Nyköpingsån

Nyköpingsån is a river primarily flowing through Södermanland County in Sweden. The river is named after Nyköping, where it flows into the Baltic Sea. Nyköping is also the largest settlement on the river proper and a large part of the drainage area water is in the corresponding municipality. Nyköpingsån is one of two rivers to flow into the harbour of Nyköping, the other being Kilaån that winds through the southwestern part of the municipality eastwards from Kolmården.

Nyköpingsån
Nyköpingsån near its outflow in downtown Nyköping.
Location
Country	Sweden
Counties	Södermanland, Östergötland, Örebro
Municipalities	Askersund, Finspång, Flen, Gnesta, Hallsberg, Katrineholm, Norrköping, Nyköping, Vingåker, Örebro
Physical characteristics
Source
• location	Åsbro, Askersund Municipality
• elevation	105 metres (344 ft)
Mouth
• location	Nyköping
• elevation	0 metres (0 ft)
Length	150 km (93 mi)[1]
Basin size	3,631.6 km2 (1,402.2 sq mi)[2]
Discharge
• average	23 m3/s (810 cu ft/s)[1]

The furthermost interior part of the river is the western shore of lake Tisaren at Åsbro in Askersund Municipality, Örebro County. Although a shorter route, it also leads into the lake of Tisnaren in Östergötland County in the north of Finspång Municipality and further down towards but not quite all the way to Simonstorp in Norrköping Municipality, making it a tri-county river. The river flows out of several sizeable lakes in Södermanland's interior, the two largest being Båven and Yngaren.

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 the drainage areas of Nyköpingsån and the one of Vättern is less than 1 mile (1.6 km), which narrowly avoids making the area between Motala and Nyköping a natural island. Also near Simonstorp the system is also about a mile from where the source of the aforementioned Kilaån is.