17.76.215 Coastal high hazard areas.
Located within areas of special flood hazard established in BMC 17.76.030 are coastal high hazard areas, designated as zones V1-30, VE and/or V. These areas have special flood hazards associated with high velocity waters from surges and, therefore, in addition to meeting all provisions in this chapter, the following provisions shall also apply:
A. All new construction and substantial improvements in zones V1-30 and VE (V if base flood elevation data is available) on the community’s FIRM shall be elevated on pilings and columns so that:
1. The bottom of the lowest horizontal structural member of the lowest floor (excluding the pilings or columns) is elevated one foot or more above the base flood level; and
2. The pile or column foundation and structure attached thereto are anchored to resist flotation, collapse and lateral movement due to the effects of wind and water loads acting simultaneously on all building components. Wind and water loading values shall each have a one percent chance of being equaled or exceeded in any given year (100-year mean recurrence interval).
A registered professional engineer or architect shall develop or review the structural design, specifications and plans for the construction, and shall certify that the design and methods of construction to be used are in accordance with accepted standards of practice for meeting the provisions of subsections (A)(1) and (2) of this section.
B. Obtain the elevation (in relation to mean sea level) of the bottom of the lowest structural member of the lowest floor (excluding pilings and columns) of all new and substantially improved structures in zones V1-30, VE, and V on the community’s FIRM and whether or not such structures contain a basement. The public works director shall maintain a record of all such information.
C. All new construction within zones V1-30, VE, and V on the community’s FIRM shall be located landward of the reach of mean high tide.
D. Provide that all new construction and substantial improvements within zones V1-30, VE, and V on the community’s FIRM have the space below the lowest floor either free of obstruction or constructed with nonsupporting breakaway walls, open wood latticework, 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 purposes of this section, a breakaway wall shall have a design safe loading resistance of not less than 10 and no more than 20 pounds per square foot. Use of breakaway walls which exceed a design safe loading resistance of 20 pounds per square foot (either by design or when so required by local or state codes) may be permitted only if a registered professional engineer or architect certifies that the design proposed meets the following conditions:
1. Breakaway wall collapse shall result from water load less than that which would occur during the base flood; and
2. The elevated portion of the building and supporting foundation system shall not be subject to collapse, displacement, or other structural damage due to the effects of wind and water loads acting simultaneously on all building components (structural and nonstructural). Maximum wind and water loading values to be used in this determination shall each have a one percent chance of being equaled or exceeded in any given year (100-year mean recurrence interval).
If breakaway walls are utilized, such enclosed space shall be useable solely for parking of vehicles, building access, or storage. Such space shall not be used for human habitation.
E. Prohibit the use of fill for structural support of buildings within zones V1-30, VE, and V on the community’s FIRM.
F. Prohibit manmade alteration of sand dunes within zones V1-30, VE, and V on the community’s FIRM which would increase potential flood damage.
G. All manufactured homes to be placed or substantially improved within zones V1-30, V, and VE on the community’s FIRM on sites:
1. Outside of a manufactured home park or subdivision;
2. In a new manufactured home park or subdivision;
3. In an expansion to an existing manufactured home park or subdivision; or
4. In an existing manufactured home park or subdivision on which a manufactured home has incurred substantial damage as the result of a flood;
shall meet the standards of subsections (A) through (F) of this section and manufactured homes placed or substantially improved on other sites in an existing manufactured home park or subdivision within zones V1-30, V, and VE on the FIRM shall meet the requirement of BMC 17.76.200(B).
H. Recreational vehicles placed on sites within zones V1-30, V, and VE on the community’s FIRM shall either:
1. Be on the site for fewer than 180 consecutive days; or
2. Be fully licensed and ready for highway use, on their wheels or jacking system, attached to the site only by quick disconnect type utilities and security devices, and have no permanently attached additions; or
3. Meet the requirements of BMC 17.76.080 (Establishment of development permit) and subsections (A) through (F) of this section. [Ord. 2018-07-012 § 10].