Skip to main content
Loading…
Article II. Definitions
This article is included in your selections.
This section is included in your selections.

Unless specifically defined below, terms or phrases used in this chapter shall be interpreted so as to give them the meaning they have in common usage and to give this chapter its most reasonable application.

A. “Adversely affect/adverse effect” means effects that are a direct or indirect result of the proposed action or its interrelated or interdependent actions and the effect is not discountable, insignificant, or beneficial. Discountable effects are extremely unlikely to occur. Insignificant effects relate to the size of the impact and should never reach the scale where a take occurs. Based on best judgment, a person would not: (1) be able to meaningfully measure, detect, or evaluate insignificant effects, or (2) expect discountable effects to occur. Beneficial effects are contemporaneous positive effects without any adverse effects. In the event that the overall effect of the proposed action is beneficial, but is also likely to cause some adverse effects, then the proposed action is considered to result in an adverse effect.

B. “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.

C. “Appurtenant structure” means a structure which is on the same parcel as the principal structure to be insured and the use of which is incidental to the use of the principal structure.

D. “Area of shallow flooding” means 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. Also referred to as the sheet flow area.

E. “Area of special flood hazard” means the land in the floodplain within a community subject to a one percent 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.”

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

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

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

I. “Basement” means any area of the structure having its floor subgrade (below ground level) on all sides.

J. “Building code” means the currently effective versions of the International Building Code and the International Residential Code adopted by the Washington State Legislature and any further amendments adopted by the city of Auburn.

K. “Channel migration zone” (CMZ) means the area within the lateral extent of likely stream channel movement due to stream bank destabilization and erosion, rapid stream incision, aggradation, avulsions, and shifts in location of stream channels.

1. The channel migration area shall be the total area occupied by the river channel, the severe channel migration hazard area, and the moderate channel migration hazard area as delineated in the Green River Channel Migration Study published by King County dated December 1993 plus 50 feet.

2. The channel migration area shall be the total area occupied by the river channel, the severe channel migration hazard area, and the moderate channel migration hazard area as delineated in the Channel Migration Zone Delineation for the Middle Green River, RM 31.10 to 33.25 dated December 28, 2018, plus 50 feet which supersedes the study referenced above.

3. A site specific channel migration delineation may also be performed per the Washington State Department of Ecology’s current requirements with recommended setbacks (A Framework for Delineating Channel Migration Zones) prepared by a qualified engineer. The delineation shall be prepared by a qualified consultant as that term is defined in these regulations. The city may retain a qualified consultant paid for by the applicant to review and confirm the applicant’s reports, studies and plans if the following circumstances exist:

a. The city has technical information that is unavailable to the applicant; or

b. The applicant has provided inaccurate or incomplete information on previous proposals or proposals currently under consideration.

L. “Critical facility” means a facility necessary to protect the public health, safety and welfare during a flood. Critical facilities include, but are not limited to, schools, nursing homes, hospitals, police, fire and emergency operations installations, water and wastewater treatment plants, electric power stations, and installations which produce, use, or store hazardous materials or hazardous waste (other than consumer products containing hazardous substances or hazardous waste intended for household use).

M. “Development” means any human-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 located within the area of special flood hazard.

N. “Dry floodproofing” means any combination of structural and nonstructural measures that prevent floodwaters from entering a structure.

O. “Elevation certificate” means an administrative tool of the National Flood Insurance Program (NFIP) that can be used to provide elevation information, 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).

P. “Essential facility” has the same meaning as “essential facility” defined in ASCE 24. Table 1-1 in ASCE 24-14 further identifies building occupancies that are essential facilities.

Q. “FEMA” means the Federal Emergency Management Agency, the agency responsible for administering the National Flood Insurance Program.

R. “Flood” or “flooding” means a general and temporary condition of partial or complete inundation of normally dry land areas from:

1. The overflow of inland or tidal waters; and/or

2. The unusual and rapid accumulation of runoff of surface waters from any source;

3. Mudslides (i.e., mudflows) which are proximately caused by flooding as defined in subsection (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;

4. 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) of this definition.

S. “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).

T. “Flood Insurance Rate Map (FIRM)” means the official map on which the Federal Insurance Administrator has delineated both the Special Flood Hazard Areas and the risk premium zones applicable to the community.

U. Flood Insurance Study (FIS). See “Flood elevation study.”

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

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

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

Y. “Flood protection elevation (FPE)” means the elevation above the datum of the effective FIRM to which new and substantially improved structures must be protected from flood damage.

Z. “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. Also referred to the “regulatory floodway.”

AA. “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.

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

CC. “Historic structure” means 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.

DD. “Hyporheic zone” means a saturated layer of rock or sediment beneath and/or adjacent to a stream channel that contains some proportion of channel water or that has been altered by channel water infiltration.

EE. “Impervious surface” means a nonvegetated surface area which either prevents or retards the entry of water into the soil mantle as under natural conditions prior to development. A nonvegetated surface area which causes water to run off the surface in greater quantities or at an increased rate of flow from the flow present under natural conditions prior to development. Common impervious surfaces include, but are not limited to, roof tops, walkways, patios, driveways, parking lots or storage areas, concrete or asphalt paving, gravel roads, packed earthen materials, and oiled, macadam or other surfaces which similarly impede the natural infiltration of storm water.

