Svartån

Svartån in Västmanland County, Sweden is a river that is 91 kilometers long. It passes through the towns of Skultuna and Västerås and has its outlet in Mälaren. The name Västerås derives from the Sueco-Latin term Västra Aros meaning "western outlet."
The river played an important role in the industrial development in this region from the 17th century until the early 20th century as a source for hydropower. Small-scale hydroelectric dams are located in Västerås, Skerike, and Skultuna, among others. The river also provided power for the many water wheels associated with Skultuna's centuries-old copper foundry Skultuna mässingsbruk.