This chapter establishes regulations for the protection of environmentally critical areas (ECAs) including critical areas, natural resource lands, and protective buffers. While it is intended that this chapter fulfill the mandates of the Washington State Growth Management Act, that is not its sole purpose: Its primary purpose is to fulfill the legislative intent of the city, which is to protect the public health, safety, and welfare of the citizens of the city by providing for the long-term preservation of natural systems and their functions. This is to be accomplished by establishing prohibitions, mitigation requirements, and minimum standards for the use and development of properties that contain or adjoin environmentally critical areas. Additionally, this chapter is intended to:

(1)

If at all possible, avoid impacts to environmentally critical areas. If this is not practicable, then:

(A)

Minimize or limit the degree or magnitude of actions and their implementation by using appropriate technology or by taking affirmative steps to avoid or reduce impacts.

(B)

Mitigate any impacts by repairing, rehabilitating, or restoring the affected environment.

(C)

Reduce or eliminate any impacts over time by preservation and maintenance operations during the life of the action.

(D)

Compensate for unavoidable impacts by replacing, enhancing or providing substitute resources or environments through monitoring of specific and cumulative impacts.

(2)

Protect the public from personal injury, loss of life, or property damage due to flooding, erosion, landslides, seismic events, or soil subsidence.

(3)

Protect against publicly financed expenditures due to the misuse of environmentally critical areas that cause:

(A)

Unnecessary maintenance and replacement of public facilities;

(B)

Publicly funded mitigation of avoidable impacts;

(C)

Cost for public emergency rescue and relief operations where the causes are avoidable;

(D)

Degradation of the natural environment.

(4)

Protect aquatic resources.

(5)

Protect unique, fragile, and valuable elements of the environment, including wildlife and its habitat.

(6)

Alert appraisers, assessors, owners, potential buyers, or lessees to the development limitations of environmentally critical areas.

(7)

Provide city officials with sufficient information to adequately protect environmentally critical areas when approving, conditioning, or denying applications for public or private development proposals.

(8)

Give guidance to the development of comprehensive plan policies in regard to the natural systems and environment of the city watershed(s).

(9)

Provide property owners and developers with succinct information regarding the city's requirements for property development, thus rationalizing and accelerating the development permit application process.

(Ord. No. 2011-029, § 1, 12-5-2011; Ord. No. 2016-013, § 3, 7-18-2016)

For the purposes of this chapter, the following definitions shall apply:

"Agricultural activities, existing and ongoing" means those activities conducted on lands defined in RCW 84.34.020(2), and those activities involved in the production of crops and livestock, including but not limited to operation, maintenance and conservation measures of farm and stock ponds or drainage ditches, irrigation systems, changes between agricultural activities, and normal operation, maintenance or repair of existing serviceable structures, facilities, or improved areas. Activities which bring an area into agricultural use are not part of an ongoing activity. An operation ceases to be ongoing when the area in which it was conducted is proposed for conversion to nonagricultural use or has lain idle for a period of longer than five years unless the idle land is registered in a federal or state soils conservation program.

"Alteration(s)" means any human-induced change in an existing condition of a critical area or its buffer. Alterations include, but are not limited to, grading, filling, channelizing, dredging, clearing of vegetation, construction, compaction, excavation, or any other activity that changes the character of the critical area.

"AMC" means the Arlington Municipal Code.

"Applicant" means a person who applies for any permit or approval to do anything governed by this code and who is either the owner of the subject property, the authorized agent of the owner, or the city.

"Best available science" means current scientific information used in the process to designate, protect, or restore critical areas; that is, derived from a valid scientific process as defined WAC 365-195-900 through 365-195-925.

"Best Management Practices (BMPs)" means conservation practices or systems of practices and management measures that:

(a)

Control soil loss and reduce water quality degradation caused by high concentrations of nutrients, animal waste, toxics, or sediment;

(b)

Minimize adverse impacts to surface water and ground water flow and circulation patterns and to the chemical, physical, and biological characteristics of wetlands;

(c)

Protect trees, vegetation, and soils designated to be retained during and following site construction and use native plant species appropriate to the site for re-vegetation of disturbed areas; and

(d)

Provide standards for proper use of chemical herbicides within critical areas.

