Dammträsk


Dammträsk is a small man made lake within the Tyresån Lake System, located in Haninge Municipality, south of central Stockholm, Sweden.
The lake receives water from Övre and Nedre Rudasjön south of the lake and empties into Drevviken 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.

Environmental impact

The lake and the surrounding wetlands, together with local forests, are regarded as a valuable local natural resource worth to protect. However, while the lake system as a whole is regarded as sensitive to further loads of surface runoff, Dammträsk is one of the lakes in Haninge already to contaminated to be regarded as vulnerable. It has been a conscious decision to redirect water from Rudasjön to Dammträsk, and, as much of the waste the lake receives is sedimented into the lake, Drevviken, the lake downstream is saved from contamination. The price to pay, has been the dense vegetation in the lake. Two abandoned facilities by the lake, a dry cleaner and a gas station, has contaminated the area surrounding the lake. In 2005, the area was restored and some 276 tons of earth containing chlorinated hydrocarbons and 595 tons containing petroleum was removed.

Biodiversity

An inventory of the local vegetation concluded there are 27 species of vascular plants around the lake, which makes it relatively biodiverse. One of the interesting species of aquatic plants in the lake is Common Mare's Tail. Grass Carp has been introduced in the lake.