After a massive rainstorm surged through Michigan last week causing two hydro dams to fail, residents engulfed in a flooding emergency are gradually learning details about whether there were warning signs around the nearly century-old infrastructure.
Beginning on May 16, a storm system moved through the State of Michigan, resulting in six to eight inches of rain over a 48-hour period. A state of emergency was declared in Midland County, where some 10,000 residents were evacuated. Emergencies later followed in the counties of Saginaw and Arenac, leading to FEMA’s approval of the governor’s request for federal emergency assistance.
“Thousands of people were forced to evacuate as water surged into their streets, homes and businesses in the county of Midland,” said Gov. Governor Gretchen Whitmer in an official statement. “Despite our efforts, local and state resources have been insufficient to respond to the situation. The availability of equipment and personnel is further limited due to the ongoing effects and response requirements of the coronavirus pandemic.” Whitmer added.
The Sanford Dam collapsed a few hours after the failure of the Edenville Dam upstream.
Gradually, more information about the troubled history of the Edenville Dam, built in 1924, is beginning to circulate. Owned by Boyce Hydro Power, the Edenville Dam had been under scrutiny for years by federal regulators, namely the Federal Energy Regulatory Commission. Edenville’s operators were cited for the dam’s failure to increase project spillway capacity, through which surplus water can be released safely from the dam. This meant the dam was unable to pass a “probable maximum flood” test.
But there were other issues with the dam, according to a document from the Federal Energy Regulatory Commission. The dam’s operators performed unauthorized repairs; performed unauthorized earth-moving activities; failed to file an adequate Public Safety Plan; failed to construct approved recreation facilities; failed to acquire all necessary project property rights; and failed to comply with the Commission’s 1999 Order approving Boyce Hydro’s Water Quality Monitoring Plan.
After 14 years of unresolved issues, Edenville had its hydro power generating license revoked in 2018. Regulatory authority for the Edenville Dam was then transferred to the Michigan Department of Environment, Great Lakes and Energy (EGLE).
In a Federal Energy Regulatory Commission document, Boyce Hydro stated that the probability of a substantial flood occurring in the next 5 to 10 years ranges from 5 to 10 in one million.
Boyce Hydro said it planned to build an auxiliary spillway on the Tittabawassee River and was studying the need for another on the Tobacco River. But the company failed to complete either project.
In a statement following the Edenville Dam collapse, Boyce Hydro Power owners accused Michigan regulators of being more concerned with preserving aquatic life and appeasing property owners than ensuring public safety.