100-year flood means a flood having a recurrence interval of one-percent chance of being equaled or exceeded during any given year (one-percent-annual-chance flood). The terms "one-hundred-year flood" and "one percent chance flood" are synonymous with the term "100-year flood." The term does not imply the flood will necessarily happen once every 100 years.

100-year floodplain means the area of land susceptible to being inundated as a result of the occurrence of a one-hundred-year flood.

500-year flood means a flood having a recurrence interval of 0.2-percent chance of being equaled or exceeded during any given year (0.2-percent-chance-annual-flood). The term does not imply the flood will necessarily happen once every 500 years.

500-year floodplain means the area of land susceptible to being inundated as a result of the occurrence of a 500-year flood.

Addition means any activity that expands the enclosed footprint or increases the square footage of an existing structure.

Alluvial fan flooding means a fan-shaped sediment deposit formed by a stream that flows from a steep mountain valley or gorge onto a plain or the junction of a tributary stream with the main stream. Alluvial fans contain active stream channels and boulder bars, and recently abandoned channels. Alluvial fans are predominantly formed by alluvial deposits and are modified by infrequent sheet flood, channel avulsions and other stream processes.

Area of shallow flooding means a designated zone AO or AH as designated on the City's FIRM with a one percent chance 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 elevation (BFE) means the elevation shown on a FEMA FIRM for zones AE, AH, AR, AR/A, AR/AE, AR/A1-A30, AR/AH, AR/AO, that indicates the water surface elevation resulting from a flood that has a one percent chance of equaling or exceeding that level in any given year.

Basement means any area of a building having its floor sub-grade (below ground level) on all sides.

Channel means the physical confine of stream or waterway consisting of a bed and stream banks, existing in a variety of geometries.

Channelization means the artificial creation, enlargement or realignment of a stream channel.

Code of Federal Regulations (C.F.R.) means the codification of the general and permanent rules published in the Federal Register by the executive departments and agencies of the federal government.

Conditional Letter of Map Revision (CLOMR) means FEMA's comment on a proposed project, which does not revise an effective floodplain map, which would, upon construction, affect the hydrologic or hydraulic characteristics of a flooding source and thus result in the modification of the existing regulatory floodplain.

Critical facility means a structure or related infrastructure, but not the land on which it is situated, as specified Rule 6 of the Rules and Regulations for Regulatory Floodplains in Colorado (2 C.C.R. 408-6) that if flooded may result in significant hazards to public health and safety or interrupt essential services and operations for the City at any time before, during and after a flood.

Development means any man-made change in improved and 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.

DFIRM database means the database (usually spreadsheets) containing data and analyses that accompany DFIRMs. The FEMA Mapping Specifications and Guidelines outline requirements for the development and maintenance of DFIRM databases.

Digital Flood Insurance Rate Map (DFIRM) means the FEMA digital floodplain map. These digital maps serve as regulatory floodplain maps for insurance and floodplain management purposes.

Elevated building means a non-basement building (i) built, in the case of a building in zones AE, A, A99, AO, AH, B, C, X, and D, to have the top of the elevated floor above the ground level by means of pilings, columns (posts and piers), or shear walls parallel to the flow of the water; (ii) adequately anchored so as not to impair the structural integrity of the building during a flood of up to the magnitude of the base flood. In the case of zones AE, A, A99, AO, AH, B, C, X, and D, elevated building also includes a building elevated by means of fill or solid foundation perimeter walls with openings sufficient to facilitate the unimpeded movement of flood waters.

Existing manufactured home park or subdivision means a manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed before the effective date of the floodplain management regulations adopted by the City.

Expansion to an existing manufactured home park or subdivision means the preparation of additional sites by the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads).

Federal Emergency Management Agency (FEMA) means the agency responsible for administering the NFIP.

Federal Register means the official daily publication for rules, proposed rules, and notices of federal agencies and organizations, as well as executive orders and other presidential documents.

Flood or flooding means general and temporary condition of partial or complete inundation of normally dry land areas from:

Flood control structure means a physical structure designed and built expressly or partially for the purpose of reducing, redirecting, or guiding flood flows along a particular waterway. These specialized flood modifying works are those constructed in conformance with sound engineering standards.

Flood fringe means that part of the floodplain located between the boundary of the floodway and the boundary of the 100-year floodplain.

Flood insurance rate map (FIRM) means an official map of the City, on which FEMA has delineated both the SFHA and the risk premium zones applicable to the City.

Flood insurance study (FIS) means the official report provided by FEMA. The report contains the FIRM as well as flood profiles for studied flooding sources that can be used to determine BFEs for some areas.

Floodplain or flood-prone area means any land area susceptible to being inundated as the result of a flood, including the area of land over which floodwater would flow from the spillway of a reservoir.

Floodplain administrator is the city official designated by title to administer and enforce the floodplain management regulations.

Floodplain development permit means a permit required before construction or development begins within any SFHA. If FEMA has not defined the SFHA within the City, the city shall require permits for all proposed construction or other development in the City, including the placement of manufactured homes, so it may determine whether such construction or other development is proposed within flood-prone areas. Permits are required to ensure the proposed development projects meet the requirements of the NFIP and this floodplain management ordinance.

Floodplain management means 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 management regulations means zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances (such as a floodplain ordinance, grading ordinance and erosion control ordinance) 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 means any combination of structural and/or 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.

Floodway (regulatory floodway) means the channel of a river or other watercourse and 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. The Colorado statewide standard for the designated height to be used for all newly studied reaches is one-half foot (six inches). LOMRs to existing floodway delineations may continue to use the floodway criteria in place at the time of the existing floodway delineation.

