TRAVERSE CITY — A string of near-misses at aging dams across northern Michigan could lead to major changes in how the state regulates the safety of more than 2,000 dams throughout Michigan.
Officials monitoring water levels at the Cheboygan Dam announced Friday that flooding had receded enough to remove the structure from the “Ready, Set, Go” evacuation protocol, according to a release from the Cheboygan County Office of Emergency Management.
Black, Burt and Mullet lakes all drain into the river that passes through the dam, and officials said they will keep an eye out for increasing water levels.
State Sen. John Damoose, R-Harbor Springs, told a recent dam safety roundtable in Traverse City that he visited the Cheboygan Dam and couldn’t believe it didn’t fail.
“There was a certain air of hopefulness and trying to present the best story, but there was a sense in the air that this wasn’t going to end well,” Damoose said. “The point is, it only did because so many people rolled up their sleeves and got to work.”
Now, state regulators and lawmakers are questioning everything from how private dam owners are regulated, to whether dams that would pose a threat to life or property if they failed need to be built to higher standards. Luke Trumble, who manages the state Department of Environment, Great Lakes and Energy’s Dam Safety Unit, said he thinks the current 200-year flood requirement for those dams isn’t enough.
PRIVATE DAMS
EGLE Director Phillip Roos led the recent roundtable, where Damoose said lawmakers are considering requirements for private dam owners to show they have the finances to maintain them through their useful lives — if not outlawing private dam ownership outright. He acknowledged it’s a departure from his typically pro-private ownership stance, but the Cheboygan case underscored that something has to change.
In that case, Damoose said a private dam owner wasn’t properly managing the structure, putting the whole city at risk as a result.
“I’m literally willing to consider anything within those two extremes there, because we can’t keep let this happening,” he said.
The lawmaker also stressed other possibilities, like creating a statewide office of emergency management to take over those duties from the Michigan State Police, and shoring up state finances, especially its “rainy day fund.” Other requirements would be more simple, like creating contingency plans for each dam and ensuring that people know what those plans are.
Several ideas that Lansing lawmakers are considering come from a dam safety task force that Gov. Gretchen Whitmer formed after the 2020 Edenville Dam washed out, said Gillian Gainsley, Roos’s chief of staff.
City Mayor Pro Tem Laura Ness pointed out that any change requiring, say, increased frequency of inspections would require more funding from the state so that each agency has the staff it needs. And past dam failures and near-misses reinforces the fact that aging infrastructure is everywhere in Michigan.
NEW WEIR
In Traverse City’s case, Zielinski told the roundtable of federal state, local and tribal officials and experts that the old Union Street Dam would’ve raised upstream water levels by 2 more feet.
That would have caused even more problems at the Traverse City Regional Wastewater Treatment Plant, which can’t discharge as much clean water when Boardman Lake levels are high, Traverse City Municipal Utilities Director Art Krueger said.
Higher upstream levels could have caused the South Airport Road river crossing to wash out, Krueger said. As it was, the Grand Traverse County Road Commission had to close the road there after water overtopped it.
Krueger also was the latest to say the old Union Street Dam most likely would not have survived the mid-April flood.
Jason Plum, AECOM’s engineer of record for the FishPass project, echoed this as well. The new structure was designed to pass at least a 200-year flood, and it handled the huge flow so well because it’s designed to pass water more efficiently as flows increase, he said.
That project included digging out half of the old Union Street Dam and building the weir for its first phase. Plum said the new weir passed 2,300 cubic feet of water per second at the peak of the mid-April floods for 12 to 15 hours, according to best estimates.
That’s 1,000 cubic feet per second more than the highest recorded flow at the same location, said Dan Zielinski, FishPass’s project manager for Great Lakes Fishery Commission. River gauges in place since 1952 previously recorded what would have been a 10- to 15-year flood, but mid-April’s was just shy of a 500-year flood event.
FLOOD AVOIDED
If the old dam had failed, it could’ve caused major flooding downriver — well beyond the inundation of the FishPass construction site and an apartment building’s lower-level parking deck, said Carl Platz, a civil engineer and Great Lakes program manager for the U.S. Army Corps of Engineers.
Upriver, the Boardman Lake would have dropped by 8 feet if the Union Street Dam had failed, Plum said.
Three upstream dams removed between 2012 and 2018 might not have survived, either, said Brett Fessell, Grand Traverse Band of Ottawa and Chippewa Indians’ river ecologist.
He stressed that he’s not an engineer, but pointed to the dams being more than 100 years old if they were still in place at the time of the flooding. If one gave way, it probably would have caused a cascading – and disastrous – effect on downriver dams and road crossings.
“That to me, it speaks to really the importance of taking a close look at which dams, whether they’re serving their purpose or not, and how they’re regulated and how they’re treated, and not just kick the can down the road,” he said. “We end up doing that quite a bit in terms of costly projects.”
The washout of the Keystone Dam in 1962 — previously near where Beitner, Keystone and River roads meet — shows that’s not hyperbole, Platz said.
Estimating the sort of damage such a catastrophe would cause could help lawmakers make a better pitch for dam safety-focused federal funding, Damoose said.
And Ness pointed out that the economic damages of a disaster like the Edenville Dam washout go well beyond flooded homes and businesses.
COMING TOGETHER
Roos said at the end of the roundtable that he wanted to celebrate the success of replacing the Union Street Dam in Traverse City – as well as consider the lessons learned from both the recent floods and the Edenville disaster.
“I think we got a lot of people motivated to try to come together on some things, whether we’ve got to legislation, whether maybe there’s funding, maybe there’s broader issues, I don’t know. That’s what this is about,” he said. “I think this may be one of those issues where we can really come together, it doesn’t matter what party you’re in, whether you’re in the city or work for state.
“It’s a collective issue that’s important to everybody.”