Edenville and Sanford Dam Failures

Prepared by the Embankments, Dams, and Slopes Committee of the Geo-Institute of ASCE. Following heavy rain over 2 days, the Edenville Dam experienced a slope instability on May 19, 2020 and failed catastrophically. Waters released by the breach of the Edenville Dam overwhelmed the Sanford Dam which was overtopped and failed on the morning of May 20, 2020 resulting in the evacuation of 11,000 people in the surrounding areas of Midland, Michigan, and along the Tittabawassee and Tobacco rivers. Edenville and Sanford Dam Failures: Field Reconnaissance Report, GSP 327, presents the results of on-ground and aerial assessments that took place in the weeks following the failures. The team employed aerial reconnaissance using optical, thermal, and LiDAR sensors; geophysical testing including seismic surveys and electrical resistivity surveys; geological reconnaissance to assess the nature of the geological materials; geotechnical sampling and laboratory testing including, moisture, density, grain size distribution, shear strength, and permeability testing; post-failure condition assessments; and reviewed historical documents and pre-failure LiDAR and satellite data. This Geotechnical Special Publication focuses on the application of multi-sensor techniques to collect perishable data immediately after a disaster. It illustrates a range of site characterization technologies and extensive data analysis that will be of interest to practitioners, researchers, and community stakeholders in areas where old earth dams are nearing the end of their design life.