Accessory structure means a vehicular parking or storage structure located on the same parcel of property as a principal structure.

Appeal means a request for a review of the Floodplain Administrator’s interpretation of any provision of this chapter or a request for a variance.

Area of shallow flooding means a designated AO or AH Zone on a community’s flood insurance rate map (FIRM). These zones have 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.

Base flood means a flood that has a one percent chance of being equaled or exceeded in any given year (also called the "100-year flood").

Base flood elevation (BFE) means the computed water surface elevation resulting from a flood that has a one percent or greater chance of being equaled or exceeded in any given year.

Basement means any area of the building having its floor below grade on all sides.

Building. See Structure.

CLOMR means Conditional Letter of Map Revision issued by FEMA.

Community means any state, area or city thereof, or any Indian tribe or authorized tribal organization, or authorized native organization, which has authority to adopt and enforce floodplain management regulations for the areas within its jurisdiction.

Development means any manmade change to improved or unimproved real estate, including but not limited to buildings or other structures, utilities, pipelines, mining, dredging, filling, grading, paving, or excavation or drilling operations or storage of equipment or materials.

Elevation certificate means an administrative tool of the National Flood Insurance Program (NFIP) that is used to provide elevation information necessary to ensure compliance with community floodplain management ordinances, to determine the proper insurance premium rate, and to support a request for a Letter of Map Amendment (LOMA) or Letter of Map Revision based on fill (LOMR-F).

Encroachment means the advance or infringement of uses, plant growth, fill, excavation, buildings, permanent structures or development into a floodplain, which may impede or alter the flow capacity of a floodplain.

Erosion means the gradual wearing away process of landmasses.

FEMA means the Federal Emergency Management Agency.

Flood or flooding means a general and temporary condition of partial or complete inundation of normally dry land areas from: (1) the overflow of floodwaters; and/or (2) the unusual and rapid accumulation or runoff of surface waters from any source.

Flood insurance rate map (FIRM) means the official map on which FEMA has delineated both the special flood hazard areas and the risk premium zones applicable to the community.

Flood insurance study (FIS) means the official report provided by FEMA that includes flood profiles, FIRM, and the water surface elevations of the base flood.

Floodplain or flood prone area means any land area susceptible to being inundated by water from any source. See Flood or flooding.

Floodplain Administrator means the City of Phoenix City Engineer, or a City Engineer appointed designee, who is charged with administering and enforcing these floodplain management regulations.

Floodplain Board or Board means the City of Phoenix City Council or a board appointed by the Phoenix City Council.

Floodplain management means the operation of an overall program of corrective and preventive measures for reducing flood damage and preserving and enhancing, where possible, natural resources in the floodplain, including but not limited to emergency preparedness plans, flood control works, floodplain management regulations, and open space plans.

Floodplain management regulations means this chapter and other zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances (such as grading and erosion control) and other application of enforcement power which control development in flood prone areas. This term describes Federal, State or local regulations in any combination thereof, which provide standards for preventing and reducing flood loss and damage.

Floodproofing means any combination of structural and nonstructural additions, changes, or adjustments to structures which reduce or eliminate the risk of flood damage to real estate or improved real property, water and sanitary facilities, structures, and their contents.

Flood-related erosion means the collapse or subsidence of land along the shore of a lake or other body of water as a result of 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 a flash flood or an abnormal tidal surge, or by some similarly unusual and unforeseeable event which results in flooding.

Floodway means 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. This is also referred to as "regulatory floodway."

Functionally dependent use means a use which cannot perform its intended purpose unless it is located or carried out proximate to water. The term includes only docking facilities, port facilities that are necessary for the loading and unloading of cargo or passengers, and ship building and ship repair facilities, and does not include long-term storage or related manufacturing facilities.

Governing body means the local governing unit, i.e., county or municipality, which is empowered to adopt and implement regulations to provide for the public health, safety and general welfare of its citizenry.

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 means any structure that is:

LOMR means Letter of Map Revision issued by FEMA. It is an official amendment to the currently effective FEMA map.

