User:Raven in Orbit/Workshop

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For now 
Below is an attempt to create an article about the Tyresån Lake System. I've started to create articles about individual lakes and nature reserves within the catchment area. It is still disorganised but I hope I will be able to develop it further without much delay. Feel free to edit it - if you do, comment your edits on my talk page, thanks.

/ Mats


Tyresån Lake System
Catchment area 251 km²
Basin countries Sweden
Settlements Stockholm, Tyresö, Botkyrka, Haninge, Nacka, Huddinge, Botkyrka

Tyresån Lake System (Swedish: Tyresåns sjösystem) or Tyresån ("Tyres Brook") for short, is a system of more than 30 interconnected lakes south of Stockholm. Sweden.

The lakes system encompasses parts of the municipalities of Stockholm, Huddinge, Tyresö, Botkyrka, Haninge, and Nacka, i.e. large parts of the southern suburbs of Stockholm. Since 1993, a collaboration between these six municipalities and the Stockholm County Council, Tyresåsamarbetet, is aiming at improving the environmental quality of the lake system.

Contents

[edit] Catchment area

The catchment area is densely populated. 47 per cent of the area is taken up by man-made structures, 40 per cent by forest, 5 per cent is used for agriculture, and the lakes themselves are covering 6 per cent of the area. A relatively small amount of land is used for agriculture, but there is a considerable number of small-scale stables in the area. There are 260.000 people living within the catchment area, which makes it densely populated by Swedish standards. However, these densely populated residential areas are separated by green areas and a number of nature reserves encompassing several of the lakes in the lake system. Additionally, the Tyresta National Park reaches into the southern part of the catchment area. Notwithstanding the density of the population, several areas within the catchment area are important natural resources and it contains several well-known bird lakes such as Ågestasjön.[1]

Nature reserves in Huddinge Municipality[2]
  1. Björksättra Peninsula Nature Reserve Björksättra
  2. Flemingsbergsskogen Nature Reserve Flemingsbergsskogen
  3. Gömmaren Nature Reserve Gömmaren
    1. Fullersta kvarn Fullersta Natura 2000 area
  4. Gladöskogen Nature Reserve Gladöskogen
  5. Gömsta Äng Nature Reserve Gömsta äng
  6. Lännaskogen Nature Reserve Lännaskogen
    1. Lissma-Kvarnsjö Natura 2000 area
    2. Lännaskogen Natura 2000 area
  7. Orlången Nature Reserve Orlången
  8. Paradiset Nature Reserve Paradiset
    1. Granby (add to Granby) Natura 2000 area
    2. Hanveden Natura 2000 area
  9. Trångsundsskogen Trångsund

[edit] Environmental impact

Eutrophication and a historical lack of adequate sewage treatment is characteristic for the lake system. Local treatment plants were discontinued in the 1970s when effluents was rerouted to the treatment plant in Henriksdal. Since then, continuous efforts have radically decreased loads on the lakes, while internal loads, such as phosphorus released from sediments, continue to cause high levels of nutrients in several lakes. Shortage of sufficient sewage treatment in historical seasonal residential areas which are gradually developed into permanent residential areas, is responsible for most of the loads of nutritive salts. These areas are however being connected to the municipal sewage network. Acidity has decreased during the last ten years, and as a result liming of the uppermost lakes in the system, such as Trehörningen, Hanveden, has been discontinued. None of the lakes are recipients for direct industrial discharge. High population density and a permanent human presence have produced a considerable number of migration obstacles throughout the area, including four dams. A small hydroelectric plant, the only in Stockholm County, is located by the mouth of the lake system.[1]

[3]

[4]

[5]

[edit] Lake structure

[6]
Kalvfjärden
Fatburen
Albysjön
Albysjön
Tyresö-Flaten
Tyresö-Flaten
Grändalssjön
Barnsjön
Långsjön
Långsjön
Drevviken
Drevviken
Magelungen
Magelungen
Flaten
Flaten
Damm-
träsk
Lycksjön
Ågestasjön
Kvarnsjön,
Lissma
Lissmasjön
Ramsjön
Mörtsjön
Orlången
Ådran
Ådran
Ormputten
Svartsjön
Träsket
Trehörningen-
Sjödalen
Kvarnsjön
Kärrsjön
Rudträsk
Övre
Rudasjön
Bylsjön
Gömmaren
Gömmaren
Hacksjön
Trehörningen
Trehörningen-
Hanveden
Trylen
Nedre
Rudasjön
  • Kvarnsjön, Lissma (to Drevviken)
  • Lissmasjön
    • Ormputten
    • Ådran
      • Rudträsket
      • Trehörningen, Hanveden
  • Lycksjön (to Drevviken)
    • Träsket, Haninge
      • Bylsjön
      • Ramsjön ?
        • Svartsjön ?
  • Karptjärn ?

[edit] See also

[edit] Notes

  1. ^ a b Vattenmyndigheterna
  2. ^ Huddinge Municipality, Nature reserves of Huddinge
  3. ^ Tyresåsamarbetet
  4. ^ City of Stockholm, Våra fantastiska sjöar...
  5. ^ Tyresö Municipality, Tyresåns vattensystem
  6. ^ Chart is mainly based on maps produced by Lantmäteriet (see PDF below) and IVL (PDF page 46, illustration 25). Dotted lines are estimates.

[edit] References

[edit] External links

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