On Tuesday, May 19, 2020, the result of heavy flooding on the Tittabawassee and Tobacco rivers, the Edenville Dam and Sanford Dam in Midland County, Michigan failed. The Edenville Dam was the first failure. The Sanford Dam, which was downstream of the Edenville Dam, was also a complete breach and total failure. These dams are operated by Boyce Hydro LLC.
Boyce Hydro LLC had been notified for 14 years of deficiencies on the Edenville Dam and after inaction the Federal Energy Regulatory Commission revoked their license in September 2018 over unaddressed safety problems, such as not having sufficient spillway capabilities during a flood event. This revoked license however did not address the deficiencies as the Michigan Department of Environment, Great lakes and Energy (EGLE) classified the dam as “fair” in 2018, but also expressed concern over the spillway. The owner of the dams has said their inaction to fix the dam is due to a lack of funds.
“Michigan has more than 2,500 dams, ranging from small berms making tiny ponds at hunting cabins Up North to larger hydro-dams like the Edenville and Sanford dams that failed in Midland County last week, causing the evacuation of 10,000 people and creating a disaster area.
Some 1,061 of Michigan’s dams are regulated by the state — many because they are over 6 feet in height and hold back 5 acres of water or more; some because of circuit court orders establishing lake levels. Another 99 Michigan dams that generate hydropower are managed by the Federal Energy Regulatory Commission.”
The article quoted above discussed the State of Michigan’s regulatory capability of monitoring all of the dams and enforcement ability they have for high hazard dams. See more about this discussion here: https://www.freep.com/story/news/local/michigan/2020/05/24/dam-safety-unit-2-staff-supervisor-1000-dams/5247566002/
The AGU Advancing Earth and Space Science Blog has a technical narrative of the Edenville Dam failure from the above video from https://blogs.agu.org/landslideblog/2020/05/21/edenville-dam-failure-2/
The American Society of Civil Engineers (ASCE) has rated Michigan’s dam Report Card as a C-minus in 2018, an improvement from a D in 2009 after several poor rated dams were removed. The report notes that two-thirds of the dams are older than their 50-year design life, and in the next 5 years, 80% of the dams will be older than their design life.
Do you have a dam that needs an inspection or an assessment for maintenance? Reach out to Maurer-Stutz to discuss our Dam Safety services.