An overlay zone is created by superimposing the overlay zone's lines on the zoning map for a hazard area, a special resource area, or a development area that has provisions that apply in the overlay area in addition to all other provisions of this title. Overlay zones create a framework for protection of persons and property, conservation, or development of special geographical areas. (Ord. 392, 8-16-2021)

   A.   Idaho Code Sections 46-1020, 46-1022 and 46-1023 authorizes local governments to adopt floodplain management regulations designed to promote the public health, safety and general welfare of its citizens, to ensure the residents of Latah County will be eligible for federal flood insurance, and to minimize the threat of flood damage in Latah County.

   B.   The purpose of this article is to:

      1.   Protect human life, health, and property;

      2.   Minimize expenditure of public money for costly flood control projects;

      3.   Minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;

      4.   Minimize prolonged business interruptions;

      5.   Minimize damage to public facilities and utilities such as water and gas mains, electric, telephone, sewer lines, roads and bridges located in flood hazard areas;

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

      7.   Provide that developers are notified that property is in a flood hazard area; and

      8.   Ensure that those who occupy the flood hazard areas assume responsibility for their actions. (Ord. 392, 8-16-2021)

   A.   Basis For Establishing Flood Hazard Areas: This article shall apply to all special flood hazard areas within unincorporated Latah County. The special flood hazard areas identified by the Federal Insurance Administrator in a scientific and engineering report entitled "The Flood Insurance Study, Latah County, Idaho (Unincorporated Areas)" dated February 1980, and revised September 1, 1983 and April 15, 2002 with accompanying Flood Insurance Rate Maps and the Flood Boundary-Floodway Maps dated August 15, 1980, April 13, 1982, and April 15, 2002, and any revisions thereto, are hereby adopted by reference and declared to be a part of this title. The Flood Insurance Study and accompanying maps are available for review by contacting the Latah County Planning and Building Department.

   B.   Noncompliance: No structure in a special flood hazard area shall hereafter be constructed, located, or altered and no land shall be excavated or filled without full compliance with the terms of this title. In addition to any other enforcement remedies available under this title, any violation of this article shall result in notification being sent to the Federal Emergency Management Agency.

   C.   Warning And Disclaimer of Liability: The degree of flood protection required by this article is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur. This article does not imply that land outside the special flood hazard area or uses within such areas will be free from flooding or flood damages. This article shall not create liability on the part of Latah County, any officer or employee thereof, or the Federal Emergency Management Agency, for any flood damages that result from reliance on this article or any administrative decision lawfully made thereunder.

   D.   Administration: The Director of the Planning and Building Department shall act as the Floodplain Administrator but may assign designees to implement these provisions. The Floodplain Administrator or their designee(s) shall administer, implement, and enforce this article by granting or denying floodplain development permits in accordance with its provisions. In accordance with Idaho Code, the Planning and Building Department shall maintain records pertaining to the provisions of this title for public inspection.

   E.   Prohibition On New Activities: There shall be no new construction of dwellings or placement of manufactured housing in the special flood hazard area or floodway, or new construction or placement of accessory buildings in the floodway, unless an applicant can show that there is no other portion of their parcel available for their intended purpose that is outside of the special flood hazard area. Parcels created after the effective date hereof shall only be allowed to develop on portions of these parcels that are outside of the designated special flood hazard area. If an act of nature destroys a residence, and the infrastructure for that residence is still useable, the residence may be replaced at that location so long as the remaining portions of the old structure, the new structure, and any additional improvements that need to be made are brought into compliance with this title, and so long as its location is not in the floodway.

   F.   Development: For the purposes of this article, "development" is defined as any man made 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, storage of equipment or materials, or sewage lagoons. (Ord. 392, 8-16-2021)

   A.   Establishment And Purpose of Permit: A floodplain development permit and fee is hereby established and required for all construction and other development to be undertaken in areas of special flood hazard in Latah County. It shall be a violation of this title to undertake any development in a special flood hazard area, as shown on the maps identified in subsection 9-5A-2A of this article, without a valid floodplain development permit. Application for a permit shall be made on forms furnished by the Planning and Building Department and may require reports and drawings which the Floodplain Administrator or designee deems necessary to issue the permit.

   B.   Application For Floodplain Development Permit: The applicant shall provide the following information when applicable:

      1.   The proposed elevation, in relation to mean sea level, of the lowest floor (including basement) of any new or substantially improved structure to be located in special flood hazard areas. Upon completion of the lowest floor, the permittee shall submit to the Floodplain Administrator or designee the as built elevation of the lowest floor (including basement) certified by a professional surveyor or professional engineer licensed in the State of Idaho. If no base flood elevation data are available the permittee shall submit to the Floodplain Administrator or designee verification that the as built elevation of the lowest floor is three feet (3') above the highest adjacent ground elevation.

