sisävesialueet

Sisävesialueet are Finland’s inland water bodies, referring to lakes, rivers and other freshwater areas situated within the country’s land boundaries and not part of the Baltic Sea or coastal marine areas. The term is used in legal, ecological and administrative contexts to distinguish freshwater systems from marine waters. Inland waters can include natural lakes, reservoirs and certain man-made channels that belong to the national waterway network.

Inland waters are typically freshwater systems characterized by seasonal variation and, in winter, ice cover. They host diverse aquatic and semi-aquatic habitats and species, such as various fish, water birds and invertebrates. These waters serve multiple uses, including municipal drinking water, recreation, fishing, hydropower and inland navigation along canal networks. They also contribute to flood regulation and regional climate processes and are integral to regional biodiversity and landscape value.

Management and protection of sisävesialueet fall under national water legislation and environmental protection rules. Monitoring and assessment are conducted by the Finnish Environment Institute (SYKE) and regional authorities. The waters are managed for water quality, ecological integrity, and sustainable use, with fisheries management, habitat protection, and pollution prevention playing key roles. The Natura 2000 network also includes inland-water habitats, aiming to preserve vulnerable ecosystems.

Challenges facing inland waters include eutrophication from nutrient runoff, sedimentation and habitat alteration, invasive species, and the impacts of climate change such as changing ice cover duration and water temperatures. Integrated watershed planning and ongoing monitoring are important for maintaining healthy sisävesialueet and their services.