(a) General standards. In all special flood hazard areas the following provisions are required:
(1) All new construction and substantial improvements shall be designed (or modified) and adequately anchored to prevent flotation, collapse, and lateral movement of the structure.
(2) All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.
(3) All new construction and substantial improvements shall be constructed by methods and practices that minimize flood damages.
(4) Electrical, heating, ventilation, plumbing, air conditioning equipment, and other service facilities shall be designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding to the regulatory flood protection elevation. These include, but are not limited to, HVAC equipment, water softener units, bath/kitchen fixtures, ductwork, electric/gas meter panels/boxes, utility/cable boxes, appliances (washers, dryers, refrigerators, freezers, etc.), hot water heaters, and electric outlets/switches.
(5) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system.
(6) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharges from the systems into flood waters.
(7) On-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding.
(8) Any alteration, repair, reconstruction, or improvements to a structure, which is in compliance with the provisions of this chapter, shall meet the requirements of "new construction" as contained in this chapter.
(9) Nothing in this chapter shall prevent the repair, reconstruction, or replacement of a building or structure existing on the effective date of this chapter and located totally or partially within the floodway, non-encroachment area, or stream setback, provided there is no additional encroachment below the regulatory flood protection elevation in the floodway, non-encroachment area, or stream setback, and provided that such repair, reconstruction, or replacement meets all of the other requirements of this chapter.
(10) New solid waste disposal facilities and sites, hazardous waste management facilities, salvage yards, and chemical storage facilities shall not be permitted, except by variance as specified in section 8-4(e)(10). A structure or tank for chemical or fuel storage incidental to an allowed use or to the operation of a water treatment plant or wastewater treatment facility may be located in a special flood hazard area only if the structure or tank is either elevated or floodproofed to at least the regulatory flood protection elevation and certified according to the provisions of section 8-4(b)(3) of this chapter.
(11) All subdivision proposals and other development proposals shall be consistent with the need to minimize flood damage.
(12) All subdivision proposals and other development proposals shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize flood damage.
(13) All subdivision proposals and other development proposals shall have adequate drainage provided to reduce exposure to flood hazards.
(14) All subdivision proposals and other development proposals shall have received all necessary permits from those governmental agencies for which approval is required by federal or state law, including section 404 of the Federal Water Pollution Control Act Amendments of 1972, 33 U.S.C. 1334.
(15) When a structure is partially located in a special flood hazard area, the entire structure shall meet the requirements for new construction and substantial improvements.
(16) When a structure is located in multiple flood hazard zones or in a flood hazard risk zone with multiple base flood elevations, the provisions for the more restrictive flood hazard risk zone and the highest base flood elevation shall apply.
(1) Residential construction. New construction and substantial improvement of any residential structure (including manufactured homes) shall have the reference level, including basement, elevated no lower than the regulatory flood protection elevation, as defined in section 8-2 of this chapter.
(2) Non-residential construction. New construction and substantial improvement of any commercial, industrial, or other non-residential structure shall have the reference level, including basement, elevated no lower than the regulatory flood protection elevation, as defined in section 8-2 of this chapter. Structures located in A, AE, AH, AO, and A1—30 zones may be floodproofed to the regulatory flood protection elevation in lieu of elevation provided that all areas of the structure, together with attendant utility and sanitary facilities, below the regulatory flood protection elevation are watertight with walls substantially impermeable to the passage of water, using structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy. For AO zones, the floodproofing elevation shall be in accordance with section 8-5(h)(3). A registered professional engineer or architect shall certify that the standards of this subsection are satisfied. Such certification shall be provided to the floodplain administrator as set forth in section 8-4(b)(3), along with the operational and maintenance plans.
