Watonwan River

Maximum discharge along the river is currently at the reporting a streamflow rate of cfs. This is also the highest stage along the Watonwan River, with a gauge stage of ft at this location. This river is monitored from 1 different streamgauging stations along the Watonwan River, the highest being situated at an altitude of ft, the .

It begins in the northeastern corner of Watonwan County and flows through Brown County before joining the Blue Earth River. The river's name comes from the Dakota word "Watanwan" meaning "fish bait."

The Watonwan River has a watershed area of 1,007 square miles and is largely influenced by agricultural practices. There are five dams along the river, including the Madelia Dam, which creates the Madelia Lake Reservoir. The reservoir is used for fishing and boating, and the surrounding area is popular for camping and picnicking.

The river is also used for agricultural purposes, including irrigation and livestock watering. However, the river has struggled with water quality issues due to agricultural runoff and sedimentation. Efforts are underway to improve the water quality of the river through conservation practices and watershed management.