      2.   The proposed elevation, in relation to mean sea level, to which any new or substantially improved nonresidential structure will be floodproofed. Upon completion of the floodproofed portion of the structure, the permittee shall submit to the Floodplain Administrator or designee the as built floodproofed elevation, certified by a professional surveyor or a professional engineer licensed in the State of Idaho. If no base flood elevation data are available, the permittee shall submit to the Floodplain Administrator or designee verification, certified by a professional surveyor or professional engineer licensed in the State of Idaho, that the elevation of floodproofing is three feet (3') above the highest adjacent ground elevation.

      3.   A certificate from a professional engineer licensed in the State of Idaho that any nonresidential floodproofed structure will meet the criteria of section 9-5A-4 of this article.

      4.   A technical analysis, by a professional engineer licensed in the State of Idaho, which shows whether a proposed development to be located in a special flood hazard area may result in physical damage to any property.

      5.   In Flood Zone A, when no base flood elevation data are available, base flood elevation data from a professional engineer licensed in the State of Idaho shall be provided by the permit applicant for development proposals, including subdivisions or manufactured home parks greater than five (5) acres or fifty (50) lots, whichever is the lesser.

      6.   A description of the extent to which any watercourse will be altered or relocated as a result of proposed development. Computations by a professional engineer licensed in the State of Idaho must be submitted that demonstrate that the altered or relocated segment will provide equal or greater conveyance than the original stream segment. The applicant must provide legally binding commitments that the conveyance capacity of the altered or relocated stream segment will be maintained. The applicant must also provide the Federal Emergency Management Agency with all documentation it deems necessary to revise the documents listed in subsection 9-5A-2A of this article.

      7.   The applicant shall notify adjacent communities, the Army Corps of Engineers, the Idaho Department of Environmental Quality, and the Idaho Department of Water Resources prior to any alteration or relocation of a watercourse, and submit evidence of such notification to the Floodplain Administrator or designee and to the Federal Insurance Administrator through appropriate notification means .

      8.   When base flood elevation data have not been provided by the study or maps listed above, the Floodplain Administrator or designee, in order to administer this article, may review and reasonably utilize information presented from the applicant that has been verified by a professional engineer licensed in the State of Idaho regarding any base flood elevation and floodway data available from a Federal, State, or other qualified source.

   C.   Permit Application Review And Issuance: Prior to issuance of a development permit, the Floodplain Administrator or designee shall review each application to ensure the permit requirements of this article have been satisfied and to verify the completeness of information required by subsection B of this section and submission of plans indicating compliance with the standards of this title as provided in section 9-5A-4 of this article. As a condition of development permit issuance, the permittee shall receive all necessary permits from those Federal, State, or local governmental agencies from which approval is required. The Floodplain Administrator or designee shall also notify the Idaho Department of Water Resources and the U.S. Army Corps of Engineers for their determination if any additional permits are necessary.

   D.   Permit Administration: Upon issuance of a development permit, the Floodplain Administrator or designee may make periodic inspections of the site to monitor compliance with permit conditions and shall issue stop work orders for any floodplain development found ongoing without a permit or noncompliant with the provisions of this title or the conditions of the development permit. (Ord. 392, 8-16-2021)

   A.   Encroachments:

      1.   Within special flood hazard areas Zone A1-30, where the base flood elevation has been determined but the floodway has not been determined, no new construction, substantial improvement, or other development (including fill) shall be permitted unless a technical evaluation by a professional engineer licensed in the State of Idaho demonstrates that the proposed development along with existing development will not increase the base flood elevation more than one foot (1') above the base flood elevation at any point in the community.

      2.   Within a regulatory floodway, no new construction, substantial improvements or other development (including fill) shall be permitted unless it has been demonstrated through hydrologic and hydraulic analysis performed in accordance with standard engineering practice (including a no rise certification that includes both a step backwater analysis and a conveyance compensation computation) by a professional engineer licensed in the State of Idaho demonstrates that the proposed development will not result in any increase in base flood elevation.

      3.   All residential and nonresidential structures in the special flood hazard area and all development in the floodway shall be designed or reviewed and approved by a professional engineer licensed in the State of Idaho who shall ensure that all elevations, structural design, and other requirements of this title and the Building Code ordinances are met and who shall also certify that the completed construction is in compliance with their approved plans.

      4.   At the discretion of the Floodplain Administrator or designee, the Floodplain Administrator or designee can require an elevation certificate, a letter of map amendment or revision be sent to FEMA, or an as-built verification for any development permit in the special flood hazard area.

   B.   Standards For Residential Structures:

      1.   If base flood elevation data are given, new construction and substantial improvements, together with attendant utility and sanitary facilities, shall have the lowest floor elevated one foot (1') above base flood elevation. If no base flood elevation data are given, new and substantially improved structures shall have the lowest floor elevated at least three feet (3') above the highest adjacent ground elevation. Basements for residences are not permitted in special flood hazard areas.

