It is the purpose of this chapter to promote the public health, safety, and general welfare, and to minimize public and private losses due to flood conditions in specific areas by provisions designed:

   A.   To protect human life and health;

   B.   To minimize expenditure of public money and costly flood control projects;

   C.   To minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;

   D.   To minimize prolonged business interruptions;

   E.   To minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets, and bridges located in areas of special flood hazard;

   F.   To help maintain a stable tax base by providing for the sound use and development of areas of special flood hazard so as to minimize future flood blight areas; and

   G.   To ensure that those who occupy the areas of special flood hazard assume responsibility for their actions.

The floodplain overlay (FP) district is created to designate areas of the county or cities needing such consideration and is superimposed over other districts. The FP district is the same area as the area of the county or cities identified by the federal insurance administration/emergency management agency flood insurance rate map (FIRM) promulgated for the county or the city, which map is adopted by reference and declared to be part of this chapter and which map shall be maintained on file in the records of the county or city clerk of the county or city at all times hereafter. (Ord. 830, 8-6-2002)

Unless specifically defined below, words or phrases used in this chapter shall be interpreted so as to give them the meanings they have in common usage and to give this chapter its most reasonable application.

AREA OF SPECIAL FLOOD HAZARD: The land in the floodplain within a community subject to a one percent (1%) or greater chance of flooding in any given year. Designation on maps always includes the letters A or V.

BASE FLOOD: The flood having a one percent (1%) chance of being equaled or exceeded in any given year. Also referred to as the 100-year flood. Designation on maps always includes the letters A or V.

DEVELOPMENT: Any manmade change to improved or unimproved real estate, including, but not limited to, buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations located within the area of special flood hazard.

FLOOD INSURANCE RATE MAP (FIRM): The official map on which the federal insurance administration has delineated both the areas of special flood hazard and the risk premium zones applicable to the community.

FLOOD INSURANCE STUDY: The official map on which the federal insurance administration has delineated both the areas of special flood hazard and the risk premium zones applicable to the community.

FLOOD OR FLOODING: A general and temporary condition of partial or complete inundation of normally dry land areas from:

   A.   The overflow of inland or tidal waters, and/or

   B.   The unusual and rapid accumulation of runoff of surface waters from any source.

FLOODWAY: The channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than one foot (1').

LOWEST FLOOR: The lowest floor of the lowest enclosed area (including basement). An unfinished or flood resistant enclosure, usable solely for parking of vehicles, building access or storage, in an area other than a basement area, is not considered a building's lowest floor, provided that such enclosure is not built so as to render the structure in violation of the applicable nonelevation design requirements found at subsection 5-7-5B1b of this chapter.

MANUFACTURED HOME: A structure, transportable in one or more sections, which is built on a permanent chassis and is connected to the required utilities. For floodplain management purposes the term "manufactured home" also includes park trailers, travel trailers, and other similar vehicles placed on a site for greater than one hundred eighty (180) consecutive days. For insurance purposes the term "manufactured home" does not include park trailers, travel trailers, and other similar vehicles.

NEW CONSTRUCTION: Structures for which the "start of construction" commenced on or after the effective date hereof.

START OF CONSTRUCTION: Includes substantial improvement, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, placement or other improvement was within one hundred eighty (180) days of the permit date. The actual start means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or foundation or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not part of the main structure.

STRUCTURE: Anything constructed or erected, the use of which requires location on the ground or attachment to something having a fixed location on the ground. Among other things, structures include buildings, mobile homes, walls, gas or liquid storage tanks and billboards.

SUBSTANTIAL IMPROVEMENT: Any repair, reconstruction, or improvement of a structure, the cost of which equals or exceeds fifty percent (50%) of the market value of the structure either:

   A.   Before the improvement or repair is started, or

   B.   If the structure has been damaged and is being restored, before the damage occurred.

For the purposes of this definition "substantial improvement" is considered to occur when the first alteration of any wall, ceiling, floor, or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure. (Ord. 830, 8-6-2002)

   A.   Lands To Which This Chapter Applies: This chapter shall apply to all areas designated on the map referred to in section 5-7-1 of this chapter designated as the floodplain overlay (FP) district.

   B.   Basis For Establishing The Areas Of Special Flood Hazard: The areas of special flood hazard identified by the federal insurance administration in a scientific and engineering report entitled the "Flood Insurance Study" for the applicable jurisdiction, which is most current at the time of the adoption of this title, with accompanying flood insurance maps, is hereby adopted by reference and declared to be a part of this chapter. The "Flood Insurance Study" is on file at the office of the county or city clerk. (Ord. 830, 8-6-2002)

   A.   Development Permit Required: A development permit shall be obtained before construction or development begins within any area of special flood hazard established in subsection 5-7-3B of this chapter. The permit shall be for all structures, including manufactured homes, as set forth in the definitions, and for all development including fill and other activities, also as set forth in the definitions.

   B.   Designation Of The Building Official: The building official is hereby appointed to administer and implement this title by granting or denying development permit applications in accordance with its provisions. This process may be combined with any building permit process otherwise required by the city.

   C.   Duties And Responsibilities Of The Administrator: Duties of the administrator shall include, but not be limited to:

      1.   Permit Review:

         a.   Review all development permits to determine that the permit requirements of this chapter have been satisfied.

         b.   Review all development permits to determine that all necessary permits have been obtained from those federal, state or local governmental agencies from which prior approval is required.

         c.   Review all development permits to determine if the proposed development is located in the floodway. If located in the floodway, assure that the encroachment provisions of subsection 5-7-5C1 of this chapter are met.

