Ankeny, IA Environmental Rules: Flood Elevation Requirements (2026)

Ankeny Code of Ordinances § 193.01(11)(B)(2)(b) sets the elevation standard for residential construction in the Floodway Fringe (Overlay) Subdistrict: new or substantially improved residential structures must have the lowest floor, including basements, elevated a minimum of one foot above the base flood elevation, built on compacted fill that stays at or above that one-foot elevation at every point and extends at least 18 feet beyond the structure's limits. Piers or extended foundations may substitute for fill only with a conditional use permit from the Board of Adjustment where topography or street grades preclude filling.

Section 193.01(11)(B)(2)(c) applies the same one-foot floor elevation to non-residential buildings, or allows floodproofing certified by an Iowa-registered professional engineer to that level. Sections 193.01(11)(B)(2)(f) and (g) extend the one-foot elevation requirement to electric meters, service panels, water heaters, HVAC equipment, plumbing, gas lines and water and gas meters. Separately, § 193.01(11)(B)(2)(o) requires flood control structural works such as levees and flood walls to provide, at a minimum, protection from the base flood with three feet of design freeboard, plus adequate interior drainage, and any such structural works must be approved by the Iowa Department of Natural Resources.

Detached garages and sheds under 600 square feet are exempt from the one-foot elevation rule under § 193.01(11)(B)(2)(s) if built of flood-resistant material below that line, not used for habitation, anchored against flotation, and vented per the code's opening requirements.