As part of a utility company’s resiliency initiative to improve power supply reliability, we designed flood proofing modifications for various at-risk substations located within the floodway/floodplain associated with different flooding sources and waterways. To minimize subsurface utility conflicts, the design at some substation flood walls included a precast concrete block wall system wrapped with an impermeable ethylene propylene diene monomer liner. Other design aspects included ingress/egress openings equipped with a removable flood plank system and a pump station to handle interior drainage. Our flood proofing improvements were fast tracked and involved extensive coordination and permitting with DuPage County, the Metropolitan Water Reclamation District of Greater Chicago, and the Illinois Department of Natural Resources Office of Water Resources.