It was apparently not a surprise to some people that the dam was in danger. Feds revoked failed Edenville dam’s license in 2018 over inability to handle big floods.
Federal regulators in 2018 revoked the hydro-power generating license for the collapsed Edenville Dam in Midland and Gladwin counties, citing years of failure by the dam’s owners to address safety problems — especially the dam’s ability to withstand a major flood.
The Edenville Dam ruptured Tuesday after heavy rains
There is a short video, 35 seconds or so, at the link above that shows the extent of the flooding.
The details on the dam…
The Edenville Dam is a 6,600-foot [1.25 miles or just over 2 kilometers] earthen embankment up to 54.5 feet in height, spanning both the Tittabawassee and Tobacco Rivers in Midland and Gladwin counties. The dam creates a 2,600-acre reservoir known as Wixom Lake, with a gross storage capacity of about 40,000 acre-feet [4.934×107 cubic meters] of water and a 49-mile-long shoreline when full. The dam was equipped with two, 2.4 megawatt turbine generators and was licensed for hydro-power generation in 1998.
According to the Wiki, the dam was completed in 1925. So probably there were both design and maintenance issues with a dam that old.
Apparently they had been trying for 14 years to get some safety concerns addressed, before they finally revoked the license.
So with no ability to generate power, were the turbines just closed off, and not able to help drain the lake? It doesn’t say anywhere that I can find. And in any event, the dam seems to have been designed only to handle about 50% of the “probable maximum flood.” Which is apparently what they got. Water in that quantity over the spillway caused erosion of the earthen structure, and we see the result.
And while politicians are busy doing all the things that are popular today, like art in the park, and funding cultural centers, or whatever, infrastructure is left to crumble.
A 2018 report card on Michigan dams by the state chapter of the American Society of Civil Engineers found that while the state had improved its D-grade from the society’s 2009 report card, it still had persistent issues.
“There are approximately 2,600 dams in Michigan, of which about two-thirds are older than their typical 50-year design life. In the next five years, about 80 percent of Michigan’s dams will be over 50 years old,” their report stated.
There were 19 high-hazard dams in unsatisfactory or poor condition in Michigan in 2018, ranking 20th among the 45 states and Puerto Rico for which The Associated Press obtained condition assessments.
This won’t be the last dam to fail, or even the last one in Michigan. And I doubt politicians even think about infrastructure.
Nothing lasts forever. And an earthen dam built in 1925 is going to need some maintenance, and maybe even some improvements, and eventually it will need to be replaced. The “What could go wrong?” attitude has got to stop.
There is fairly good video of the breached dam at this link. It is only 35 seconds or so, but part of the video is a clear view of the breach in the dam from an airplane. Not the best video. (People hold your phones horizontal, when taking videos!) but it is clear. There are a few seconds at the end that show the breach from the shore.