Section D(5)

Floodplain

• Alterations to compliant buildings

  Any alteration, repair, reconstruction or improvements to a building that is in compliance with the provisions of this section shall meet the requirements of new construction as contained in this section.

• Anchoring

  New construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure.

• Elevated building requirements

  Enclosed areas of new construction or substantially improved structures which are below the regulatory flood protection elevation shall: [1] 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 partitioned or finished into separate rooms, except to enclose storage areas. [2] Be constructed entirely of flood-resistant materials below the regulatory flood protection elevation. [3] Include, in Zones A, AO, AE, and A1-30, measures 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 the following minimum design criteria: [a] Provide a minimum of two openings on different sides of each enclosed area subject to flooding. [b] The total net area of all openings must be at least one square inch for each square foot of enclosed area subject to flooding. [c] If a building has more than one enclosed area, each area must have openings to allow floodwaters to automatically enter and exit. [d] The bottom of all required openings shall be no higher than one foot above the adjacent grade. [e] Openings may be equipped with screens, louvers, or other opening coverings or devices, provided they permit the automatic flow of floodwaters in both directions. [f] Foundation enclosures made of flexible skirting are not considered enclosures for regulatory purposes, and, therefore, do not require openings. Masonry or wood underpinning, regardless of structural status, is considered an enclosure and requires openings as outlined above.

• Flood-carrying capacity

  The flood-carrying capacity within an altered or relocated portion of any watercourse shall be maintained.

• Floodway encroachment restrictions

  Encroachments, including fill, new construction, substantial improvements and other developments are prohibited unless certification (with supporting technical data) by a registered professional engineer is provided demonstrating that encroachments shall not result in any increase in flood levels during occurrence of the base flood discharge. Development activities which increase the water surface elevation of the base flood be allowed, provided that the developer or applicant first applies – with Hillsville's endorsement – for a conditional Flood Insurance Rate Map and floodway revision, and receives the approval of the Federal Emergency Management Agency.

• Manufactured homesManufactured homeA dwelling built in a factory to a federal standard and transported to the site. in floodway

  The placement of manufactured homes (mobile homes) is prohibited, except in an existing manufactured homes (mobile homes) park or subdivision. A replacement manufactured home may be placed on a lot in an existing manufactured home park or subdivision, provided the anchoring, elevation, and encroachment standards are met.

• Manufactured homeManufactured homeA dwelling built in a factory to a federal standard and transported to the site. standards

  All manufactured homes placed, or substantially improved, on individual lots or parcels, in expansions to existing manufactured home parks or subdivisions, in a new manufactured home park or subdivision or in an existing manufactured home park or subdivision in which a manufactured home has incurred substantial damage as the result of a flood, must meet all the requirements for new construction, including the elevation and anchoring requirements in Subsection D(2)(a) and (b) and D(3)(a). All manufactured homes placed or substantially improved in an existing manufactured home park or subdivision in which a manufactured home has not incurred substantial damage as the result of a flood must be elevated so that either: [b] The lowest floor of the manufactured home is elevated no lower than two feet above the base flood elevation; or [c] The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade. [d] The manufactured home must be securely anchored to the adequately anchored foundation system to resist flotation, collapse and lateral movement.

• Flood-resistant materials

  New construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.

• Construction methods

  New construction or substantial improvements shall be constructed by methods and practices that minimize flood damage.

• Alterations to nonconformingNonconformingLawful when built, but not compliant with the rules now in force; usually allowed to continue but not to expand. buildings

  Any alteration, repair, reconstruction or improvements to a building that is not in compliance with the provisions of this section shall be undertaken only if said nonconformity is not furthered, extended, or replaced.

• Nonresidential elevation or floodproofing2 ft

  New construction or substantial improvement of any commercial, industrial, or non-residential building (or manufactured home) shall have the lowest floor, including basement, elevated to no lower than two feet above the base flood elevation. Buildings located in all A1-30, AE, and AH zones may be floodproofed in lieu of being elevated provided that all areas of the building components below the elevation corresponding to the BFE plus one foot are watertight with walls substantially impermeable to the passage of water, and use 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 subsection are satisfied.

• Overlay districtOverlay districtA second set of rules laid over the base district, adding requirements without replacing it.

  The Floodplain Districts described above shall be overlays to the existing underlying districts as shown on the Official Zoning Ordinance Map, and as such, the provisions for the Floodplain Districts shall serve as a supplement to the underlying district provisions.

• Zoning permit required

  All uses, activities, and development occurring within any Floodplain District shall be undertaken only upon the issuance of a zoning permit.

• Recreational vehicle standards

  All recreational vehicles placed on sites must either: [a] Be on the site for fewer than 180 consecutive days; [b] 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 security devices and has no permanently attached additions); or [c] Meet all the requirements for manufactured homes in Subsection D(3)(d).

• Residential lowest floor elevation2 ft

  New construction or substantial improvement of any residential structure (including manufactured homes) shall have the lowest floor, including basement, elevated no lower than two feet above the base flood elevation.

• Sanitary sewage systems

  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.

• Subdivision standards

  All subdivision proposals shall be consistent with the need to minimize flood damage; All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize flood damage; All subdivision proposals shall have adequate drainage provided to reduce exposure to flood hazards; and Base flood elevation data shall be provided for subdivision proposals and other proposed development proposals (including manufactured home parks and subdivisions) that exceed 50 lots or five acres, whichever is the lesser.

• Utility equipment

  Electrical, heating, ventilation, plumbing, air-conditioning equipment and other service facilities, including duct work, shall be designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

• On-site waste disposal

  On-site waste disposal systems shall be located and constructed to avoid impairment to them or contamination from them during flooding.

• Water supply systems

  New and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system.

• Watercourse notification

  In riverine situations, adjacent communities and the Department of Conservation and Recreation (Department of Floodplain Management) shall be notified prior to any alteration or relocation of a watercourse, and copies of such notifications shall be submitted to FEMA.