE

TRIWA LIFE, The Torne River International Watershed LIFE, is a cooperation project with Finland that aims to restore habitats in streams and wetlands that are affected by human activities. The project will benefit the biodiversity in these areas.

Background

The Torne River with tributaries has, like other rivers, been used for timber floating. To facilitate the timber floating, streams were straightened and cleared of boulders and stones. Side channels were closed, the main riverbeds were narrowed, and dams were built. By doing this, the variation in the streams disappeared and hence the habitats for aquatic animals and plants.

When the timer floating ended, many forestry roads were built to transport the timber by trucks. With the roads came new problems, for instance, road culverts can be migration barriers for aquatic animals. Many wetlands have been ditched to created forest- or agricultural land. This has destroyed the hydrology and the habitats of the wetlands. Road ditches can also have a negative impact in the environment.

Restoration of streams and wetlands to more natural states

The project TRIWA will re-create the environment in several of the tributaries within the Torne River watershed to enhance the biodiversity that is lost due to human activities. Our objectives are to restore almost 100 kilometres of streams, remove 399 migration barriers in streams and restore 2 500 hectares of wetlands.

To move boulders into the streams we will use excavators. Parts of the work will be done by hand, for instance when we create spawning beds for fish. We will remove dams and build arches or bridges instead of culverts that are migration barriers. In Finland, we will create two bypasses for fish at two hydropower dams in Tengeliönjoki. Wetlands in both Finland and Sweden will be restored by filling the ditches and building plugs. The project will recreate natural habitats for all species in the targeted streams and wetlands. Species such as salmon, otter, freshwater pearl mussel and bullhead will benefit from the work done in the project.

The project TRIWA will continue between 2023—2030 and it will contribute to reach the goals of the Water Framework Directive “good or hight ecological status” in the streams. The project will also improve the status for streams, wetlands, and species according to the Natura 2000 directives.

TRIWA will continue the work done in previous projects, for instance the two LIFE projects Remibar and ReBorN but also on the experience we have received during the work with wetland restorations.

Objectives of TRIWA LIFE

• Restore 96 km of streams.
• Remove 399 migration barriers in streams.
• Restore 2 500 hectares of wetlands.
• Reduce green house gases emission and developed a Greener Best Practice.
• Improve habitats for the targeted species atlantic salmon, green snaketail, bullhead, freshwater pearl mussel and otter.