Dammträsk ( Swedish for "Pond Swamp") is a small man made

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

within the Tyresån Lake System, located in

Haninge Municipality Haninge Municipality () is a municipality in Stockholm County in east central Sweden. Its seat is located in Handen, a part of the Stockholm urban area. Haninge Municipality was formed in 1971 when ''Västerhaninge'' and ''Österhaninge'' wer ...

, south of central

Stockholm Stockholm (; ) is the Capital city, capital and List of urban areas in Sweden by population, most populous city of Sweden, as well as the List of urban areas in the Nordic countries, largest urban area in the Nordic countries. Approximately ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

. The lake receives water from Övre and Nedre Rudasjön south of the lake and empties into

Drevviken Drevviken is a lake in southern Stockholm, Sweden, shared by the four municipalities Stockholm, Haninge, Huddinge, and Tyresö. While much of the surrounding area is used for one-family houses, the lake and the green space north of it are consid ...

north of it. Located just south of the residential area Kvarntorp, and north of the densely populated central Haninge, the wetland lake receives considerable amount of nutritive salts.Tyreså Collaboration

Environmental impact

The lake and the surrounding wetlands, together with local forests, are regarded as a valuable local natural resource.Haninge Municipality, ''Kvarntorp'' However, while the lake system as a whole is regarded as sensitive to

surface runoff Surface runoff (also known as overland flow or terrestrial runoff) is the unconfined flow of water over the ground surface, in contrast to ''channel runoff'' (or ''stream flow''). It occurs when excess rainwater, stormwater, meltwater, or other ...

, Dammträsk is already too contaminated to be regarded as vulnerable.Haninge Municipality, ''Dagvattenstrategi'' Water has been deliberately redirected from Rudasjön to Dammträsk, which reduces contamination of the downstream lake, Drevviken, since much of the waste is sedimented into the lake. The price to pay has been the dense vegetation in the lake. Two abandoned facilities by the lake, a

dry cleaner Dry cleaning is any cleaning process for clothing and textiles using a solvent other than water. Clothes are instead soaked in a water-free liquid solvent (usually non-polar, as opposed to water which is a polar solvent). Perchloroethylene (kn ...

and a

gas station A filling station (also known as a gas station [] or petrol station []) is a facility that sells fuel and engine lubricants for motor vehicles. The most common fuels sold are gasoline (or petrol) and diesel fuel. Fuel dispensers are used to ...

, contaminated the surrounding area. A restoration project in 2005 removed 276 tons of earth containing

chlorinated hydrocarbons Organochlorine chemistry is concerned with the properties of organochlorine compounds, or organochlorides, organic compounds that contain one or more carbon–chlorine bonds. The chloroalkane class (alkanes with one or more hydrogens substituted ...

and 595 tons containing

petroleum Petroleum, also known as crude oil or simply oil, is a naturally occurring, yellowish-black liquid chemical mixture found in geological formations, consisting mainly of hydrocarbons. The term ''petroleum'' refers both to naturally occurring un ...

.Stockholm County Council, ''Samarbete''

Biodiversity

An inventory of the local vegetation concluded there are 27 species of

vascular plant Vascular plants (), also called tracheophytes (, ) or collectively tracheophyta (; ), are plants that have lignin, lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified Ti ...

s around the lake, which makes it relatively

biodiverse Biodiversity is the variability of life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and phylogenetic diversity. Diversity is not distributed evenly on Earth ...

(3/5 on a scale where 1 means high biodiversity). One of the interesting species of

aquatic plant Aquatic plants, also referred to as hydrophytes, are vascular plants and Non-vascular plant, non-vascular plants that have adapted to live in aquatic ecosystem, aquatic environments (marine ecosystem, saltwater or freshwater ecosystem, freshwater ...

s in the lake is

Common Mare's Tail ''Hippuris vulgaris'' (from – ''horse'' and – ''tail''), known as mare's-tail or common mare's-tail, is a common aquatic ecosystem, aquatic flowering plant in the family Plantaginaceae. Its distribution ranges from Eurasia and North America ...

Grass carp The grass carp (''Ctenopharyngodon idella'') is a species of large herbivorous freshwater fish in the family Cyprinidae, native to the Pacific Far East, with a native range stretching from northern Vietnam to the Amur River on the Sino-Russian ...

have been introduced to the lake.

Notes

References

* * * * * {{DEFAULTSORT:Dammtrask Geography of Stockholm Lakes of Stockholm County

Environmental impact

Biodiversity

See also

Notes

References