FF. “Lowest floor” means the lowest floor of the lowest enclosed area (including 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 found in ACC 15.68.270 (i.e., provided there are adequate flood ventilation openings).

GG. “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 attached to the required utilities. The term “manufactured home” does not include a “recreational vehicle.”

HH. “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.

II. “Market value” shall mean the current assessed value as established by the most recent tax roll of the county assessor in which the property is located. An applicant may, at applicant’s expense, provide an appraisal to determine market value.

JJ. “Mean sea level” means, 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.

KK. “Native vegetation” means plant species that are indigenous to the community’s area and that reasonably could be expected to naturally occur on the site.

LL. “Natural floodplain functions” means the contribution that a floodplain makes to support habitat, including, but not limited to, providing flood storage and conveyance, reducing flood velocities, reducing sedimentation, filtering nutrients and impurities from runoff, processing organic wastes, moderating temperature fluctuations, and providing breeding and feeding grounds, shelter, and refugia, for aquatic or riparian species.

MM. “New construction” means, for the 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 the ordinance adopted by a community and includes any subsequent improvements to such structures.

NN. “Principal structure” means a structure in which the principal use of the lot on which it is located is conducted.

OO. “Protected area” means the lands that lie within the boundaries of the floodway, the riparian buffer zone, and the channel migration area. Because of the impact that development can have on flood heights and velocities and habitat, special rules apply in the Protected Area.

PP. “Reasonably safe from flooding” means 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.

QQ. “Recreational vehicle” means a vehicle:

1. Built on a single chassis; and

2. Four hundred square feet or less when measured at the largest horizontal projection; and

3. Designed to be self-propelled or permanently towable by an automobile or light-duty truck; and

4. Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel or seasonal use.

RR. “Riparian” means of, adjacent to, or living on the bank of a stream, lake, pond, sound, or other water body.

SS. “Riparian buffer zone” means the land located adjacent to streams, and other bodies of water, where the natural soil, hydrology, and native flora and fauna perform important ecological functions such as protecting the water body by filtering out pollutants, preventing erosion and sedimentation, stabilizing stream banks, and providing natural shade. They are often thin lines of green containing native grasses, flowers, shrubs and trees that line the banks of streams and other bodies of water. The riparian buffer zone for the Puget Sound biological opinion applies only to areas mapped within the Special Flood Hazard Area, unless the area is undeveloped with predominately native vegetation that has benefits to endangered species, in which case the regulations for riparian habitat zones shall apply.

TT. ”Riparian habitat zone” means the water body and adjacent land areas that are likely to support aquatic and riparian habitat.

UU. “Special flood hazard area (SFHA)” means the land subject to inundation by the base flood. Special flood hazard areas are designated on Flood Insurance Rate Maps with the letters “A” or “V” including AE (floodway), AO, AH, A1-99 and VE. The Special Flood Hazard Area is also referred to as the area of special flood hazard or SFHA.

VV. “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 180 days of the date of the permit. 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.

WW. “Structure” means a walled and roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured home.

XX. “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 before the damage occurred.

YY. “Substantial improvement” means any reconstruction, rehabilitation, addition, replacement or improvement of a structure, the cost of which 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:

1. Any project for improvement of a structure to correct 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.”

ZZ. “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.

AAA. “Violation” means the failure of a structure or other development to be constructed or implemented in conformance with the community’s applicable floodplain development regulations.

BBB. “Water typing” means a system for classifying water bodies according to their size and fish habitat characteristics. The Washington Department of Natural Resources Forest Practices Water Typing Classification System is hereby adopted by reference. The system defines four water types:

1. Type “S” – Shoreline: Streams that are designated “shorelines of the state,” including marine shorelines.

2. Type “F” – Fish: Streams that are known to be used by fish or meet the physical criteria to be potentially used by fish.

3. Type “Np” – Nonfish perennial streams.

4. Type “Ns” – Nonfish seasonal streams.

CCC. “Zone” means one or more areas delineated on the FIRM. The following zones may be used on the adopted FIRM. The special flood hazard area is comprised of the A and V Zones.

1. A: SFHA where no base flood elevation is provided.

2. AE: SFHA with a base flood elevation.

3. AO: SFHA subject to inundation by shallow flooding usually resulting from sheet flow on sloping terrain, with average depths between one and three feet. Average flood depths are shown.

4. AH: SFHA subject to inundation by shallow flooding (usually areas of ponding) with average depths between one and three feet. Base flood elevations are shown.

5. D: Area of undetermined but possible flood hazard.

6. X: The area outside the mapped SFHA with a low risk of flooding.

7. Shaded X: An area of moderate risk of flooding from the base flood, and defined as:

a. Areas of shallow (i.e., less than one foot) flooding;

b. 0.2% chance (or 500-year) flooding;

c. Has a drainage area less than one square mile; or

d. Areas protected by a levee. (Ord. 6761 § 1 (Exh. A), 2020.)