Whitmer ordered the Michigan Department of Environment, Great Lakes and Energy to look into the May 19 failures of the Edenville and Sanford dams, operated by Boyce Hydro.
"I'm committed to doing everything I can to hold those responsible for the dams' safety accountable," she told reporters in Midland, one of the communities that was submerged. "I also asked EGLE to review the issue of dam safety in Michigan and provide recommendations on policy, legislative and enforcement reforms that can prevent these harms from being repeated elsewhere."
Boyce Hydro did not responded to an email seeking comment.
Heavy rain preceded the dam troubles along the Tittabawassee River and connected lakes in Midland County. The National Weather Service had urged all who lived near the river to seek higher ground. Scores of homes and businesses were destroyed or damaged by the rising river water.
"Experts are saying that this is a 500-year event," Whitmer said Wednesday. "It's going to have a major impact on Midland County and beyond for the time to come."
Some residents have filed civil lawsuits against Boyce Hydro seeking damages. EGLE and the Michigan Department of Natural Resources also have been named as a defendants in a civil lawsuit.
Boyce Hydro's license for the nearly century-old Edenville Dam at Wixom Lake was revoked in 2018 by federal regulations over safety violations. The Federal Energy Regulatory Commission said it repeatedly raised concerns about the dam's ability to prevent flooding during extreme conditions because of its inadequate spillway capacity.
The company twice lowered Wixom Lake's level without permission after the federal license was revoked, according to EGLE, which has overseen the Edenville barrier since the federal license was withdrawn.
A lawsuit filed April 30 says the lengthy drawdowns in 2018 and 2019 killed "thousands, if not millions" of freshwater mussels, many listed as endangered species.
Boyce Hydro said in a statement last week that the sale of electricity generated by the dams was not enough to make probable maximum flood improvements required by the Federal Energy Regulatory Commission. The company also said had it been allowed to maintain the Edenville Dam at run of river levels "the dam would have been able to handle and safely pass the volume of water generated by this storm."
"There are a lot of problems that come with the owner of this particular dam," Whitmer said. "There is a lot of information out there that is not exactly accurate, one of which is the assumption that it was the state that said to raise the levels."
"Now, of course they have all sorts of ecological concerns, but it also was because of a court order is my understanding," she continued. "That's precisely why it's important that we get the facts, we share the results of the investigation so that people can understand all of the different actions or non-actions that contributed to the failing of these two dams."
Last week, Michigan Republican Party Chair Laura Cox said in a news elease that Attorney General Dana Nessel should recuse her office from investigating the Edenville Dam failure and transfer her inquiry to federal authorities.
When asked if a third party should be brought in to investigate, Whitmer said she was following procedure in having EGLE conduct the investigation.
"We have to go to the agency that has the expertise," she said. "There are very few that have the kind of expertise that is really needed to be able to properly do this investigation."