Sec. 70-346 through 70-367

Floodplain

• Coastal A zone freeboard

  Buildings and structures within this zone, including manufactured homes, shall have the lowest floor elevated to or above the base flood elevation plus one foot of freeboard.

• Floodway encroachment

  Within any floodway area, no encroachments, including fill, new construction, substantial improvements, or other development shall be permitted unless it has been demonstrated through hydrologic and hydraulic analysis performed in accordance with standard engineering practice that the proposed encroachment will not result in any increase in flood levels within the community during the occurrence of the base flood discharge.

• Hydrostatic openings

  Include 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: Provide a minimum of two openings on different sides of each enclosed area subject to flooding. The total net area of all openings must be at least one square inch for each square foot of enclosed area subject to flooding. The bottom of all required openings shall be no higher than one foot above the adjacent grade.

• Lowest floor elevation

  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 to one foot or more above the base flood level.

• Manufactured homesManufactured homeA dwelling built in a factory to a federal standard and transported to the site. prohibitedProhibitedNot allowed in the district at all, short of rezoning or a variance. in floodway

  The placement of manufactured homes (mobile homes) is prohibited, except in an existing manufactured home (mobile home) park or subdivision.

• Non-residential flood-proofing

  Buildings located in all A1—30, AE, and AH zones may be flood-proofed in lieu of being elevated provided that all areas of the building components below the elevation corresponding to the BFE plus one foot are water tight with walls substantially impermeable to the passage of water.

• 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 in section 70-365(d)(1).

• Space below lowest floor use

  Fully enclosed areas, of new construction or substantially improved structures, which are below the regulatory flood protection elevation 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.

• VE zone breakaway walls

  All new construction and substantial improvements shall have the space below the lowest floor either free of obstruction or constructed with nonsupporting breakaway walls, open wood-lattice work, or insect screening intended to collapse under wind and water loads without causing collapse, displacement, or other structural damage to the elevated portion of the building or supporting foundation system. For the purpose of this section, a breakaway wall shall have a design safe loading resistance of not less than ten and no more than 20 pounds per square foot.

• VE zone elevation

  All new construction and substantial improvements in zones V and VE (V if base flood elevation is available), including manufactured homes, shall be elevated on pilings or columns so that the bottom of the lowest horizontal structural member of the lowest floor (excluding the pilings or columns) is elevated to at least one foot above the base flood level.

• VE zone fillGrading (cut & fill)Reshaping land by removing earth (cut) or adding it (fill), often capped by volume. prohibitedProhibitedNot allowed in the district at all, short of rezoning or a variance.

  The use of fill for structural support of buildings is prohibited.