Blue Mounds State Park:
Lower Mound Lake and Dam

Flood waters in June 2014 overtopped the historic Upper and Lower dams at Blue Mounds State Park and eventually washed out the western spillway of the Lower Dam. This created a breach approximately 100 feet across, draining Lower Mound Lake.

Since 2014, Lower Mound Lake has remained drained and a new stream channel has formed in the former lake bed. This channel is allowing sediment to move downstream and impair water quality. It must be stabilized to prevent further erosion and sedimentation.

DNR staff gathered field data during 2015 to determine the feasibility of reconstructing the dam, lake and a naturalized stream channel. An interdivisional work group then reviewed the research and information to determine impacts and alternatives to removing or rebuilding the dam. After much consideration, two alternatives remain viable future options for the dam site.

Research

The two alternatives were developed based on facts gathered through:

  • Research completed during the summer of 2015 by DNR and US Fish and Wildlife Service personnel, as well as previous years species monitoring efforts.

  • Annually monitored water quality data from Minnesota Pollution Control Agency.

  • Engineering, hydrologic and hydraulics information/graphics as determined by DNR Engineering Unit with assistance from Minnesota Valley Testing Labs, Braun InterTech, DNR Lands and Minerals Division, and DNR Dam Safety Unit.

Overview of the Blue Mounds State Park Dam alternatives

Project

Description

Estimated cost

Mound Creek restoration

One alternative would be total removal of the dam and returning Mound Creek to its' natural meandering flow. Once completed, the creek and floodplain would look and function naturally, similar to before the dam was built in 1937.

$1.4 million

Dam and reservoir restoration

The second alternative would include full restoration of the dam and 20-acre reservoir. Rebuilding the dam to current safety standards would keep it functional, but would compromise its historic appearance and the natural flow of Mound Creek.

$6.1 million

 

Additional information to consider

What does it take to rebuild a dam in 2016?

  • Engineering aspects, costs and maintenance.

Mound Creek Basics 

  • Dynamics of Mound Creek as a prairie stream (habitat, water quality, flood control).

Animals and Plants of Blue Mounds State Park 

  • Blue Mounds prairie as a high quality natural landscape of state and national value.

Blue Mounds State Park Today and Tomorrow 

  • Economics, tourism and changing visitor needs.

Next steps

The public was invited to provide input on the two alternatives for restoring the Blue Mounds State Park dam site. A public meeting was held in Luverne on Feb. 9, 2016 and was attended by approximately 150 people. An online comment period extended to Feb. 15, 2016, for those who were unable to attend the meeting. Public comments from the open house and website are being considered by DNR officials making a decision about how to repair or rehabilitate the dam site. Updates will continue to appear in this section as they become available.

For more information:

Minnesota Department of Natural Resources
Attn: Blue Mounds Dam
21371 State Hwy 15 
New Ulm, MN  56073
[email protected]

Frequently asked questions about the 2014 flooding.

Stream Habitat Program

U.S. Fish and Wildlife Service: