(A) General standards. In all Special Flood Hazard Areas the following provisions are required:
(1) All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or 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 or 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. These include but are not limited to HVAC equipment, water softener units, bath/kitchen fixtures, ductwork, electric meter panels/boxes, utility/cable boxes, appliances (i.e., washers, dryers, refrigerator, etc.), hot water heaters, electric outlets/switches.
(5) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system.
(6) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters 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 subchapter, shall meet the requirements of "new construction" as contained in this subchapter.
(9) Non-conforming structures or other development may not be enlarged, replaced, or rebuilt unless such enlargement or reconstruction is accomplished in conformance with the provisions of this subchapter. Provided, however, nothing in this subchapter shall prevent the repair, reconstruction, or replacement of a building or structure existing on the effective date of this subchapter and located totally or partially within the floodway, non-encroachment area, or stream setback, provided that the bulk of the building or structure below the regulatory flood protection elevation in the floodway, non-encroachment area, or stream setback is not increased and provided that such repair, reconstruction, or replacement meets all of the other requirements of this subchapter.
(10) New solid waste disposal facilities, hazardous waste management facilities, salvage yards, and chemical storage facilities shall not be permitted in Special Flood Hazard Areas. 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 § 154.328(B)(3) of this subchapter.
(1) Residential construction. New construction or 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.
(2) Non-residential construction. New construction or 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. Structures located in A, AO, AE and A1-30 Zones may be floodproofed to the regulatory flood protection elevation in lieu of elevation provided that all areas of the structure below the required 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. A registered professional engineer or architect shall certify that the standards of this division are satisfied. Such certification shall be provided to the official as set forth in § 154.328(B)(3).
(3) Manufactured homes.
(a) New or replacement manufactured homes shall be elevated so that the reference level of the manufactured home is no lower than the regulatory flood protection elevation.
(b) Manufactured homes shall be securely anchored to an adequately anchored foundation to resist flotation, collapse, and lateral movement in accordance with the State of North Carolina Regulations for Manufactured/Mobile Homes, 1995 Edition, and any revision thereto adopted by the Commissioner of Insurance pursuant to G.S. § 143-143.15 or a certified engineered foundation. Additionally, when the elevation would be met by an elevation of the chassis 36 inches or less above the grade at the site, the chassis shall be supported by reinforced piers or other foundation elements of at least equivalent strength. When the elevation of the chassis is above 36 inches in height, an engineering certification is required.
(c) All foundation enclosures or skirting shall be in accordance with § 154.329(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. New construction or substantial improvements of elevated buildings that include fully enclosed areas that are below the regulatory flood protection elevation shall not be designed to be used for human habitation, but shall be designed to be used only for parking of vehicles, building access, or limited storage of maintenance equipment used in connection with the premises, be constructed entirely of flood resistant materials below the regulatory flood protection level in A, AO, AE, and A1-30 zones and meet the following design criteria:
(a) Measures for complying with this requirement shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. To meet this requirement, the foundation must either be certified by a professional engineer or architect or meet the following minimum design criteria:
1. Provide a minimum of two openings on different sides of each enclosed area subject to flooding;
2. The total net area of all openings must be at least one square inch for each square foot of each enclosed area subject to flooding;
3. If a building has more than one enclosed area, each area must have openings on exterior walls to allow floodwater to directly enter;
4. The bottom of all required openings shall be no higher than one foot above the adjacent grade; and
5. Openings may be equipped with screens, louvers, or other opening coverings or devices provided they permit the automatic flow of floodwaters in both directions.
6. Foundation enclosures:
a. Vinyl or sheet metal skirting is not considered an enclosure for regulatory and flood insurance rating purposes. Therefore such skirting does not require hydrostatic openings as outlined above.
b. Masonry or wood underpinning, regardless of structural status, is considered an enclosure and requires hydrostatic openings as outlined above to comply with this subchapter.
(b) Access to the enclosed area shall be the minimum necessary to allow for parking of vehicles (garage door) or limited storage of maintenance equipment used in connection with the premises (standard exterior door) or entry to the living area (stairway or elevator). The interior portion of such enclosed area shall not be partitioned or finished into separate rooms, except to enclose storage areas.
(5) Additions/improvements.
(a) Additions and/or improvements to pre-FIRM structures whereas the addition and/or improvements in combination with any interior modifications to the existing structure.
1. Are 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. Are 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 shall require only the addition to comply with the standards for new construction.
(c) Additions and/or improvements to post-FIRM structures whereas the addition and/or improvements in combination with any interior modifications to the existing structure:
1. Are not a substantial improvement, the addition and/or improvements only must comply with the standards for new construction.
2. Are a substantial improvement, both the existing structure and the addition and/or improvements must comply with the standards for new construction.
(d) Where a fire wall or independent perimeter load-bearing wall is provided between the addition and the existing building, the addition(s) shall be considered a separate building and only the addition must comply with the standards for new construction.
