Sec. 9.3.5. Flood Hazard Reduction Standards

  1. General SFHA Standards
    Work permitted within all SFHAs shall meet the following general standards:
    1. The permitting and enforcement provisions set forth in Article 11.4, Enforcement Provisions.
    2. All new construction and substantial improvements shall be designed (or modified) and adequately anchored to prevent flotation, collapse, or lateral movement of the structure.
    3. 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 (the most recent document shall be utilized).
    4. All new electrical, heating, ventilation, plumbing, air conditioning equipment, and other service facilities shall be designed and/or located at or above the RFPE to prevent water from entering or accumulating within the components during conditions of flooding. Such service facilities or equipment shall include, but are not limited to, HVAC equipment, ductwork, electric/gas meters panels/boxes, utility/cable boxes, appliances (washers, dryers, refrigerators, freezers, etc.), hot water heaters, and electric outlets/switches.
      1. When an existing service facility and/or equipment is proposed to be replaced and is part of a substantial improvement, the electrical, heating, ventilation, plumbing, air conditioning equipment, and/or other service equipment shall meet the above standards in Sec. 9.3.5.A.4.
      2. When an existing service facility and/or equipment is proposed to be replaced and is not part of a substantial improvement, the service facility and/or equipment may be installed at the original location provided the addition and/or improvements comply with the standards for new construction consistent with the City Code and requirements for the original structure.
    5. All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system.
    6. All 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. All new and replacement on-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding.
    8. Nothing in this Article shall prevent the repair, reconstruction, or replacement of a building or structure existing on July 19, 2022 and located totally or partially within the floodway, non-encroachment area, or stream setback, provided there is no additional encroachment below the RFPE 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 Article and Article 11.4.
    9. No chemical storage facilities which store or process acetone, acetylene gas, ammonia, benzene, calcium carbide, carbon disulfide, celluloid, chlorine, gasoline, hydrochloric acid, hydrocyanic acid, magnesium, materials or fuel which are flammable or explosive, nitric acid, oxides of nitrogen, petroleum products, phosphorus, potassium, sodium, sulfur, or any other items which in time of flooding are buoyant or could be injurious to human, animal, or plant life are allowed in any SFHA.
    10. No new solid waste disposal facilities, hazardous waste management facilities, and salvage yards are allowed in any SFHA.
    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, but not limited to, Section 404 of the Federal Water Pollution Control Act Amendments of 1972, 33 U.S.C. 1334.
    15. For new construction and substantial improvements, when a structure is partially located within a SFHA, the entire structure shall meet the SFHA standards for new construction and substantial improvements.
    16. For new construction and substantial improvements, when a structure is in a flood hazard risk zone with multiple BFEs, the standards for the more restrictive flood hazard risk zone and the highest BFE shall apply.
    17. For new construction and substantial improvements, buildings and structures that are in more than one SFHA shall comply with the standards associated with the most restrictive SFHA.
  2. Specific SFHA Standards
    Work permitted within all SFHAs shall meet the following specific standards:
    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 RFPE and meet the provisions of Sec. 11.4.6 and this Article.
    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 RFPE. Structures may be floodproofed to the RFPE in lieu of elevation provided that all areas of the structure, together with attendant utility and sanitary facilities, below the RFPE 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 licensed in the State of North Carolina shall certify that the floodproofing standards of this Article and provisions of Sec. 11.4.6. are satisfied.
    3. Manufactured Homes
      1. All new and replacement manufactured homes placed within a SFHA shall be elevated so that the reference level of the manufactured home is no lower than the RFPE.
      2. All new and replacement manufactured homes placed within a SFHA 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 N.C. Gen. Stat. § 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 signed and sealed by a professional engineer licensed in the State of North Carolina is required.
      3. For new and replacement manufactured homes placed within a SFHA, all enclosures or skirting below the lowest floor shall meet the requirements of Sec. 9.3.5.B.5.
      4. An evacuation plan must be developed for the evacuation of all residents of all new, substantially improved, or substantially damaged manufactured home parks or subdivisions located within a SFHA. This plan shall be filed with and approved by the Floodplain Administrator and the City Emergency Management coordinator.
