§ 9-62. Specific standards.

In all areas of special flood hazard where base flood elevation data have been provided as set forth, the following provisions shall apply:

(1)

Residential construction. New construction and substantial improvement of any residential structure shall have the lowest floor (including basement) elevated to a minimum of one (1) foot above the base flood elevation. A registered professional engineer, architect or land surveyor shall submit an elevation certificate to the floodplain administrator. All new and substantially improved residential structures shall have the ductwork, and exposed plumbing and electrical components elevated one (1) foot above the base flood elevation.

(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 to a minimum of one (1) foot above the base flood elevation or, together with attendant utility and sanitary facilities, be designed so that below the 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 the 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 and shall submit an elevation certificate to the floodplain administrator. 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 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 (2) openings on separate walls having a total net area of not less than one (1) 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 (1) 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.

Require that all manufactured homes to be placed within zone A shall be installed using methods and practices which minimize flood damage. For the purpose 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 ties to ground anchors. This requirement is in addition to applicable state and local anchoring requirements for resisting wind forces.

b.

All manufactured homes shall be in compliance with section 9-62(1).

c.

Require that all manufactured homes to be placed or substantially improved within zones A1-30, AH and AE on the community's FIRM be elevated on a permanent foundation such that the lowest floor of the manufactured home is at a minimum of two (2) feet above the base flood elevation and be securely anchored to an adequately anchored foundation system in accordance with the provisions of this section 9-62(4).

d.

Require that manufactured homes that are placed or substantially improved within zones A1-30, AH, and AE on the community's FIRM on sites (i) outside of a manufactured home park or subdivision, (ii) in a new manufactured home park or subdivision, (iii) in an expansion to an existing manufactured home park or subdivision, or (iv) in an existing manufactured home park or subdivision on which a manufactured home has incurred "substantial damage" as a result of a flood, be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated to two (2) feet above the base flood elevation and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

e.

Require that manufactured homes be placed or substantially improved on sites in an existing manufactured home park or subdivision with zones Al-30, AH and AE on the community's FIRM that are not subject to the provisions of paragraph (r) of this subsection be elevated so that either: (i) the lowest floor of the manufactured home is at or above the base flood elevation, or (ii) the manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than thirty-six (36) inches in height above grade and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

f.

Require that recreational vehicles placed on sites within zones A1-30, AH, and AE on the community's FIRM either (i) be on the site for fewer than one hundred eighty (180) consecutive days, (ii) be fully licensed and ready for highway use, or (iii) meet the permit requirements of article 4, section C(1), and the elevation and anchoring requirements for "manufactured homes" in paragraph (4) of this subsection. 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.

(5)

Accessory structures . Small, low-cost detached accessory structures are exempt from the requirements to elevate or dry floodproof nonresidential structures. They may be used only for limited parking of light vehicles and storage of low cost items.

(6)

Unmapped areas and areas adjacent to SFHA.

a.

Approximate zone A requirements shall include the following:

1.

If a structure is to be constructed in an approximate A zone, and a detailed BFE is unavailable, the lowest flood of the structure shall be elevated a minimum of two (2) feet above the highest adjacent grade.

2.

When a residential or nonresidential structure is intended to be constructed in an approximate A zone, a BFE must be determined by using the same engineering standards and methods that are used to develop BFE's in a flood insurance study (FIS).

b.

Unmapped areas and areas outside of the SFHA:

1.

If a new or substantially improved residential structure is constructed outside the SFHA but is within one hundred (100) feet of a known but unmapped water course (including an intermittent water course) on the community's FIRM, then it shall be elevated such that the lowest floor (including basement) is a minimum of two (2) feet above the highest adjacent grade.

2.

All new and substantially improved residential structures located in the SFHA shall be elevated to a level that will make them eligible to be removed from the SFHA. They shall be elevated so that the lowest adjacent grade is equal to or higher than the BFE. The BFE must be determined using detailed study methods.

3.

All residential structures, except manufactured homes, that are constructed outside of the SFHA shall be elevated one (1) foot above the highest adjacent grade.

(Ord. No. 2058, § 1, 5-26-09)