Lowest floor means the lowest floor of the lowest enclosed area, including the 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 of this chapter.

Manufactured home means a structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when connected to the required utilities. For floodplain management purposes the term manufactured home also includes park trailers, travel trailers, and other similar recreational vehicles placed on a site for greater than 180 consecutive days. For insurance purposes the term manufactured home does not include park trailers, travel trailers, and other similar recreational vehicles.

Manufactured home park or subdivision means a parcel (or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale.

Market value means replacement cost of a structure less depreciation since construction.

Mean sea level means, for purposes of the National Flood Insurance Program, the National Geodetic Vertical Datum (NGVD of 1929), North American Vertical Datum (NAVD) of 1988, or other datum, to which base flood elevations shown on a community’s flood insurance rate map are referenced.

New construction means, for purposes of determining insurance rates, structures for which the "start of construction" commenced on or after the effective date of an initial flood insurance rate map or after December 31, 1974, whichever is later, and includes any subsequent improvements to such structures. For floodplain management purposes, new construction means structures 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.

Obstruction includes, but is not limited to, any dam, wall, wharf, embankment, levee, dike, pile, abutment, protection, excavation, channelization, bridge, conduit, culvert, building, wire, fence, rock, gravel, refuse, fill, structure, vegetation or other material in, along, across or projecting into any watercourse which may alter, impede, retard or change the direction and/or velocity of the flow of water, or due to its location, its propensity to snare or collect debris carried by the flow of water, or its likelihood of being carried downstream.

One-hundred-year flood or 100-year flood means a flood having a one percent chance of being equaled or exceeded in any given year. See Base flood.

Person means any individual or the individual’s agent, a firm, partnership, association, corporation, or any agent of the aforementioned groups, or this State or its agencies or cities.

Principal structure means a structure used or intended to be used for the principal use as permitted on such lot by the regulations of the zoning district in which it is located, exclusive of any detached accessory structures.

Recreational vehicle means a vehicle that is:

Regulatory flood elevation (RFE) means an elevation one foot above the base flood elevation for a watercourse.

Regulatory floodway means 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.

Riverine means relating to, formed by, or resembling a river (including tributaries), stream, or brook.

Sheet Flow Area. See Area of shallow flooding.

Special flood hazard area (SFHA) means the land in the floodplain within a community subject to a one percent or greater chance of flooding in any given year. These areas are designated as Zone A, AO, AE, A99, or AH on the FIRM and other areas as determined by the criteria adopted by the Director of the Arizona Department of Water Resources.

Start of construction includes substantial improvement and other proposed new development, 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 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 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 the alteration affects the external dimensions of the building.

Structure means a walled and roofed building that is principally above ground; this includes a gas or liquid storage tank or a manufactured home.

Substantially damaged building means damage of any origin sustained by a structure whereby the cost of restoring the structure to its before damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.

Substantial improvement means any reconstruction, rehabilitation, addition, or other improvement of a structure, the total cumulative cost of which tracked over a rolling five-year period equals or exceeds 50 percent 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:

Variance means a grant of relief from the requirements of this chapter which permits construction in a manner that would otherwise be prohibited by this chapter.

Violation means the failure of a structure or other development to be fully compliant with the community’s floodplain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required by this chapter is presumed to be in violation until such time as that documentation is provided.

Water surface elevation means the height, in relation to the National Geodetic Vertical Datum (NGVD) of 1929, North American Vertical Datum (NAVD) of 1988, or other datum, of floods of various magnitudes and frequencies in the floodplains of coastal or riverine areas.

Watercourse means any lake, river, creek, stream, wash, arroyo, channel, or other topographic feature on or over which waters flow at least periodically. The term may include specifically designated areas in which flood damage may occur. (Ord. No. G-2027, § 2; Ord. No. G-3092, § 2; Ord. No. G-5707, 2012; Ord. No. G-6611, 2019; Ord. No. G-7116, § 2, 2023)