Långsjön, Älvsjö

Långsjön
View looking east
Långsjön
Coordinates59°16′3″N 17°57′59″E / 59.26750°N 17.96639°E / 59.26750; 17.96639
Primary outflowsLake Mälaren
Catchment area243 ha (600 acres)
Basin countriesSweden
Surface area29 ha (72 acres)
Average depth2.2 m (7 ft 3 in)
Max. depth3.3 m (11 ft)
Water volume617,000 m3 (500 acre⋅ft)
Residence time9-10 months
Shore length14,940 m (16,210 ft) (including islands)
Surface elevation30.6 m (100 ft)
IslandsThree (0.17 hectares or 0.42 acres)
SettlementsHuddinge, Stockholm
References
1 Shore length is not a well-defined measure.

Långsjön (English: The Long Lake) is a lake in southern Stockholm, Sweden. The lake is situated in an old residential neighbourhood located between the municipalities of Stockholm and Huddinge and most of the shoreline is private property. The water level is controlled by a sluice in the north-western end of the lake where the lake empties into Lake Mälaren through a system of dikes and culverts. Polluted waste water was poured directly into the lake during the early 20th century which caused up to two-thirds of the lake to be choked-up until the 1940s. It was subsequently one of the first lakes in Stockholm to undergo restoration. The northern shores are waterlogged whilst the bedrock surfaces along the southern. The lake has no major feeders, the inflow instead coming from local stormwater and surface runoff.