Mid-Michigan dam failures were preventable, report says

MIDLAND CO., Mich. (WNEM) - A five-member panel appointed by federal officials said the catastrophic flooding caused by multiple mid-Michigan dam failures could have been prevented.

In May 2020, multiple dams breached causing unimaginable destruction and flooding that displaced thousands of residents.

During a zoom call Thursday, the independent forensic team investigating the failures of the Edenville and Sanford Dams discussed their findings in a 500-page report. John France, the lead investigator of the IFT said both human and physical factors played a role in the 2020 flood.

“The Edenville and Sanford Dam failures cannot be attributed to a single factor. Rather they’re a result of a combination of factors,” France said. “Since human factors contributed to the failures, they really have to be viewed as preventable. Human actions or inactions were contributors, and had those been different, these failures would not have occurred.”

France said the Edenville Dam was built in the 1920s.

At the time, the construction wasn’t consistent with design plans and specifications. Resulting in embankments with loose sands, making them susceptible to liquefaction. Liquefaction happens when saturated soil loses strength and stiffness and behaves like a liquid.

“If that had not been true, if those embankments had been originally compacted and the sands were denser, the failure of Edenville Dam almost certainly would not have happened,” France said.

France said the rain that fell in the three days before the dam failure came almost all at once. Resulting in Wixom Lake water levels that were three feet higher than any measurement previously recorded.

“Something the neighborhood of ninety percent of it fell with 18 hours at an almost constant rate of 0.22 inches per hour, which is a pretty heavy rate of rainfall,” France said.

The report found the failure could not be attributed to any individual, group or organization. Instead, saying it was the overall system for financing, designing, constructing, operating, and upgrading the four dams that fell short.

“We identify at the end of the report a number of lessons to be learned for our industry,” France said.

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