    4. Recreational Vehicles
      Recreational vehicles placed within a SFHA shall either be for:
      1. Temporary placement and 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 wheels or jacking system, is attached to the site only by quick-disconnect type utilities and security devices, and has no permanently attached additions); or
      2. Permanent placement and meet the requirements for new construction and permitting pursuant to Article 11.4, Enforcement Provisions.
    5. Elevated Buildings
      Fully enclosed areas of new construction and substantially improved structures within a SFHA, which are below the lowest floor:
      1. 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 such enclosed areas 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 living areas (stairway or elevator).
        The interior portions of such enclosed areas shall not be finished or partitioned into separate rooms, except to enclose storage areas;
      2. Shall not be temperature-controlled or conditioned;
      3. Shall be constructed entirely of flood resistant materials at least to the RFPE; and
      4. 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 licensed in the State of North Carolina or meet or exceed the following minimum design criteria:
        1. A minimum of two (2) flood openings in at least two (2) 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 below the RFPE;
        3. The bottom of all required flood openings shall be no higher than one (1) foot above the higher of the interior or exterior adjacent grade;
        4. 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
        5. 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.
    6. Additions/Improvements
      1. The following standards apply to additions and/or improvements to structures located entirely or partially within a SFHA:
        1. If the work proposed is not a substantial improvement, then only the addition and/or improvement shall comply with the standards for new construction as set forth in Sec. 9.3.5 and Sec. 11.4.6.
        2. If the work proposed is a substantial improvement, then both the existing structure and the addition and/or improvement shall comply with the standards for new construction as set forth in Sec. 9.3.5 and Sec. 11.4.6.
      2. The addition and/or improvement standards listed above do not apply to the following:
        1. Any project for improvement of a structure required to correct existing health, sanitary, or safety City Code violations identified by a City inspector and that are the minimum necessary to assume safe living conditions; or
        2. Any alteration of a historic structure provided that the alteration will not preclude the structure’s continued designation as a historic structure.
    7. Temporary Non-residential Structures
      Prior to the issuance of a flood permit for a temporary structure proposed to be placed within a SFHA, the following requirements must be met:
      1. All applicants must submit to the Floodplain Administrator and/or his or her designee prior to the issuance of the flood permit 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 structure will be permitted. Time specified may not exceed three (3) months, renewable up to one (1) year;
        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 any flood warning notification);
        4. A copy of the contract or other suitable instrument with the entity responsible for physical removal of the structure; and
        5. Designation, accompanied by documentation, of a location outside the SFHA, to which the temporary structure will be moved.
    8. Accessory Structures
      When new accessory structures (such as sheds and detached garages) are proposed to be placed within a SFHA, the following criteria shall be met:
      1. Accessory structures shall not be used for human habitation (including work, sleeping, living, cooking or restroom areas);
      2. Accessory structures shall not be temperature-controlled;
      3. Accessory structures shall be designed to have low flood damage potential;
      4. Accessory structures shall be constructed and placed on the property to offer the minimum resistance to the flow of floodwaters;
      5. Accessory structures shall be firmly anchored in accordance with Sec. 9.3.5.A.2.;
      6. All service facilities such as electrical shall be installed in accordance with Sec. 9.3.5.A.4.; and
      7. Flood openings to relieve hydrostatic pressure during a flood shall be provided below the RFPE in conformance with Sec. 9.3.5.B.5.d.
    9. Tanks
      When gas and liquid storage tanks are proposed to be placed within a SFHA, the following criteria shall be met:
      1. Underground Tanks
        Underground tanks in a SFHA 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.
      2. Above-Ground Tanks, Elevated
        Above-ground tanks in a SFHA shall be elevated to or above the RFPE 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 SFHA.
      3. Above-Ground Tanks, Not Elevated
        Above-ground tanks that do not meet the elevation requirements of Sec. 9.3.5.B.2. shall be permitted in SFHAs provided the tanks are designed, constructed, installed, and anchored to resist all flood-related and other loads whether such tanks are empty or contain contents, 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.
      4. Tank Inlets and Vents
        Tank inlets, fill openings, outlets, and vents shall be:
        1. At or above the RFPE 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.