"Bog" means a low-nutrient, acidic wetland with organic soils and characteristic bog plants, as described in Washington State Wetland Rating System for Western Washington: 2014 Update (Washington State Department of Ecology Publication #14-06-29, Olympia, WA, October 2014).

"Buffer or buffer zone" means they are contiguous with a critical area that maintains the functions and/or structural stability of the critical area.

"Classes" means taxonomic classification system of the United States Fish and Wildlife Service (Cowardin, et al 1978).

"Coastal lagoon" means a shallow body of water partly or completely separated from the sea by a barrier beach that receives periodic influxes of salt water, as described in Washington State Wetland Rating System for Western Washington: 2014 Update (Washington State Department of Ecology Publication #14-06-29, Olympia, WA, October 2014).

"Commercial" means activity with goods, merchandise, or services for sale or rent.

"Compensation" means in-kind replacement of damaged wetlands with substitute wetlands whose characteristics closely approximate those destroyed or degraded by a regulated activity. It does not mean replacement-in-category. When compensatory measures are appropriate pursuant to the mitigation priority sequence above, preferential consideration shall be given to measures that replace the impacted functions directly and in the immediate vicinity of the impact. However, alternative compensatory mitigation within the watershed sub-basin that addresses limiting factors or identified critical needs for shoreline resource conservation based on watershed or comprehensive resource management plans applicable to the area of impact may be authorized. If there are no previously identified mitigation opportunities in the impacted sub-basin identified in local watershed or comprehensive plans the applicant will use a watershed approach in selecting mitigation sites utilizing Selecting Wetland Mitigation Sites Using a Watershed Approach (Western Washington) (Publication #09-06-32).

"Constructed stormwater wetland" means a stormwater management system that is designed and built to function similar to the naturally occurring wetland including native trees and shrubs allowed to grow to maturity.

"Creation" means the manipulation of the physical, chemical, or biological characteristics to develop a wetland on an upland or deep-water site where a wetland did not previously exist. Creation results in a gain in wetland acreage and function. A typical action is the excavation of upland soils to elevations that will produce a wetland hydroperiod and hydric soils and support the growth of hydrophytic plat species.

"Critical areas" includes any of the following areas or ecosystems: Critical aquifer recharge areas, fish and wildlife habitat conservation areas, geologically hazardous areas, frequently flooded areas, and wetlands, as defined in RCW 36.70A and this chapter.

"Cumulative impacts or effects" means the combined, incremental effects of human activity on ecological or critical area functions and values. Cumulative impacts result when the effects of an action are added to or interact with the effects of other actions in a particular place and within a particular time. It is the combination of these effects, and any resulting environmental degradation, that should be the focus of cumulative impact analysis and changes to policies and permitting decisions.

"Dedication" means deliberate appropriation of land by an owner for public use or purpose, reserving no other rights than those that are compatible with the full exercise and enjoyment of the public use or purpose to which the property has been devoted.

"Degraded wetland" means a wetland in which the vegetation, soils, and/or hydrology have been adversely altered, resulting in lost or reduced functions and values.

"Developable area" means land outside of critical areas and environmentally critical area setbacks and buffers.

"Development" means a land use consisting of the construction or exterior alteration of structures; grading, dredging, drilling, or dumping; filling; removal of sand, gravel, or minerals; bulk heading; driving of pilings; or any project of a temporary or permanent nature which modifies structures, land, wetlands, or shorelines and which does not fall within the allowable exemptions contained in the city code.

"Development permit" means any permit or approval under this code or the AMC that must be issued before initiating a use or development activity.

"Ditch" means a long narrow excavation dug in the earth for drainage with its top width less than ten feet at design flow and that does not meet the definition of a stream. A ditch may be regulated if it conveys stream flow.

"Easement" means land which has specific air, surface or subsurface rights conveyed for us by an entity other than the owner of the subject property or to benefit some property other than the subject property.

"Edge" means the boundary of a wetland as delineated based on the criteria contained in this chapter.

"Emergent wetland" means a wetland with at least thirty percent of its surface covered by erect, rooted, herbaceous vegetation at the uppermost vegetative strata.

