Övre Rudasjön or Övre Rudan for short, is a lake

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

 in Haninge Municipality

Haninge Municipality

Haninge Municipality is a municipality in Stockholm County in east central Sweden. Its seat is located in Handen.Haninge Municipality was formed in 1971 when Västerhaninge and Österhaninge were united....

, 18 km (11 mi) south of central Stockholm

Stockholm

Stockholm is the capital and the largest city of Sweden and constitutes the most populated urban area in Scandinavia. Stockholm is the most populous city in Sweden, with a population of 851,155 in the municipality , 1.37 million in the urban area , and around 2.1 million in the metropolitan area...

, Sweden

Sweden

Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

. Forming part of the Tyresån Lake System

Tyresån Lake System

Tyresån Lake System is a number of lakes in Sweden with a common basin of 251.5 km2....

, its major inflow comes from lakes Nedre Rudasjön

Nedre Rudasjön

Nedre Rudasjön is a lake of Södermanland, Sweden....

 ("Lower Crucian carp Lake") and Trylen

Trylen

Trylen is a small lake 17 km south of central Stockholm, Sweden. Shared by Huddinge Municipality and Haninge Municipality, it forms part of the Tyresån Lake System.- Catchment area :...

 to the south, while its outflow passes over Dammträsk

Dammträsk

Dammträsk is a small man made lake within the Tyresån Lake System, located in Haninge Municipality, south of central Stockholm, Sweden....

 into Drevviken to the north.

The tall buildings of Handen

Handen

Handen is a part of Metropolitan Stockholm, and the seat of Haninge Municipality in Stockholm County in eastern Sweden. It had 11,524 inhabitants in 2003...

 commercial centre along the eastern shore of the lake contrast the dense forest of the Rudan Open-air Area on the opposite shore. The proximity to the commuter train

Stockholm commuter rail

Stockholm Commuter Rail is the commuter rail system in Stockholm County, Sweden. The system is an important part of the public transport in Stockholm, and is controlled by Stockholm Transport; the trains are operated under contract by Stockholmståg...

 station at Handen, makes the lake easily accessible to a large number of people, while the forests surrounding it makes it attractive to open-air lovers. It is used for bathing in summers and cross-country skiing

Cross-country skiing

Cross-country skiing is a winter sport in which participants propel themselves across snow-covered terrain using skis and poles...

 in winters.

Compared to other lakes in the Tyresån Lake System, levels of phosphorus in the lake are moderate.

Nutrition levels

PTOT Phosphorus Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...	NTOT Nitrogen Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...	N/P-quota	Chlor Chlorophyll Chlorophyll is a green pigment found in almost all plants, algae, and cyanobacteria. Its name is derived from the Greek words χλωρος, chloros and φύλλον, phyllon . Chlorophyll is an extremely important biomolecule, critical in photosynthesis, which allows plants to obtain energy from light...	Sight depth	Colour	TOC Total organic carbon Total organic carbon is the amount of carbon bound in an organic compound and is often used as a non-specific indicator of water quality or cleanliness of pharmaceutical manufacturing equipment....	pH PH In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...	Alk Alkalinity Alkalinity or AT measures the ability of a solution to neutralize acids to the equivalence point of carbonate or bicarbonate. The alkalinity is equal to the stoichiometric sum of the bases in solution...
17 ug/l	456 ug/l	27	6 a ug/l	3,8 m (max)	34 mg/l	8 mg/l	7,2	0,28 mekv/l

With are 28 species of vascular plant

Vascular plant

Vascular plants are those plants that have lignified tissues for conducting water, minerals, and photosynthetic products through the plant. Vascular plants include the clubmosses, Equisetum, ferns, gymnosperms and angiosperms...

s by the lake and 1 species of Stoneworth

Charales

Charales is an order of pondweeds, freshwater algae in the division Charophyta. They are green plants believed to be the closest relatives of the green land plants. Linnaeus established the genus Chara in 1753.-Description:...

in it, the lake fauna is considered relatively rich in species.