The Site is a coherent river system which is representative of the European Boreal region. It features large streams, small creeks mixed with tree-dominated freshwater areas, and small ponds. River Nittälven and its delta make up one of the most natural catchment areas in Örebro County. Situated in a transition zone between northern and southern mire types, the Site is an important area for breeding birds, fish and mammal species included in the national red list. The Site supports endangered bryophytes and lichens such as Ramalina thrausta, which are important for the maintenance of the biological diversity of the region. The Site supports nurseries and migratory routes for several fish species, including the brown trout Salmo trutta which reproduces in the upper part of the river and its tributaries. The mires are an important carbon sink. Nittälven is very popular among outdoor and wilderness enthusiasts, and the main human activities are moose-hunting, canoeing, hiking and angling. Potential threats to the ecological character of the Site are unsustainable forestry practices, such as clear-cutting, drainage and excessive use of fertilizers. Management plans for overlapping nature reserves are being implemented. Monitoring of water quality and inventories covering forest habitats, birds, flora and wood fungi have also been carried out.