As used in this chapter, the following words and terms shall have the meanings ascribed to them in this section:
ADMINISTRATOR: See Floodplain Administrator.
BASE FLOOD: The flood having a one percent (1%) chance of being equaled or exceeded each year.
BASE FLOOD ELEVATION (BFE): A determination by the Federal Insurance Administrator of the water surface elevations of the base flood, that is, the flood level that has a one percent (1%) or greater chance of occurrence in any given year. When the BFE has not been provided in a special flood hazard area, it may be obtained from engineering studies available from a Federal, State, or other source using FEMA-approved engineering methodologies. This elevation, when combined with the freeboard, establishes the flood protection elevation.
BASEMENT: The portion of a structure with its floor subgrade (below ground level) on all sides.
BUILDING: See definition of structure.
COMPENSATORY STORAGE: Sometimes referred to as "cut-and-fill", this provision requires developers to compensate for the loss of flood storage caused by filling in the floodplain fringe by removing an equal amount of material in the floodplain near the proposed development. This mitigation tool helps to maintain flood storage and ensure that floodwaters will not be displaced onto someone else's property as a result of the floodplain fill. Engineering analysis is required when considered for mitigation to offset fill in the floodplain.
DEVELOPMENT: Any manmade change to improved or unimproved real estate, including, but not limited to, the construction of buildings, structures or accessory structures, or the construction of additions or substantial improvements to buildings, structures or accessory structures; the placement of mobile homes; mining, dredging, filling, grading, paving, excavation or drilling operations or storage of equipment or materials; and the deposition or extraction of materials, including the construction of dikes, berms and levees.
FLOOD INSURANCE RATE MAP (FIRM): An official map of a community, on which the Federal Insurance Administrator has delineated both the special hazard areas and the risk premium zones applicable to the community. A FIRM that has been made available digitally is called a Digital Flood Insurance Rate Map (DFIRM).
FLOOD INSURANCE STUDY (FIS): An examination, evaluation, and determination of flood hazards and, if appropriate, corresponding water surface elevations; or an examination, evaluation and determination of mudslide (i.e., mudflow) and/or flood-related erosion hazards. Also known as Flood Elevation Study.
FLOOD OR FLOODING:
A. A general and temporary condition of partial or complete inundation of normally dry land areas from:
1. The overflow of inland waters from streams, rivers, and other watercourses.
2. The unusual and rapid accumulation or runoff of surface waters from any source.
3. Mudslides (i.e., mudflows) which are proximately caused by flooding as defined in subsection A2 of this definition and are akin to a river of liquid and flowing mud on the surface of normally dry land areas, as when earth is carried by a current of water and deposited along the path of the current.
B. The collapse or subsidence of land along the shore of a lake or other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding as defined in subsection A1 of this definition.
FLOOD PROOFING: Any combination of structural and nonstructural additions, changes, or adjustments to structures which reduce or eliminate risk of flood damage to real estate or improved real property, water and sanitary facilities, structures, and their contents.
FLOOD PROTECTION ELEVATION (FPE): The base flood elevation plus the freeboard.
A. In "special flood hazard areas" where base flood elevations (BFEs) have been determined, this elevation shall be the BFE plus two feet (2') of freeboard; and
B. In "special flood hazard areas" where no BFE has been established, this elevation shall be at least two feet (2') above the highest adjacent grade.
FLOODPLAIN: Floodplain or flood-prone area means any land area susceptible to being inundated by water from any source (see definition of flooding).
FLOODPLAIN ADMINISTRATOR: Referred to as the “Administrator” in this Chapter, is the Administrator of the Land Use and Building Services Department, and is hereby appointed to administer, implement and enforce this Chapter. The Administrator may delegate authority to implement these provisions.
FLOODPLAIN MANAGEMENT: The operation of an overall program of corrective and preventive measures for reducing flood damage, including but not limited to emergency preparedness plans, flood control works and floodplain management regulations.
FLOODPLAIN MANAGER: The person appointed by the Administrator to manage and implement the provisions of the Floodplain Overlay District regulations.
FLOODWAY (REGULATORY): 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 a designated height.
