(A) 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. The base or floor of an enclosed area shall be considered above-grade and not a structure’s basement or lowest floor if the enclosed area is above-grade on at least one side of the structure, it is designed to internally flood and is constructed with flood-resistant materials and it is used solely for parking of vehicles, building access or storage. The above-noted alternative elevation methods are subject to the following additional standards.
(1) 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’s 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.
(2) 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:
(a) A minimum area of openings in the walls where internal flooding is to be used as a flood proofing 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 floodwaters without any form of human intervention; and
(b) That the enclosed area will be designed of flood-resistant materials in accordance with the FP-3 or FP-4 classifications in the state’s Building Code and shall be used solely for building access, parking of vehicles or storage.
(B) Basements, as defined by § 159.010 of this code, shall be subject to the following.
(1) Residential basement construction shall not be allowed below the regulatory flood protection elevation.
(2) Nonresidential basements may be allowed below the regulatory flood protection elevation provided the basement is structurally dry flood proofed in accordance with division (C) below.
(C) All areas of nonresidential structures including basements to be placed below the regulatory flood protection elevation shall be flood proofed in accordance with the structurally dry flood proofing classifications in the state’s Building Code. Structurally dry flood proofing must meet the FP-1 or FP-2 flood proofing classification in the state’s Building Code and this shall require making the structure watertight 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 flood proofed to the FP-3 or FP-4 classification shall not be permitted.
(D) When at any one time more than 1,000 cubic yards of fill or other similar material is located on a parcel for the activities as on-site storage, landscaping, sand and gravel operations, landfills, roads, dredge spoil disposal or construction of flood control works, an erosion/sedimentation control plan must be submitted unless the community is enforcing a state approved shoreland management ordinance. In the absence of a state approved shoreland ordinance, the plan must clearly specify methods to be used to stabilize the fill on site for a flood event at a minimum of the 100-year or regional flood event. The plan must be prepared and certified by a registered professional engineer or other qualified individual acceptable to the governing body. The plan may incorporate alternative procedures for removal of the material from the floodplain if adequate flood warning time exists.
(E) Storage of materials and equipment shall be subject to the following.
(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.
(F) The provisions of § 159.049 of this code shall also apply.
(Prior Code, § 12-1008) Penalty, see § 159.999