How a Single Dam Failure Triggered a Catastrophic Chain Reaction in Michigan
In May 2020, the Edenville Dam embankment suffered a catastrophic failure during heavy rainfall, draining Wixom Lake and sending a massive wall of water downstream. This surge overwhelmed the Sanford Dam, leading to its subsequent failure. The event forced the evacuation of over 10,000 residents and caused widespread structural damage.
The failure of the 96-year-old Edenville Dam on May 19, 2020, serves as a stark reminder of the vulnerabilities inherent in aging infrastructure. Following the revocation of its hydropower license by the Federal Energy Regulatory Commission, the Michigan Department of Environment, Great Lakes, and Energy assumed regulatory authority for the dam in late 2018. When the heavy rainfall event occurred, the earthen embankment could not withstand the pressure, leading to a breach that fundamentally altered the local landscape.
The resulting flood wave did not stop at the initial site. Because the Edenville breach sent a massive volume of water down the Tittabawassee River, the downstream Sanford Dam was quickly overwhelmed. The structure was overtopped, leading to its own failure. This cascading event highlights the interconnected nature of water management systems, where the failure of one upstream component can rapidly compromise downstream safety measures, regardless of their individual design specifications.
In the aftermath, the scale of the disaster became clear. Official reports indicate that over 11,000 people were evacuated from the surrounding areas of Sanford, Midland, and Saginaw, while approximately 2,500 structures sustained damage from the flooding. An independent forensic team was tasked with investigating the specific mechanics of the collapse, releasing an interim report in September 2021. This investigation focused on identifying the precise causes, including the potential role of rare phenomena specific to earthen dams, to better understand how such a total system failure could occur.
