In all areas of special flood hazard, the following standards are required:
(A) Anchoring.
(1) All new construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy; and
(2) All manufactured homes shall meet the anchoring standards of § 151.44(B).
(B) Construction materials and methods.
(1) All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.
(2) All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.
(3) All new construction, substantial improvement and other proposed new development shall be constructed with electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.
(4) Within Zones AH or AO, require that adequate drainage paths around structures on slopes guide flood waters around and away from proposed or existing structures.
(C) Elevation and floodproofing.
(1) Residential construction.
(a) Residential construction, new or substantial improvement, shall have the lowest floor, including basement:
1. In an AO Zone, elevated to or above the regulatory flood elevation, or elevated at least two feet above the highest grade if no depth number is specified.
2. In an A Zone where a BFE has not been determined, elevated to or above the regulatory flood elevation, or elevated in accordance with the criteria developed by the Director of the Arizona Department of Water Resources.
3. In Zones AE, AH and A1-30, elevated to or above the regulatory flood elevation.
(b) Upon completion of the structure, the elevation of the lowest floor, including basement, shall be certified by a registered professional engineer or surveyor, and verified by the community’s building inspector to be properly elevated. Such certification and verification shall be provided to the Floodplain Administrator.
(2) Nonresidential construction. Nonresidential construction, new or substantial improvement, shall either be elevated to conform with § 151.40(C)(1), together with attendant utility and sanitary facilities:
(a) Be floodproofed below the regulatory flood elevation under § 151.40(C)(1) so that the structure is watertight, with walls substantially impermeable to the passage of water;
(b) Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and
(c) Be certified by a registered professional engineer or architect that the standards of this section are satisfied. Such certifications shall be provided to the Floodplain Administrator.
(3) Flood openings. All new construction and substantial improvements with fully enclosed areas below the lowest floor (excluding basements) that are useable solely for parking of vehicles, building access or storage, and which are subject to flooding, shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of flood waters. Designs for meeting this requirement must meet or exceed the following criteria:
(a) Have a minimum of two openings on different sides of each enclosed area, having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding. The bottom of all openings shall be no higher than one foot above grade.
(b) If it is not feasible or desirable to meet the openings criteria stated above, a registered engineer or architect may design and certify the openings.
(5) Garages and low cost accessory structures.
(a) Attached garages.
1. A garage attached to a residential structure, constructed with the garage floor slab below the regulatory flood elevation, must be designed to allow for the automatic entry of flood waters. See § 151.40(C)(3). Areas of the garage below the regulatory flood elevation must be constructed with flood-resistant materials. See § 151.40(B).
2. A garage attached to a nonresidential structure must meet the above requirements or be dry floodproofed.
(b) Detached garages and accessory structures.
1. An “accessory structure” used solely for parking or storage may be constructed so that its floor is below the regulatory flood elevation; provided the structure is designed and constructed in accordance with the following requirements:
a. Use of the accessory structure must be limited to parking or storage;
b. The portions of the accessory structure located below the regulatory flood elevation must be built using flood-resistant materials;
c. The accessory structure must be adequately anchored to prevent flotation, collapse and lateral movement;
d. Any mechanical and utility equipment in the accessory structure must be elevated or floodproofed to or above the regulatory flood elevation;
e. The accessory structure must be designed to allow for the automatic entry of flood waters in accordance with § 151.40(C)(3).
2. Detached garages and accessory structures not meeting the above standards must be constructed in accordance with all applicable standards in § 151.40.
(Res. 1579, passed 1-10-02; Am. Ord. 759, passed 4-2-09; Am. Res. 2477, passed 4-2-09; Am. Ord. 889, passed 5-18-17; Am. Res. 3024, passed 5-18-17) Penalty, see § 151.99