Chapter 18.32

No development, including landfill, may be permitted within zones A1—A30 unless the applicant has demonstrated that the proposed use, when combined with all other existing and reasonably anticipated uses, will not increase the water surface elevation of the one-hundred-year flood more than one foot on the average cross-section of the reach in which the development or landfill is located.

New construction or substantial improvements of nonresidential structures shall have the lowest floor, including basement, elevated to or above the regulatory base flood elevation or, together with attendant utility and sanitary facilities, be designed so that below the base flood elevation the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy.

New construction or substantial improvements of residential structures shall have the lowest floor, including basements, elevated to or above the regulatory base flood elevation.

In case any watercourse is allowed to be relocated or altered, the flood-carrying capacity within the altered or relocated portion of any watercourse shall be maintained.

New construction, substantial improvements, prefabricated buildings and other developments shall be designed or anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.

A development permit shall be obtained before any construction or other development begins within any area of special flood hazard identified in Section 18.32.030.

New development and substantial improvements shall use construction materials and utility equipment that are resistant to flood damage as specified in FEMA Technical Bulleting TB 2-93; and use construction methods and practices that will minimize flood damage consistent with economic practicability; and be constructed with electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

Applicants shall provide certification by a registered professional engineer or architect that floodproofing plans are adequate to be watertight with walls impermeable to the passage of water, withstand the hydrostatic and hydrodynamic forces associated with the one-hundred-year flood depths, pressures, velocities, impact and uplift forces and other factors associated with the base flood.

Utility and sanitary facilities shall be floodproofed to one foot above the one-hundred-year flood elevation, unless a higher elevation is recommended by the floodplain administrator...

Variances may be issued for new construction, substantial improvement, and other proposed new development to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing that the procedures and provisions for flood hazard reduction in this chapter have been fully considered.

Water and sanitary sewer systems shall be designed to minimize or eliminate infiltration of floodwaters and discharges into floodwaters, and on-site waste disposal systems shall be located so as to avoid impairment or contamination during flooding.

All recreational vehicles placed on sites within Zones A1-30 and intended for temporary occupancy... will be on the site for no longer than a maximum of one year, and be fully licensed and ready for highway use.