Oronoco Dam Removal and Zumbro River Restoration Project

Construction Dates: 2017 - July 2018


 Lake Shady was a reservoir on the Zumbro River created in 1937 by a dam constructed by the federal Works Progress Administration. By the late 1970s, sedimentation had largely ended recreational use of the lake. In July of 1989, the Lake Shady Restoration and Preservation Committee was established to work with federal, state, and local governmental agencies in an effort to restore the Lake. 

2010 Flood

Much of Southern Minnesota received extensive rain in late September, 2010. This major storm system cause severe flooding throughout many communities in the area.

With eventual rainfall totals surpassing seven inches in the Zumbro Watershed, the river swelled to historic levels. By noon on September 23, 2010, flood waters had washed away the north embankment of the Oronoco Dam and had heavily damaged the bridge on Minnesota Avenue.

Restoration Project

The Zumbro River Restoration Project received $4.1 million in funding from the State of Minnesota, Olmsted County, and the City of Oronoco. Construction began in November 2016 and ultimately transformed the lakebed into a public space that provides a variety of recreational opportunities. The dam was replaced by a rock arch rapids, the stream restored to natural meanders, and excess sediment was placed out of the floodway so it could not be washed downstream. 

Zumbro River Restoration Project (8 MB)



For More Information, Contact:
Caitlin Brady, Water Resources Coordinator
Olmsted County Environmental Resources
2122 Campus Drive SE, Ste 200
Rochester, MN 55904
507 328-7070

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