Hjälmaren is Sweden’s fourth largest lake with an area of 483 km². It is located in Svealand and is divided between Västmanland, Södermanland and Närke. The three counties are adjacent to each other in Tjugholmen, east of Vinön. One of Sweden’s larger cities, Örebro, has the shores of Lake Hjälmaren across Rynningeviken, although the city has no settlements on the lake.
General information
The maximum depth is 22 metres and the average depth is 6.1 metres. The lake drains through Eskilstunaån into Lake Mälaren. There is a boat connection to Lake Mälaren via the Hjälmare Canal. Largest island of Hjälmaren is Vinön, which is inhabited all year round and from where a ferry runs to Hampetorp, one of the few villages on the coast of Hjälmaren. The only village with more than a thousand inhabitants on the immediate shore of Hjälmaren is Ekeby-Almby a few kilometres east of Örebro. The main tributaries are the Svartån and the Kvismare Canal, both from the west.
Largest town around the lake is Örebro to the west. The built-up part of the city extends about one kilometre from the shore, where the wetland begins. The town centre is located along the Svartån River, a few kilometres upstream of the lake. Unlike Sweden’s three largest lakes, Hjälmaren is not a national lake but a municipal water. The lake area is administered by the counties of Södermanland, Västmanland and Örebro. Other municipalities with shorelines are Arboga, Eskilstuna, Katrineholm and Vingåker. All municipalities are located at some distance from Hjälmaren and no municipality except Örebro has a municipal district on the shore.
Lowering of the Hjälmar 1878-1887
In 1878-1887 the river level was lowered by lowering the lake level. This was due to the release of additional agricultural land. In addition, the intention was to reduce the risk of flooding by being able to better regulate the water level in the lake.
Figures vary as to how much the surface of Hjälmaren has been lowered. Waldén states that the average water level has been lowered by 130 cm. This has freed up approximately 15 000 hectares of fields and meadows and approximately 3 500 hectares of other land. However, the cleared land was not always prime arable land.
