§ 24-161. Specific standards.

In all areas of special flood hazards where base flood elevation data has been provided as set forth in section 24-140, 24-151(a)(8) or 24-162(c) and the area shown to be floodprone along drainage areas, the following provisions are required:

(1)

Residential construction. New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated at least 24 inches (two feet) above the base flood elevation in an A zone; at least 12 inches (one foot) above the base elevation in a B zone; and at least eight inches above adjacent street crown elevations in areas where streets have been shown to cause drainage to pool, causing flooding of structures. A registered professional engineer, architect and/or surveyor shall submit a certification to the floodplain administrator that the standard of this subsection, as proposed in section 24-152(a)(1), is satisfied.

(2)

Nonresidential construction. New construction and substantial improvements of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated at least 18 inches above the base flood level in A zones; at least 12 inches above the base flood level in B zones; and at least eight inches above the crown of adjacent streets which have been shown to cause drainage waters to pool, causing flooding of structures or, together with attendant utility and sanitary facilities, be designed so that any structure below the 18-inch, 12-inch or eight-inch levels, respectively, be 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. A registered professional engineer or architect shall develop and/or review structural design specifications and plans for the construction, and shall certify that the design and methods of construction are in accordance with accepted standards of practice as outlined in this subsection. A record of such certification, which includes the specific elevation in relation to mean sea level to which such structures are floodproofed, shall be maintained by the floodplain administrator.

(3)

Enclosures. New construction and substantial improvements, with fully enclosed areas below the lowest floor that are usable solely for the parking of vehicles, building access or storage in an area other than a basement and which are subject to flooding, shall be designated to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting such requirement must either be certified by a registered professional engineer or architect or meet or exceed the following minimum criteria:

a.

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.

b.

The bottom of all openings shall not be higher than one foot above grade.

c.

Openings may be equipped with screens, louvers, valves or other coverings or devices, provided that they permit the automatic entry and exit of floodwaters.

(4)

Manufactured homes.

a.

All manufactured homes to be placed within zone A on the city's FHBM or FIRM shall be required to be installed using methods and practices which minimize flood damage. For the purposes of this subsection, manufactured homes must be elevated and anchored to resist flotation, collapse or lateral movement. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors. Such requirement is in addition to applicable state and local anchoring requirements for resisting wind forces.

b.

Manufactured homes that are placed or substantially improved within zones A1-30, AH and AE on the city'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 a result of a flood;

shall be required to be elevated on a permanent foundation so that the lowest floor of the manufactured home is elevated at least 24 inches (two feet) above the base flood level in A zones and at least eight inches above the crown of adjacent streets which have shown to cause drainage waters to pool causing flooding of structures and be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement.

c.

Manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision with zones A1-30, AH and AE on the city's FIRM that are not subject to the provisions of subsections (4)a. and b. of this section, shall be required to be elevated so that either the:

1.

Lowest floor of the manufactured home is at or above the base flood elevation; or

2.

Manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are not less than 36 inches in height above grade and be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement.

(5)

Recreational vehicles. Recreational vehicles placed on sites within zones A1-30, AH and AE on the city's FIRM shall be required to either:

a.

Be on the site for fewer than 180 consecutive days;

b.

Be fully licensed and ready for highway use; or

c.

Meet the permit requirements of section 24-152(a), and the elevation and anchoring requirements for manufactured homes in subsection (4) of this section. A recreational vehicle is ready for highway use if it is on its wheels or jacking system; is attached to the site only by quick disconnect type utilities and security devices; and has no permanently attached additions.

(Code 1961, § 13:232; Ord. No. 883, § 1, 4-20-1981; Ord. No. 977, § 1(13:232), 3-2-1987; Ord. No. 1220, § 1, 12-4-1995)