Coastal high hazard areas are special flood hazard areas established in § 151.07 and designated as Zones VE. These areas have special flood hazards associated with high velocity waters from storm surges or seismic activity and, therefore, all new construction and substantial improvements shall meet the following provisions in addition to the provisions of §§ 151.50 and 151.51:
(A) All new construction and substantial improvements shall be located landward of the reach of mean high tide.
(B) All new construction and substantial improvements shall be elevated so that the bottom of the lowest horizontal structural member of the lowest floor (excluding pilings or columns) is no lower than the regulatory flood protection elevation. Flood proofing shall not be utilized on any structures in coastal high hazard areas to satisfy the regulatory flood protection elevation requirements.
(C) All new construction and substantial improvements shall have the space below the bottom of the lowest horizontal structural member of the lowest floor free of obstruction so as not to impede the flow of flood waters, with the following exceptions:
(1) Open wood or plastic latticework or insect screening may be permitted below the lowest floor for aesthetic purposes only and must be designed to wash away in the event of wave impact and in accordance with the provisions of § 151.51(D)(5). Design plans shall be submitted in accordance with the provisions of § 151.32(A)(4)(c)1.; or
(D) All new construction and substantial improvements shall be securely anchored to pile or column foundations. All pilings and columns and the structure attached thereto shall be anchored to resist flotation, collapse, and lateral movement due to the effect of wind and water loads acting simultaneously on all building components.
(1) Water loading values used shall be those associated with the base flood.
(2) Wind loading values used shall be those required by the current edition of the North Carolina State Building Code.
(E) For concrete pads, including patios, decks, parking pads, walkways, driveways, pool decks, etc., the following is required:
(1) Shall be structurally independent of the primary structural foundation system of the structure and shall not adversely affect structures through redirection of floodwaters or debris;
(2) Shall be constructed to break away cleanly during design flood conditions, shall be frangible, and shall not produce debris capable of causing damage to any structure (Note: The installation of concrete in small segments (approximately 4 feet by 4 feet) that will easily break up during the base flood event, or score concrete in 4 feet by 4 feet maximum segments is acceptable to meet this standard);
(3) Reinforcing, including welded wire fabric, shall not be used in order to minimize the potential for concreted pads being a source of debris; and
(4) Pad thickness:
(a) Shall not exceed 4 inches; or
(b) Be certified by a design professional that the design and method of construction to be used shall be compliant with the applicable criteria of this section.
(5) The provisions above shall not apply to non-residential or multi-family construction that is designed by a professional engineer and constructed with self-supporting structural slabs capable of remaining intact and functional under base flood conditions, included expected erosion.
(F) For swimming pools and spas, the following is required:
(1) Be designed to withstand all flood-related loads and load combinations.
(2) Be elevated so that the lowest horizontal structural member is elevated above the RFPE; or
(3) Be designed and constructed to break away during design flood conditions without producing debris capable of causing damage to any structure; or
(4) Be sited to remain in the ground during design flood conditions without obstructing flow that results in damage to any structure.
(5) Registered design professionals must certify to local officials that a pool or spa beneath or near a VE Zone building will not be subject to flotation or displacement that will damage building foundations or elevated portions of the building or any nearby buildings during a coastal flood.
(G) All elevators, vertical platform lifts, chair lifts, etc., the following is required:
(1) Elevator enclosures must be designed to resist hydrodynamic and hydrostatic forces as well as erosion, scour, and waves.
(2) Utility equipment in coastal high hazard areas (VE Zones) must not be mounted on, pass through, or be located along breakaway walls.
(3) The cab, machine/equipment room, hydraulic pump, hydraulic reservoir, counter weight and roller guides, hoist cable, limit switches, electric hoist motor, electrical junction box, circuit panel, and electrical control panel shall:
(a) Be elevated to or above the regulatory flood protection elevation; or
(b) Constructed using flood damage-resistant components/materials.
(H) A registered professional engineer or architect shall certify that the design, specifications and plans for construction are in compliance with the provisions of §§ 151.32(B)(C) and 151.55 on the current version of the North Carolina V-Zone certification form or equivalent local version. In addition, prior to the certificate of compliance/ occupancy issuance, a registered professional engineer or architect shall certify the finished construction is compliant with the design, specifications and plans for VE Zone construction.
(I) Fill/grading. Fill material shall not be used for structural support of building. Minor grading and the placement of minor quantities of non-structural fill may be permitted for landscaping and for drainage purposes under and around buildings and for support of parking slabs, pool decks, patios and walkways. Fill material shall not prevent free passage of floodwaters and waves beneath elevated buildings. Fill must not divert floodwaters or deflect waves such that increased damage is sustained by adjacent or nearby buildings. FEMA Technical Bulletins may be consulted for appropriate evaluation criteria on the placement of non-structural fill in VE Zones.
(J) There shall be no alteration of sand dunes or mangrove stands which would increase potential flood damage.
(K) No manufactured homes shall be permitted except in an existing manufactured home park or subdivision. A replacement manufactured home may be placed on a lot in an existing manufactured home park or subdivision provided the anchoring and elevation standards of this Section have been satisfied.
(L) Recreational vehicles may be permitted in coastal high hazard areas provided that they meet the recreational vehicle criteria of § 151.51(F).
(M) A deck that is structurally attached to a building or structure shall have the bottom of the lowest horizontal structural member at or above the regulatory flood protection elevation and any supporting members that extend below the regulatory flood protection elevation shall comply with the foundation requirements that apply to the building or structure, which shall be designed to accommodate any increased loads resulting from the attached deck. The increased loads must be considered in the design of the primary structure and included in the V-Zone certification required under § 151.32(C)(6).
(N) A deck or patio that is located below the regulatory flood protection elevation shall be structurally independent from buildings or structures and their foundation systems, and shall be designed and constructed either to remain intact and in place during design flood conditions or to break apart into small pieces to minimize debris during flooding that is capable of causing structural damage to the building or structure or to adjacent buildings and structures.
(O) In coastal high hazard areas, development activities other than buildings and structures shall be permitted only if also authorized by the appropriate state or local authority; if located outside the footprint of, and not structurally attached to, buildings and structures; and if analyses prepared by qualified registered design professionals demonstrate no harmful diversion of floodwaters or wave run-up and wave reflection that would increase damage to adjacent buildings and structures. Such other development activities include, but are not limited to:
(1) Bulkheads, seawalls, retaining walls, revetments, and similar erosion control structures;
(2) Solid fences and privacy walls, and fences prone to trapping debris, unless designed and constructed to fail under flood conditions less than the design flood or otherwise function to avoid obstruction of floodwaters.
(P) Accessory structures, regardless of size or cost, shall not be permitted below elevated structures in VE Zones.
(Ord. passed 9-20-2006; Am. Ord. passed 5-3- 2020)