Nyköpingsån is a

river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...

primarily flowing through

Södermanland County Södermanland County ( sv, Södermanlands län) is a county or '' län'' on the southeast coast of Sweden. In the local Sörmlandic dialects it is virtually universally shortened and pronounced as Sörmlands län, or simply Sörmland, which is t ...

Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...

. The river is named after

Nyköping Nyköping () is a Urban areas in Sweden, locality and the seat of Nyköping Municipality, Södermanland County, Sweden with 32,759 inhabitants as of 2017. The city is also the capital of Södermanland County. Including Arnö, the locality on the ...

, where it flows into the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...

. Nyköping is also the largest settlement on the river proper and a large part of the drainage area water is in the corresponding

municipality A municipality is usually a single administrative division having corporate status and powers of self-government or jurisdiction as granted by national and regional laws to which it is subordinate. The term ''municipality'' may also mean the go ...

. Nyköpingsån is one of two rivers to flow into the harbour of Nyköping, the other being

Kilaån Kilaån is a river primarily running through the southern parts of Södermanland County in Sweden. Its exodus is in south Nyköping on the Södermanland coast. The river's mouth is only a few hundred metres from the larger river of Nyköpingsån. T ...

that winds through the southwestern part of the municipality eastwards from

Kolmården Kolmården () is a long and wide densely forested rocky ridge that separates the Swedish provinces of Södermanland and Östergötland, two of the country's main agricultural areas, from each other, and in historic times, along with Tylöskog and ...

. The highest source of the river is the small lake of

Svartsjön ''Black Lake'' ( sv, Svartsjön) is a Scandinavian thriller television series, devised by Ulf Kvensler and co-produced by TV3 Sverige, TV3 Danmark, TV3 Norge, Viaplay, and Jarowskij, that first broadcast in Sweden and Denmark in October 2016 ...

Hallsberg Municipality Hallsberg Municipality (''Hallsbergs kommun'') is a municipality in Örebro County in central Sweden. Its seat is located in the town of Hallsberg. The present municipality was created in 1971 when the market town (''köping'') of Hallsberg was a ...

Örebro County Örebro County ( sv, Örebro län) is a county or '' län'' in central Sweden. It borders the counties of Västra Götaland, Värmland, Dalarna, Västmanland, Södermanland and Östergötland. It is frequently culturally divided into the hilly n ...

at above sea level. The innermost and most elevated riverside locality is in

Åsbro Åsbro is a locality situated in Askersund Municipality, Örebro County Örebro County ( sv, Örebro län) is a county or '' län'' in central Sweden. It borders the counties of Västra Götaland, Värmland, Dalarna, Västmanland, Södermanland ...

at when the river passes through the lake of Tisaren. Although a shorter and lower route, it also leads into the lake of Tisnaren in

Östergötland County Östergötland County ( sv, Östergötlands län) is a county or ''län'' in southeastern Sweden. It has land borders with the counties of Kalmar to the southeast, Jönköping to the southwest, Örebro to the northwest, and Södermanland to the n ...

in the north of

Finspång Municipality Finspång Municipality (''Finspångs kommun'') is a municipality in Östergötland County in Sweden. Its seat is located in the town of Finspång, with some 13,000 inhabitants. Nature The municipality refers to itself as Sweden's most lake-den ...

. That source is further down towards but not quite at

Simonstorp Simonstorp is a locality situated in Norrköping Municipality, Östergötland County, Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Ki ...

Norrköping Municipality Norrköping Municipality (''Norrköpings kommun'') is a municipality in Östergötland County in southeast Sweden. Its seat is located in the city of Norrköping, with some 90,000 inhabitants. It is the largest municipality in Östergötland. By ...

, making it a tri-county river. The river flows out of several sizeable lakes in Södermanland's interior, the two largest being

Båven Båven () is a lake in the municipalities Flens, Gnesta, and Nyköping in Södermanland, Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is th ...

and

Yngaren Yngaren is a lake in Södermanland County, Sweden. It is the second largest lake within Södermanland's interior after Båven. Geography Yngaren is located in south-central Södermanland and drains into small river Nyköpingsån through lakes Ha ...

. Most of the river and its drainage area lakes are navigable by small boats, except for hydroelectrical, artificial waterfalls in Nyköping. Some river passages between lakes are very narrow. At the innermost part, the gap between two lakes in the drainage area of Nyköpingsån and the one of

Vättern Vättern ( , ) is the second largest lake by surface area in Sweden, after Vänern, and the sixth largest lake in Europe. It is a long, finger-shaped body of fresh water in south central Sweden, to the southeast of Vänern, pointing at the tip of ...

and

Motala ström Motala ström is the river system that drains lake Vättern, the second largest lake in Sweden, into the Baltic Sea in Norrköping. It is named from the city Motala where it begins. In the early 19th century, the Göta Canal The Göta Can ...

is just above . This narrowly avoids making the area between

Motala Motala () is a locality and the seat of Motala Municipality, Östergötland County, Sweden with 29,823 inhabitants (41,956 in the entire municipality) in 2010. It is the third largest city of Östergötland, following Linköping and Norrköping. M ...

and Nyköping a natural island. Also near Simonstorp the system is also merely a kilometer away from where the source of the aforementioned Kilaån is.

Locations in the drainage area

The localities are listed sorted after distance to the maritime outflow in

. *

* Svennevad * Kilsmo * Brevens bruk * Högsjö *

Vingåker Vingåker () is a Urban areas in Sweden, locality and the seat of Vingåker Municipality, Södermanland County, Sweden with 4,282 inhabitants in 2010. It is located by road from the nearest larger city Örebro and north-west of county seat Nyköp ...

* Regna * Hävla *

Katrineholm Katrineholm (pronunciation: or ) is a locality and the seat of Katrineholm Municipality, Södermanland County, Sweden with 24,271 inhabitants in 2018. It is located in the inland of Södermanland and is the third largest urban area in the county ...

Flen Flen (local pronunciation ''Flén'') is a locality and the seat of Flen Municipality, Södermanland County, Sweden with 6,229 inhabitants in 2010. Flen evolved as a railway junction and got the title of a city in 1949. Since 1971 it is the seat of ...

Sparreholm Sparreholm is a locality situated in Flen Municipality, Södermanland County, Sweden with 741 inhabitants in 2010. Riksdag The Riksdag (, ; also sv, riksdagen or ''Sveriges riksdag'' ) is the legislature and the supreme decision-making ...

* Vadsbro *

Björkvik Björkvik is a Urban areas in Sweden, locality situated in Katrineholm Municipality, Södermanland County, Sweden with 492 inhabitants in 2010. It is primarily a farming community interspersed by forests and lakes, with some larger estates dating ...

Bettna Bettna is a locality situated in Flen Municipality, Södermanland County, Sweden with 412 inhabitants in 2010. It is also a parish with the same name. Bettna is located at a similar distance from Flen, Katrineholm and Nyköping (20-30 km) and abou ...

Vrena Vrena (local pronunciation ''Vréna'') is a Urban areas in Sweden, locality situated in Nyköping Municipality, Södermanland County, Sweden with 630 inhabitants as of 2015. Geography Vrena is located between the lakes of Hallbosjön and Långha ...

* Stigtomta *

Larger lakes

* Hallbosjön * Kolsnaren * Lidsjön * Långhalsen * Sottern * Tisnaren *

References

{{DEFAULTSORT:Nykopingsan Rivers of Sweden