(6) Recreational vehicles. Recreation vehicles placed on sites within a Special Flood Hazard Area shall either:
(a) Be on site for fewer than 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
(7) Temporary structures. Prior to the issuance of a floodplain development permit for a temporary structure, the following requirements must be met:
(a) Applicants must submit to the Floodplain Administrator a plan for the removal of such structure(s) in the event of a hurricane or flash flood warning notification. The plan must include the following information:
1. A specified time period for which the temporary use will be permitted;
2. The name, address, and phone number of the individual responsible for the removal of the temporary structure;
3. The time frame prior to the event at which a structure will be removed (i.e. minimum of 72 hours before landfall of a hurricane or immediately upon flood warning notification);
4. A copy of the contract or other suitable instrument with a trucking company to insure the availability of removal equipment when needed; and
5. Designation, accompanied by documentation, of a location outside the Special Flood Hazard Area to which the temporary structure will be moved.
(b) The above information shall be submitted in writing to the Floodplain Administrator for review and written approval.
(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 work, sleeping, living, cooking or restroom areas);
(b) Accessory structures shall be designed to have low flood damage potential;
(c) Accessory structures shall be constructed and placed on the building site so as to offer the minimum resistance to the flow of floodwaters;
(d) Accessory structures shall be firmly anchored in accordance with § 154.329(A)(1);
(e) All service facilities such as electrical and heating equipment shall be installed in accordance with § 154.329(A)(4); and
(f) Openings to relieve hydrostatic pressure during a flood shall be provided below regulatory flood protection elevation in conformance with § 154.329(B)(4)(a).
(g) An accessory structure with a footprint less than 150 square feet does not require an elevation or floodproofing certificate. Elevation or floodproofing certifications are required for all other accessory structures in accordance with § 154.328(B)(3).
(C) Subdivisions, manufactured home parks and major developments. All subdivision, manufactured home park and major development proposals located within Special Flood Hazard Areas shall:
(1) Be consistent with the need to minimize flood damage;
(2) Have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize flood damage;
(3) Have adequate drainage provided to reduce exposure to flood hazards; and
(4) Have Base Flood Elevation (BFE) data provided if development is greater than the lesser of five acres or 50 lots/manufactured home sites. Such Base Flood Elevation (BFE) data shall be adopted by reference per § 154.328(B) to be utilized in implementing this code.
(D) Standards for floodplains without established Base Flood Elevations. Within the Special Flood Hazard Areas established in § 154.328(B), where no Base Flood Elevation (BFE) data has been provided, the following provisions shall apply:
(1) No encroachments, including fill, new construction, substantial improvements or new development shall be permitted within a distance of 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) If § 154.329(C)(1) is satisfied and 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 subchapter and shall be elevated or floodproofed in accordance with elevations established in accordance with § 154.328(C)(11) and (12). When Base Flood Elevation (BFE) data is not available from a federal, state, or other source, the reference level, including basement, shall be elevated at least two feet above the highest adjacent grade.
(E) Standards for floodplains with BFE but without established floodways or non-encroachment areas. Along rivers and streams where Base Flood Elevation (BFE) data is provided but neither floodway nor non-encroachment areas are identified for a Special Flood Hazard Area on the FIRM or in the FIS, 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. Located within the Special Flood Hazard Areas established in § 154.327(B) are areas designated as floodways or non-encroachment areas. 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 shall apply to all development within such areas:
(1) No encroachments, including fill, new construction, substantial improvements and other developments shall be permitted unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment would not result in any increase in the flood levels during the occurrence of the base flood. Such certification and technical data shall be presented to the Floodplain Administrator prior to issuance of floodplain development permit.
(2) If § 154.329(F)(1) is satisfied, all development shall comply with all applicable flood hazard reduction provisions of this subchapter.
(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 § 154.329(B)(3); and
(b) The no encroachment standards of § 154.329(F)(1) are met.
(G) Standards for areas of shallow flooding (AO Zones). Located within the Special Flood Hazard Areas established in § 154.327(B), are areas designated as shallow flooding areas. These areas have special flood hazards associated with base flood depths of one to three feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and indeterminate. The following provisions shall apply within such areas:
(1) All new construction and substantial improvements of all structures shall have the lowest floor, including basement, elevated to the depth number specified on the Flood Insurance Rate Map (FIRM), in feet, above the highest adjacent grade. If no depth number is specified, the lowest floor, including basement, shall be elevated at least to the regulatory flood protection elevation as defined for the Special Flood Hazard Areas where no BFE has been established.
(2) All new construction and substantial improvements of non-residential structures shall have the option to, in lieu of elevation, be completely floodproofed together with attendant utilities and sanitary facilities to or above that level so that any space below that level is 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 as per § 154.328(B)(3) and § 154.329(B)(2).
(1989 Code, Title V, Ch. 51, Art. XXI, § 2105) (Ord. passed 11-11-2003; Ord. 2021-03, passed 6-8-2021)