§ 5-12. Specific standards.

In all areas of special flood hazard where base flood elevation data has been provided, as set forth in section 5-3 or as determined in section 5-4(4), the following provisions, in addition to those in section 5-11, are required:

(1)

Residential structures. New construction or substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to or above the base flood elevation.

(2)

Nonresidential structures. New construction or substantial improvement of any commercial, industrial, or nonresidential structure located in a special flood hazard area shall have the lowest floor, including basement, elevated to or above the level of the base flood elevation.

(3)

Floodproofing. Nonresidential structures located in all A Zones may be floodproofed in lieu of being elevated provided that together with all attendant utilities and sanitary facilities the areas of the structure below the required elevation are water tight with walls substantially impermeable to the passage of water and use structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy. A registered professional engineer or architect shall review and/or develop structural design, specifications, and plans for the construction, and shall certify that the design and methods of construction are in accordance with acceptable standards of practice for meeting the provisions of this subsection.

(4)

Elevated building. New construction or substantial improvements of elevated buildings that include fully enclosed areas formed by foundation and other exterior walls below the base flood elevation shall be designed to preclude finished living space and designed to allow for the entry and exit of floodwaters to automatically equalize hydrostatic flood forces on exterior walls. Designs for complying with this requirement must either be certified by a professional engineer or architect or meet the following minimum criteria:

a.

Provide a minimum of two (2) openings having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding.

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 they permit the automatic flow of floodwaters in both directions.

(5)

Manufactured homes. Manufactured homes which are placed or substantially improved (i) outside of a manufactured home park, (ii) in a new manufactured home park, (iii) in an expansion to an existing manufactured home park, or (iv) in an existing manufactured home park in which a manufactured home has incurred "substantial damage" as a result of a flood, shall have the lowest floor elevated to or above the base flood level. They shall be placed on a permanent, securely anchored foundation. The structure must be securely anchored to the foundation to resist floatation, collapse, and lateral movement. Manufactured homes which are placed or substantially improved in an existing manufactured home park shall 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 floatation, collapse, and lateral movement.

(6)

A Zones. In A Zones where base flood elevations have been determined, but before a floodway is designated, require that no new construction, substantial improvement, or other development (including fill) be permitted which would increase base flood elevations more than one (1) foot at any point along the watercourse when all anticipated development is considered cumulatively with the proposed development.

(7)

Area of special flood hazard AO. Within any AO zone, all new construction and substantial improvements of residential structures must 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). Within any AO zone, all new construction and substantial improvements of nonresidential structures must have (i) 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), or (ii) together with attendant utility and sanitary facilities, be completely floodproofed above the highest adjacent grade to or above the depth number specified in feet on the community's FIRM (at least two (2) feet if no depth is specified), so that any space below that level 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. Designs for complying with this requirement must be certified by either a registered professional engineer or architect.

(8)

Recreational vehicles. Recreational vehicles shall either be on the site for fewer than one hundred eighty (180) consecutive days and be fully licensed and ready for highway use, or meet all the general standards of article II and the elevation and anchoring requirements of subsections 5-11(3) and 5-12(5) for a manufactured home. 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.

(9)

Equal conveyance. Within the floodplain, except those areas which are tidally influenced on the flood insurance rate map (FIRM) for the community, encroachments resulting from filling, new construction or substantial improvements involving an increase in footprint of the structure, are prohibited unless the applicant provides certification by a registered professional engineer demonstrating, with supporting hydrologic and hydraulic analyses performed in accordance with standard engineering practice, that such encroachments shall not result in any (0.00 feet) increase in flood levels (base flood elevation). Work within the floodplain and the land adjacent to the floodplain, including work to provide compensatory storage shall not be constructed in such a way so as to cause an increase in flood stage or flood velocity.

(10)

Compensatory storage. The water holding capacity of the floodplain, except those areas which are tidally influenced, shall not be reduced. Any reduction caused by filling, new construction or substantial improvements involving an increase in footprint to the structure, shall be compensated for by deepening and/or widening of the floodplain. Storage shall be provided on-site, unless easements have been gained from adjacent property owners; it shall be provided within the same hydraulic reach and a volume not previously used for flood storage; it shall be hydraulically comparable and incrementally equal to the theoretical volume of floodwater at each elevation, up to and including the 100-year flood elevation, which would be displaced by the proposed project. Such compensatory volume shall have an unrestricted hydraulic connection to the same waterway or water body. Compensatory storage can be provided off-site if approved by the municipality.

(11)

Aboveground storage tanks. Aboveground storage tanks (oil, propane, etc.) which are located outside or inside of the structure must either be elevated above the base flood elevation (BFE) on a concrete pad, or be securely anchored with tie-down straps to prevent flotation or lateral movement, have the top of the fill pipe extended above the BFE, and have a screw-fill cap that does not allow for the infiltration of floodwater.

(12)

Portion of structure in flood zone. If any portion of a structure lies within the special flood hazard area (SFHA), the entire structure is considered to be in the SFHA. The entire structure must meet the construction requirements of the flood zone. The structure includes any attached additions, garages, decks, sunrooms, or any other structure attached to the main structure. Decks or porches that extend into a more restrictive flood zone will require the entire structure to meet the standards of the more restrictive zone.

(13)

Structures in two flood zones. If a structure lies within two (2) or more flood zones, the construction standards of the most restrictive zone apply to the entire structure (i.e., V Zone is more restrictive than A Zone; structure must be built to the highest BFE). The structure includes any attached additions, garages, decks, sunrooms, or any other structure attached to the main structure. (Decks or porches that extend into a more restrictive zone will require the entire structure to meet the requirements of the more restrictive zone.)

(14)

No structures entirely or partially over water. New construction, substantial improvements and repair to structures that have sustained substantial damage cannot be constructed or located entirely or partially over water unless it is a functionally dependent use or facility.

(Ord. No. 623, § 5.2, 6-13-91; Ord. No. 743, § (a)7., 6-8-00; Ord. No. 847, § 5.2, 4-8-10)