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Flood Elevation (BFE) in any given year shown on the Flood Insurance Rate Map (FIRM) zones A, AE, AH, A1–A30, AR, AR/A, AR/AE, AR/A1–A30, AR/AH, and AR/AO. When used in reference to the development of a structure in this ordinance, A Zones are not inclusive of Coastal A Zones because of the higher building code requirements for Coastal A Zones.
AH ZONES– Areas subject to inundation by 1-percent-annual-chance shallow flooding (usually areas of ponding) where average depths are between one and three feet. Base Flood Elevations (BFEs) derived from detailed hydraulic analyses are shown in this zone.
AO ZONES – Areas subject to inundation by 1-percent-annual-chance shallow flooding (usually sheet flow on sloping terrain) where average depths are between one and three feet.
ACCESSORY STRUCTURE – Accessory structures are also referred to as appurtenant structures. An accessory structure is a structure which is on the same parcel of property as a principal structure and the use of which is incidental to the use of the principal structure. For example, a residential structure may have a detached garage or storage shed for garden tools as accessory structures. Other examples of accessory structures include gazebos, picnic pavilions, boathouses, small pole barns, storage sheds, and similar buildings.
AGRICULTURAL STRUCTURE - A structure used solely for agricultural purposes in which the use is exclusively in connection with the production, harvesting, storage, drying, or raising of agricultural commodities, including the raising of livestock. Communities must require that new construction or substantial improvements of agricultural structures be elevated or floodproofed to or above the Base Flood Elevation (BFE) as any other nonresidential building. Under some circumstances it may be appropriate to wet-floodproof certain types of agricultural structures when located in wide, expansive floodplains through issuance of a variance. This should only be done for structures used for temporary storage of equipment or crops or temporary shelter for livestock and only in circumstances where it can be demonstrated that agricultural structures can be designed in such a manner that results in minimal damage to the structure and its contents and will create no additional threats to public safety. New construction or substantial improvement of livestock confinement buildings, poultry houses, dairy operations, similar livestock operations and any structure that represents more than a minimal investment must meet the elevation or dry-floodproofing requirements of 44 CFR 60.3(c)(3).
AREA OF SHALLOW FLOODING – A designated Zone AO, AH, AR/AO or AR/AH (or VO) on a community’s Flood Insurance Rate Map (FIRM) with a one percent or greater annual chance of flooding to an average depth of one to three feet where a clearly defined channel does not exist, where the path of flooding is unpredictable, and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow. AREA OF SPECIAL FLOOD HAZARD – see SPECIAL FLOOD HAZARD AREA
ALTERATION OF A WATERCOURSE – A dam, impoundment, channel relocation, change in channel alignment, channelization, or change in cross-sectional area of the channel or the channel capacity, or any other form of modification which may alter, impede, retard or change the direction and/or velocity of the riverine flow of water during conditions of the base flood.
ASCE 7 – The standard for the Minimum Design Loads for Buildings and Other Structures, referenced by the building code and developed and published by the American Society of Civil Engineers, Reston, VA. which includes but is not limited to methodology and equations necessary for determining structural and flood-related design requirements and determining the design requirements for structures that may experience a combination of loads including those from natural hazards. Flood related equations include those for determining erosion, scour, lateral, vertical, hydrostatic, hydrodynamic, buoyancy, breaking wave, and debris impact.