"Enhancement" means the manipulation of the physical, chemical, or biological characteristics of a wetland to heighten, intensify, or improve specific function(s) or to change the growth stage or composition of the vegetative present. Enhancement is undertaken for specified purposes such as water quality improvement, flood water retention, or wildlife habitat. Enhancement results in a change in wetland function(s) and can lead to a decline in other wetland functions but does not result in a gain in wetland acres. Examples are planting vegetation, controlling non-native or invasive species, and modifying site elevations to alter hydroperiods.

"Erosion hazard area" means a landform or soil type subject to being worn away by the action of water, wind, freeze-thaw, or ice.

"Estuarine wetland" means a vegetated wetland with a water regime that is predominately tidal, as described in Washington State Wetland Rating System for Western Washington: 2014 Update (Washington State Department of Ecology Publication #14-06-29, Olympia, WA, October 2014).

"Exotic species" means plants or animals that are not native to the Puget Sound Lowlands region.

"Extraordinary hardship" means prevention of all reasonable economic use of the parcel due to strict application of this chapter and/or programs adopted to implement this chapter.

"Fish and wildlife habitats (of local importance)" means a seasonal range or habitat element with which a given species has a primary association, and which, if altered, may reduce the likelihood that the species will maintain and reproduce over the long-term. These might include areas of relative density or species richness, breeding habitat, seasonal range, and movement corridors. These also include habitats of limited availability or high vulnerability to alteration, such as cliffs and wetlands.

"Forested wetland" means wetlands with at least thirty percent of the surface area covered by woody vegetation greater than twenty feet in height or ≥ three-inch diameter at breast height.

"Forest land" means land used for growing trees, not including Christmas trees, for commercial purposes (as shown by record of any income) that has long-term (six years or more) commercial significance.

"Functions and values" means the services provided by critical areas to society, including, but not limited to, improving, and maintaining water quality, providing fish and wildlife habitat, supporting terrestrial and aquatic food chains, reducing flooding and erosive flows, wave attenuation, historical or archaeological importance, educational opportunities, and recreation.

"Geologically hazardous areas" means includes areas susceptible to erosion, sliding, seismic activity, or other geological events. They pose a threat to the health and safety of citizens when used as sites for incompatible commercial, residential, or industrial development.

"Grading" means the physical manipulation of the earth's surface and/or drainage pattern in preparation of an intended use or activity.

"Hazardous substances" means any liquid, solid, gas, or sludge, including any material, substance, product, commodity, or waste, regardless of quantity, that exhibits any of the physical, chemical, or biological properties described in WAC 173-303-090 or 173-303-100.

"High quality native wetlands" will be classified by the state wetland rating system for Western Washington. However, the following elements may be considered when identifying locally important functions of a wetland:

(1)

No, or isolated, human alteration of the wetland topography;

(2)

No human-caused alteration of the hydrology or else the wetland appears to have recovered from the alteration;

(3)

Low cover and frequency of exotic plant species;

(4)

Relatively little human-related disturbance of the native vegetation, or recovery from past disturbance;

(5)

If the wetland system is degraded, it still contains a viable and high-quality example of a native wetland community; and

(6)

No known major water quality problems.

"Hydric soil" means soil that is saturated, flooded, or ponded long enough during the growing season to develop anaerobic conditions in the upper part. The presence of hydric soil shall be determined following the methods as defined by the National Technical Committee for Hydric Soils. The presence of hydric soil shall be determined following the methods described in the Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region.

"Hydrophyte or hydrophytic vegetation" means plant life growing in water or on a substrate that is at least periodically deficient in oxygen as a result of excessive water content. The presence of hydrophytic vegetation shall be determined following the methods described in the Washington State Wetland Delineation Manual adopted pursuant to RCW 90.58.380.

"Impervious surface" means a surface area which either prevents or retards the entry of water into the soil mantle as under natural conditions prior to development. A non-vegetated 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 pre-development or pre-developed conditions. 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 stormwater.

"Improvement" means any structure or manmade feature.

"In-kind compensation" means to replace critical areas with substitute areas whose characteristics and functions closely approximate those destroyed or degraded by a regulated activity.

"In-lieu-fee program" means an agreement between a regulatory agency (state, federal, or local) and a single sponsor, generally a public natural resource agency or non-profit organization. Under an in-lieu-fee agreement, the mitigation sponsor collects funds from an individual or a number of individuals who are required to conduct compensatory mitigation required under a wetland regulatory program. The sponsor may use the funds pooled from multiple permittees to create one or a number of sites under the authority of the agreement to satisfy the permittees' required mitigation.

