Flooding Triggers Partial Dam Failure in Minnesota, Midwest Road Closures

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flooded highway South Dakota
In South Dakota, the Department of Transportation continues to monitor receding waters, and crews are being mobilized to begin debris cleanup.
South Dakota DOT

Recent heavy rains have forced multiple road closures across three Midwest states and a partial dam failure in Minnesota.

At least 20 rivers in Iowa, Minnesota and South Dakota had reached record-high crests, and two deaths had been reported related to the flooding, according to a Fox Weather report June 26.

Local Government Monitors Minnesota Dam

Flooding in southern Minnesota has put the spotlight on the concrete, gravity Rapidan Dam in the Blue Earth River, which Blue Earth County officials have been monitoring as the river continues to widen due to flooding. According to county officials, the dam, which was built in 1908, experienced a partial failure on its west abutment on June 25.

A house along the Blue Earth River next to the dam collapsed into the water on the morning of June 26, according to a CNN report. 

A Facebook update from the Blue Earth County Sherriff’s Office on the morning of June 26 listed the following information for residents:

“State and Federal partners and contractors have been onsite last evening and this morning assessing the situation. We have seen dramatic changes overnight and this morning as the channel around the west abutment of the dam has continued to cut wider and deeper. There is currently little to no flow through the gates of the dam as the majority of the flow is going around the west side of the dam. Although the waterflow has slowed slightly, the water is still flowing at a rate that inhibits emergency mitigation strategies. The focus has shifted from the dam to the bridge given the recent erosion.”

As of June 26, the Minnesota DOT’s 511 map showed several road closures in downtown Mankato in the south-central portion of the state, as well as closures and detours along highways to the north of Mankato.

flooded i-90 magnolia minnesotaIn Minnesota, heavy rain and flooding are still impacting road conditions.Minnesota DOT

Roads Begin to Reopen in South Dakota

After portions of Interstate 29 in southeast South Dakota were closed on the evening of Sunday, June 23, the South Dakota DOT website showed, as of June 26, that Interstate 29 had reopened north of North Sioux City.

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The South Dakota 511 map, however, still showed 11 road closures due to flooding in southeast South Dakota surrounding Interstate 29.

Iowa Roads Close, Bridge Construction Halted

The video below was posted June 25 to Facebook by the Iowa DOT of flooding at U.S. 20 in Correctionville:

In Iowa, the DOT announced June 19 it was postponing intermittent closures of the Mississippi River Bridge at Lansing until water levels returned to a safe level, which would allow the construction of a new pier and driving the pier foundation for a new bridge.

The Iowa DOT website says, regarding the current Lansing bridge, that “depreciation over time and changing vehicle size and traffic patterns now call for a new, wider, safer crossing.”

On June 22, the Iowa DOT announced several road closures in northwest Iowa due to flooding on primary highways. Two days later, the department closed portions of I-29 and I-680.

As of June 26, the Iowa DOT 511 map showed over a dozen road closures due to flooding in northwest Iowa, as well as several ramps blocked in Sioux City.