§ 8.5-47. Specific standards.

In all areas of special flood hazards where base flood elevation data has been provided as set forth in section 8.5-17, 8.5-32(7), or 8.5-48(3), 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 to or above the base flood elevation. A registered professional engineer, architect, or land surveyor shall submit a certification to the building inspector that the standard of this subsection, as proposed in section 8.5-33(1)(a), 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 to or above base flood level 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 effects of buoyancy. The registered professional engineer or architect shall develop and/or review structural design, specifications, and plans for construction, and certify that the design and methods of construction are in accordance with accepted standards of practice as outlined by this subsection. A record of such certification which includes specific elevation (in relation to the mean sea level) to which such structures are floodproofed shall be maintained by the building inspector.

(3)

Enclosures. New construction as 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 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 and exit of floodwaters.

(4)

Manufactured homes:

a.

Require that all manufactured homes to be placed within zone A on a community's FHBM or FIRM 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. Specific requirements shall be:

1.

Over-the-top ties at each of the four (4) corners of the manufactured home, with two (2) additional ties per side at intermediate locations and manufactured homes less than fifty (50) feet long requiring one initial tie per side;

2.

Frame ties at each corner of the home with five (5) additional ties per side at intermediate points and manufactured homes less than fifty (50) feet long requiring four (4) additional ties per side;

3.

All components of the anchoring system be capable of carrying a force of four thousand eight hundred (4,800) pounds;

4.

Any additions to the manufactured home be similarly anchored.

b.

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 in 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 or above the base flood elevation and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

c.

Require that manufactured homes be placed or substantially improved on sites in an existing manufactured home park or subdivision within Zones A1—30, AH, and AE on the community's FIRM that are not subject to the provisions of paragraph (4)b. of this section be elevated so that either:

1.

The lowest floor of the manufactured home is at or 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 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.

d.

Require that all manufactured homes to be placed are 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 or above the base flood elevation; and be securely anchored to an adequately anchored foundation system in accordance with the provisions of section 8.5-47(4).

(5)

Recreational vehicles. 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 8.5-33(1), 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)

Standards for areas of shallow flooding (AO and AH zones). Located within the areas of special flood hazard, established in section 8.5-17, are areas designated as shallow flooding. These areas have special flood hazards associated with base flood depths of one to three (3) feet where a clearly defined channel does not exist and where the path of flooding and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow; therefore, the following provisions apply:

a.

All new construction and substantial improvements of residential structures shall have the lowest floor (including basement) elevated above the highest adjacent grade at least as high as the depth number specified in feet on the community's FIRM (at least two (2) feet if no depth number is specified).

b.

All new construction and substantial improvements of nonresidential structures shall:

1.

Have the lowest flood (including basement) elevated above the highest adjacent grade at least as high as the depth number specified in feet on the community's FIRM (at least two (2) feet if no depth number is specified), or

2.

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 effects of buoyancy.

c.

A registered professional engineer or architect shall submit a certification to the building inspector that the standards of this section, as proposed in section 8.5-33(1)(a) are satisfied.

d.

Require within zones AH or AO adequate drainage paths around structures on slopes, to guide floodwaters around and away from proposed structures.

(Ord. No. 223, Art. V, § B, 3-14-78; Ord. No. 241, § 3, 8-28-80; Ord. No. 323, §§ 11—13, 15, 3-10-87; Ord. No. 423, Art. V, § B, 7-8-97)