PROJECT DESCRIPTION
BACKGROUND
The Torne river basin is a large water system (over 40,000 km²) shared by Sweden (approximately 60%), Finland (around 40%) and Norway (less than 1%). The Torne is one of the largest rivers in Europe that has not been exploited for hydropower production, however the basin’s river channels were widely used for log driving (i.e. moving timber from forests to sawmills by floating) during the 1950s and 1960s. In the main channel, only slight modifications of rapid areas were made, but in shallow tributaries almost all rapids were heavily modified to enable smooth log driving, causing adverse ecological effects and destruction of natural habitats. Dams built to regulate water levels and for construction of roads are blocking fish migration routes and fragment the aquatic habitats of numerous other species. Due to the modifications, natural variation in the flow of water is disturbed and vast spawning and nursery areas are unavailable for fish, having a negative effect on biodiversity overall. These migration barriers and the modified status of natural river channels and hydrology prevent favourable conservation status and good ecological status being achieved for the Torne river system, a Natura 2000 site. Large-scale actions are needed to repair the damage in the Torne river basin, including restoration of ecological connectivity, hydrology and morphology in the river system and halting pollution originating in the ditched catchment areas.
OBJECTIVES
The TRIWA LIFE project aims to improve the conservation status of several habitats and species in the Torne river system. It also seeks to enhance the condition of previously modified natural waters in order to achieve good ecological status, in accordance with the EU Water Framework Directive.
The target habitats are Fennoscandian natural rivers and water courses of plain to montane levels with Ranunculion fluitantis and Callitricho-Batrachion vegetation. The project’s actions are expected to increase the area of these habitats and improve their quality. The species targeted are the Atlantic salmon (Salmo salar),otter (Lutra lutra), freshwater pearl mussel (Margaritifera margaritifera), bullhead (Cottusgobio) and green snaketail (Ophiogomphus cecilia).
The specific objectives and results are to:
- Restore more than 100 ha of river habitats (over 10 ha of Fennoscandian natural rivers and more than 90 ha of water courses of plain to montane levels) from modified to natural-like status, to improve their quality and benefit the target species;
- Enhance the ecological connectivity of these aquatic habitats and populations of target species in the Torne river Natura 2000 site by removing almost 400 barriers to migration and dispersal of aquatic species along more than 3,300 km of rivers and streams;
- Improve the water quality and hydrological regime of the Natura 2000 site and the target habitats through catchment restoration work which controls the influx of excess nutrients and organic and inorganic matter from over 2,500 ha of land historically ditched for forestry, by filling 270 km of forest ditches and plugging over 260 leaking ditches; and
- Minimise the negative climate and environmental impact of the project’s actions, reducing greenhouse gas emissions by at least 63% compared to the baseline and thereby accelerating the green transition in the region, and develop greener best practice for similar large-scale nature restoration projects.
