Östersundsjön

Östersundsjön is a medium-sized lake situated in Dalarna County in central Sweden. It lies approximately 30 kilometres south of the city of Gävle and is part of the larger Dalälven river basin. The lake covers an area of about 20 square kilometres, with a maximum depth of roughly 70 metres and an average depth of around 15 metres. Its shoreline stretches for more than 60 kilometres and features a mix of rocky outcrops and gently sloping beach areas.

The hydrology of Östersundsjön is characterised by inflows from several smaller streams, notably the Särna Brook and the Sörälv River, and an outflow through the lake’s southern channel that feeds into the Österån river system. Seasonal variations in water level are modest, typically ranging between 4.5 and 5.5 metres above sea level. The lake’s water quality is generally good, with low concentrations of nutrients and a clear trophic status that supports a diverse range of aquatic life.

Ecologically, Östersundsjön hosts numerous species of fish, including perch, pike, and European whitefish, making it a popular site for fishing. The surrounding wetlands support a variety of waterfowl, such as swans, geese, and ducks, and several protected plant species thrive along the shoreline. Conservation efforts in the area focus on maintaining water quality, preventing invasive species, and protecting wildlife habitats, with local authorities categorising parts of the lake as a national nature reserve.

Human use of Östersundsjön includes recreational activities such as sailing, windsurfing, and canoeing, particularly during late summer and early autumn when the weather is particularly favourable. The lake’s scenic beauty attracts both local and visiting tourists, and there are several small resorts and campgrounds nearby that offer lodging and access to the water. Historically, the lake has played a role in the transport of timber and other goods during the 19th and early 20th centuries, although its economic importance has declined as road and rail transport became dominant.