Hervantajärvi is a

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 ...

Pirkanmaa Pirkanmaa (; ; ), 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 Southwest Finland. Most of the wate ...

Finland Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, ...

, located in the between of

Tampere Tampere is a city in Finland and the regional capital of Pirkanmaa. It is located in the Finnish Lakeland. The population of Tampere is approximately , while the metropolitan area has a population of approximately . It is the most populous mu ...

's Hervantajärvi district and

Lempäälä Lempäälä () is a municipality in Finland, located in the Pirkanmaa region. It lies south of the regional capital, Tampere. The population of Lempäälä is approximately , while the Tampere metropolitan area, metropolitan area has a population ...

'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 Päij� ...

–

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–H ...

area in the

Kokemäki River Kokemäki (; ) 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 Swedish speakin ...

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 In ecology, a marsh is a wetland that is dominated by herbaceous plants rather than by woody plants.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p More in genera ...

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 or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term ''algae'' encompass ...

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 (, 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), Messukylä was the ...

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

holiday home A holiday is a day or other period of time set aside for festivals or recreation. ''Public holidays'' are set by public authorities and vary by state or region. Religious holidays are set by religious organisations for their members and are oft ...

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. Hervanta currently covers an area of 13.8 km² and is continuing to grow. Home to a population of over ...

.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