A final independent report from a forensic team backed by the Association of State Dam Safety Officials found that rapid, static liquefaction of earthen embankments caused the May 2020 collapse of the Edenville and downstream Sanford Dams in Michigan.
Heavy rains leading to a rather new phenomenon, static liquefaction of sand embankments, only previously observed in tailings dams led to property damage and flooding in central Michigan.
U.S. dam safety frameworks have helped prevent major calamities, but the May collapse of a 95-year-old Michigan structure shows failure risks remain, with multiple causes.
Now a tropical depression with heavy rainfall, storm slows to a crawl and builds significant flood risk across Carolinas and SW Virginia; power still out for 450,000 Duke Energy customers.