Lake Havasu City, AZ Environmental Rules: Flood Elevation Requirements (2026)

City Code § 8.22.050 defines the Regulatory Flood Elevation (RFE) as an elevation one foot above the base flood elevation (BFE) for a watercourse where the BFE has been determined, or an elevation set by the criteria of the Director of the Arizona Department of Water Resources for watercourses without a determined BFE. That one-foot freeboard is not just a definition; § 8.22.190.A.3 applies it directly to construction. In Zones AE, AH and A1-30, new or substantially improved residential construction must have its lowest floor, including any basement, elevated to or above the RFE.

In an AO Zone, the lowest floor must reach the RFE or be raised at least two feet above the highest adjacent grade if no flood depth number is specified. Manufactured homes must have the bottom of the structural frame, or the lowest point of any attached appliance, at or above the RFE under § 8.22.230.A. Garages attached to a residential structure with a floor below the RFE must be designed to let floodwaters enter automatically, and any portion of an attached or detached accessory structure below the RFE must use flood-resistant materials and have its utility equipment elevated or flood-proofed to the RFE under § 8.22.190.A.6.

Along the Colorado River Floodway Fringe, § 8.22.300.A adds a second freeboard layer: buildings must have their lowest floor at least one foot above the Colorado River Base Flood Elevation specifically, and any fill placed on the lot cannot dip below that elevation within 25 feet of the structure. Upon completion, a registered professional engineer or surveyor must certify the as-built lowest floor elevation to the Floodplain Administrator.