Historic June flooding knocked out a small dam in northeast Minnesota and battered two larger ones, creating dramatic scenes like the tree-clogged Rapidan Dam in the roaring Blue Earth River near Mankato.
The state dodged major consequences, but the episodes drew a national spotlight to what is a common problem in Minnesota and elsewhere: old and creaky dams that are costly to fix, replace or remove.
“Most of these projects were built in the [1930s], so they’re either nearing the end of their life cycle or have reached the end of their life cycle,” said Jason Boyle, who oversees Minnesota’s dams as the state’s top safety engineer. “Some might have been designed not up to current standards.”
Boyle said Minnesota has addressed nearly all of the dams in shaky condition that would be the most dangerous if they collapsed. Failures, however, are not unheard of: State records show 26 dams or related infrastructure have failed in minor and significant ways from 2010 to 2023.
Boyle’s department also has a list of 73 state and locally owned dams in need of $33.6 million in work, mainly to boost safety. At the top of that list is a Nest Lake dam near Spicer, but there are needs across the state. The Coon Rapids Dam in the Twin Cities metro ranks No. 9.
State lawmakers have approved money for dam projects, though inconsistently in recent years. And independent groups have mixed reviews of Minnesota’s infrastructure.