Areas of shallow flooding are designated as AO or AH Zones within areas of special flood hazard. These shallow flooding areas have special flood hazards with base flood depths of one to three feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and indeterminate, and where velocity flow may be evident. Such flooding is characterized by pond or sheet flow; therefore, in these areas the following provisions shall apply:
(a) All new construction and substantial improvements of residential structures must have the lowest floor (including basement, finished garage, and machinery or equipment servicing the building) elevated two feet above the fully developed base flood elevation or the FEMA regulatory base flood elevation, or two feet above the highest adjacent grade, or two feet above the depth number specified in feet on the FIRM (at least two feet if no depth number is specified), whichever is higher controls.
(b) All new construction and substantial improvement of nonresidential structures shall comply with either (b)(1) or (b)(2) below.
(1) The lowest floor (including basement, finished garage, and machinery or equipment servicing the building) must be elevated two feet above the fully developed base flood elevation or the FEMA regulatory base flood elevation, or two feet above the highest adjacent grade at least as high as the depth number specified in feet on the FIRM (at least two feet if no depth number is specified), whichever is higher controls; or
(2) The structure and attendant utility and sanitary facilities must be floodproofed to or above the controlling elevation described in subsection (b)(1) above, so that below the base specified flood depth in an AO Zone, or below the base blood elevation in an AH Zone, and any space below that elevation 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 effects of buoyancy.
(c) A registered professional engineer, or architect, as applicable, shall submit a certification to the floodplain administrator that the standards of this article are satisfied.
(d) Adequate drainage paths shall be provided around structures on slopes within Zones AH or AO to guide flood waters around and away from proposed structures.
(Ord. 11998, § 1, passed 6-13-1995; Ord. 25350-03-2022, § 1, passed 3-8-2022, eff. 3-23-2022)