Svartådalen is a complex of four nutrient-rich freshwater lakes which support emergent and submerged vegetation and are surrounded by low-lying wet meadows. The lakes are connected by the meandering river Svartän. The area is internationally important for staging whooper swans (Cygnus cygnus), with 2,500 birds representing 4% of the population of north-west mainland Europe; it also supports a diversity of breeding wetland birds. Maintenance of traditional hay-cutting is encouraged by payment of subsidies.