"Infiltration" means the downward entry of water into the immediate surface of soil.

"Interdunal wetland" means a wetland that forms in the deflation plains and swales that are geomorphic features in areas of coastal dunes, as described in Washington State Wetland Rating System for Western Washington: 2014 Update (Washington State Department of Ecology Publication #14-06-29, Olympia, WA, October 2014).

"Isolated wetlands" means a wetland that is hydrologically isolated from other aquatic resources, as determined by the United States Army Corps of Engineers (USACE). Isolated wetlands may perform important functions and are protected by state law (RCW 90.48) whether or not they are protected by federal law.

"Landslide hazard areas" means areas potentially subject to risk of mass movement due to a combination of factors, including historic failures.

"Land uses, high intensity" means a zone classification allowing more than one dwelling unit per acre.

"Land uses, low intensity" means includes land uses which are associated with low levels of human disturbance or low habitat impacts, including, but not limited to, passive recreation, open space, or those uses listed in Section 20.93.220 (Allowed activities).

"Land uses, medium intensity" means includes land uses which are associated with moderate levels of disturbance such as open space parks with biking and jogging, etc., conversion of moderate-intensity agriculture (orchards, hay fields, etc.), paved trails, gravel roads, utility corridors or right-of-way shared by several utilities including access/maintenance roads.

"Mature and old-growth forested wetland" means a wetland having at least one contiguous acre of either old-growth forest or mature forest, as described in Washington State Wetland Rating System for Western Washington: 2014 Update (Washington State Department of Ecology Publication #14-06-29, Olympia, WA, October 2014).

"Mineral resource lands" means lands primarily devoted to the extraction of gravel, sand, other construction materials, or valuable metallic or mineral substances.

"Mitigation" means avoiding, minimizing, or compensating for adverse critical areas impacts. Mitigation, in the following sequential order of preference, is:

(a)

Avoiding the impact altogether by not taking a certain action or parts of an action;

(b)

Minimizing impacts by limiting the degree of magnitude of the action and its implementation by using appropriate technology or by taking affirmative steps to avoid or reduce the impacts;

(c)

Rectifying the impact to wetlands, critical aquifer recharge areas, and habitat conservation areas by repairing, rehabilitating, or restoring the affected environment to the conditions existing at the time of the initiation of the project;

(d)

Reducing or eliminating the impact or hazard over time by preservation and maintenance operations during the life of the action;

(e)

Compensating for the impact to wetlands, critical aquifer recharge areas, and habitat conservation areas by replacing, enhancing, or providing substitute resources or environments; and

(f)

Monitoring the hazard or other required mitigation and taking remedial action when necessary.

Mitigation for individual actions may include a combination of the above measures.

"Monitoring" means evaluating the impacts of development proposals on the biological, hydrological, and geological elements of such systems, and assessing the performance of required mitigation measures through the collection and analysis of data by various methods for the purpose of understanding and documenting changes in natural ecosystems and features. Monitoring includes gathering baseline data.

"Native vegetation" means plant species that are indigenous to the Puget Sound Lowlands region.

"Natural condition" means lands that retain native vegetation, forest duff and naturally occurring contours and drainage patterns not modified by human activity.

"Natural resource lands" means agriculture, forest, and mineral resource lands as defined in this section.

"Nonconforming" means any use, structure, lot, condition, activity, or any other feature or element of private property or the use or utilization of private property that does not conform to any of the provisions of this code or that was not approved by the city through the appropriate decision-making process required under this code.

"Off-site compensation" means to replace critical areas away from the site on which a critical area has been impacted.

"On-site compensation" means to replace critical areas at or adjacent to the site on which a critical area has been impacted.

"Open space" means land not covered by buildings, roadways, parking areas, or other surfaces through which water cannot percolate into the underlying soils.

"Ordinary high-water mark" means that mark which is found by examining the bed and banks of water bodies and ascertaining where the presence and action of waters are so common and usual, and so long continued in all ordinary years, that the soil has a character distinct from that of the abutting upland in respect to vegetation and as defined by RCW 90.58.030(2)(b), as now or hereafter amended.

