This chapter establishes the flood hazard overlay (FHO) and detailed performance standards for development in that district. (Ord. 2000-02, 3-3-2000)

The FHO shall consist of all special flood hazard areas identified on the most current flood insurance rate maps (FIRM) of Fremont County and the city of Teton prepared by the federal emergency management agency (FEMA). The flood insurance study for Fremont County and the accompanying FIRMs are adopted, by reference, as supplements to the "official zoning map of Teton" established in TCC 9.12.030. (Ord. 2000-02, 3-3-2000)

Development in the FHO shall be by permit only, as provided in TCC 9.10.010. For the purposes of this chapter, development shall include any activity that may potentially affect flood flows. This includes all land disturbance (including clearing, grading, and the construction of fills), as well as building construction. Some developments that are exempt from permit requirements in other areas must obtain a permit in the FHO. (Ord. 2000-02, 3-3-2000)

All applications for permits in the FHO shall be accompanied by a signed and dated acknowledgment stating:

1. I understand that, while the degree of flood protection required by this title is considered reasonable for regulatory purposes and is based on scientific and engineering considerations, larger floods can and will occur.
2. I understand that the projected flood levels at my development site may be increased by manmade or natural causes.
3. I understand that this title does not imply that land outside the area of special flood hazard or uses permitted within such areas will be free from flooding or flood damage.
4. I understand that this title does not create any liability on the part of the city of Teton or any officer or employee thereof, or on the part of the federal insurance administration, for flood damages. (Ord. 2000-02, 3-3-2000)

Applications for permits in the FHO shall be accompanied by the following information:

1. Elevation of the lowest floor, including basements, of all proposed buildings.
2. Elevation to which any existing or proposed building has been or will be floodproofed.
3. For all buildings other than a single-family dwelling, certification by an engineer or architect that the floodproofing methods used comply with these performance standards.
4. Where alteration of a watercourse is proposed, a description of the extent to which the watercourse will be altered or relocated as a result of the proposed development, and proof that all state or federal permits required for that alteration have been approved. The developer shall provide the base flood elevation data for all subdivisions or other developments that include fifty (50) or more lots or dwelling units, or five (5) or more acres. (Ord. 2000-02, 3-3-2000)
   

The administrator shall serve as a local floodplain ordinance administrator and perform the following duties:

1. Determine that all required state and/or federal permits have been obtained before reviewing any application for a permit in the FHO.
2. Where base flood elevation data are not provided by FEMA, obtain and reasonably utilize any base flood elevation and floodway data available from state, federal, or other sources as a basis for the administration of this chapter.
3. Maintain a record of the actual elevation of the lowest floor of all new or substantially improved buildings, and whether or not the building contains a basement.
4. Maintain a record of floodproofing certifications required by TCC 9.20.130 Paragraph C.
5. Notify downstream communities and the Idaho department of water resources prior to the alteration or relocation of a watercourse, and submit evidence of that notification to FEMA.
6. Maintain records of appeal actions and report all variances allowed to FEMA. (Ord. 2000-02, 3-3-2000)
   

New construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure. Manufactured homes shall be anchored to prevent flotation, collapse, or lateral movement, and shall be installed using methods and practices that minimize flood damage. Anchoring methods may include, but are not limited to, the use of over the top or frame ties to ground anchors. (Ord. 2000-02, 3-3-2000)

New construction and substantial improvements shall be constructed with materials and utility equipment that is resistant to flood damage, and using methods and practices that minimize flood damage. All electrical, heating, ventilation, plumbing, and air conditioning equipment, and other service facilities shall be designed, or elevated, or located, so as to prevent water from entering or accumulating within their components during flooding. (Ord. 2000-02, 3-3-2000)

1. New and replacement potable water systems shall be designed to prevent infiltration of floodwaters into the system.
2. New and replacement sewage disposal systems shall be designed to prevent infiltration of floodwaters into the system and discharge from the system into floodwaters.
3. Commercial or industrial solid waste handling and storage facilities shall not be located in the FHO. (Ord. 2000-02, 3-3-2000)
   

The storage and handling of hazardous substances in the FHO shall be prohibited. (Ord. 2000-02, 3-3-2000)

Design and construction of all subdivisions and uses for which a class II permit is required shall minimize flood damage. Utilities shall be located and designed to minimize flood damage, and the site shall be graded and drained to guide floodwaters around and away from existing and/or proposed buildings. (Ord. 2000-02, 3-3-2000)

Standards in Paragraphs A and B of this section apply only in areas where base flood elevation data have been provided by FEMA or, as required by TCC 9.20.050, the developer.