(3) Manufactured homes.
a. New and replacement manufactured homes shall be elevated so that the reference level of the manufactured home is no lower than the regulatory flood protection elevation, as defined in section 8-2 of this chapter.
b. Manufactured homes shall be securely anchored to an adequately anchored foundation to resist flotation, collapse, and lateral movement, either by certified engineered foundation systems or in accordance with the current Edition of the State of North Carolina Regulations for Manufactured Homes, adopted by the commissioner of insurance pursuant to G.S. 143-143.15. Additionally, when the elevation would be met by an elevation of the chassis thirty-six (36) inches or less above the grade at the site, the chassis shall be supported by reinforced piers or engineered foundation. When the elevation of the chassis is above thirty-six (36) inches in height, an engineering certification is required.
c. All enclosures or skirting below the lowest floor shall meet the requirements of section 8-5(b)(4).
d. An evacuation plan must be developed for evacuation of all residents of all new, substantially improved or substantially damaged manufactured home parks or subdivisions located within flood-prone areas. This plan shall be filed with and approved by the floodplain administrator and the local emergency management coordinator.
(4) Elevated buildings. Fully enclosed areas of new construction and substantially improved structures, which are below the lowest floor:
a. Shall not be designed or used for human habitation, but shall only be used for parking of vehicles, building access, or limited storage of maintenance equipment used in connection with the premises. Access to the enclosed area shall be the minimum necessary to allow for parking of vehicles (garage door) or limited storage of maintenance equipment (standard exterior door), or entry to the living area (stairway or elevator). The interior portion of such enclosed area shall not be finished or partitioned into separate rooms, except to enclose storage areas;
b. Shall be constructed entirely of flood resistant materials at least to the regulatory flood protection elevation;
c. Shall include, in zones A, AO, AE, and A1—30, flood openings to automatically equalize hydrostatic flood forces on walls by allowing for the entry and exit of floodwaters. To meet this requirement, the openings must either be certified by a professional engineer or architect or meet or exceed the following minimum design criteria;
1. A minimum of two (2) flood openings on different sides of each enclosed area subject to flooding;
2. The total net area of all flood openings must be at least one (1) square inch for each square foot of enclosed area subject to flooding;
3. If a building has more than one (1) enclosed area, each enclosed area must have flood openings to allow floodwaters to automatically enter and exit;
4. The bottom of all required flood openings shall be no higher than one (1) foot above the adjacent grade;
5. Flood openings may be equipped with screens, louvers, or other coverings or devices, provided they permit the automatic flow of floodwaters in both directions; and
6. Enclosures made of flexible skirting are not considered enclosures for regulatory purposes, and, therefore, do not require flood openings. Masonry or wood underpinning, regardless of structural status, is considered an enclosure and requires flood openings.
d. Shall, in coastal high hazard areas (zones VE), either be free of obstruction or constructed with breakaway walls, open wood latticework or insect screening, provided they are not part of the structural support of the building and are designed so as to breakaway under abnormally high tides or wave action without causing damage to the elevated portion of the building or supporting foundation system or otherwise jeopardizing the structural integrity of the building. The following design specifications shall be met:
1. Material shall consist of open wood latticework or insect screening; or
2. Breakaway walls shall meet the following design specifications:
(i) Design safe loading resistance shall be not less than ten (10) nor more than twenty (20) pounds per square foot; or
(ii) Breakaway walls that exceed a design safe loading resistance of twenty (20) pounds per square foot (either by design or when so required by state or local codes) shall be certified by a registered professional engineer or architect that the breakaway wall will collapse from a water load less than that which would occur during the base flood event, and 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). The water loading values used shall be those associated with the base flood. The wind loading values used shall be those required by the North Carolina State Building Code.
(5) Additions/improvements.
a. Additions and/or improvements to pre-FIRM structures when the addition and/or improvements in combination with any interior modifications to the existing structure are:
1. Not a substantial improvement, the addition and/or improvements must be designed to minimize flood damages and must not be any more non-conforming than the existing structure.
2. A substantial improvement, both the existing structure and the addition and/or improvements must comply with the standards for new construction.
b. Additions to post-FIRM structures with no modifications to the existing structure other than a standard door in the common wall shall require only the addition to comply with the standards for new construction.
c. Additions and/or improvements to post-FIRM structures when the addition and/or improvements in combination with any interior modifications to the existing structure are:
1. Not a substantial improvement, the addition and/or improvements only must comply with the standards for new construction.
2. A substantial improvement, both the existing structure and the addition and/or improvements must comply with the standards for new construction.
d. Except in VE zones, where an addition to a nonresidential structure has an independent load-bearing perimeter wall adjacent to the existing structure with only minimal changes to the existing structure, the addition shall be considered a separate structure and only the addition must comply with the standards for new construction and substantial improvements.