"Palustrine wetland" means freshwater with open water, emergent herbaceous vegetation, scrub-shrub vegetation, and/or trees.

"Pond" means any inland body of water, either naturally or artificially formed or increased, that has a surface area of one thousand square feet or more, except: These do not include ponds deliberately designed and created from dry sites such as canals, detention facilities, wastewater treatment facilities, farm ponds, and landscape amenities.

"Practicable alternative" means an alternative that is available and capable of being carried out after taking into consideration cost, existing technology, and logistics in light of overall project purposes, and having less impacts to environmentally critical areas. It may include an area not owned by the applicant that can reasonably be obtained, utilized, expanded, or managed in order to fulfill the basic purpose of the proposed activity.

"Preservation" means the removal of a threat to, or preventing the decline of, wetland conditions by an action in or near a wetland. This term includes the purchase of land or conservation easements, repairing water control structures or fences, or structural protection. Preservation does not result in a gain of wetland acres but may result in a gain of functions over the long term.

"Prior converted croplands" means prior converted croplands (PCCs) are defined in federal law as wetlands that were drained, dredged, filled, leveled, or otherwise manipulated, including the removal of woody vegetation, before December 23, 1985, to enable production of an agricultural commodity, and that: 1) have had an agricultural commodity planted or produced at least once prior to December 23, 1985; 2) do not have standing water for more than fourteen consecutive days during the growing season; and 3) have not since been abandoned.

"Priority habitats" means areas with which priority species have a primary association, as determined by the Washington Department of Fish and Wildlife. Priority habitats have one or more of the following attributes: comparatively high or significant species density or richness, significant breeding habitat, significant seasonal ranges, significant wildlife movement corridors, limited availability, and/or high vulnerability.

"Priority species" means wildlife species of concern due to their population status and their sensitivity to habitat alteration.

"Project area" means all areas, including those within fifty feet of the area, proposed to be disturbed, altered, or used by the proposed activity or the construction of any proposed structures. When the action binds the land, such as a subdivision, short subdivision, binding site plan, planned unit development, or rezone, the project area shall include the entire parcel, at a minimum.

"Qualified wetland professional" means a person with professional wetland experience that meets the following criteria:

a.

A Bachelor of Science or Bachelor of Arts or equivalent degree in hydrology, soil science, botany, ecology, resource management, or related field, or four years of full-time work experience as a wetland professional may substitute for a degree, and

b.

At least two additional years of full-time work experience as a wetland professional; including delineating wetlands, preparing wetland reports, conducting function assessments, and developing and implementing mitigation plans, and

c.

Completion of additional wetland-specific training programs. This could include a more comprehensive program such as the University of Washington Wetland Science and Management Certificate Program or individual workshops on topics such as wetland delineation, function assessment, mitigation design, hydrophytic plat or hydric soil identification.

A person certified as a professional wetland scientist through the Society of Wetland Scientists professional certification program meets the above criteria.

"Re-establishment" means the manipulation of the physical, chemical, or biological characteristics of a site with the goal of returning natural or historical functions to a former wetland. Re-establishment results in rebuilding a former wetland and results in a gain in wetland acres and functions. Activities could include removing fill, plugging ditches, or breaking drain tiles.

"Rehabilitation" means the manipulation of the physical, chemical, or biological characteristics of a site with the goal of repairing natural or historic functions and processes of a degraded wetland. Rehabilitation results in a gain in wetland function but does not result in a gain in wetland acres. Activities could involve breaching a dike to reconnect wetlands to a floodplain or returning tidal influence to a wetland.

"Repair or maintenance" means an activity that restores the character, scope, size, and design of a serviceable area, structure, or land use to its previously authorized and undamaged condition. Activities that change the character, size, or scope of a project beyond the original design and drain, dredge, fill, flood, or otherwise alter critical areas are not included in this definition.

"Restoration" means measures taken to restore an altered or damaged natural feature, including:

(a)

Active steps taken to restore damaged wetlands, streams, protected habitat, or their buffers to the functioning condition that existed prior to an unauthorized alteration; and

(b)

Actions performed to re-establish structural and functional characteristics of a critical area that have been lost by alteration, past management activities, or catastrophic events.

"Riparian habitat" means an ecosystem that occurs in the transition zone between aquatic and upland environments.