      2.   Use Of Other Base Flood Data: When base flood elevation data has not been provided in accordance with subsection 5-7-3B, "Basis For Establishing The Areas Of Special Flood Hazard", of this chapter, the administrator shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a federal, state or other source, in order to administer subsection 5-7-5B, "Specific Standards", and subsection 5-7-5C, "Floodways", of this chapter.

      3.   Information To Be Obtained And Maintained:

         a.   Where base flood elevation data is provided through the flood insurance study or required as in subsection C2 of this section, obtain and record the actual elevation (in relation to mean sea level) of the lowest floor (including basement) of all new or substantially improved structures, and whether or not the structure contains a basement.

         b.   For all new or substantially improved floodproofed structures:

            (1)   Verify and record the actual elevation (in relation to mean sea level),

            (2)   Maintain the floodproofing certifications required in subsection 5-7-5B of this chapter, and

            (3)   Maintain for public inspection all records pertaining to the provisions of this chapter.

      4.   Alteration Of Watercourses:

         a.   Notify adjacent communities and the Idaho department of water resources prior to any alteration or relocation of a watercourse, and submit evidence of such notification to the federal insurance administration.

         b.   Require that maintenance is provided within the altered or relocated portion of watercourse so that the flood carrying capacity is not diminished.

      5.   Interpretation Of FIRM Boundaries: Make interpretations where needed, as to exact location of the boundaries of the areas of special flood hazard (for example, where there appears to be a conflict between a mapped boundary and actual field conditions). The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation. Such appeals shall be granted consistent with the standards of section 60.6 of the rules and regulations of the national flood insurance program (44 CFR 59-76). (Ord. 830, 8-6-2002)

   A.   General Standards: In all areas of special flood hazard, the following standards are required:

      1.   Anchoring:

         a.   All new construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure.

         b.   All manufactured homes must likewise 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, use of over the top or frame ties to ground anchors (reference FEMA's "Manufactured Home Installation In Flood Hazard Areas" guidebook for additional techniques).

      2.   Construction Materials And Methods:

         a.   All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.

         b.   All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.

         c.   Electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities shall be designed and/or otherwise elevated or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

      3.   Utilities:

         a.   All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system;

         b.   New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharge from the systems into floodwaters; and

         c.   On site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.

      4.   Subdivision Proposals:

         a.   All subdivision proposals shall be consistent with the need to minimize flood damage;

         b.   All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize flood damage;

         c.   All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage; and

         d.   Where base flood elevation data has not been provided or is not available from another authoritative source, it shall be generated for subdivision proposals and other proposed developments which contain at least fifty (50) lots or five (5) acres (whichever is less).

      5.   Review Of Building Permits: Where elevation data is not available either through the flood insurance study or from another authoritative source (subsection 5-7-4C2 of this chapter), applications for building permits shall be reviewed to assure that proposed construction will be reasonably safe from flooding. The test of reasonableness is a local judgment and includes use of historical data, high water marks, photographs of past flooding, etc., where available. Failure to elevate at least two feet (2') above grade in these zones may result in higher insurance rates.

   B.   Specific Standards: In all areas of special flood hazard where base flood elevation data has been provided as set forth in subsection 5-7-3B, "Basis For Establishing The Areas Of Special Flood Hazard" or subsection 5-7-4C2, "Use Of Other Base Flood Data", of this chapter, the following provisions are required:

      1.   Residential Construction:

         a.   New construction and substantial improvements of any residential structure shall have the lowest floor, including basement, elevated to or above base flood elevation.

         b.   Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or 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 must 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, or other coverings or devices, provided that they permit the automatic entry and exit of floodwaters. Any residential structure shall have the lowest floor, including basement, elevated to or above 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 the level of the base flood elevation; or, together with attendant utility and sanitary facilities, shall:

         a.   Be floodproofed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water.

         b.   Have structural components capable of resisting hydrostatic and hydrodynamic loads and effect of buoyancy.

         c.   Be certified by a registered professional engineer or architect that the design and methods of construction are in accordance with accepted standards of practice for meeting provisions of this subsection based on their development and/or review of the structural design. Such certifications shall be provided to the administrator as set forth in subsection 5-7-4C3b of this chapter.

         d.   Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space below the lowest floor as described in subsection B1b of this section.

         e.   Applicants floodproofing nonresidential buildings shall be notified that flood insurance premiums will be based on rates that are one foot (1') below the floodproofed level (e.g., a building constructed to the base flood level will be rated as 1 foot below that level).

      3.   Manufactured Homes: All manufactured homes to be placed or substantially improved within zones A1-30, AH and AE shall 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 A1b of this section.

   C.   Floodways: Located within areas of special flood hazard established in subsection 5-7-3B of this chapter are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwater which carries debris, potential projectiles, and erosion potential, the following provisions apply:

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

      2.   If subsection C1 of this section is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this section. (Ord. 830, 8-6-2002)

The granting of approval of any structure or use shall not constitute a representation, guarantee or warranty of any kind or nature of the city or its governing body or by any officer or employee thereof, of the practicality or safety of any structure or use proposed and shall create no liability upon or cause action against such public body, officer or employee for any damage that may result pursuant thereto. (Ord. 830, 8-6-2002)

Restrictions regarding height, rear yards, side yards, front yard setback, minimum lot area, signs, vision clearance and parking space shall be the same as set forth in each specific district located within the floodplain overlay zone area. (Ord. 830, 8-6-2002)

It shall be unlawful to erect, alter, maintain or establish in a floodplain overlay zone any building, use or occupancy not permitted or allowed in the foregoing provisions, except existing nonconforming uses may continue as herein provided. (Ord. 830, 8-6-2002)