Bridge near Rapidan Dam demolished
Bridge near Rapidan Dam demolished
The bridge that runs over the Blue Earth River near the Rapidan Dam was demolished on Wednesday, following last summer's breach that eroded the bridge's foundation.
RAPIDAN TOWNSHIP, Minn. (FOX 9) - Multiple explosions demolished the County Road 9 bridge near the Rapidan Dam after last summer's breach that led to the dam's partial failure.
County Road 9 bridge demolition
What they're saying:
WATCH: Co. Road 9 bridge by Rapidan Dam demolished
Blue Earth County officials shared footage of the County Road 9 bridge demolition on Wednesday. The bridge was set to be replaced after the nearby Rapidam Dam was breached in June 2024. The rushing water destroyed an Xcel Energy substation and caused a home along the bank to fall into the river. The nearby Dam Store was also demolished.
County leaders voted to remove the dam and replace the County Road 9 bridge after both structures were assessed multiple times.
Blue Earth County shared the following statement in a social media post:
"The Blue Earth County Road 9 bridge beams were severed and felled earlier today with explosive charges.
"The roadway surface and majority of the bridge deck was removed over the last several weeks.
"Today's events went as planned.
"In the coming weeks, the contractor will be working on removing the bridge beam debris and demolishing the standing bridge piers."
READ MORE: Rapidan Dam failure: County makes decision on future of dam
This is the latest development in a $10 million plan that Minnesota Governor Tim Walz set aside in the state's infrastructure budget.
READ MORE: Gov. Walz unveils $887 million infrastructure plan at Rapidan Dam
Rapidan Dam partial failure
Video of Rapidan Dam in imminent failure condition
SkyFOX over Rapidan Dam in south central Minnesota. The dam is reported to be in imminent failure condition. The City of North Mankato is building an earthen levee as a precaution and to protect lower North Mankato.
Timeline:
On the evening of Sunday, June 23, the dam was experiencing high flows and additional debris, but was still at adequate capacity.
Around 1:30 a.m. on June 24, there was water overlapping the dam, and at 3 a.m., notifications were sent to regulatory agencies per the requirements of the dam Emergency Action Plan.
On June 24, there was a partial failure of the west abutment, which caused an Xcel Energy substation to wash away, resulting in power outages.
The term "imminent threat" was used as outlined in the County’s Emergency Action Plan.
Water peaked on June 24 at 34,800 cubic feet per second and lowered to 33,000 cubic feet per second as of June 25.
House falls into river at Rapidan Dam
Credit: AW Aerial. Video shows a white house fall into the Blue Earth River at the Rapidan Dam in south central Minnesota.
Blue Earth County Officials said a section of the white house collapsed into the river just before 10 p.m. on June 25, after it was over the edge of an eroded bluff.
The soil under the home had been washed away by the heavy flow of the river that overlapped and eventually breached the west side of the dam.
The homeowners were evacuated before it fell, so no one was injured.
The backstory:
The Rapidan Dam, constructed in 1910, at one time supplied half of Mankato's energy.
By 2024, the dam was well past its lifespan. Civil engineers say concrete can last 50 to 100 years in dams, but maintenance is key. High water events in 1965, 2010, 2019, and 2020 did significant damage and Blue Earth County started considering removing the dam as far back as the year 2000.
Federal inspectors deemed it to be in poor condition two years ago. The county board had been weighing its options for the dam in recent years.
The Source: Footage shared by Blue Earth County officials and past FOX 9 reporting.