Orlangen

Story

Orlången is a lake in central Huddinge Municipality, just south of Stockholm, Sweden.Orlången, one of the lakes in the Tyresån Lake System, forms part of the Orlången Nature Reserve.Catchment areaThe catchment area is composed of criss-crossing fractured valleys with alternating agricultural lands and forests. The lake and its shores are highly popular for open-air activities such as fishing, bathing, birdwatching, tour skating, canoeing, skiing, and walking. The Bottnen ("The Bottom") wetland near the inflow from Mörtsjön is an important bird locale. There are several public baths by the lake, but its many cliffs are also popular spots to spend a summer day. Approximately half of the lake is available for angling for people with the required angling card.Environmental impactThough the mud-filled valleys surrounding Orlången originally made it moderately eutrophic, extended accumulation of nutrients from neighbouring populated areas has made it highly eutrophic. The deepest areas of the lake are depleted of oxygen during both winters and summers, which can indicate that internal loads are worsening the situation; the lake is possibly self-fertilising, as nutrients are released from its sediments. The present discharge of phosphorus, mostly deriving from three residential areas by the lake, is still too high although it remains controllable.