Hervantajärvi is a

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

Pirkanmaa Pirkanmaa (; sv, Birkaland; la, Birkaria, link=no), also known as ''Tampere Region'' in government documents, is a region of Finland. It borders the regions of Satakunta, South Ostrobothnia, Central Finland, Päijät-Häme, Kanta-Häme and Sou ...

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...

, located in the between of

Tampere Tampere ( , , ; sv, Tammerfors, ) is a city in the Pirkanmaa region, located in the western part of Finland. Tampere is the most populous inland city in the Nordic countries. It has a population of 244,029; the urban area has a population o ...

's Hervantajärvi district and

Lempäälä Lempäälä (; Swedish also ) is a municipality in the Pirkanmaa region of Finland with inhabitants (). Lempäälä is located south of the city of Tampere. The municipality covers an area of of which is water. The population density is . Th ...

's Sääksjärvi district, which belongs to the Moisionjoki catchment area of the

Vanajavesi Vanajavesi is a large lake in southern Finland, in the provinces of Pirkanmaa and Kanta-Häme. It is part of the Kokemäenjoki basin. The lake gathers waters from a wide area in the regions of Pirkanmaa, Tavastia Proper and parts of the Päijänn ...

–

Pyhäjärvi Pyhäjärvi (1993–1995 ''Pyhäsalmi'') is a town and municipality in the south of Northern Ostrobothnia region, Finland. Pyhäjärvi also borders the Northern Savonia and Central Finland regions. The town belongs to the subregion of Nivala–Ha ...

area in the

Kokemäki River Kokemäki (; sv, Kumo) is a town and municipality in the Satakunta Region of Finland. The town has a population of () and covers an area of of which is water. The population density is . Finland is constitutionally bi-lingual with a Swedis ...

watershed. Lake Hervantajärvi is part of the catchment area of Lake Höytämönjärvi. Hervantajärvi belongs to the small and medium-sized low-humic lakes. Its water is clear, but runoff from the

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found at ...

es on the east and south sides of the lake brings

humus In classical soil science, humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a kind of soil organic matter. It is rich in nutrients and retains moisture in the soil. Humus is the Lati ...

to the lake. In the 1980s, Hervantajärvi was considered a lake at risk of

acidification Acidification may refer to: * Ocean acidification, decrease in the pH of the Earth's oceans * Freshwater acidification, atmospheric depositions and soil leaching of SOx and NOx * Soil acidification, buildup of hydrogen cations, which reduces the ...

. Then the acidity of the water regularly went below six. Today, as the acid load has decreased, the acidity value of the water has remained consistently above 6,4 and the buffering capacity of the water has increased to avoid. The water quality of Hervantajärvi is between good and satisfactory class. The lake is still sensitive to acidification, and especially in winter the accompanying load of runoff consumes the lake's oxygen resources.

Algae bloom An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in Fresh water, freshwater or Ocean, marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term ...

s are also occasionally found on the lake.Hervantajärvi - Järvi-meriwiki
(in Finnish) On the 1953 basic map, there were two small

farm A farm (also called an agricultural holding) is an area of land that is devoted primarily to agricultural processes with the primary objective of producing food and other crops; it is the basic facility in food production. The name is used fo ...

s on the south shore of the lake. A road led to them from

Messukylä Messukylä ( sv, Messukylä, also ) is a former municipality of Finland which was annexed by the city of Tampere in 1947. The medieval stone church (built c. 1540) in Messukylä is the oldest building in Tampere. During the Civil War (1918), Mess ...

in the north. Already at that time, more than 20

holiday home A holiday cottage, holiday home, vacation home, or vacation property is accommodation used for holiday vacations, corporate travel, and temporary housing often for less than 30 days. Such properties are typically small homes, such as cottage ...

s had been marked on the beaches. On the map of 1975, the cottage village of Majaranta was marked on the north-western basin. Other cottages also appeared on the shores of the lake. The road to the lake improved considerably when construction began on

Hervanta Hervanta is a large suburb, or satellite city, of Tampere in Finland, located next to Hallila some 10 km south of the city centre. Home to a population of over 26,000, Hervanta is best known for its prefabricated blocks of flats. The total ...

.Peruskartta 1:20 000. 2123 11 Messukylä. Helsinki: Maanmittauslaitos, 1991
Kartta Vanhat painetut kartat -palvelussa (JPG)
(in Finnish)

References

Kokemäenjoki basin Lakes of Tampere {{WesternFinland-geo-stub