(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 in accordance with the FEMA Technical Bulletin 2, Flood Damage-Resistant Materials Requirements.
(3) All new construction and substantial improvements shall be constructed by methods and practices that minimize flood damages.
(4) All new electrical, heating, ventilation, plumbing, air conditioning equipment, and other service equipment shall be located at or above the RFPE or designed and installed to prevent water from entering or accumulating within the components during the occurrence of the base flood. These include, but are not limited to, HVAC equipment, water softener units, bath/kitchen fixtures, ductwork, electric/gas meter panels/boxes, utility/cable boxes, hot water heaters, and electric outlets/switches.
(5) Replacements part of a substantial improvement, electrical, heating, ventilation, plumbing, air conditioning equipment, and other service equipment shall also meet the above provisions.
(6) Replacements that are for maintenance and not part of a substantial improvement, may be installed at the original location provided the addition and/or improvements only comply with the standards for new construction consistent with the code and requirements for the original structure.
(7) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system.
(8) 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.
(9) On-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding.
(10) 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 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 subchapter.
(11) 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 § 154.535(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 in accordance with the provisions of § 154.535(B)(3).
(12) All subdivision proposals and other development proposals shall be consistent with the need to minimize flood damage.
(13) 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.
(14) All subdivision proposals and other development proposals shall have adequate drainage provided to reduce exposure to flood hazards.
(15) 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.
(16) 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.
(17) When a structure is located in a flood hazard risk zone with multiple base flood elevations, the provisions for the more restrictive flood hazard risk zone and the highest BFE shall apply.
(18) Buildings and structures that are located in more than one flood hazard area shall comply with the provisions associated with the most restrictive flood hazard area.
(B) Specific standards. In all special flood hazard areas where BFE data has been provided, as set forth in § 154.534(B), or division (C) below of this section, the following provisions, in addition to the provisions of division (A) above of this section, are required:
(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 § 154.533 of this subchapter.
(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 § 154.533 of this subchapter. Structures located in Zones A, AE, AH, AO, and A1-30 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 division (F)(2) below of this section. A registered professional engineer or architect shall certify that the floodproofing standards of this section are satisfied. Such certification shall be provided to the Floodplain Administrator as set forth in § 154.535(B)(3), along with the operational plan and the inspection and maintenance plan.
(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 § 154.533 of this subchapter.
(b) Manufactured homes shall be securely anchored to an adequately anchored foundation to resist flotation, collapse, and lateral movement, either by certified engineered foundation system, or in accordance with the most 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 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 36 inches in height, an engineering certification is required.
(c) All enclosures or skirting below the lowest floor shall meet the requirements of Article division (B)(4) below of this section.
(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 area, of new construction and substantially improved structures, which is 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 not be temperature-controlled or conditioned;
(c) Shall be constructed entirely of flood resistant materials at least to the regulatory flood protection elevation; and
(d) Shall include 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 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 square inch for each square foot of enclosed area subject to flooding;
3. If a building has more than one 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 foot above the higher of the interior or exterior 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 as outlined above.
(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, with modifications/rehabilitations/ improvements to the existing structure or the common wall is structurally modified more than installing a doorway, both the existing structure and the addition must comply with the standards for new construction.
(b) Additions to pre-FIRM or post-FIRM structures that are a substantial improvement with no modifications/rehabilitations/improvements 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 consistent with the code and requirements for the original structure.
2. A substantial improvement, both the existing structure and the addition and/or improvements must comply with the standards for new construction.
(d) Where an 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. Recreational vehicles shall either:
(a) Temporary placement.
1. Be on site for fewer than 180 consecutive days; or
2. 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.)
(b) Permanent placement. Recreational vehicles that do not meet the limitations of temporary placement shall 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 may not exceed three months, renewable up to one 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 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 division (A) above of this section;
(f) All service facilities such as electrical shall be installed in accordance with the provisions of division (A)(4) above of this section; and
(g) Flood openings to facilitate automatic equalization of hydrostatic flood forces shall be provided below regulatory flood protection elevation in conformance with the provisions of division (B)(4)(d) above of this section.
(h) An accessory structure with a footprint less than 150 square feet that satisfies the criteria outlined above is not required to meet the elevation or floodproofing standards of division (B)(2) above. Elevation or floodproofing certifications are required for all other accessory structures in accordance with § 154.535(B)(3).
