Nyköpingsån is a

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

primarily flowing through

Södermanland County Södermanland County (, ) is a Counties of Sweden, 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 the ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

. 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 the countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden, and the North European Plain, North and Central European Plain regions. It is the ...

. 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 municipal corporation, corporate status and powers of self-government or jurisdiction as granted by national and regional laws to which it is subordinate. The term ''municipality' ...

. 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 ...

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

Svartsjön ''Black Lake'' () is a Scandinavian thriller (genre), 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 201 ...

Hallsberg Municipality Hallsberg Municipality () is a municipality in Örebro County in central Sweden. Its seat is located in the town of Hallsberg, which is the main railway hub for the central Swedish interior. The present municipality was created in 1971 when the m ...

Örebro County Örebro County () 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 northern region of ...

at above sea level. The innermost source and furthest western part is Norra Dovrasjön also in Hallsberg Municipality at a somewhat lower elevation. The innermost and most elevated riverside locality is in

Åsbro Åsbro is a locality situated in Askersund Municipality, Örebro County, Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to th ...

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

Tisnaren Tisnaren () is a lake of Södermanland, Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to ...

Östergötland County Östergötland County () 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 northeast. It also has a ...

in the north of

Finspång Municipality Finspång Municipality () is a municipality in Östergötland County in Sweden. Its seat is located in the town of Finspång, with some 21 654 (30 September 2024), 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, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders ...

Norrköping Municipality Norrköping Municipality () 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 the time of the local g ...

, 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 of Flen, Gnesta, and Nyköping in Södermanland, Sweden. The lake is characterized by branches and many islands, with over 500 km of shoreline. Around Båven there are a number of estates and manors ...

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 ...

. Notably, the village of

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

northwest of Nyköping is surrounded by lakes in the drainage area and the small river passing through the village connects the western and eastern parts of the river system. 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 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 Scandinavia. ...

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 Motala () is a Urban areas in Sweden, locality and the seat of Motala Municipal ...

is just above . This narrowly avoids making the area between

Motala Motala () is a Urban areas in Sweden, locality and the seat of Motala Municipality, Östergötland County, Sweden with a municipal population of 43,717 inhabitants in 2024. It is the third largest city of Östergötland, following Linköping and N ...

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 Högsjö is a locality situated in Vingåker Municipality, Södermanland County, Sweden with 713 inhabitants in 2010. Riksdag The Riksdag ( , ; also or , ) is the parliament and the parliamentary sovereignty, supreme decision-making bod ...

Vingåker Vingåker () is a 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 Nyköping. It was partly bui ...

* Regna * Hävla *

Katrineholm Katrineholm (pronunciation: or ) is a Urban areas in Sweden, 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 ur ...

Flen Flen () 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 the much larger Flen Munici ...

Sparreholm Sparreholm is a locality situated in Flen Municipality, Södermanland County, Sweden with 741 inhabitants in 2010. Riksdag The Riksdag ( , ; also or , ) is the parliament and the parliamentary sovereignty, supreme decision-making body of ...

* Vadsbro *

Björkvik Björkvik is a locality situated in Katrineholm Municipality, Södermanland County, Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders ...

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 ...

Stigtomta Stigtomta is a locality situated in Nyköping Municipality, Södermanland County, Sweden with 1,942 inhabitants in 2010. It is located around 15 kilometres outside the city centre of Nyköping. Riksdag The Riksdag ( , ; also or , ) is t ...

Larger lakes

* Hallbosjön * Kolsnaren * Lidsjön *

Långhalsen Långhalsen is a lake predominantly in Nyköping Municipality, Södermanland, Sweden that is part of the Nyköpingsån drainage area. There is a very small portion of the lake's northern inlet that is part of Flen Municipality Flen Municipalit ...

* Sottern *

References

{{DEFAULTSORT:Nykopingsan Rivers of Sweden