Alteration of watercourse

“Alteration of watercourse” means any action that will change the location of the channel occupied by water within the banks of any portion of a riverine waterbody.

Appeal

“Appeal” means a request for a review of the interpretation of any provision of this chapter or a request for a variance.

Area of shallow flooding

“Area of shallow flooding” refers to a designated zone AO, AH, AR/AO or AR/AH (or VO) on a Flood Insurance Rate Map (FIRM) with a one percent (1%) or greater annual chance of flooding to an average depth of one (1) to three (3) 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. Also referred to as the sheet flow area.

Area of special flood hazard

“Area of special flood hazard” refers to land in the floodplain subject to a one percent (1%) or greater chance of flooding in any given year. It is shown on the Flood Insurance Rate Map (FIRM) as zone A, AO, AH, A1-30, AE, A99, AR (V, VO, V1-30, VE). “Special flood hazard area” is synonymous in meaning with the phrase “area of special flood hazard.”

ASCE 24

“ASCE 24” refers to the most recently published version of ASCE 24, Flood Resistant Design and Construction, published by the American Society of Civil Engineers.

Base flood

“Base flood” means the flood having a one percent (1%) chance of being equaled or exceeded in any given year and is also referred to as the one-hundred- (100-) year flood.

Base flood elevation

“Base flood elevation” means the elevation to which floodwater is anticipated to rise during the base flood.

Basement

“Basement” means any area of the building having its floor subgrade below ground level on all sides.

Building

See “Structure.”

Critical facility

“Critical facility” means the following:

•    Structures or facilities that produce, use or store highly volatile, flammable, explosive, toxic and/or water-reactive materials;

•    Hospitals, nursing homes, and housing likely to contain occupants who may not be sufficiently mobile to avoid death or injury during a flood;

•    Police stations, fire stations, vehicle and equipment storage facilities, and emergency operations centers that are needed for flood response activities before, during and after a flood; and

•    Public and private utility facilities that are vital to maintaining or restoring normal services to flooded areas before, during, and after a flood;

•    Critical aviation facilities such as control towers, air traffic control centers, and hangars for aircraft used in emergency response.

Development

“Development” means, in addition to the definition in Section 40.100.070:

•    Storage of equipment and materials.

Elevated building

“Elevated building” means, for insurance purposes, a nonbasement building that has its lowest elevated floor raised above ground level by foundation walls, shear walls, posts, piers, pilings, or columns.

Elevation certificate

“Elevation certificate” means the official FEMA form used to record the elevation of a structure on a given property.

Encroachment

“Encroachment” means the intrusion of any building, structure, vegetation, fill, excavation, or other development or use into a special flood hazard area which may impede or alter the flow through or storage capacity of a special flood hazard area.

Essential facility

See “Critical facility.”

Farmhouse

“Farmhouse” refers to a single-family dwelling located on a farm site where resulting agricultural products are not produced for the primary consumption or use by the occupants and the farm owner.

FEMA

“FEMA” means the Federal Emergency Management Agency.

Flood or flooding

“Flood” or “flooding” means:

(1) A general and temporary condition of partial or complete inundation of normally dry land areas from:

(a)    The overflow of inland or tidal waters.

(b)    The unusual and rapid accumulation or runoff of surface waters from any source.

(c)    Mudslides (i.e., mudflows) which are proximately caused by flooding as defined in subsection (1)(b) 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.

(2)    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 (1)(a) of this definition.

Flood Elevation Study

“Flood Elevation Study” means 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 a Flood Insurance Study (FIS).

Flood Insurance Rate Maps

“Flood Insurance Rate Maps” (FIRMs) mean the official map on which the Federal Insurance Administration has delineated both the areas of special flood hazards and the risk premium zones applicable to the county. A FIRM that has been made available digitally is called a Digital Flood Insurance Rate Map (DFIRM).

Floodplain or flood prone area

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

Floodplain administrator

“Floodplain administrator” refers to the community official designated by title to administer and enforce the floodplain management regulations.

Floodproofing

“Floodproofing” means any combination of structural and nonstructural additions, changes or adjustments to properties and structures which reduce or eliminate flood damages to lands, water and sanitary facilities, and structures and their contents. Floodproofed structures are those that have the structural integrity and design to be impervious to floodwater below the base flood elevation.

Floodway

“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. Also referred to as regulatory floodway.

Functionally dependent use

“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, 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.

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

“Historic structure” refers to any structure that is:

(1)    Listed individually in the National Register of Historic Places (a listing maintained by the Department of the Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register;

(2)    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;

(3)    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

(4)    Individually listed on a local inventory of historic places in communities with historic preservation programs that have been certified either:

(a)    By an approved state program as determined by the Secretary of the Interior, or

(b)    Directly by the Secretary of the Interior in states without approved programs.

Lowest floor

“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 or for 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 Section 40.420.020(E)(1)(d).

Mean sea level

“Mean sea level” refers to, for purposes of the National Flood Insurance Program, the vertical datum to which base flood elevations shown on a community’s Flood Insurance Rate Map are referenced.

One-hundred-year flood or 100-year flood

See “Base flood.”

Reasonably safe from flooding

“Reasonably safe from flooding” refers to development that is designed and built to be safe from flooding based on consideration of current flood elevation studies, historical data, high water marks and other reliable data known to the community. In unnumbered A zones where flood elevation information is not available and cannot be obtained by practicable means, “reasonably safe from flooding” means that the lowest floor is at least two feet above the highest adjacent grade.

Start of construction

“Start of construction” refers to the definition in Section 40.100.070. In addition, for a substantial improvement, 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

“Structure” means, in addition to the definition in Section 40.100.070:

•    For floodplain management purposes, a walled and roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured home.

Substantial damage

“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 fifty percent (50%) of the market value of the structure before the damage occurred.

Substantial improvement

“Substantial improvement” means 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:

(1)    Any project for improvement of a structure to correct previously identified existing violations of state or local health, sanitary, or safety code specifications that have been identified by the local code enforcement official and that are the minimum necessary to assure safe living conditions; or

(2)    Any alteration of a historic structure; provided, that the alteration will not preclude the structure’s continued designation as a historic structure.

Variance

“Variance” means a grant of relief by Clark County from the terms of a floodplain management regulation.

Water surface elevation

“Water surface elevation” refers to the height, in relation to the vertical datum utilized in the applicable Flood Insurance Study of floods of various magnitudes and frequencies in the floodplains of coastal or riverine areas.