12-1-9: SPECIFIC FLOOD HAZARD REDUCTION STANDARDS:

In all areas of special flood hazard where base flood elevation data has been provided as set forth in: a) subsection 12-1-4B8 of this chapter; b) subsection 12-1-5B of this chapter; or c) subsection 12-1-10C of this chapter; the following provisions are required:

   A.   Residential Construction: New construction and 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 floodplain administrator that the standard of this subsection as proposed in subsection 12-1-6A1 of this chapter is satisfied.

   B.   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 the 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. 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.

   C.   Enclosures: New construction and substantial improvements, with fully enclosed areas below the lowest floor that 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:

      1.   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.

      2.   The bottom of all openings shall be no higher than one foot (1') above grade.

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

   D.   Manufactured Homes:

      1.   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.

      2.   All manufactured homes shall be in compliance with subsection 12-1-8A of this chapter.

      3.   Require that all manufactured homes to be placed or substantially improved within zones Al-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 subsection D1 of this section. (Ord. 2717, 6-2-1987)

12-1-10: SUBDIVISION PROPOSALS:

   A.   Compliance Required: All subdivision proposals including manufactured home parks and subdivisions shall be consistent with subsection 12-1-1B and section 12-1-2 of this chapter.

   B.   Development Permit Requirements: All proposals for the development of subdivisions including manufactured home parks and subdivisions shall meet development permit requirements of subsection 12-1-5C and section 12-1-6 of this chapter; and the provisions of sections 12-1-8 through 12-1-12 of this chapter.

   C.   Base Flood Elevation: Base flood elevation data shall be generated for subdivision proposals and other proposed development, including manufactured home parks and subdivisions, which is greater than fifty (50) lots or five (5) acres, whichever is lesser, if not otherwise provided pursuant to subsection 12-1-4B8 or 12-1-5B of this chapter.

   D.   Drainage: All subdivision proposals including manufactured home parks and subdivisions shall have adequate drainage provided to reduce exposure to flood hazards.

   E.   Utilities: All subdivision proposals including manufactured home parks and subdivisions shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize or eliminate flood damage. (Ord. 2717, 6-2-1987)

12-1-11: AREAS OF SHALLOW FLOODING:

Located within the areas of special flood hazard established in subsection 12-1-5B of this chapter are areas designated as shallow flooding. These areas have special flood hazards associated with base flood depths of one foot (1') to three feet (3') where a clearly defined channel does not exist and where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow; therefore, the following provisions apply:

   A.   Residential Structures: All new construction and substantial improvements of residential structures 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 2 feet if no depth number is specified).

   B.   Nonresidential Structures: All new construction and substantial improvements of nonresidential structures:

      1.   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 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 or effects of buoyancy.

   C.   Certification: A registered professional engineer or architect shall submit a certification to the floodplain administrator that the standards of this section, as proposed in subsection 12-1-6A1 of this chapter, are satisfied.

   D.   Drainage Paths: Require within zones AH or AO adequate drainage paths around structures on slopes, to guide floodwaters around and away from proposed structures. (Ord. 2717, 6-2-1987)

12-1-12: FLOODWAYS:

Floodways, located within areas of special flood hazard established in subsection 12-1-5B of this chapter, are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters which carry debris, potential projectiles and erosion potential, the following provisions shall apply;

   A.   Encroachments: Encroachments are prohibited, including fill, new construction, substantial improvements and other development unless certification by a professional registered engineer or architect is provided demonstrating that encroachments shall not result in any increase in flood levels within the community during the occurrence of the base flood discharge.

   B.   New Construction, Substantial Improvements: If subsection A of this section is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this section and sections 12-1-8 through 12-1-11 of this chapter. (Ord. 2717, 6-2-1987)