§ 165-702.18

Floodplain

• Anchoring required

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

• Flood-resistant materials required

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

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

  Manufactured homes shall be anchored to prevent flotation, collapse, or lateral movement.

• Maximum accessoryAccessory useA secondary activity customarily incidental to the main use of the lot — a garage, a home office. structure floor area600 sqftsq ftSquare feet. An acre is 43,560 sq ft; a typical suburban lot is 7,000–10,000.

  Be limited to no more than 600 square feet in total floor area;

• Maximum heightMaximum heightThe tallest a building may be, given in feet, in storeys, or both — whichever binds first. of flood opening bottom above grade1 ft

  The bottom of all required openings shall be no higher than one foot above the adjacent grade.

• Mechanical equipment elevation

  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.

• Minimum elevation in AO zone without depth number2 ft

  If no flood depth number is specified, the lowest floor, including basement, shall be elevated no less than two feet above the highest adjacent grade.

• Minimum lowest floor elevation above BFE for nonresidential1 ft

  New construction or substantial improvement of any commercial, industrial, or nonresidential building (or manufactured home) shall have the lowest floor, including basement, elevated to no lower than one foot above the base flood elevation.

• Minimum lowest floor elevation above BFE for residential1 ft

  New construction or substantial improvement of any residential structure (including manufactured homes) in Zones A1-30, AE, AH, and A with detailed base flood elevations shall have the lowest floor, including basement, elevated no lower than one foot above the base flood elevation.

• Minimum flood opening area ratio1 sq in per sq ftsq ftSquare feet. An acre is 43,560 sq ft; a typical suburban lot is 7,000–10,000.

  The total net area of all openings must be at least one square inch for each square foot of enclosed area subject to flooding.

• Permit required

  All uses, activities, and development occurring within any floodplain district, including placement of manufactured homes, shall be undertaken only upon the issuance of a permit.

• Recreational vehicle requirements

  All recreational vehicles placed on sites must either be on the site for fewer than 180 consecutive days, be fully licensed and ready for highway use, or meet all the requirements for manufactured homes.

• BFE data required for large subdivisions

  Base flood elevation data shall be obtained from other sources or developed using detailed methodologies comparable to those contained in an FIS 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.