For the purposes of this article, the terms, as herein defined, shall be used in the administration of this article:
A ZONE: | A special flood hazard area delineated on the flood insurance rate map (FIRM) that is subject to inundation by the one percent (1%) annual chance flood event generally determined using approximate methodologies. Because detailed hydraulic analyses have not been performed, no base flood elevations or flood depths are shown. |
AE ZONE: | A special flood hazard area delineated on the flood insurance rate map (FIRM) that is subject to inundation by the one percent (1%) annual chance flood event determined by detailed methods. Base flood elevations are shown. |
AH ZONE: | A special flood hazard area delineated on the flood insurance rate map (FIRM) that is subject to inundation by one percent (1%) annual chance shallow flooding, usually in the form of a pond, where average depths are between one and three feet (3'). Base flood elevations derived from detailed hydraulic analyses are shown at selected intervals in this zone. |
AO ZONE: | A special flood hazard area delineated on the flood insurance rate map (FIRM) that is a river or stream hazard area and subject to inundation by one percent (1%) annual chance shallow flooding, usually in the form of sheet flow, where average depths are between one and three feet (3'). Average flood depths derived from detailed hydraulic analyses are shown in this zone. |
AREA OF SHALLOW FLOODING: | An area within the flood fringe shown on the flood insurance rate map (FIRM) as an AO or an AH zone; and where the base flood depths range 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. See AO ZONE. |
BASE FLOOD: | The flood having a one percent (1%) chance of being equaled or exceeded each year. Also known as the "regulatory flood." |
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 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: | Any area of a structure having its floor subgrade (below ground level) on all sides, including a crawl space. |
CHECK DAM: | A structure erected perpendicular to the direction of flow of floodwaters in a foothill or other hillside tributary floodplain, and which does not exceed ten feet (10') in height or fifty (50) acre-feet of storage capacity and is constructed for the purpose of reducing the velocity of floodwaters or reducing flood flows downstream or both. For the purposes of this article, energy dissipating devices shall be considered check dams. |
CLEANING: | Mowing, cutting, or burning of weeds, trees and other nuisance growth, including algae growth, application of pesticides as permitted, removal of beaver dams, and removal of trash or other debris whether floating, lodged or otherwise obstructing the conveyance of water flow through channels and works. |
CRITICAL FACILITIES: | Facilities that are vital to flood response activities or critical to the health and safety of the public before, during, and after a flood, such as a hospital, emergency operations center, electric substation, police station, fire station, nursing home, school, vehicle and equipment storage facility, or shelter; and facilities that, if flooded, would make the flood problem and its impacts much worse, such as a hazardous materials facility, power generation facility, water utility, or wastewater treatment plant. |
DEVELOPMENT: | Development: 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, or storage of equipment or materials. |
DEVELOPMENT ACTIVITY: | Any activity defined as Development which will necessitate a Floodplain Permit; This includes 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; filling, mining, dredging, grading, paving, excavation or drilling operations; storage of equipment and materials; and the deposition or extraction of materials; specifically including the construction of dikes, berms and levees. |
DIGITAL FLOOD INSURANCE RATE MAP (DFIRM): | A digital representation of a flood insurance rate map (FIRM) within an electronic mapping application depicting both the special flood hazard areas and the risk premium zones applicable within Ada County. |
DREDGING: | The removal of sediment from the bottom of streams creeks, irrigation and drainage channels and works. |
ELEVATION CERTIFICATE: | The Elevation Certificate is an important administrative tool of the NFIP. It is used to determine the proper flood insurance premium rate; it is used to document elevation information; and it may be used to support a request for a Letter of Map Amendment (LOMA) or Letter of Map Revision based on fill (LOMR-F). |
FLOOD ELEVATION STUDY (FES): | An examination, evaluation and determination of flood hazards, flood profiles, floodway boundaries and water surface elevation of the base flood. |
FLOOD FRINGE: | The area between the floodway and the one hundred (100) year floodplain boundary, including the AO and A zones where no floodway is identified (see section 8-1A-2
, figure 18 of this title). |
FLOOD INSURANCE RATE MAP (FIRM): | The official map of Ada County, on which the Federal Insurance Administrator has delineated both the special flood hazard areas and the risk premium zones applicable to Ada County. 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. |
