Imminent Failure of Rapidan Dam Raises Alarm in Blue Earth County, Minnesota
Blue Earth County, Minnesota, is facing a significant threat as the Rapidan Dam is currently in an “imminent failure condition” due to accumulating debris and rising floodwaters.
This situation has been closely monitored by local authorities and emergency management teams since Sunday, as they work to mitigate potential downstream impacts and ensure public safety.
The alert regarding the dam’s precarious state was initially posted on Blue Earth County’s official Facebook page.
The county’s emergency management was informed of the accumulating debris, which includes contributions from Xcel Energy and other county infrastructure, exacerbating the strain on the dam. The situation has prompted continuous monitoring by Blue Earth County Public Works, Emergency Management, and the Sheriff’s Offices.
To address the immediate threat, North Mankato officials have declared a flood emergency. Crews are constructing a temporary earthen levee at the intersection of Lookout Drive and Lee Boulevard to protect the lower areas of North Mankato.
This precautionary measure highlights the urgency of the situation, as city officials continue to monitor the river levels and adjust their response accordingly.
The Rapidan Dam, constructed between 1908 and 1910, stands about 475 feet long and 87 feet tall from the stream bed.
Over the years, the dam has faced several significant flooding events, notably in March 2019 and March 2020, which have raised questions about its structural integrity. In 2021, local engineers conducted a thorough review to determine its future viability.
Currently, the river has significantly eroded the west side of the dam. Authorities are unsure whether the dam will fail completely or remain intact, but they have deemed it necessary to notify downstream residents and relevant agencies of the potential risk.
The flooding has already had tangible impacts on local infrastructure. An Xcel Energy substation at Rapidan was washed away, resulting in power outages for approximately 600 customers. Xcel Energy crews are on-site, working to deploy a mobile unit to restore power to the affected areas.
Bridges on County Road 33 and County Road 90 are being closely monitored for debris. While they remain open as of now, closures may be implemented if the situation worsens.
These bridges are crucial for local transportation and any disruption could significantly impact daily commutes and emergency responses.
The imminent failure of the Rapidan Dam is part of a broader pattern of severe flooding across southern Minnesota. Recent storms have brought unprecedented rainfall, with some areas receiving a month’s worth of rain in just 48 hours.
Cities like North Mankato and Waterville are experiencing historic flooding, with local lakes and rivers, such as the Cannon River, reaching uncontrollable levels.
In response to the widespread flooding, communities are rallying together. For instance, volunteers in Dundas helped sandbag Memorial Field, although the effort was insufficient to keep the infield dry. Public health officials are also issuing warnings about floodwater contamination and organizing drop-off points for flood-damaged items .
Governor Tim Walz and state emergency officials are actively monitoring the situation at the Rapidan Dam and the broader flooding events.
The state’s Homeland Security and Emergency Management Director, Kristi Rollwagen, emphasized the ongoing efforts to support local officials and maintain communication infrastructure in the affected areas.
Additionally, state and federal legislators, including Senators Amy Klobuchar and Tina Smith, along with Congresswoman Angie Craig, have visited affected areas, pledging to secure federal resources to aid in recovery efforts.