Freeboard means the vertical distance in feet above a predicted water surface elevation intended to provide a margin of safety to compensate for unknown factors that could contribute to flood heights greater than the height calculated for a selected size flood such as debris blockage of bridge openings and the increased runoff due to urbanization of the watershed.

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

Highest adjacent grade means the highest natural elevation of the ground surface prior to construction next to proposed or existing walls of a structure.

Historic structure means any structure that is:

Letter of map revision (LOMR) means FEMA's official revision of an effective FIRM, or 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 BFEs, or the SFHA.

Letter of map revision based on fill (LOMR-F) means FEMA's modification of the SFHA shown on the FIRM based on the placement of fill outside the existing regulatory floodway.

Levee means a man-made embankment, usually earthen, designed and constructed in accordance with sound engineering practices to contain, control, or divert the flow of water so as to provide protection from temporary flooding. For a levee structure to be reflected on the FEMA FIRMs as providing flood protection, the levee structure must meet the requirements set forth in 44 C.F.R. 65.10.

Levee system means a flood protection system which consists of a levee, or levees, and associated structures, such as closure and drainage devices, which are constructed and operated in accordance with sound engineering practices.

Lowest floor means the lowest floor of the lowest enclosed area (including basement or crawl space). Any floor used for living purposes which includes working, storage, sleeping, cooking and eating, or recreation or any combination thereof. This includes any floor that could be converted to such a use such as a basement or crawl space. The lowest floor is a determinate for the flood insurance premium for a building, home or business. An unfinished or flood resistant enclosure, usable solely for parking or 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 requirement of Sec. 60.3 of the NFIP.

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. The term "manufactured home" does not include a recreational vehicle or travel trailers.

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.

Mean sea level means the North American Vertical Datum (NAVD) of 1988 to which BFE shown on the City's FIRM are referenced.

Material Safety Data Sheet (MSDS) means a form with data regarding the properties of a particular substance. An important component of product stewardship and workplace safety, it is intended to provide workers and emergency personnel with procedures for handling or working with that substance in a safe manner, and includes information such as physical data (melting point, boiling point, flash point, etc.), toxicity, health effects, first aid, reactivity, storage, disposal, protective equipment, and spill-handling procedures.

National Flood Insurance Program (NFIP) means FEMA's program of flood insurance coverage and floodplain management administered in conjunction with the Robert T. Stafford Relief and Emergency Assistance Act, 42 U.S.C. 5121-5207. The NFIP has applicable federal regulations promulgated in Title 44 C.F.R, Sections 59-79.

New manufactured home park or subdivision means a manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed on or after the effective date of the floodplain management regulations adopted by the City. Subdividing of an existing manufactured home park which does not require the construction of servicing facilities shall not be construed to be a new manufactured home subdivision or subdivision proposal.

No-rise certification means a record of the results of an engineering analysis conducted to determine whether a project will increase flood heights in a floodway. A no-rise certification must be supported by technical data and signed by a licensed Colorado Professional Engineer. The supporting technical data should be based on the standard step-backwater computer model used to develop the 100-year floodway shown on the FIRM or flood boundary and floodway map.

Physical map revision (PMR) means FEMA's action whereby one or more map panels are physically revised and republished. A PMR is used to change flood risk zones, floodplain and/or floodway delineations, flood elevations, and/or planimetric features.

Reach means a hydraulic engineering term describing longitudinal segments of a stream or river. Reach will generally include the segment of the flood hazard area where flood heights are primarily controlled by manmade or natural obstructions or constrictions. In an urban area, an example of a reach would be the segment of a stream or river between two consecutive bridge crossings.

Recreational vehicle means a vehicle which is:

Regulatory flood protection elevation means the elevation to which uses regulated by this chapter are required to be elevated or flood-proofed.

Special flood hazard area (SFHA) means the land in the floodplain within the city subject to a one percent or greater chance of flooding in any given year, i.e., the 100-year floodplain or regulatory floodplain.

Start of construction means the date the building permit was issued, including substantial improvements, 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 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 manufactured homes not within a manufactured home park or manufactured home subdivision, start of construction means the date of the manufactured homes is affixed to its permanent site. For manufactured homes within the manufactured home parks or manufactured home subdivisions, start of construction is the date on which the construction of facilities for servicing the site on which the manufactured homes is to be affixed, including, at a minimum, the construction of streets, either final site grading or the pouring of concrete pads, and installation of utilities, is completed, and start of construction shall not refer to the date on which any repair or reconstruction of existing facilities for servicing such site is undertaken or completed. 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 means a walled and roofed building, including a gas or liquid storage tank, which is principally above ground, as well as a manufactured home.

Substantial damage 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 just prior to when the damage occurred.

Substantial improvement means any reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure before start of construction of the improvement. The value of the structure shall be determined by the local jurisdiction having land use authority in the area of interest. This includes structures which have incurred substantial damage, regardless of the actual repair work performed. The term does not, however, include either:

Threshold planning quantity (TPQ) means a quantity designated for each chemical on the list of extremely hazardous substances that triggers notification by facilities to the state that such facilities are subject to emergency planning requirements.

Variance means a grant of relief to a person from the requirement of this article when specific enforcement would result in unnecessary hardship. A variance, therefore, permits construction or development in a manner otherwise prohibited by this article. (For full requirements see 44 C.F.R. 60.6).

Violation means the failure of a structure or other development to be fully compliant with the City's floodplain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required in 44 C.F.R. Section 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.

Watercourse means a channel, natural depression, slough, artificial channel, gulch, arroyo, stream, creek, pond, reservoir, or lake which storm runoff and flood water flows either regularly or infrequently. This includes major drainage ways for carrying storm runoff.

Water surface elevation means the height, in relation to the North American Vertical Datum of 1988, of floods of various magnitudes and frequencies in the floodplains of riverine areas.