SAME MSP Post and MNAFPM Joint Meeting

After an unprecedented wet spring throughout the state of Minnesota, the Rapidan Dam near Mankato, MN, suffered an uncontrolled breach in late June 2024, when the dam was both overtopped and breached near its western abutment. Early in the breach’s timeline, the dam’s owner, Blue Earth County, reached out to the USACE’s St. Paul office for technical assistance as they implemented their emergency management plan; a team of emergency operations, engineers, and geologists was deployed to the site the afternoon of the breach. Directly upstream from the bridge lies MnDOT Bridge 07542, who’s structural stability was drastically affected by the sudden change in stream flow as the Blue Earth River re-directed itself through the bridge and around the dam.

The presentation will focus on the following.

· General Background

· Geology

· Hydraulics

· Repairs

· Event Timeline

· Recent Updates

About the Speaker:

Dan Flittie is a Professional Engineer with the US Army Corps of Engineers, St. Paul District who has 25 years of experience in the heavy Civil Engineering industry. He has held Project Manager and Structural Engineer roles for many city, county, state, and federal agencies, on a variety of flood control, structural, and transportation engineering projects. He is a Registered Professional Engineer in Minnesota and North Dakota.