What is "vorma"

Vorma is a river in Norway that brings water from lake Mjøsa into the Glomma river. The Vorma is long and flows through the town of Eidsvoll. The Vorma flows from Lake Mjøsa at the village of Minnesund to join with the Glomma at Årnes.

Vorma was so named because it was a "warm" river that never freezes over, while both the Glomma and the Gudbrandsdalslågen routinely freeze. The junction of the Vorma with the Glomma at Årnes and Nes is the site of the Funnefoss on the Glomma, a fall.