Bridge near Rapidan Dam at risk for failure, officials say

Severe flooding on the Blue Earth River, which deeply cut down the river elevation and caused the Rapidan Dam to partially fail last week, has now imperiled the County Road 9 bridge, according to officials.

The bridge remains closed to vehicle traffic and is at risk for partial or complete failure, Ryan Thilges, the Blue Earth County public works director, said during a media briefing Tuesday.

"Currently, the county is very concerned about the condition of the bridge," Thilges said, standing alongside Gov. Tim Walz during the governor's latest visit to the community.

Blue Earth County Commissioner Kevin Paap said its a "difficult and overwhelming" time for the community.

"Seeing this today puts a hole in many of our hearts," Paap said, standing near the Rapidan Dam.

The Rapidan Dam Store, a pie shop and diner previously located on the eroded river bank, was acquired by the county and demolished last week.

Prior to the demolition of the business, the home of the Hruska family, which operated the Dam Store, collapsed into the river .

"The Dam Store was an integral part of the community and remains embedded in the memories of many residents," the Blue Earth County Sheriff's Office shared. "Our thoughts are with the Hruska family and everyone close to them."

Future of the County Road 9 bridge

Blue Earth County is among the 22 counties in Minnesota recently approved for a federal disaster declaration and more declarations are expected as damage assessments continue.

Nearly 50 counties have been impacted by the recent flooding statewide.

During Tuesday's media briefing, Thilges and other county officials expressed gratitude for the assistance they've received from local, state and federal partners.

Walz said that support will continue, offering assurances to local leaders in a difficult time when local leaders are facing many unknowns.

One looming question is whether or not the County Road 9 bridge will need to be replaced.

According to Thilges, the bridge piers are constructed on top of sandstone bedrock and the stability of the bridge depends on the sediment that had been impounded into the river basin over the life of the dam.

Officials are concerned about the stability of the bridge now that massive amounts of sediment have washed away, changing how much of a load the bridge takes from the water.

Efforts were made to protect and stabilize one of the bridge piers, but further mitigation efforts were called off due to safety concerns.

Thilges said officials also attempted to conduct an underwater survey, but were unsuccessful due to the turbidity of the water.

The future of the Rapidan Dam is also unclear.

The dam structure itself is still intact, according to Thilges, but the west embankment adjacent to the dam has failed.

Officials have not yet detailed what the ecological impacts of the flooding event might be.