(6) Recreational vehicles. Recreational vehicles shall either:
a. Be on site for fewer than one hundred eighty (180) consecutive days and be fully licensed and ready for highway use (a recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick disconnect type utilities, and has no permanently attached additions); or
b. Meet all the requirements for new construction.
(7) Temporary non-residential structures. Prior to the issuance of a floodplain development permit for a temporary structure, the applicant must submit to the floodplain administrator a plan for the removal of such structure(s) in the event of a hurricane, flash flood or other type of flood warning notification. The following information shall be submitted in writing to the floodplain administrator for review and written approval:
a. A specified time period for which the temporary use will be permitted. Time specified should not exceed three (3) months, renewable up to one (1) year;
b. The name, address, and phone number of the individual responsible for the removal of the temporary structure;
c. The time frame prior to the event at which a structure will be removed (i.e., minimum of seventy-two (72) hours before landfall of a hurricane or immediately upon flood warning notification);
d. A copy of the contract or other suitable instrument with the entity responsible for physical removal of the structure; and
e. Designation, accompanied by documentation, of a location outside the special flood hazard area, to which the temporary structure will be moved.
(8) Accessory structures. When accessory structures (sheds, detached garages, etc.) are to be placed within a special flood hazard area, the following criteria shall be met:
a. Accessory structures shall not be used for human habitation (including working, sleeping, living, cooking or restroom areas);
b. Accessory structures shall not be temperature-controlled;
c. Accessory structures shall be designed to have low flood damage potential;
d. Accessory structures shall be constructed and placed on the building site so as to offer the minimum resistance to the flow of floodwaters;
e. Accessory structures shall be firmly anchored in accordance with the provisions of section 8-5(a)(1);
f. All service facilities such as electrical shall be installed in accordance with the provisions of section 8-5(a)(4); and
g. Flood openings to facilitate automatic equalization of hydrostatic flood forces shall be provided in conformance with the provisions of section 8-5(b)(4)c.
An accessory structure with a footprint less than one hundred fifty (150) square feet that satisfies the criteria outlined above does not require an elevation or floodproofing certificate. Elevation or floodproofing certifications are required for all other accessory structures in accordance with section 8-4(b)(3).
(c) Reserved.
(d) Standards for floodplains without established base flood elevations. Within the special flood hazard areas designated as approximate zone A and established in section 8-3(b), where no base flood elevation (BFE) data is available, the following provisions, in addition to the provisions of sections 8-5(a) and (b), shall apply:
(1) No encroachments, including fill, new construction, substantial improvements or new development shall be permitted within a distance of twenty (20) feet each side from top of bank or five times the width of the stream, whichever is greater, unless certification with supporting technical data by a registered professional engineer is provided demonstrating that such encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge.
(2) The BFE used in determining the regulatory flood protection elevation shall be determined based on one (1) of the following criteria:
a. When base flood elevation (BFE) data is available from other sources, all new construction and substantial improvements within such areas shall also comply with all applicable provisions of this chapter and shall be elevated or floodproofed in accordance with standards in sections 8-5(a) and (b).
b. All subdivision, manufactured home park and other development proposals shall provide base flood elevation (BFE) data if development is greater than five (5) acres or has more than fifty (50) lots/manufactured home sites. Such base flood elevation (BFE) data shall be adopted by reference in accordance with section 8-3(b) to be utilized in implementing this chapter.
c. When base flood elevation (BFE) data is not available from a federal, state, or other source as outlined above, the reference level shall be elevated to or above the regulatory flood protection elevation, as defined in section 8-2
(e) Standards for riverine floodplains with BFE but without established floodways or non-encroachment areas. Along rivers and streams where BFE data is provided by FEMA or is available from another source but neither floodway nor non-encroachment areas are identified for a special flood hazard area on the FIRM or in the FIS report, the following requirements shall apply to all development within such areas:
(1) Standards of sections 8-5(a) and (b); and
(2) Until a regulatory floodway or non-encroachment area is designated, no encroachments, including fill, new construction, substantial improvements, or other development, shall be permitted unless certification with supporting technical data by a registered professional engineer is provided demonstrating that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than one foot at any point within the community.
