Building rules for coastal high hazard areas

Coastal high hazard areas are identified as Zone V or Zone VE on the Flood Insurance Rate Maps. Within coastal high hazard areas, the following standards shall apply: (1) All new construction, improvements to repetitive loss structures, and substantial improvements in a coastal high hazard area shall be constructed with materials and utility equipment resistant to flood damage and using methods and practices that minimize flood damage. (2) New construction, improvements to repetitive loss structures, and substantial improvement shall be elevated on adequately anchored pilings or columns and securely anchored to such pilings or columns so that the lowest horizontal portion of the structural members of the lowest floor, excluding the pilings and columns, is elevated to or above the base flood level. The pile or column foundation and structure attached thereto shall be anchored to resist flotation, collapse, and lateral movement due to the effects of wind and water loads acting simultaneously on all building components. The wind and water loading values shall each have a one percent chance of being equaled or exceeded in any given year. (3) New construction, improvements to repetitive loss structures, and other development shall be located on the landward side of the reach of mean high tide. (4) New construction, improvements to repetitive loss structures, and substantial improvement shall have the enclosed space, if any, below the lowest floor free of obstructions and constructed with breakaway walls as defined in section 27-12. Such enclosed space shall not be used for human habitation and will be useable solely for parking of vehicles, building access, or storage. Machinery and equipment which service the building, such as furnaces, air conditioners, heat pumps, hot water heaters, washers, dryers, elevator lift equipment, electrical junction and circuit boxes, and food freezers are not permitted in such enclosed spaces. The enclosed space must only be achieved with breakaway walls, open wood latticework, or insect screening intended to collapse under wind and water loads without causing collapse, displacement, or other structural damage to the elevated portion of the building or supporting foundation system. A breakaway wall shall have a design safe loading resistance of not less than ten and no more than twenty pounds per 27-23 SUPP. 3 (1-2018) square foot. Use of breakaway walls which exceed a design safe loading resistance of twenty pounds per square foot may be permitted only if a licensed professional structural engineer certifies that the design proposed meets the following conditions: (A) Breakaway wall collapse shall result from a water load less than that which would occur during the base flood; and (B) The elevated portion of the building and supporting foundation system shall not be subject to collapse, displacement, or other structural damage due to the effects of wind and water loads acting simultaneously on all building components (structural and nonstructural). Maximum wind and water loading values to be used in this determination shall each have a one percent chance of being equaled or exceeded in any given year (one- hundred-year mean recurrence interval). (5) Fill shall not be used for structural support of buildings. (6) Man-made alteration of sand dunes and mangroves which would increase potential flood damage is prohibited. (7) All new construction, improvements to repetitive loss structures, development, and substantial improvement within coastal high hazard areas shall be certified as required by section 27-17. (8) Recreational vehicles placed on sites within Zones V and VE on the FIRM shall be elevated and anchored or be on the site for less than one hundred eighty consecutive days or be fully licensed and highway ready. (1993, ord 93-78, sec 3; am 2007, ord 07-169, sec 14; am 2010, ord 10-115, sec 6; am 2017, ord 17-56, sec 10.)27-23