1331.11 NONRESIDENTIAL STRUCTURES.

   (a)   New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall meet the requirements of Section 1331.10(a)-(c) and (e)-(h), and shall either have the lowest floor, including basement, elevated to or above the level of the flood protection elevation; or, together with attendant utility and sanitary facilities, shall meet the following standards:

      (1)    Be dry floodproofed so that the structure is watertight with walls substantially impermeable to the passage of water to the level of the flood protection elevation;

      (2)    Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and

      (3)    Be certified by a registered professional engineer or architect through the use of a Federal Emergency Management Agency Floodproofing Certificate that the design and methods of construction are in accordance with this Section.

   (b)   In Zone AO areas with no elevations specified, the structure shall have the lowest floor, including basement, elevated at least two feet above the highest adjacent natural grade.

   (c)   An exemption to the elevation or dry floodproofing standards may be granted for accessory structures (e.g. detached garages) containing 400 square feet or less in gross floor area. Such structures must meet the encroachment provisions of this Chapter and the following additional standards:

      (1)    They shall not be used for human habitation.

      (2)    They shall be constructed of flood resistant materials;

      (3)   They shall be constructed and placed on the building site so as to offer the minimum resistance to the flow of flood waters.

      (4)   They shall be firmly anchored to prevent flotation.

      (5)    Service facilities, such as electrical and heating equipment, shall be elevated or floodproofed to or above the level of the flood protection elevation; and

      (6)    They shall have a minimum of two openings on different walls having a total net area not less than one square inch for every square foot of enclosed area, and the bottom of all such openings being no higher than one foot above grade. The openings may be equipped with screens, louvers, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.

         (Ord. 10-125. Enacted 11-22-10.)