Lawton, OK Environmental Rules: Flood Elevation Requirements (2026)

Division 19A-2-4 of the Lawton Code, Provisions for Flood Hazard Reduction, requires that all new construction and substantial improvements in an area of special flood hazard be designed and anchored to prevent flotation, collapse, or lateral movement from hydrodynamic and hydrostatic loads, built with flood-resistant materials, and built so electrical, heating, plumbing, and HVAC equipment sits at least two feet above the base flood elevation to keep water from entering during flooding under Section 19A-2-4-241(A). Section 19A-2-4-242 sets the specific freeboard standard: both residential and nonresidential structures must have their lowest floor, including any basement, elevated at least two feet above the base flood elevation.

A registered professional engineer, architect, or land surveyor must certify to the floodplain administrator that this standard is met before the city issues a building permit for above-slab construction, and a second certificate is required before a certificate of occupancy is granted. Enclosed areas below the lowest floor used only for parking, access, or storage must have at least two permanent flood openings totaling one square inch per square foot of enclosed area, with the lowest opening no higher than one foot above grade. Manufactured homes placed in Zone A must have the bottom of the I-beam elevated two feet above the base flood elevation and be anchored against flotation and lateral movement by a licensed installer.

In the regulatory floodway, fill, new construction, and other encroachments are prohibited unless hydrologic and hydraulic analysis proves no increase in flood levels under Section 19A-2-4-242(D)(1). 3.