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 or tidal waters. 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 paragraph A.2. of this definition and are akin to a river of liquid and flowing mud on the surfaces 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 paragraph A.1 of this definition. |
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 flood plain management regulations. |
FLOODPLAIN MANAGEMENT REGULATIONS: | Zoning articles, subdivision regulations, building codes, health regulations, special purpose articles (such as a flood plain article, grading article, and erosion control article), and other applications of police power. The term describes such state or local regulations, in any combination thereof, which provide standards for the purpose of flood damage prevention and reduction. |
FLOODPROOFING: | Any combination of structural and non-structural additions, changes, or adjustments to structures which reduce or eliminate 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 one and a half feet (1.5') 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: | Any land area susceptible to being inundated by floodwaters (see section 8-1A-2
, figure 18 of this title). |
FLOODPLAIN AND BANK RESTORATION: | Is the reestablishment of the structure and function of ecosystems and floodplains to return the ecosystem as closely as possible to its natural conditions and functions prior to being developed or impacted by a natural event. |
FLOODPROOFING: | Any combination of structural and nonstructural additions, changes, or adjustments to structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, structures and their contents. |
FLOODPROOFING CERTIFICATE: | A FEMA form used to certify a floodproofing design for a nonresidential structure that is being floodproofed as an alternative to elevating the structure to or above the base flood elevation. |
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 a designated height. |
FOOTHILL OR HILLSIDE TRIBUTARY FLOODPLAIN: | A watercourse or drainageway located in the foothills or other hillside tributary that collects and carries waters draining from an area of greater than ten (10) acres in size. |
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 one and half feet (1.5'). |
FUNCTIONALLY DEPENDENT USE: | A facility that cannot be used for its intended purpose unless it is located or carried out in close proximity to water, such as a docking or port facility necessary for the loading and unloading of cargo or passengers, shipbuilding, or ship repair facilities. The term does not include long-term storage, manufacture, sales, or service facilities. |
HIGHEST ADJACENT GRADE: | The highest natural elevation of the ground surface prior to construction, adjacent to the proposed walls of a structure. Refer to the FEMA Elevation Certificate for HAG related to building elevation information. |
HISTORIC STRUCTURE: | A structure that is: A. Listed individually in the National Register of Historic Places (a listing maintained by the U.S. 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 to a district preliminarily determined by the Secretary to qualify as a registered historic district; C. Individually listed on a state inventory of historic places and determined as eligible by 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 and determined as eligible by 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. |
IRRIGATION OR DRAINAGE CHANNEL: | A man-made or natural channel used to convey or deliver water for irrigation, drainage, or other uses, by irrigation districts, canal companies, lateral associations, drainage districts, or other water delivery entities. Irrigation and drainage channels include man-made canals, ditches, laterals, culverts, flumes, tiled drains, pipes, storage reservoirs, and natural channels (including reservoirs on natural channels), used to convey storage or other sources of water owned or controlled by an irrigation or drainage entity. |
IRRIGATION AND DRAINAGE WORKS: | Man-made structures used to divert, regulate, and measure water from natural channels (streams, rivers, lakes, and springs) and in man-made irrigation and drainage channels. Irrigation and drainage works include diversions or regulation structures, including but not limited to control gates or head gates, check dams or diversion dams, culverts, measuring devices and their housing (including stilling wells and staff gages), flumes, siphons, pumps, pipes, protective structures, energy dissipaters, fish passage structures, and trash screens or trash racks. |
LETTER OF MAP CHANGE (LOMC): | A general term used to refer to the several types of revisions and amendments to FIRMs that can be accomplished by letter. They include Letter of Map Amendment (LOMA), Letter of Map Revision (LOMR), Letter of Map Revision based on Fill (LOMR-F), and Conditional Letters of Map Revision (CLOMR). |
A. Letter Of Map Amendment (LOMA): | An official amendment, by letter, to an effective National Flood Insurance Program (NFIP) map. A 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) or a Flood Boundary and Floodway Map (FBFM) or both. 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 Flood Insurance Rate Map (FIRM) or Flood Boundary and Floodway Map (FBFM), 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, FBFM, or FIS report. |
