(A) (1) Alternative elevation methods other than the use of fill may be utilized to elevate a structure’s lowest floor above the regulatory flood protection elevation. These alternative methods may include the use of stilts, pilings, parallel walls and the like or above-grade, enclosed areas such as crawl spaces or tuck under garages.
(2) The base or floor of an enclosed area shall be considered above-grade and not a structure’s basement or lowest floor if:
(a) The enclosed area is above-grade on at least one side of the structure;
(b) It is designed to internally flood and is constructed with flood resistant materials; and
(c) It is used solely for parking of vehicles, building access or storage.
(3) The above-noted alternative elevation methods are subject to the following additional standards.
(a) Design and certification. The structure’s design and as-built condition must be certified by a registered professional engineer or architect as being in compliance with the general design standards of the State Building Code and, specifically, that all electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities must be at or above the regulatory flood protection elevation or be designed to prevent flood water from entering or accumulating within these components during times of flooding.
(b) Specific standards for above-grade, enclosed areas. Above-grade, fully enclosed areas such as crawl spaces or tuck-under garages must be designed to internally flood and the design plans must stipulate:
1. A minimum area of openings in the walls where internal flooding is to be used as a floodproofing technique. There shall be a minimum of two openings on at least two sides of the structure and the bottom of all openings shall be no higher than one-foot above grade. The automatic openings shall have a minimum net area of not less than one square inch for every square foot of enclosed area subject to flooding unless a registered professional engineer or architect certifies that a smaller net area would suffice. The automatic openings may be equipped with screens, louvers, valves or other coverings or devices provided that they permit the automatic entry and exit of flood waters without any form of human intervention; and
2. That the enclosed area will be designed of flood resistant materials in accordance with the FP-3 or FP-4 classifications in the State Building Code and shall be used solely for building access, parking of vehicles or storage.
(B) Basements, as defined by § 154.011 of this chapter, shall be subject to the following.
(1) Residential basement construction shall not be allowed below the regulatory flood protection elevation.
(2) Non-residential basements may be allowed below the regulatory flood protection elevation provided the basement is structurally dry floodproofed in accordance with division (C) below.
(C) All areas of non-residential structures including basements to be placed below the regulatory flood protection elevation shall be floodproofed in accordance with the structurally dry floodproofing classifications in the State Building Code. Structurally dry floodproofing must meet the FP-1 or FP-2 floodproofing classification in the State Building Code and this shall require making the structure water-tight with the 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. Structures floodproofed to the FP-3 or FP-4 classification shall not be permitted.
(D) (1) The storage or processing of materials that are, in time of flooding, flammable, explosive or potentially injurious to human, animal or plant life is prohibited.
(2) Storage of other materials or equipment may be allowed if readily removable from the area within the time available after a flood warning and in accordance with a plan approved by the governing body.
(E) The provisions of § 154.059 of this chapter shall also apply.
(Ord. 1475, passed 11-1-2011)