Indianapolis, IN Environmental Rules: Flood Elevation Requirements (2026)

The freeboard rule sits in Article V of Chapter 565, the flood damage prevention ordinance, and applies throughout the Consolidated City of Indianapolis and Marion County plus the excluded cities of Beech Grove, Lawrence, Southport and Speedway, so the two-foot standard is genuinely countywide (Sec. 565-104). In the floodway fringe, Sec. 565-501(b)(2)a bars erecting, reconstructing, expanding, converting, relocating, restoring or improving a building unless the lowest floor, including any basement, sits at or above the flood protection grade, defined at Sec. 565-201 as base flood elevation (BFE) plus two feet.

Nonresidential structures may substitute structural flood-proofing to that same elevation, but the design must be certified on a flood-proofing certificate by a professional engineer or architect licensed in Indiana (Sec. 565-501(b)(2)b). The same two-foot lowest-floor standard is repeated in the general standards at Sec. 565-502(j) for sites crossed by multiple flood zones or base flood elevations, and in the specific standards at Sec. 565-503 for residential, non-residential, and manufactured-home construction. Every project needs a floodplain development permit from the floodplain administrator, an employee of the division of construction and business services within the Department of Business and Neighborhood Services (Sec.

565-401, 565-303). Larger jobs also carry a floodplain performance surety of one percent of construction cost, never less than $2,000 per building, held until the administrator releases it after reviewing the required elevation or flood-proofing certificates (Sec. 565-502(o)). An applicant who disputes the administrator's call has ten calendar days to file a written notice of appeal by certified mail or personal service; the Board of Business and Neighborhood Services hears it at its next regular meeting and must issue a written decision within thirty calendar days (Sec. 565-406).