Lenne

The Lenne is a tributary of the river Ruhr in the Sauerland hills, western Germany. It has caused flooding in recent years.

Having its source on top of the Kahler Asten near Winterberg in an intermittent spring at an elevation of 2,687 ft, the Lenne ends after a course of 129 km flowing into the Ruhr river near the city of Hagen. With an average discharge of 25 m³/s near its mouth, it is the main tributary of the Ruhr.