"Scrub-shrub wetlands" means a wetland with at least thirty percent of its surface area covered with woody vegetation less than twenty feet in height or ≤ three-inch diameter at breast height.

"Seismic hazard areas" means areas subject to the risk of damage as a result of earthquake induced ground shaking, slope failure, settlement, soil liquefaction or surface faulting. Ground shaking is a primary risk, followed by some unstable slopes causing damage below them.

"Service area" means the geographic area within which impacts can be mitigated at a specific mitigation bank or an in-lieu-fee program, as designated in its instrument.

"Soil survey" means the most recent soil survey for the local area or county by the National Resources Conservation Service, U.S. Department of Agriculture.

"Slope". See Section 20.93.600 (Geological hazardous areas—Classification).

"Species" means any group of animals or plants classified as a species or subspecies as commonly accepted by the scientific community.

"Species, listed" means any species listed under the federal Endangered Species Act or state endangered, threatened, and sensitive, or priority lists (see WAC 232-12-297 or page 6 of "Priority Habitat and Species List," Washington Department of Fish and Wildlife, 2008, Olympia, Washington. 177 pp.)

"Sphagnum" means any of a large genus of mosses that grows only in wet acidic soils and whose remains become compacted with other plant debris to form peat.

"Streams" means those areas where surface waters flow sufficiently to produce a defined channel or bed. A defined channel or bed is indicated by hydraulically sorted sediments or the removal of vegetative litter or loosely rooted vegetation by the action of moving water. The channel or bed need not contain water year-round. This includes DNR Stream Types S, F, F-ESA, Np, Ns (WAC 222-16-030, or as amended hereafter). This definition is not meant to include irrigation ditches, canals, stormwater runoff devices or other entirely artificial watercourses unless they are used to convey any stream naturally occurring prior to construction. Those topographic features that resemble streams but have no defined channels (i.e., swales) shall be considered streams when hydrologic and hydraulic analyses done pursuant to a development proposal predict formation of a defined channel after development.

"Steep slope". See Section 20.93.600 (Geological hazardous areas—Classification).

"Structure" means anything which is built or constructed; an edifice or building of any kind, or any piece of work artificially built-up or composed of parts joined together in some definite manner. Not included are fences less than six feet in height, retaining wall, rockeries, and similar improvements of a minor character less than three feet in height.

"Unavoidable impacts" means adverse impacts that remain after all appropriate and practicable avoidance and minimization has been achieved.

"Use development" means as that term is defined in Chapter 90.58 RCW. Also means the nature of the activities taking place on private property or within structures thereon.

"Water-dependent" means a use for which the use of surface water would be essential in fulfilling the purpose of the proposed project.

"Wetland" or "wetlands" means areas that are inundated or saturated by surface water or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas. Wetlands do not include those artificial wetlands intentionally created from non-wetland sites, including, but not limited to, irrigation and drainage ditches, grass-lined swales, canals, detention facilities, wastewater treatment facilities, farm ponds, and landscape amenities, or those wetlands created after July 1, 1990, that were unintentionally created as a result of the construction of a road, street, or highway. Wetlands may include those artificial wetlands intentionally created from non-wetland areas created to mitigate conversion of wetlands.

"Wetland of high conservation value" means a wetland that has been identified by scientists from the Washington Natural Heritage Program (WHNHP) as an important ecosystem for maintaining plant diversity in Washington State. See http://www.dnr.wa.gov/data-information-natural-heritage-features.

"Wetland mitigation bank" means a site where wetlands are restored, created, enhanced, or in exceptional circumstances, preserved, expressly for the purpose of providing compensatory mitigation in advance of unavoidable impacts to wetlands or other aquatic resources that typically are unknown at the time of certification to compensate for future, permitted impacts to similar resources.

"Wetland mosaic" means an area with a concentration of multiple small wetlands, in which each patch of wetland is less than one acre; on average, patches are less than one hundred feet from each other; and areas delineated as vegetated wetland are more than fifty percent of the total area of the entire mosaic, including uplands and open water.

(Ord. No. 2011-029, § 1, 12-5-2011; Ord. No. 2016-013, §§ 4, 5, 7-18-2016;Ord. No. 2022-030, § 1, 10-17-2022)

This chapter applies to environmentally critical areas within the city's jurisdiction. No action shall be taken by any person that results in any alteration of any environmentally critical area or their buffers except as consistent with the purposes, objectives, and goals of this chapter.

