In all areas of special flood hazards the following standards are required:
A. Anchoring.
1. All new construction and substantial improvements shall be adequately anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.
2. All manufactured homes shall meet the anchoring standards of Section 15.56.180.
B. Construction Materials and Methods.
1. All new construction and substantial improvement shall be constructed with materials and utility equipment resistant to flood damage.
2. All new construction and substantial improvement shall be constructed using methods and practices that minimize flood damage.
3. All new construction and substantial improvement shall 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.
4. Require within Zones AH or AO that adequate drainage paths around structures on slopes to guide flood waters around and away from proposed structures.
C. Elevation and Floodproofing.
1. New construction and substantial improvement shall have the lowest floor, including basement, elevated a minimum one foot above the base flood elevation (i.e. finish floor elevation one foot above base flood elevation). Nonresidential structures may meet the standards in subsection (C)(3) of this section. Upon the completion of the structure the elevation of the lowest floor including basement shall be certified by a registered professional engineer or surveyor, or verified by the city building inspector to be properly elevated. Such certification or verification shall be provided to the floodplain administrator.
2. New construction and substantial improvement in Zone AO shall have the lowest floor, including basement, elevated above the highest adjacent grade at least as high as a minimum one foot above the depth number specified in feet on the FIRM, or at least two feet if no depth number is specified. Nonresidential structures may meet the standards in subsection (C)(3) of this section. Upon the completion of the structure the elevation of the lowest floor including basement shall be certified by a registered professional engineer or surveyor, or verified by the building inspector to be properly elevated. Such certification or verification shall be provided to the floodplain administrator.
3. Nonresidential construction shall either be elevated to conform to subsection (C)(1) or (C)(2) of this section or together with attendant utility and sanitary facilities:
a. Be floodproofed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water;
b. Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and
c. Be certified by a registered professional engineer or architect that the standards of this subsection are satisfied. Such certifications shall be provided to the floodplain administrator.
4. Require, for all new construction and substantial improvement that fully enclosed areas below the lowest floor that are usable solely for parking of vehicles, building access or storage in an area other than a basement and which are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwater. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or meet or exceed the following minimum criteria:
a. Either a minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided. The bottom of all openings shall be no higher than one foot above grade. Openings may be equipped with screens, louvers, valves or other coverings or devices provided that they permit the automatic entry and exit of floodwater; or
b. Be certified to comply with a local floodproofing standard approved by the Federal Insurance Administration, Federal Emergency Management Agency.
5. Manufactured homes shall also meet the standards in Section 15.56.180.
(Ord. 424-09 § 5, 2009; Ord. 70 § 1 (part), 1992: Ord. 3 § 1 (part), 1991: prior code § 2.42.190)