5-2-5-4: STANDARDS FOR SHALLOW FLOODING AREAS:

Shallow flooding areas appear on FIRMs as AO zones with depth designations or as AH zones with base flood elevations. For AO zones the base flood depths range from one (1) to three (3) feet above ground where a clearly defined channel does not exist, or where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is usually characterized as sheet flow. For both AO and AH zones, adequate drainage paths are required around structures on slopes to guide floodwaters around and away from proposed structures.

   A.   Standards For AH Zones: Development within AH zones must comply with the standards in sections 5-2-5-1, 5-2-5-2, and 5-2-5-4A.

   B.   Standards For AO Zones: In AO zones, the following provisions apply in addition to the requirements in sections 5-2-5-1 and 5-2-5-4A.

      1.   New construction and substantial improvement of residential structures and manufactured dwellings within AO zones shall have the lowest floor, including basement, elevated above the highest grade adjacent to the building, at minimum above the depth number specified on the flood insurance rate maps (FIRM) (at least two (2) feet if no depth number is specified). For manufactured dwellings the lowest floor is considered to be the bottom of the longitudinal chassis frame beam.

      2.   New construction and substantial improvements of non-residential structures within AO zones shall either:

         a.   Have the lowest floor (including basement) elevated above the highest adjacent grade of the building site, at minimum above the depth number specified on the flood insurance rate maps (FIRM) (at least two (2) feet if no depth number is specified); or

         b.   Together with attendant utility and sanitary facilities, be completely flood proofed to or above the depth number specified on the FIRM or a minimum of two (2) feet above the highest adjacent grade if no depth number is specified, so that any space below that level is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy. If this method is used, compliance shall be certified by a registered professional engineer or architect as stated in section 5-2-5-2C3.

      3.   Recreational vehicles placed on sites within AO zones on the community’s flood insurance rate maps (FIRM) shall either:

         a.   Be on the site for fewer than one hundred eighty (180) consecutive days; and

         b.   Be fully licensed and ready for highway use, on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions; or

         c.   Meet the elevation requirements of section 5-2-5-4A above, and the anchoring and other requirements for manufactured dwellings of section 5-2-5-2D.

      4.   In AO zones, new and substantially improved appurtenant structures must comply with the standards in section 5-2-5-2F.

      5.   Enclosed areas beneath elevated structures shall comply with the requirements in section 5-2-5-2A. (Ord. 219, 11-13-2019)