EGLE assumed regulatory authority for the 96-year-old Edenville Dam in late 2018 after its license to generate hydropower was revoked by the Federal Energy Regulatory Commission. EGLE was in the process of reviewing federal records and conducted an initial inspection in October of 2018, finding that it was in fair structural condition. That preliminary assessment was not intended to determine if the dam met state safety standards. EGLE had concerns that the dam might not have enough spillway capacity – which allows water to flow out of the Wixom Lake impoundment –to meet state requirements, and therefore ordered a comprehensive structural assessment of the dam to help determine if it met state spillway, and other, safety requirements. That study had not been received by EGLE prior to the dam failure.

Additionally, EGLE was working with a local stakeholders group to facilitate their purchase of the dam from its owner, Boyce Hydro. That group, the Four Lakes Task Force, had aggressive plans to upgrade the dam and reacquire its federal hydropower generating license. That purchase was imminent when the failure occurred.

Gov. Gretchen Whitmer has ordered EGLE to coordinate an independent investigation into the causes of the Edenville failure, and to recommend ways that policies, practices, budgeting and other reforms might enhance dam safety in Michigan. EGLE has already initiated the search for an independent investigator, and looks forward to exploring ways Michiganders can be better protected from such risks.

Michigan has approximately 2,523 dams. Of those, 1,153 are regulated by either state (1,059 state) or federal (92) agencies. Some 1,370 smaller dams are not regulated. Of regulated dams, 803 are privately owned and 350 are publicly owned.

Michigan Dams by the Numbers

There are 2 full time EGLE staff dedicated to the safety of Michigan-regulated dams. Out of the 2,521 dams in Michigan, 730 are privately-owned dams regulated by the state, and 329 are publicly-owned dams regulated by the state. 85 state-regulated dams are classified as high hazard, meaning in the event of a breach, there is expectation of severe damage and potential loss of life. Of those dams classified as high hazard, 0 are rated 'unsatisfactory' and 5 are rated in 'poor' condition. All numbers are approximate, as Michigan's dam inventory constantly changes. 

In the 2018 Michigan Infrastructure Report Card, the American Society of Civil Engineers assigned Michigan's dams a C- grade, citing more than $225 million necessary to address the state's aging dams. 271 Michigan dams are over 100 years old. 12% of Michigan dams have a "high" or "significant" hazard potential rating. 67% of Michigan's dams have reached their intended 50-year design life. (Infographic: Michigan Dams by the Numbers)

Background Information

• EGLE's Chronology of Boyce Hydro
• Edenville Dam Failure FAQs - Revised 6/30/2020
• Edenville Dam Emergency Order FAQs - Posted 9/21/2020
• EGLE's Edenville Dam Failure Internal and External Reviews (8/26/2020)

Michigan Regulated Dam Statistics

Database of Michigan Regulated Dams (pdf)

Database of Michigan Regulated Dams (xlsx)

Database of Michigan Regulated Dams (csv)