Pima County, AZ Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Governing section
- Pima County Code § 16.26.030
- Freeboard
- 1 foot above base flood elevation
- Applies to
- Unincorporated floodway fringe, A/AO/AE/AH zones
- AO zones
- 1 ft above FIRM depth number, or 2 ft if none
- Flood vents
- 1 sq in per sq ft, openings 1 ft above grade max
- Certification
- Elevation cert required under § 16.20.070
- Appeals
- To Board of Supervisors under Chapter 16.56
Summary
In unincorporated Pima County's floodway fringe and other regulatory floodplain areas, Code § 16.26.030(A) requires new construction and substantial improvements of habitable structures to elevate the lowest floor at least one foot above the base flood elevation. Non-habitable structures can flood-proof instead, and numbered AO zones follow a separate grade-based standard.
A. New construction and substantial improvement of any habitable structure, either residential or nonresidential, shall have the lowest floor, including the basement, or in the case of manufactured housing the lowest structural member, elevated at or above the regulatory flood elevation, which is one-foot above the base flood elevation. Certification of elevation shall be required pursuant to Section 16.20.070. ... E. All new construction and substantial improvements with fully enclosed areas below the regulatory flood elevation that are useable solely for parking of vehicles, building access or limited storage in an area other than a basement and which are subject to flooding shall be constructed of flood resistant materials to the regulatory flood elevation, have all service facilities elevated at or above the regulatory flood elevation, and be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of flood waters.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-64: Contains Supplement, with local legislation through Ordinance 2026-9, passed 7-28-2026, current through 7-28-2026).
Full Breakdown
S. Title 48, Chapter 21), sets the elevation standard for the floodway fringe and other regulatory floodplain areas, including A, AO, AE, AH and A1-30 zones shown on adopted FIRMs. 070. Subsection B sets a separate rule for numbered AO zones: the lowest floor must sit at least one foot above the flood depth number shown on the FIRM, or two feet above adjacent natural grade if no depth number is given. Non-habitable, nonresidential structures may flood-proof instead of elevating under subsection D, but the shell must stay watertight to the regulatory flood elevation, resist hydrostatic and hydrodynamic loads, and be certified by an Arizona registered engineer or architect on a form the floodplain administrator approves.
Subsection E requires any enclosed area below the regulatory flood elevation used only for parking, building access or limited storage to use flood-resistant materials and either engineer-certified design or, at minimum, two openings on different walls totaling at least one square inch of net area per square foot of enclosed area, with each opening's bottom no higher than one foot above grade. 34. 080.
Violations & Fines
Under § 16.08.690, a structure lacking the required elevation certificate or other compliance documentation is presumed to be in violation until the owner produces it. A written finding of noncompliance from the chief engineer, including denial of a permit or a floodplain delineation dispute, may be appealed to the Board of Supervisors sitting as the flood control district board, or a property owner may instead request a variance from the Board through the chief engineer, both under Chapter 16.56 (§ 16.26.090).
Frequently Asked Questions
How much higher than FEMA's base flood elevation does Pima County require?
Does this rule apply inside Tucson?
Can a garage or storage area sit below the required flood elevation?
What if a structure can't be elevated a full foot above base flood?
What happens if a structure lacks proof of compliance?
Sources & Official References
Other rules in Pima County
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