Scottsdale, AZ Environmental Rules: Flood Elevation Requirements (2026)

Section 37-5 defines Regulatory Flood Elevation (RFE) as one foot above the base flood elevation for a watercourse where the base flood elevation has been determined, or as set by Arizona Department of Water Resources criteria for other watercourses. Section 37-22(a) applies that freeboard to residential construction: in Zones AE, AH, and A1-30 the lowest floor, including basement, must sit at or above the RFE; in Zone AO it must reach the Regulatory Flood Depth or, absent a depth number, at least two feet above the highest adjacent grade; and in Zone A where no base flood elevation has been set, the lowest floor must meet the RFE or Arizona Department of Water Resources criteria.

S. Army Corps of Engineers' October 1973 Indian Bend Wash Project design memorandum. Section 37-22(b) requires a registered professional engineer or surveyor to certify the as-built lowest floor elevation and RFE or RFD once construction is complete, with that certification reviewed by a city inspector and submitted to the Floodplain Administrator, who under Section 37-15 is the city manager or a designee and must keep the certification on file for public inspection. Nonresidential buildings get an alternative path under Section 37-23: they may either meet the Section 37-22 elevation or be floodproofed below that elevation and certified watertight by an engineer or architect.