FREEBOARD: A factor of safety usually expressed in feet above a flood level for the purposes of floodplain management. Freeboard tends to compensate for the many unknown factors that could contribute to flood heights greater than the height calculated for a selected size flood and floodway conditions, such as wave action, obstructed bridge openings, debris and ice jams and the hydrologic effects of urbanization in a watershed. The base flood elevation (BFE) plus the freeboard establishes the flood protection elevation (FPE). Freeboard shall be two feet (2').
HAND EQUIPMENT: Any construction machinery such as chain saws, wheelbarrows, post hole diggers (not attached to vehicles) and all handheld tools.
HIGHEST ADJACENT GRADE: Highest adjacent grade means the highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure.
HISTORIC STRUCTURE: Any structure that is:
A. Listed individually in the National Register of Historic Places (a listing maintained by the Department of Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register;
B. Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district;
C. Individually listed on a State Inventory of Historic Places in states with historic preservation programs which have been approved by the Secretary of the Interior; or
D. Individually listed on a local Inventory of Historic Places in communities with historic preservation programs that have been certified either:
1. By an approved State program as determined by the Secretary of the Interior or
2. Directly by the Secretary of the Interior in states without approved programs.
LETTER OF MAP CHANGE (LOMC): An official FEMA determination, by letter, to amend or revise effective flood insurance rate maps, flood boundary and floodway maps, and flood insurance studies. LOMCs are issued in the following categories:
A. Letter Of Map Amendment (LOMA): An official amendment, by letter, to an effective National Flood Insurance Program (NFIP) map. An LOMA establishes a property's or structure's location in relation to the special flood hazard area (SFHA). LOMAs are usually issued because a property or structure has been inadvertently mapped as being in the floodplain but is actually on natural high ground above the base flood elevation.
B. Letter Of Map Revision (LOMR): FEMA's modification to an effective Flood Insurance Rate Map (FIRM). LOMRs are generally based on the implementation of physical measures that affect the hydrologic or hydraulic characteristics of a flooding source and thus result in the modification of the existing regulatory floodway, the effective base flood elevations (BFEs), or the special flood hazard area (SFHA). The LOMR officially revises the FIRM, and sometimes the Flood Insurance Study (FIS) report, and when appropriate, includes a description of the modifications. The LOMR is generally accompanied by an annotated copy of the affected portions of the FIRM.
C. Letter Of Map Revision Based On Fill (LOMR-F): FEMA's modification of the special flood hazard area (SFHA) shown on the Flood Insurance Rate Map (FIRM) based on the placement of fill outside the existing regulatory floodway. The LOMR-F does not change the FIRM or FIS report.
D. Conditional Letter Of Map Revision (CLOMR): A formal review and comment as to whether a proposed flood protection project or other project complies with the minimum NFIP requirements for such projects with respect to delineation of special flood hazard areas. A CLOMR does not revise the effective Flood Insurance Rate Map (FIRM) or Flood Insurance Study (FIS). Upon submission and approval of certified as-built documentation, an LOMR may be issued by FEMA to revise the effective FIRM. Building permits cannot be issued based on a CLOMR, because a CLOMR does not change the NFIP map.
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 non-elevation design requirements of 44 CFR section 60.3 and this chapter.
MANUFACTURED HOME: A structure transportable in one or more sections, built on a permanent chassis and designed to be used with or without a permanent foundation when connected to the required utilities. The term "manufactured home" does not include a "recreational vehicle".
NEW CONSTRUCTION: For floodplain management purposes, new construction means structures for which the start of construction commenced on or after May 14, 1971 (effective date of the initial regulations adopted by the County) and includes any subsequent improvements to such structures.
NO ADVERSE IMPACT: No adverse impact floodplain management takes place when the actions of one property owner shall not adversely affect the rights of other property owners or the County's NFIP eligibility. Adverse impacts include increased flood peaks, flood stage, flood velocity, erosion and sedimentation, or decreased water quality or quality of riparian habitat.
ORDINARY HIGH WATER MARK: The mark on all watercourses, where the presence and action of waters is so common and continued in all ordinary years as to mark upon the soil a character distinct from that of the abutting upland, in respect to vegetation and destroy its value for agricultural purposes. With respect to the riparian setback, in areas where riprap bank stabilization has occurred, the measurement shall begin on the landward side of such stabilization work.
