Over 2,500 homes and buildings were damaged by flooding in mid-Michigan on May 19, 2020, when an aging dam failed on the Tittabawassee River, causing the cascading failure of a second dam immediately downstream. Initial reports indicated that as many as 150 homes and businesses were damaged beyond repair. Approximately 11,000 residents were hurriedly evacuated ahead of the flooding that caused as much as $200 million in damages. Fortunately, no deaths or serious injuries were reported.
In any other year, the choices made by Boyce Hydro Power, the owner of the failed dams, and state regulators, working in the Department of Environment, Great Lakes, and Energy, might not have led to the failure of the Edenville and Sanford dams. But a major rainstorm compounded the regulatory and financial storms facing Boyce Hydro, and, together, these factors stressed the dams beyond their breaking point.
The Edenville Dam had survived heavy spring flooding in the past. The National Weather Service reports that 11.89 inches fell on Midland County and 7.69 inches fell in Gladwin County from Sept. 10 to 12, 1986, causing the Great Michigan Flood of 1986.[1] Just three years ago, on June 23, 2017, the NWS reports more than six inches of rain fell across Midland and Bay counties.[2]
Preliminary information from the NWS indicates that from May 17 to 19, 2020, Midland County received 4.7 inches of rain, and Gladwin County received as much as eight inches. Rising water levels in Wixom Lake were compounded by strong winds and waves that eventually led to the failure of the Edenville Dam, washing away a 900-foot section of the earthen embankment.[3]
After this dam failed, a surge of water flowed down the Tittabawassee River, flooding portions of Edenville. Sanford Lake, downstream from Edenville, rose rapidly and soon overtopped the Sanford Dam. The combined power of the rain and water from two lakes flowed through Sanford and then flooded low-lying parts of downtown Midland and portions of Freeland.
The Tittabawassee River, which normally runs at approximately 11 feet, crested at the highest level ever recorded in Midland: 35.05 feet.[4] The rain that fell in the Tittabawassee River watershed was a once in a 200-year event and the resulting flood was a once-in-500- year event.[5]
The growing weight of evidence appears to show that both the dams’ owner and the state agency charged with regulating the dam allowed for the conditions that enabled a historic flood to push the Edenville Dam to rupture.
Rapt media attention has been focused on the increasingly acrimonious legal and verbal battles between government regulators and executives of Boyce Hydro. In the aftermath of the destruction, lawyers and residents of flood-ravaged communities are entering the fray as well. Many are pressing to determine the causes that led to the failure of the two dams. While the legal wrangling continues, the citizens of the flood-ravaged areas are left to rebuild their homes and to try to find a way to restore their communities and the way of life that had grown up around these dams and lakes.