(Ord. No. 2011-029, § 1, 12-5-2011; Ord. No. 2016-013, § 6, 7-18-2016)

(a)

All land use and/or development activities on lands containing environmentally critical areas or affecting off-site environmentally critical areas are subject to this chapter and are prohibited unless:

(1)

The use or activity is found to be exempt by the community and economic development director per the allowed uses sections of this chapter; or,

(2)

The use or activity meets the performance standards found in the requirements sections of this chapter.

(b)

Land use and development activities include, but are not limited to, the following activities:

(1)

The removal, excavation, grading, or dredging of soil, sand, gravel, minerals, organic matter, or material of any kind.

(2)

The dumping, discharging, or filling with any material.

(3)

The draining, flooding, or disturbing of the water level or water table.

(4)

The driving of pilings.

(5)

The placing of obstructions.

(6)

The construction, reconstruction, demolition, or expansion of any structure.

(7)

The destruction or alteration of vegetation in an environmentally critical area through clearing, harvesting, shading, intentional burning, or planting of vegetation that would alter the character and function of an environmentally critical area.

(8)

Activities that result in a significant change of water temperature, a significant change of physical or chemical characteristics of water sources, including quantity, or the introduction of pollutants.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

Unless specifically prohibited elsewhere in this chapter, or unless the use affects a critical area structure, function or value, the following uses are allowed in any environmentally critical area:

(1)

Conservation or preservation of soil, water, vegetation, fish, shellfish, and other wildlife.

(2)

Outdoor recreational activities (including fishing, bird watching, hiking, boating, swimming, canoeing, etc.) and aquatic recreation facilities authorized by this chapter (unless otherwise prohibited from a particular area because of site-specific issues.

(3)

When approval is granted by the city, the recreational harvesting of wild crops in a manner that is not injurious to natural reproduction of such crops and provided the harvesting does not require killing the plant, tilling of soil, planting of crops, or alteration of a wetland by changing existing topography, water conditions or water sources.

(4)

Education, scientific research, and use of nature trails.

(5)

Navigation aids and boundary markers.

(6)

Site investigative work necessary for land use application submittals such as surveys, soil logs, percolation tests and other related activities. In every case, impacts shall be minimized and disturbed areas shall be immediately restored.

(7)

Normal maintenance, repair, or operation of existing structures, facilities, or improved areas.

(8)

Environmentally critical area restoration work or relocation work which would improve the function of the environmentally critical area, when done pursuant to a plan approved by the city.

(Ord. No. 2011-029, § 1, 12-5-2011)

All land uses or development applications shall be reviewed to determine whether an environmentally critical area exists on the property for which the application is filed, what the action's impacts to any existing environmentally critical area would be, and what actions are required for compliance with this chapter. No construction activity, including land clearing or grading, shall be permitted until the information required by this section is reviewed and the city approves a plan.

(Ord. No. 2011-029, § 1, 12-5-2011)

Criteria for classification as an environmentally critical area will be listed under the pertinent sections of this chapter.

(Ord. No. 2011-029, § 1, 12-5-2011)

The City of Arlington shall not grant any approval or permission to conduct development or use in an environmentally critical area prior to the applicant's fulfillment of the requirements of this chapter. The community and economic development director is authorized to adopt administrative procedures for the purpose of carrying out the provisions of this chapter.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

To enable the city to determine compliance with this chapter, at the time of application submittal the applicant shall file a SEPA environmental checklist (if use is subject to SEPA), site/resource specific reports as specified in Section 20.93.270 (General provisions—Site/resource specific reports), and any other pertinent information requested by the department of community development. The community and economic development director may waive any of these submittal requirements if it is deemed unnecessary to make a compliance determination.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

Unless waived per Section 20.93.260 (General provisions—Submittal requirements), all applications for land use or development permits proposed on properties containing or adjacent to environmentally critical areas or their defined buffers (see section specific requirements) shall include site/resource specific reports prepared to describe the environmental limitations of the site. These reports shall conform in format and content to guidelines prepared by the department of community and economic development, which is hereby authorized to do so.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

