Virtual Assessment Report: Midland Flood Event, Michigan, USA

The Midland flooding event, classified as a 500-year flood, was initiated by record breaking rainfall in central Michigan occurring from May 19th to May 20th, 2020. The extreme amount of precipitation and subsequent flooding resulted in a succession of dam failures and breaches in the region, leading to catastrophic inundation and damage of both urban and rural areas across Arenac, Gladwin, Iosco, Midland, and Saginaw counties, all of which declared a Federal State of Emergency. Even though no fatalities were reported, socio-economic impacts of the Midland flooding event were serious, where approximately 10,000-11,000 residents were evacuated from the Midland region alone. Total economic losses were on the order of $190 million across all five impacted counties. Approximately 2,500 buildings, including homes, businesses, and non-profits were destroyed by the floods. Within the housing sector, initial assessments identified a grand total of 52-260 destroyed homes; 907-2,268 homes with major damage; 740-1,480 homes with minor damage; and 642 affected homes in the disaster area. FEMA’s HAZUS-MH and USEPA’s I-WASTE models were used to predict the types and quantities of debris generated during the Midland flooding event. The total building related debris generation was estimated to range from 337,281 to 25,465,806 tons from the Midland flooding event using HAZUS-MH and I-WASTE, respectively. HAZUS-MH simulations predicted that 2,300 buildings experienced a damage level corresponding to total loss, aligned with field observations. HAZUS-MH greatly overestimated the number of homes that experienced both major and minor damage. Major differences are observed in the outputs of the two models as I-WASTE maintains a disaster independent simulation framework that assumes a worst-case debris generation scenario and also the program includes debris from open space, which is not considered in HAZUS-MH. Debris management pathways for the Midland flooding event were determined to be heavily reliant on the use of municipal solid waste landfills. The close proximity of the Midland landfill eliminated the need for establishing temporary debris staging facilities, which may have contributed to low recycling/reuse diversion rates of generated debris. Several challenges likely precluded the application of recycling and reuse practices following this event, including potential debris contamination, lack of incentives, limited public awareness, and lack of temporary debris management and staging facilities. Overall, a primary recommendation is to develop a regulatory based incentive framework that encourages practical recycling and reuse of disaster waste materials generated from catastrophic flooding events. This project encompasses the products of SUMMEER's virtual response to this disaster event: Virtual Assessment Report (VAR).