   C.   Standards For Nonresidential Structures:

      1.   For a nonresidential structure to be eligible for wet floodproofing, the structure must be used solely for limited storage, parking, or access and must meet the criteria for wet floodproofing set forth in subsection E of this section, as well as other criteria for building in a floodplain as set forth in this title.

      2.   If base flood elevation data are given, new construction and substantial improvements, together with attendant utility and sanitary facilities, shall have the lowest floor (including basements) elevated one foot (1') above base flood elevation or shall be floodproofed so that the structure is watertight up to one foot (1') above the base flood elevation. All structural components located below the floodproofed level must be capable of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy.

      3.   If no base flood elevation data are given, new and substantially improved structures shall have the lowest floor (including basements) elevated three feet (3') above the highest adjacent grade or shall be floodproofed so that the structure is watertight up to three feet (3') above the highest adjacent grade. All structural components located below the floodproofed level must be capable of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy.

   D.   Manufactured Homes And Recreational Vehicles:

      1.   Recreational vehicles may be placed in a special flood hazard area if the vehicle is fully licensed and ready for immediate highway use, subject to section 9-4C-4 of this title. 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, decks, or structures.

      2.   Manufactured homes placed or substantially improved in a special flood hazard area shall be elevated on a permanent foundation such that the lowest floor is elevated at least one foot (1') above the base flood elevation or, if no base flood elevation is given, three feet (3') above the highest adjacent grade. The home shall be securely anchored to a permanent, adequately anchored foundation system to resist flotation, collapse and lateral movement.

      3.   Manufactured homes placed in existing spaces in a previously established manufactured home park shall be elevated as specified above and attached to and supported by reinforced piers which are adequately anchored to resist flotation, collapse or lateral movement of the manufactured home.

   E.   Standards For All Construction in Special Flood Hazard Areas:

      1.   All new construction and substantial improvements (including manufactured homes) in special flood hazard areas shall be anchored to prevent flotation, collapse, or lateral movement during the base flood event resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage, as well as using methods and practices that minimize flood damage.

      2.   Spaces below the lowest floor of all new or substantially improved structures shall be used solely for parking of vehicles, building access, or storage. These spaces shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs must meet 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; and

         b.   The bottom of all such openings no higher than one foot (1') above the lowest adjacent finished grade.

   F.   Standards For Utilities In Special Flood Hazard Areas:

      1.   All mechanical, electrical, heating, ventilation, air conditioning equipment, plumbing, other utilities, and other service facilities shall be designed so as to prevent water from entering or accumulating within the components during conditions of flooding and shall be elevated one foot (1') above base flood elevation.

      2.   When located below the base flood elevation or if base flood elevation data is not available, all utilities shall be designed or reviewed and approved by a professional engineer licensed in the State of Idaho who shall ensure that all elevations, structural design, and other requirements of this title, the Building Code ordinance, or other State or local regulations are met and who shall also certify that the completed construction is in compliance with their approved plans.

      3.   New and replacement water supply and sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the system. On site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.

      4.   Sanitary sewer and storm drainage systems for buildings that have openings below the base flood elevation shall be provided with automatic backflow valves or other automatic backflow devices that are installed in each discharge line passing through a building's exterior wall.

   G.   Subdivision Proposals:

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

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

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

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

   H.   Critical Facilities:

      1.   Critical facilities constructed within the floodplain or special flood hazard area shall have the lowest floor elevated three feet (3') or more above the level of the 100-year base flood elevation at the site. When base flood elevations have not been provided, they shall be generated. Floodproofing and sealing measures are required to be taken to ensure that toxic substances will not be displaced by or released into floodwaters. Access routes to all critical facilities shall be elevated to or above the level of the base flood to the extent possible.

      2.   Critical facilities include, but are not limited to, emergency service facilities and equipment (fire stations, police stations, rescue squads, public works facilities, custodial facilities such as jails and juvenile detention centers, hospitals, and other health care facilities, etc.), communications networks (telephones, emergency service radio systems, repeater sites and base stations, television and radio stations, etc.), water supply system/facilities, wastewater treatment facilities, public utilities (power plants, substations, power lines, etc.), transportation networks (roads, bridges, airports, rail terminals), public facilities, or any other similar facilities the Planning Department deems to be a critical facility. (Ord. 392, 8-16-2021)

Any decision made by the Latah County Planning and Building Department regarding this article, may be appealed to the Land Use Board of Appeals as per subsection 9-1-11 of this title. Such appeal shall be guided by and shall not violate any provision of the Federal regulations that govern the Flood Insurance Program. (Ord. 392, 8-16-2021)