§ 18-72. Specific standards.

In all areas of special flood hazard where base flood elevation data has been provided as set forth in section 18-8, 18-39(b)(1)h, or 18-73(c), the following provisions are required:

(1)

Residential construction. New construction or substantial improvement of any residential structure shall have the lowest floor, including basement, elevated by utilization of flood-resistant materials and construction techniques to a minimum of one foot above the base flood elevation. A registered professional engineer, architect, or land surveyor shall submit a certification to the director of public works that the standard of this subsection (1) is satisfied and that the level complies with that proposed in the development permit application.

(2)

Nonresidential construction. New construction or substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated by utilization of flood-resistant materials and construction techniques to a minimum of one foot above the base flood level, or, together with attendant utility and sanitary facilities, be designed so that below that base flood level 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. 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 (2). A record of such certification which includes the specific elevation, in relation to mean sea level, to which structures are flood proofed shall be maintained by the director of public works.

(3)

Enclosures. New construction and substantial improvements, with 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 floodwaters. 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.

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 be no 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 or exit of floodwaters.

(4)

Manufactured homes.

a.

All manufactured homes to be placed within zone A on the parish's FHBM or FIRM shall be installed using methods and practices which minimize flood damage. For the purposes of this requirement, 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 times to ground anchors. This 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 parish'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 elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated to a minimum of one foot above the base flood elevation and shall be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

c.

Manufactured homes placed or substantially improved on sites in an existing manufactured home park or subdivision within zones A1-30, AH and AE on the parish's FIRM that do not fall into the categories covered in subsection (4)b of this section shall be elevated so that either:

1.

The lowest floor of the manufactured home is at a minimum of one foot above the base flood elevation; or

2.

The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no 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 parish's FIRM shall 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 18-40(b), 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.

(6)

Red River Special Flood Hazard Area. In those areas between the Caddo Parish Levee and the boundary of Caddo Parish and Bossier Parish on the Red River Special Flood Hazard Area map filed and maintained by the department of public works, the lowest floor or mechanical or electric equipment shall be elevated to a minimum of one and one-half feet above the high water mark. As to that area, the elevation established in this paragraph shall be used instead of any elevation specified in paragraphs (1) through (5) above.

(Code 1976, § 6.5-18; Code 1985, § 9-42; Ord. No. 2728, 8-8-1990; Ord. No. 2735, 9-12-1990; Ord. No. 2736, 10-26-1990; Ord. No. 5660 , 1-19-2017)