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, FBFM, 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, a Letter of Map Revision (LOMR) may be issued by FEMA to revise the effective FIRM. Building Permits and/or Flood Development 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 or subgrade crawl space). 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 article. |
MAINTENANCE: | The act of ongoing upkeep of existing structures required to keep channels in a condition adequate to support the conveyance of irrigation and drainage water (this does not include the complete replacement or substantial replacement of an existing structure). Maintenance is further defined as the care or upkeep of channels, works, appurtenances, easements, utility corridors and property; to keep in an existing state, specified state of repair, and efficiency; return to a former condition, elevation, place, and position; to preserve from failure or decline; or repair or renovate so as to return it to its original condition. Maintenance does not include dredging as defined herein. |
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.” |
MANUFACTURED HOME PARK OR SUBDIVISION: | A parcel (or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale. |
MARKET VALUE: | The building value, not including the land value and that of any accessory structures or other improvements on the lot. Market value is determined by the tax assessed values, unless revised by an independent certified appraisal (paid for by the property owner). |
NEW CONSTRUCTION: | For floodplain management purposes, a structure for which the start of construction commenced on or after the effective date of a floodplain management regulation adopted by a community and includes any subsequent improvements to such structures. Any construction started after April 4, 1984 (entry into the NFHP), and before the effective start date of this floodplain management article is subject to the article in effect at the time the permit was issued, provided the start of construction was within one hundred and eighty (180) days of permit issuance. |
NONRESIDENTIAL STRUCTURE: | A building, other than a residential structure or dwelling, or parts thereof, that is open to the public or for private use. The term nonresidential structure includes, but is not limited to: structures used for places of assembly, education, business, maintenance, storage, manufacturing, and government. |
OPERATION: | The regular and reoccurring performance of typical work by an irrigation or drainage entity including, but not limited to: the delivery or drainage of water, measurement of water, and adjustment of irrigation and drainage works and all related appurtenances. |
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 FLOODWAY. |
REPAIR: | The restoration to good or sound conditions of any part of an existing structure, channel, channel bank, or service road for the purpose of maintenance (this does not include the complete replacement or substantial replacement of an existing structure). Repair does not include dredging as defined herein. |
RESIDENTIAL STRUCTURE: | A building used as a dwelling for one or more persons. The term residential structure includes, but is not limited to: houses, family daycare homes, group daycare facilities, apartment buildings, lodging homes, dormitories, hotels, motels, hospitals, sanatoriums, and nursing homes. The term residential structure also includes accessory use areas used in conjunction with, and an integral part of, a residential structure. |
RIPERIAN AREA: | The land that directly abuts a natural body of water such as a river, lake, stream, creek, or coastal body of water and is within twenty-five feet (25') of the Floodway Boundary. |
SPECIAL FLOOD HAZARD AREA (SFHA): | The areas in Ada County in the flood plain 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." It also includes foothill or hillside tributary floodplain; and other areas determined by the floodplain administrator to be a hazard to public health, safety, and welfare due to flooding. |
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 and 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. |
STRUCTURE: | A walled and/or roofed building, including a gas or liquid storage tank that is principally above ground, as well as a manufactured home. |
SUBSTANTIAL DAMAGE (SD): | 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 damage also means flood-related damage sustained by a structure on two separate occasions during a ten (10) year period for which the cost of repairs at the time of each such flood event, on the average, equals or exceeds twenty-five percent (25%) of the market value of the structure before the damage occurred. |
SUBSTANTIAL IMPROVEMENT (SI): | 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. 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 this article. |
VIOLATION: | The failure of a structure or other development to be fully compliant with this article. A structure or other development without the Finished Construction Elevation Certificate, other certifications, or other evidence of compliance required in 44 CFR sections 60.3(b)(5), (c)(4), (c)(10), (d)(3), (e)(2), (e)(4), or (e)(5) is presumed to be in violation until such time as that documentation is provided. (Ord. 835, 12-3-2014; amd. Ord. 914, 6-10-2020) |