(f) Floodways and non-encroachment areas. Areas designated as floodways or non-encroachment areas are located within the special flood hazard areas established in section 8-3(b). The floodways and non-encroachment areas are extremely hazardous areas due to the velocity of floodwaters that have erosion potential and carry debris and potential projectiles. The following provisions, in addition to standards outlined in sections 8-5(a) and (b), shall apply to all development within such areas:
(1) No encroachments, including fill, new construction, substantial improvements and other developments shall be permitted unless:
a. It is demonstrated that the proposed encroachment would not result in any increase in the flood levels during the occurrence of the base flood, based on hydrologic and hydraulic analyses performed in accordance with standard engineering practice and presented to the floodplain administrator prior to issuance of floodplain development permit; or
b. A conditional letter of map revision (CLOMR) has been approved by FEMA. A letter of map revision (LOMR) must also be obtained upon completion of the proposed encroachment.
(2) If section 8-5(f)(1) is satisfied, all development shall comply with all applicable flood hazard reduction provisions of this chapter.
(3) No manufactured homes shall be permitted, except replacement manufactured homes in an existing manufactured home park or subdivision, provided the following provisions are met:
a. The anchoring and the elevation standards of section 8-5(b)(3); and
b. The no encroachment standard of section 8-5(f)(1).
(g) Coastal high hazard areas (zones VE). Coastal high hazard areas are special flood hazard areas established in section 8-3(b), 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 section 8-5(a) and (b):
(1) All new construction and substantial improvement shall:
a. Be located landward of the reach of mean high tide;
b. Be located landward of the first line of stable natural vegetation; and
c. Comply with all applicable CAMA setback requirements.
(2) 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. Floodproofing shall not be utilized on any structures in coastal high hazard areas to satisfy the regulatory flood protection elevation requirements.
(3) All new construction and substantial improvements shall have the space below the lowest floor free of obstruction so as not to impede the flow of flood waters, with the following exceptions:
a. Open wood 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 abnormal wave action and in accordance with the provisions of section 8-5(b)(4)d.1. Design plans shall be submitted in accordance with the provisions of section 8-4(b)(1)d.3.(ii); or
(4) 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.
a. Water loading values used shall be those associated with the base flood.
b. Wind loading values used shall be those required by the current Edition of the North Carolina State Building Code.
(5) A registered professional engineer or architect shall certify that the design, specifications and plans for construction are in compliance with the provisions of section 8-4(b), section 8-5(g)(3), section 8-5(g)(4), and section 8-5(g)(6) of this chapter on the current state "National Flood Insurance Program V-zone certification" form.
(6) Fill shall not be used for structural support. Limited non-compacted and non-stabilized fill may be used outside the perimeter of a building provided it is demonstrated through coastal engineering analysis that the proposed fill would not result in any increase in the base flood elevation and not cause any adverse impacts by wave ramping or deflection to the subject structure or adjacent properties.
(7) There shall be no alteration of sand dunes which would increase potential flood damage.
(8) 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 subsection have been satisfied.
(9) Recreational vehicles may be permitted in coastal high hazard areas provided that they meet the recreational vehicle criteria of section 8-5(b)(6)a.
(h) Standards for areas of shallow flooding (zone AO). Located within the special flood hazard areas established in section 8-3(b), are areas designated as shallow flooding areas. These areas have special flood hazards associated with base flood depths of one (1) to three (3) feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and indeterminate. In addition to section 8-5(a) and (b), all new construction and substantial improvements shall meet the following requirements:
(1) The reference level shall be elevated at least as high as the depth number specified on the flood insurance rate map (FIRM), in feet, plus a freeboard of zero (0) feet, above the highest adjacent grade; or at least two (2) feet above the highest adjacent grade if no depth number is specified.
(2) Non-residential structures may, in lieu of elevation, be floodproofed to the same level as required in section 8-5(h)(1) so that the structure, together with attendant utility and sanitary facilities, below that level shall be watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. Certification is required in accordance with section 8-4(b)(3) and section 8-5(b)(2).
(3) Adequate drainage paths shall be provided around structures on slopes, to guide floodwaters around and away from proposed structures.
(Ord. No. 2007-09, 1-9-07)