1. Construction or substantial improvement of any dwelling shall result in the lowest floor being elevated to or above base flood elevation.
2. Fully enclosed areas below the lowest floor are prohibited, except where designed to automatically equalize hydrostatic forces on exterior walls by allowing for entry and exit of floodwaters. Designs for meeting this requirement shall either be certified by an engineer or architect, or meet the following minimum standards:
   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; and
   2. The bottom of such openings shall be no higher than one foot (1') above grade. Such openings may be equipped with screens, louvers, or other coverings or devices, provided they permit automatic entry and exit of floodwaters.
3. Where base flood elevation data are not available through the flood insurance study or from another source, applications shall be reviewed to assure that the proposed construction will be reasonably safe from flooding. This determination of reasonableness shall be based on evidence submitted with the application by the developer, including historical flood records, photographs of past flood events, and similar documentation. The minimum elevation above grade in such cases shall be two feet (2').
4. Manufactured homes that are placed, replaced, or substantially improved within the FHO shall be elevated on and securely anchored to a permanent foundation, so that the lowest floor is at or above base flood elevation. Mobile home parks shall not be permitted in the FHO. (Ord. 2000-02, 3-3-2000)
   

Construction or substantial improvement of any nonresidential building shall result in the lowest floor being elevated to or above base flood elevation or, together with the attendant utility and sanitary facilities, shall:

1. Be floodproofed so that below base flood level, the building is watertight, with walls substantially impermeable to the passage of water;
2. Be designed and constructed to resist hydrostatic and hydrodynamic loads and the effects of buoyancy;
3. Present a certification from an engineer or architect that the design and methods of construction comply with accepted standards of practice for meeting the performance standards of this title; and
4. Meet the performance standard of Paragraph B of this section for enclosed spaces below the lowest floor. Developers floodproofing nonresidential buildings shall be notified that flood insurance premiums will be based on rates that are set for buildings one foot (1') below the floodproofed level. (Ord. 2000-02, 3-3-2000)
   

The floodway is the channel of a river or other watercourse and any adjacent land area that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than one foot (1'). The floodway is a hazardous area due to the velocity of floodwaters which carry debris and potential projectiles, and the high erosion potential. Encroachments into the floodway, including fill, new construction, substantial improvements, and other development shall be prohibited, unless an engineer or architect certifies that the encroachment will not result in any increase in the flood level during the base flood discharge. (Ord. 2000-02, 3-3-2000)

Continuing maintenance to prevent the reduction of flood carrying capacity in altered or relocated watercourses shall be required. (Ord. 2000-02, 3-3-2000)

An AO or AH zone on a FIRM; in these areas, base flood depth ranges from one to three feet (3'), a clearly defined channel does not exist, the path of flooding is unpredictable and indeterminate, and velocity flow may be evident.

1. Construction and substantial improvement of dwellings in AO zones shall result in the lowest floor being elevated above the highest adjacent grade of the building site to or above the depth number specified on the FIRM or to at least two feet (2'), where no depth number is specified.
2. All new construction and substantial improvement of nonresidential buildings in AO zones shall:
   1. Be graded and drained to guide floodwaters around and away from existing and/or proposed buildings; and
   2. Have the lowest floor elevated above the highest adjacent grade of the building site to or above the depth number specified on the FIRM or, where no depth number is specified, to at least two feet (2') above the highest adjacent grade; or together with its appurtenant utility and sanitary facilities, be floodproofed so that any space below that level is watertight, with substantially impermeable walls and structural components capable of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy. Compliance shall be certified by an engineer or architect. (Ord. 2000-02, 3-3-2000)
      

1. Additional Findings For Variances: The approval of any variance in the FHO shall be based on all findings required by TCC 9.08.030 Paragraph D and the additional findings that approval of the variance will not result in increased flood levels, a threat to public safety, or extraordinary public expense.
2. Notice Of Variance: Where a variance of the requirements of this chapter is approved, the administrator's notice of the decision (TCC 9.08.030 Paragraph F) shall clearly state that the county is not liable for any flood damages that result from the variance. Where a variance of the elevation requirements of this chapter is approved, the administrator shall also notify the developer that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation. (Ord. 2000-02, 3-3-2000)