RECREATIONAL VEHICLE: A vehicle that is:
A. Built on a single chassis,
B. Four hundred (400) square feet or less when measured at the largest horizontal projection,
C. Designed to be self-propelled or permanently towed by a light duty truck, and
D. Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use.
REGULATORY FLOODWAY: See definition of floodway.
RIPARIAN AREAS: Lands adjacent to a watercourse or water body that are influenced by water, have the presence of riparian vegetation and have an important function in mitigating flood damage.
RIPARIAN VEGETATION: The vegetation associated with streams that are subject to and sustained by seasonal surface water inputs, or high ground water elevations. Species commonly found in riparian areas are listed by the Idaho Conservation Data Center as "wetlands and riparian plants associations in Idaho". Riparian areas in Blaine County shall be delineated by the presence of riparian plant communities that appear on the Conservation Data Center list or other lists adopted by resolution of the Board.
SPECIAL FLOOD HAZARD AREA (SFHA): The land within the Floodplain Overlay District, subject to a one percent (1%) or greater chance of flooding in any given year. For purposes of these regulations, the term "special flood hazard area" is synonymous in meaning with the phrase "area of special flood hazard".
START OF CONSTRUCTION: Start of construction, includes substantial improvement, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition 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 foundations 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. For a substantial improvement, the actual start of construction means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or not that alteration affects the external dimensions of the building.
STREAMS: Those areas where surface water produces a defined channel or bed which demonstrates evidence of the passage of water. Dry washes, irrigation ditches, canals, surface water runoff devices or other entirely artificial water bodies/watercourses (unless specifically referred to herein) are not included. "Streams" are further defined as follows:
Class 1 Streams: Streams and/or reaches of streams with the potential to have extensive flooding, erosion and attendant hazards and include the Big Wood River.
Class 2 Streams: Streams and/or reaches of streams that flow year round during years of normal rainfall and have the potential for significant flooding and erosion. Such streams include the East Fork of the Big Wood River, Little Wood River, Salmon River (Upper), Smiley Creek, Trail Creek and Warm Springs Creek.
Class 3 Streams: Smaller perennial or intermittent streams and/or reaches of streams that are prone to periodic flooding and erosion. Class 3 streams shall include, but are not limited to, the following: Beaver Creek, Broadford Slough, Croy Creek, Deer Creek, Eagle Creek, Greenhorn Creek, Purdum Slough, Fish Creek and Rock Creek.
Class 4 Streams: All spring fed creeks and their tributaries, which are not subject to erosive flooding. Class 4 streams shall include, but are not limited to, the following: Grove Creek, Loving Creek, Mudd Creek, Patton Creek, Silver Creek, Spring Creek and Wilson Creek.
STRUCTURE: For floodplain management purposes, a walled and roofed building, including a manufactured home, as well as a gas or liquid storage tank that is principally above ground.
SUBSTANTIAL DAMAGE: Damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed fifty percent (50%) of its market value before the damage occurred. See definition of "substantial improvement".
SUBSTANTIAL IMPROVEMENT: Any reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds fifty percent (50%) of the market value of the structure before the start of construction of the improvement. This term includes structures which have incurred "substantial damage", regardless of the actual repair work performed. Permits for any improvement shall be counted cumulatively for a period of ten (10) years. If the improvement project is conducted in phases, the total of all cost associated with each phase, beginning with the issuance of the first permit, shall be utilized to determine whether "substantial improvement" will occur. The term does not, however, include either:
A. Any project for improvement of a structure to correct existing violations of State or local Health, Sanitary, or Safety Code specifications which have been identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions; or
B. Any alteration of a historic structure, provided that the alteration will not preclude the structure's continued designation as a "historic structure" and the alteration is approved by variance issued pursuant to chapter 30 of this title.
YARDSCAPE: Introduced vegetation such as grass and ornamental shrubs, forbs and trees that may require irrigation in a normal cycle. (Ord. 2019-02, 1-8-2019; amd. Ord. 2021-12, 7-20-2021)