A. Residential construction, new or substantial improvement, shall have the lowest floor, including basement:
1. Within a zone designated as AO on the approved floodplain maps on file in the office of the building division, elevated above the highest adjacent grade to a height equal to or exceeding the depth number specified in feet on the flood insurance rate map, or elevated at least two feet above the highest adjacent grade if no depth number is specified.
2. Within a zone designated as A on the approved floodplain maps on file in the office of the building division, elevated to or above the base flood elevation, as determined by the building official.
3. In all other zones, elevated to or above the base flood elevation.
Upon completion of the structure, the elevation of the lowest floor including basement shall be certified by a licensed architect or registered civil engineer, and verified by the building official to be properly elevated.
B. Nonresidential construction, new or substantial improvement, shall either be elevated to conform with Section 16R.37.060-A of this chapter or together with attendant utility and sanitary facilities:
1. Be floodproofed below the elevation required by Section 16R.37.060-A of this chapter so that the structure is watertight with walls substantially impermeable to the passage of water;
2. Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and
3. Be certified by a licensed architect or registered civil engineer that the standards of this section have been satisfied. Such certification shall be provided to the building official.
C. All new construction and substantial improvement with fully enclosed areas below the lowest floor, excluding basements, that are usable 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 floodwater. Designs for meeting this requirement must exceed the following minimum criteria:
1. Be certified by a licensed architect or registered civil engineer; or
2. Have a minimum of two openings having a total net area of not less than one square inch for every foot of enclosed area subject to flooding. The bottom of all openings shall be no higher than one foot above grade. Openings may be equipped with screens, louvers, valves or other coverings or devices provided that they permit the automatic entry and exit of floodwater.
D. Manufactured homes shall also meet the standards in Section 16R.37.080 of this chapter.
(Res. No. 124 96-97)