Section 5-3-2

Floodplain

• 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;

• AO zone minimum elevation above highest adjacent grade2 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.

• Flood opening net area ratio1 sq inch 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 1 square inch for each square foot of enclosed area subject to flooding.

• Lowest floor elevation above base flood level12 inches

  New construction or substantial improvement of any residential structure (including manufactured homes) in Zones AE, AH, and A, shall have the lowest floor, including basement, elevated to or above the base flood level plus 12 inches.

• Maximum increase in water surface elevation1 ft

  no new construction, substantial improvements, or other development (including fill) shall be permitted within the areas of special flood hazard, designated as Zones AE or AH on the FIRM, unless it is demonstrated 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 County.

• Recreational vehicle maximum consecutive days180 days

  Be on the site for fewer than 180 consecutive days and be fully licensed and ready for highway use

• Subdivision threshold for detailed study (acresacre43,560 square feet — about the size of an American football field without the end zones.)5 acresacre43,560 square feet — about the size of an American football field without the end zones.

  Any subdivision proposal or other proposed development (including proposals for manufactured home parks and subdivisions) that exceed 50 lots or 5 acres, whichever is less, in an area where BFE data is not available or the SFHA has not been delineated, shall include data using detailed methodologies

• Subdivision threshold for detailed study50 lots

  Any subdivision proposal or other proposed development (including proposals for manufactured home parks and subdivisions) that exceed 50 lots or 5 acres, whichever is less, in an area where BFE data is not available or the SFHA has not been delineated, shall include data using detailed methodologies

• Substantial improvement threshold50 pct

  The change, when added to all the changes made during a rolling 5-year period does not constitute 50% of the structure's value.

• V zone minimum elevation above base flood level12 inches

  The bottom of the lowest horizontal structural member of the lowest floor (excluding pilings and columns) elevated to or above the base flood level plus 12 inches.

• Maximum lot size for varianceVariancePermission to depart from a specific dimensional rule, granted on a showing of hardship.0.5 acresacre43,560 square feet — about the size of an American football field without the end zones.

  It is intended for variances to be granted only for lot sizes less than one-half acre

• VarianceVariancePermission to depart from a specific dimensional rule, granted on a showing of hardship. prohibitedProhibitedNot allowed in the district at all, short of rezoning or a variance. for accessoryAccessory useA secondary activity customarily incidental to the main use of the lot — a garage, a home office. structures

  Variances will not be issued for any accessory structure within the SFHA;