Oklahoma City, OK Environmental Rules: Flood Elevation Requirements (2026)

The City Engineer, designated Local Floodplain Administrator under § 16-2, requires new construction and substantial modification of residential buildings, including manufactured homes and accessory buildings, in the 100-year floodplain to have their lowest floor, including any basement, elevated one foot above the 100-year frequency flood level. Nonresidential buildings may instead be floodproofed, including above-ground utility and sanitary equipment, up to that same one-foot mark, but a registered Oklahoma engineer must certify the design and submit elevation records to the City Engineer before construction starts. Mechanical and utility equipment must also sit one foot above the 100-year flood level, and a FEMA Elevation Certificate is required once the building is finished.