Professional services firm Dewberry has been selected by the Federal Emergency Management Agency (FEMA) to assess dozens of South Carolina dams damaged during the October 2015 floods.
The firm said it will help FEMA, the State of South Carolina, community members, and dam owners incorporate resilience, mitigation, and recovery practices during dam repair and reconstruction.
The South Carolina Department of Health and Environmental Control (DHEC) reported 36 dam failures following the October 2015 storm complex that caused 500-year to 1000-year floods. After the waters subsided, DHEC and the US Army Corps of Engineers (USACE) inspected an additional 650 dams across the state and issued more than 240 maintenance notices.
As part of the work Dewberry will coordinate geographic and geologic pre-inspections and records collection to identify risks associated with dam foundations, main structures, and primary and emergency spillways. The firm will reconstruct rainfall radar to determine the storm severity at each site and compare each dam's performance to South Carolina spillway design criteria. Field members will also collect information on dam size, pre- and post-event conditions, operation and maintenance programs, and upstream and downstream watershed conditions to define inundation areas, inventory at-risk assets, and assess future breach potential.
Based on this information, Dewberry said it will recommend feasible and cost-effective mitigation and recovery strategies.