This story originally appeared in Climate news from within and is part of the Climate Table collaboration.
The century-old Rapidan Dam in Minnesota captured national attention Last week, when its partial failure destroyed a home and prompted county officials to demolish an adjacent storeBut it is just one of hundreds of dams in the Upper Midwest in similar or worse condition, according to an analysis of federal data by Inside Climate News.
The incident, which occurred amid days of historic flooding in the Midwest that left two people dead and broke records in at least 10 placeshighlights the growing threat that climate change poses to the country’s aging infrastructure as extreme weather events become more common and severe.
State and federal officials have warned for years that the nation’s nearly 92,000 dams, many of them built in the early 20th century, are increasingly affected by extreme weather, especially in the Midwest. Fifth National Climate AssessmentA study published last year found that annual rainfall increased by 5 to 15 percent across much of the Midwest in the decade leading up to 2021, compared with the decade before. Since 2018, there have been about 30 dam failures or near-failures across the Midwest, according to the assessment.
Most dams in the United States are more than 60 years old, leading to complications such as sediment buildup. That was the case at Rapidan Dam, about 90 miles southwest of the Twin Cities. Too much sediment caused water to flow around the west side of the dam, eroding much of the land.
The National Inventory of Dams, a database managed by the Army Corps of Engineers, classifies the 114-year-old Rapidan as having “significant” hazard potential and being in “poor” condition. Hazard potential indicates the likelihood that a dam failure would threaten human life or cause property damage; “significant” indicates moderate risk and “high” indicates high risk.
An analysis of that database by Inside Climate News found that nearly 4,100 dams nationwide are in poor or unsatisfactory condition and pose a potential threat to human life or property. In Minnesota, Wisconsin and Michigan, nearly 200 dams are in poor condition and 13 are also in poor condition and pose a “high” hazard risk if one of them fails.
“A high-hazard dam means that if it fails, there would likely be loss of life or significant property damage,” said Erin McCombs, regional conservation director for American Rivers, a nonprofit that advocates for dam removal. “Dams that are high-hazard and in poor condition are catastrophes waiting to happen that can and should be prevented.”
Of the 13 high-hazard dams in Minnesota, Wisconsin, and Michigan listed as in poor condition, eight dam owners who responded to Inside Climate News’ questions said their dams did not pose an immediate danger to the public and were inspected frequently, some of them weekly. The owners of the other five, all in Michigan — Portage Plant Dam, Menasha Dam, Manistique Papers Dam, Cornwall Creek Dam, and Little Black River Structure B — did not respond.
Repair, replace or remove?
Many of the country’s failing dams no longer serve any function, such as flood mitigation or electricity generation. As dams near the end of their useful lives and their licenses expire, their owners must decide whether to repair them, replace them or remove them altogether.
Congress allocated approximately 3 billion dollars in the Infrastructure Investment and Jobs Act, enacted in 2021, for dam-related projects. Repairing a dam can often prove too costly for small cities and towns, especially in the long run. Some property owners say replacing or removing dams may be the best option, and that while it may cost more up front, the savings over time make it worth it.