The Aura River is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in south-western Finland

Finland

Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

. Its sources are in the town of Oripää

Oripää

Oripää is a municipality of Finland.It is located in the province of Western Finland and is part of the Finland Proper region. The municipality has a population of and covers an area of of which is water. The population density is ....

, and it flows through Pöytyä

Pöytyä

Pöytyä is a municipality of Finland.It is located in the province of Western Finland and is part of the Finland Proper region. The municipality has a population of and covers an area of of which is water. The population density is ....

, Aura

Aura, Finland

Aura is a municipality of Finland. The name derives from the river Aura and the plough reminiscent shape of the municipality. The municipality was established in 1917 from parts of Lieto and Pöytyä....

 and Lieto

Lieto

Lieto is a municipality of Finland.It is located in the province of Western Finland and is part of the Finland Proper region. The municipality has a population of and covers an area of of which is water. The population density is ....

 before discharging into the Archipelago Sea

Archipelago Sea

Archipelago Sea is a part of the Baltic Sea between the Gulf of Bothnia, the Gulf of Finland and the Sea of Åland, within Finnish territorial waters...

 in the middle of the city of Turku

Turku

Turku is a city situated on the southwest coast of Finland at the mouth of the Aura River. It is located in the region of Finland Proper. It is believed that Turku came into existence during the end of the 13th century which makes it the oldest city in Finland...

. The total length of the river is about 70 kilometres (43.5 mi), and it contains eleven rapids, the biggest of which is Nautelankoski at Lieto. The tap water

Tap water

Tap water is a principal component of "indoor plumbing", which became available in urban areas of the developed world during the last quarter of the 19th century, and common during the mid-20th century...

 for Turku is drawn from the Aura river, the city waterworks being situated by the Halinen rapids.

The word "Aura" appears to come from an archaic Swedish

Swedish language

Swedish is a North Germanic language, spoken by approximately 10 million people, predominantly in Sweden and parts of Finland, especially along its coast and on the Åland islands. It is largely mutually intelligible with Norwegian and Danish...

 word for waterway (aathra, which is still current in the form ådra), but in Finnish

Finnish language

Finnish is the language spoken by the majority of the population in Finland Primarily for use by restaurant menus and by ethnic Finns outside Finland. It is one of the two official languages of Finland and an official minority language in Sweden. In Sweden, both standard Finnish and Meänkieli, a...

 it translates as "plow," a name the river lives up to. Situated in an agricultural zone, it's turbidied by surface runoff

Surface runoff

Surface runoff is the water flow that occurs when soil is infiltrated to full capacity and excess water from rain, meltwater, or other sources flows over the land. This is a major component of the water cycle. Runoff that occurs on surfaces before reaching a channel is also called a nonpoint source...

 from nearby farms with eutrophication

Eutrophication

Eutrophication or more precisely hypertrophication, is the movement of a body of water′s trophic status in the direction of increasing plant biomass, by the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage, to an aquatic system...

 as the biggest threat. Its condition has been improving since the 1970s and the Aura river is now clean enough to support salmon

Salmon

Salmon is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true...

.

The banks of the river have been inhabited on locations at least 6000 years ago. It is notable for the cultural heritage

Cultural heritage

Cultural heritage is the legacy of physical artifacts and intangible attributes of a group or society that are inherited from past generations, maintained in the present and bestowed for the benefit of future generations...

 in Finland. The archdiocese of Finland has been situated near the river since the thirteenth century.