(9) Tanks. When gas and liquid storage tanks are to be placed within a special flood hazard area, the following criteria shall be met:
(a) Underground tanks. Underground tanks in flood hazard areas shall be anchored to prevent flotation, collapse or lateral movement resulting from hydrodynamic and hydrostatic loads during conditions of the design flood, including the effects of buoyancy assuming the tank is empty;
(b) Above-ground tanks, elevated. Above-ground tanks in flood hazard areas shall be elevated to or above the regulatory flood protection elevation on a supporting structure that is designed to prevent flotation, collapse or lateral movement during conditions of the design flood. Tank-supporting structures shall meet the foundation requirements of the applicable flood hazard area;
(c) Above-ground tanks, not elevated. Above-ground tanks that do not meet the elevation requirements of division (B)(2) of this section shall be permitted in flood hazard areas provided the tanks are designed, constructed, installed, and anchored to resist all flood-related and other loads, including the effects of buoyancy, during conditions of the design flood and without release of contents in the floodwaters or infiltration by floodwaters into the tanks. Tanks shall be designed, constructed, installed, and anchored to resist the potential buoyant and other flood forces acting on an empty tank during design flood conditions.
(d) Tank inlets and vents. Tank inlets, fill openings, outlets and vents shall be:
1. At or above the regulatory flood protection elevation or fitted with covers designed to prevent the inflow of floodwater or outflow of the contents of the tanks during conditions of the design flood; and
2. Anchored to prevent lateral movement resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy, during conditions of the design flood.
(10) Other development.
(a) Fences in regulated floodways and NEAs that have the potential to block the passage of floodwaters, such as stockade fences and wire mesh fences, shall meet the limitations of division (E) below of this section.
(b) Retaining walls, sidewalks and driveways in regulated floodways and NEAs. Retaining walls and sidewalks and driveways that involve the placement of fill in regulated floodways shall meet the limitations of division (E) below of this section.
(c) Roads and watercourse crossings in regulated floodways and NEAs. Roads and watercourse crossings, including roads, bridges, culverts, low-water crossings and similar means for vehicles or pedestrians to travel from one side of a watercourse to the other side, that encroach into regulated floodways shall meet the limitations of division (E) below of this section.
(d) Commercial storage facilities are not considered limited storage as noted in this subchapter and shall be protected to the regulatory flood protection elevation as required for commercial structures.
(C) Standards for floodplains without established base flood elevations. Within the special flood hazard areas designated as Approximate Zone A and established in § 154.534(B), where no BFE data has been provided by FEMA, the following provisions, in addition to the provisions of division (A) above of this section, 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) The BFE used in determining the regulatory flood protection elevation shall be determined based on the following criteria:
(a) When 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 ordinance and shall be elevated or flood proofed in accordance with standards in divisions (A) and (B) above of this section.
(b) When floodway or non-encroachment data is available from a federal, state, or other source, all new construction and substantial improvements within floodway and non-encroachment areas shall also comply with the requirements of divisions (B) and (E) of this section.
(c) All subdivision, manufactured home park and other development proposals shall provide BFE data if development is greater than five acres or has more than 50 lots/manufactured home sites. Such BFE data shall be adopted by reference in accordance with § 154.534(B) and utilized in implementing this subchapter.
(d) When BFE data is not available from a federal, state, or other source as outlined above, the reference level shall be elevated or flood proofed (nonresidential) to or above the regulatory flood protection elevation, as defined in § 154.533. All other applicable provisions of division (B) above of this section shall also apply.
(D) Standards for riverine floodplains with base flood elevations 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 divisions (A) and (B) above of this section; 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.
(E) Floodways and non-encroachment areas. Areas designated as floodways or non-encroachment areas are located within the special flood hazard areas established in § 154.534(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 divisions (A) and (B) above of this section, 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 discharge, 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 within six months of completion of the proposed encroachment.
(2) If division (E)(1) above is satisfied, all development shall comply with all applicable flood hazard reduction provisions of this subchapter.
(3) Manufactured homes may be permitted provided the following provisions are met:
(a) The anchoring and the elevation standards of division (B)(3) above of this section; and
(b) The encroachment standards of division (E)(1) above of this section.
(F) Standards for areas of shallow flooding (Zone AO). Located within the special flood hazard areas established in § 154.534(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. In addition to divisions (A) and (B) above of this section, 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 four feet, above the highest adjacent grade; or at least two 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 Article 5, Section I(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 Article 4, Section B(3) and Article 5, Section B(2).
(3) Adequate drainage paths shall be provided around structures on slopes, to guide floodwaters around and away from proposed structures.
(G) Standards for areas of shallow flooding (Zone AH). Located within the special flood hazard areas established in § 154.534(B), are areas designated as shallow flooding areas. These areas are subject to inundation by 1%-annual-chance shallow flooding (usually areas of ponding) where average depths are one to three feet. Base flood elevations are derived from detailed hydraulic analyses are shown in this zone. In addition to divisions (A) and (B) above of this section, all new construction and substantial improvements shall meet the following requirements: Adequate drainage paths shall be provided around structures on slopes, to guide floodwaters around and away from proposed structures.
(Ord. 23-241, passed 7-18-2023)