Coastal high hazard areas (VE and Coastal AE Zones) are located within the areas of special flood hazard. These areas have special flood hazards associated with high velocity waters from tidal surges and hurricane wave wash; therefore, the following provisions shall apply.
(A) Location of structures.
(1) All buildings or structures shall be located landward of reach of the mean high tide.
(2) The placement of manufactured homes shall be prohibited, except in an existing manufactured home park or subdivision. Manufactured homes placed or substantially improved in an existing manufactured home park must meet the construction requirements for coastal high hazard areas provided in § 151.67. All manufactured homes within VE zones shall be placed on a permanent foundation which itself is securely anchored and to which the structure is securely anchored so that it will resist flotation, lateral movement and hydrostatic pressures. Anchoring may include, but not be limited to, the use of over-the-top or frame ties to ground anchors. All manufactured homes within VE zones shall be installed using methods and practices that minimize flood damage. Adequate access and drainage should be provided.
(B) Construction methods.
(1) All new construction, substantial improvement and repair to structures that have sustained substantial damage shall be elevated so that the bottom of the lowest horizontal structural member (excluding pilings, pile caps, and columns) is elevated at least one foot above the base flood elevation (BFE), with all space below the lowest horizontal supporting member open and free of obstruction so as not to impede the flow of water. Basement floors that are below ground on all sides are prohibited.
(2) The bottom of all electrical, plumbing, machinery or other utility equipment that service the structure must be elevated one foot above the BFE and cannot be located below the structure. Any service equipment that must be located below the BFE must be floodproofed to prevent water from entering during conditions of flooding. Electrical, mechanical and plumbing system components are not to be mounted on or penetrate through walls designed to breakaway under flood loads.
(3) To protect the building envelope, an exterior door shall be installed at the top of the stairs that provides access to the lowest floor of the structure. The lowest level in a VE zone structure is not habitable space.
(4) The base of a chimney or fireplace shall not extend below the BFE plus one foot. When vertical support is required, a chimney or fireplace shall be vertically supported on pile or column foundations embedded at least as deep as the rest of the structure foundation or deeper where needed to support the chimney against water and wind loads. The chimney and fireplace system shall be designed to minimize transfer of water and wind loads to the structure or structure foundation.
(5) Structural support.
(a) Pilings or columns used as structural support and the structure attached thereto shall be designed and anchored so as to resist flotation, collapse and lateral movement due to the effects of wind and water loads acting simultaneously on all building components.
(b) There shall be no fill used for structural support. Minor grading and the placement of minor quantities of non-compacted fill shall be permitted for landscaping and drainage purposes under and around buildings, and for support of parking slabs, pool decks, patios and walkways installed at current grade. The fill must wash out from storm surge, thereby rendering the building free of obstruction, prior to generating excessive loading forces, ramping effects, or wave deflection.
(6) Certification. A registered professional engineer or architect shall certify that the design and methods of construction to be used are in accordance with accepted standards of practice for meeting the provisions of § 151.67 with a FEMA V Zone Design Certificate.
(7) Space below the lowest floor.
(a) Any alteration, repair, reconstruction or improvement to a structure started after the enactment of this chapter shall not enclose the space below the lowest floor unless breakaway walls, open wood lattice work, or insect screening are used as provided for in this section.
(b) Non-supporting breakaway walls, open wood lattice work, or insert screening shall be allowed below the lowest floor provided they are 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.
(c) Areas enclosed by breakaway walls shall contain hydraulic flood vents per the requirements of § 151.66(C). For the purpose of this section, a breakaway wall shall have a design safe loading resistance of not less than ten and no more than 20 pounds per square foot. Use of breakaway walls which exceed a design safe loading resistance of 20 pounds per square foot (either by design or when so required by local or state codes) may be permitted only if a registered professional engineer or architect certifies that the designs proposed meet the following conditions:
1. Breakaway wall collapse shall result from a water load less than that which would occur during the base flood; and
2. 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 non-structural). Maximum wind and water loading values to be used in the determination shall each have a 1% chance of being equaled or exceed in any given year (l00 year mean recurrence interval).
(d) If breakaway walls are utilized, such enclosed space shall not be used for human habitation but solely for parking of vehicles, building access, or storage.
(e) Prior to construction, plans for any structure that will have breakaway walls must be submitted to the Zoning Official for approval.
(C) Sand dunes. There shall be no alteration of sand dunes which could increase potential flood damage.
(Ord. passed 6-22-1981; Ord. passed 12-19-1988; Ord. passed 5-31-2022)
Editor’s note:
TM Volume 14, page 122; TM Volume 16, page 262, Amended