(A) Foundations.
(1) Structures shall be supported on pilings or columns and shall be adequately anchored to such pilings or columns. Pilings shall have adequate soil penetrations to resist the combined wave and wind loads (lateral and uplift). Water loading values used shall be those associated with the base flood. Wind loading values shall be those required by applicable building codes. Pile embedment shall include consideration of decreased resistance capacity caused by scour of soil strata surrounding the piling.
(2) Slabs, pools, pool decks and walkways shall be located and constructed to be structurally independent of structures and their foundations to prevent transfer of flood loads to the structures during conditions of flooding, scour, or erosion from wave-velocity flow conditions, and shall be designed to minimize debris impacts to adjacent properties and public infrastructure.
(B) Elevation requirements.
(1) The bottom of the lowest horizontal structural member that supports the lowest floor shall be located at or above the flood protection elevation.
(2) Basement floors that are below grade on all sides are prohibited.
(3) The space below an elevated building shall either be free-of-obstruction or, if enclosed by walls, shall meet the requirements of division (D) below. [Note: See NFIP Technical Bulletin #5, "Free-of-Obstruction Requirements."]
(C) Certification of design. As required in § 81-15(A)(13), the applicant shall include in the application a certification prepared by a licensed professional engineer or a licensed architect that the design and methods of construction to be used meet the requirements of divisions (A), (B) and (D), and the Building Code.
(D) Enclosures below the lowest floor.
(1) Enclosures below the lowest floor shall be used solely for parking of vehicles, building access or limited storage.
(2) Enclosures below the lowest floor shall be less than 299 square feet in area (exterior measurement).
(3) Walls and partitions are permitted below the elevated floor, provided that such walls and partitions are designed to break away under flood loads and are not part of the structural support of the building or structure. [Note: See NFIP Technical Bulletin #9, "Design and Construction Guidance for Breakaway Walls."]
(4) Electrical, mechanical, and plumbing system components shall not be mounted on or penetrate through walls that are designed to break away under flood loads.
(5) Walls intended to break away under flood loads shall be constructed with insect screening or open lattice, or shall be designed to break away or collapse without causing collapse, displacement or other structural damage to the elevated portion of the building or supporting foundation system. Such walls, framing and connections shall have a design safe loading resistance of not less than ten pounds per square foot and no more than 20 pounds per square foot; or
(6) Where wind loading values of the building code exceed 20 pounds per square foot, the applicant shall submit a certification prepared and sealed by a licensed professional engineer or licensed architect that:
(a) The walls and partitions below the lowest floor have been designed to collapse from a water load less than that which would occur during the base flood.
(b) The elevated portion of the building and supporting foundation system have been designed to withstand the effects of wind and flood loads acting simultaneously on all building components (structural and nonstructural). Water loading values used shall be those associated with the base flood; wind loading values used shall be those required by the Building Code.
(c) In Coastal A Zones, in addition to the requirements of this section, walls below the lowest floor shall have flood openings that meet the requirements of § 81-34(C)(3).
(Ord. 02-2014, passed 4-21-2014)