Söderström is a river in central

Stockholm Stockholm () is the capital and largest city of Sweden as well as the largest urban area in Scandinavia. Approximately 980,000 people live in the municipality, with 1.6 million in the urban area, and 2.4 million in the metropo ...

that connects

Lake Mälaren A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larg ...

with 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 ...

. It runs south of

Gamla stan Gamla stan (, "The Old Town"), until 1980 officially Staden mellan broarna ("The Town between the Bridges"), is the old town of Stockholm, Sweden. Gamla stan consists primarily of the island Stadsholmen. Officially, but not colloquially, Gamla stan ...

from

Riddarfjärden Riddarfjärden (, "The Knight Firth") is the easternmost bay of Mälaren, Lake Mälaren in central Stockholm. Stockholm was founded in 1252 on an island in the stream where Lake Mälaren (from the west) drains into the Baltic Sea (to the east); to ...

to Stockholms ström (the western part of Saltsjön). It is one of two natural waterways between Mälaren and the Baltic sea, the other being

Norrström Norrström is one of the shortest rivers in Europe in central Stockholm. It connects Lake Mälaren with the Baltic Sea. It runs from Riddarfjärden, north of Gamla stan, to Stockholms ström (the western part of Saltsjön). Two islands lie within ...

north of Gamla stan. The river is

locked Lock(s) may refer to: Common meanings *Lock and key, a mechanical device used to secure items of importance * Lock (water navigation), a device for boats to transit between different levels of water, as in a canal Arts and entertainment * ''Loc ...

by Karl Johansslussen (Karl Johan's lock), and most of the time is conceived as more like a bay of Mälaren. The area around the lock is known as the Slussenområdet, and beginning in 2016 is undergoing a major revitalization. The channel of an older lock, known as the Nils Ericson lock, still exists just to the north of Karl Johansslussen. This lock is hidden by the steps leading to Karl Johans Torg, but it still allows for the discharge of water from Mälaren into the Baltic. It is planned to convert the channel of this older lock into a

fish ladder A fish ladder, also known as a fishway, fish pass, fish steps, or fish cannon is a structure on or around artificial and natural barriers (such as dams, locks and waterfalls) to facilitate diadromous fishes' natural migration as well as move ...

, as the revitalized area will include two much larger discharge channels on either side of the new lock.

References

Geography of Stockholm Mälaren Rivers of Stockholm County Waterways in Sweden {{Stockholm-geo-stub