Lake Zumbro Hydroelectric Generating Plant

The Lake Zumbro Hydroelectric Generating Plant, also known as the City of Rochester Municipal Hydro-Electric Plant, is a hydroelectric facility on the Zumbro River in Mazeppa and Zumbro Townships, Wabasha County, Minnesota, United States. The facility consists of a gravity dam and a powerhouse, and the impoundment created is called Lake Zumbro. This dam spans and is high, creating a reservoir with about of hydraulic head. The facility was designed by pioneering hydroelectric engineer Hugh Lincoln Cooper (1865–1937) and was built from 1917 to 1919. It is still operated by its original owner, Rochester Public Utilities (RPU), to supply power to Rochester, Minnesota, to the south. The Lake Zumbro Hydroelectric Generating Plant was listed on the National Register of Historic Places in 1991 for having state-level significance in the theme of engineering. It was nominated as a representative work of Cooper—one of the nation's leading hydroelectric engineers in the early 20th century—and his only project in his home state of Minnesota.
On the night of August 24, 2019, a pontoon boat with three people on board went over the dam. They were casting off from the lakeshore after patronizing a business below the dam but got caught on the lip of the spillway. A fourth person jumped off and swam to a buoy, where she yelled for help, while the other three went over the edge in the boat. It lodged right-side-up near the base of the dam, causing the people on board only minor injuries. Firefighters, sheriff's deputies, and civilian boaters rescued all four individuals. The Wabasha County Sheriff's Office ascribed the incident to alcohol and darkness, charging the driver with boating while intoxicated. 