Recent dam failures in Michigan are a reminder that humanity’s efforts to hold back rising water with aging infrastructure are not guaranteed to succeed.

The Michigan case, where two dams on the same river failed, makes it hard to point fingers at a single problem. But it provides a particularly well-documented example of what happens when a privately owned dam isn’t maintained. In a blistering piece that appeared in Slate, a former native of Midland writes about the history and current owners of one of the failed dams. The full piece is worth reading because it shows how a private dam owner can avoid making upgrades until it’s too late.

Regulatory failure is also usually a factor in dam failure: In Michigan, there are two dam safety staffers for the whole state and 2,500 dams, the Detroit Free Press reported. In New York, as of 2018, there were 11 staffers looking out for more than 5,800 dams.

In a June 2018 report on dam safety in New York, the state comptroller found that while no New York dams are rated “unsafe,” most do not have a condition rating at all.

There is also another rating for the hazard a dam poses if it fails — so the worst sort of dam is unsafe and high hazard.

In and around the Adirondacks, there are at least 53 high hazard dams, based on data compiled by the comptroller’s office for Clinton, Essex, Franklin, Hamilton, Herkimer, St. Lawrence and Warren Counties. Of those, 20 are privately owned, three are owned by a public utility and the rest are owned, at least in part, by the state or local governments. High hazard is the state’s way of saying a dam’s failure will likely result in widespread or serious damage to homes, infrastructure or the environment in a way that costs lives or lots of money.

According to the comptroller’s data, there weren’t condition ratings for 43 of those dams, five had no deficiencies and another five were considered “unsound.” The “unsound” rating applies to dams like the Penfield Dam in Ironville, which we wrote about a few months ago. It’s considered an intermediate hazard because it “may” rather than is “likely” to cause significant damage if it fails.

Statewide, more than 200 locally owned dams would cost over $300 million to repair.

Dams seem permanent, if they even get noticed, but recent history tells us how fragile they can be. Nine years ago, Hurricane Irene washed away the historic dam at Duck Hole and irrevocably damaged Marcy Dam, which the state then dismantled.

The comptroller’s report notes that even relatively small incidents can have huge costs. As an example, it cites a dam on Hadlock Pond in the Town of Fort Ann that collapsed, even though it had been recently repaired. Homeowners had to be evacuated, homes flooded, a replacement dam cost millions and it took years in court to sort everything out.

We’ll likely be taking a longer look at this in the future, but if there are particular dam safety issues that have come to your attention or that you’re curious about, drop me a line.

Photo: the former Marcy Dam/Almanack archive

Editor’s note: This piece originally appeared in Ry’s weekly “Water Line” newsletter. Click here to sign up.