The approximate location and extent of environmentally critical areas in the city are displayed on various inventory maps available at the department of community and economic development. More data will be included as inventories are completed in compliance with the requirements of the growth management act. Maps and inventory lists are guides to the general location and extent of environmentally critical areas. Environmentally critical areas not shown are presumed to exist in the city and are protected under all the provisions of this chapter. The shoreline jurisdiction areas are identified in the adopted shoreline maps. In the event that any of the designations shown on the maps or inventory lists conflict with the criteria set forth in this chapter, the criteria and site-specific conditions shall control.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

(a)

In order to protect environmentally critical areas, environmentally critical area easements or tracts, where proposed as mitigation, shall be marked as such and dedicated to the city and recorded with Snohomish County. Appropriate demarcation methods shall be as set forth in the public works construction standards and specifications, and include appropriate permanent fencing and signage unless otherwise determined by the natural resources manager. Fencing or demarcation method must be built of materials that are permanent in nature. Fencing may not be required if the site is a know migration route for wildlife and due to other constraints such as roadways or buildings a fence would prevent migration of those species. Alternative methods of demarcation will be required to replace signage when determined that effectiveness of signage may be limited.

(b)

Anyone may offer to dedicate an environmentally critical area easement or tract and its buffer to the city even if not proposed as mitigation.

(c)

Such easements or tracts shall cover the environmentally critical area as delineated by their defined boundaries and their buffers.

(d)

The basic controlling language for such easements shall be as follows, though site/resource specific modifications may be made:

"Critical Area Protection Easement: This open space tract is intended to protectinsert ECA type and native vegetation and shall preclude: grading or any recontouring of the land; placement of structures, wells, leach fields, utility lines and/or easements, and any other thing; vehicle activity; grazing; dumping; and the addition or removal of vegetation, except pursuant to an approved restoration plan, and except that vegetation may be selectively removed and/or pervious trails and/or utility lines compatible with native tree and shrub vegetation may be placed in the buffer areas in locations approved by the Director of Community and Economic Development."

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

The dedication of environmentally critical areas and their buffers may not be used for satisfying the park or open space requirements of AMC Chapter 20.52 (Recreational Facilities and Open Space).

(Ord. No. 2011-029, § 1, 12-5-2011)

The permit-issuing authority shall require increased standard buffer zone widths on a case-by-case basis when a larger buffer is necessary to protect environmentally critical area functions and values based on local conditions. This determination shall be supported by appropriate documentation showing that it is reasonably related to protection of the functions and values of the regulated environmentally critical area. Such determination shall be attached as a permit condition and shall demonstrate that:

(1)

A larger buffer is necessary to maintain viable populations of existing species; or

(2)

The environmentally critical area is used by species proposed or listed by the federal government or the state as endangered, threatened, sensitive, candidate, or monitor, critical or outstanding potential habitat for those species or has unusual nesting or resting sites such as heron rookeries or raptor nesting trees; or

(3)

The adjacent land has minimal vegetative cover or slopes greater than fifteen percent and is therefore susceptible to severe erosion, and erosion control measures will not effectively prevent adverse environmentally critical area impacts.

(4)

The recommended widths for buffers are based on the assumption that the buffer is vegetated with a native plant community appropriate for the ecoregion or with one that performs similar functions. If the existing buffer is unvegetated, sparsely vegetated, or vegetated with invasive species that do not perform needed functions, the buffer should either be planted to create the appropriate plant community or the buffer should be widened to ensure that adequate functions of the buffer are provided. Generally, improving the vegetation will be more effective than widening the buffer.

(Ord. No. 2011-029, § 1, 12-5-2011)

Buffer widths may be modified by averaging. In no instance shall the buffer width be reduced by more than twenty-five percent of the standard buffer unless specifically identified in other sections of this chapter. Buffer width averaging shall be allowed only where the applicant demonstrates all of the following:

(1)

That averaging is necessary to avoid an extraordinary hardship to the applicant caused by circumstances peculiar to the property or that there would be a benefit to the environmentally critical area;

(2)

That the least impactive aspects of the proposed land use would be located adjacent to areas where the buffer width is reduced;

(3)

That width averaging will not adversely impact the environmentally critical area functional values; and

(4)

That the total area contained within the buffer after averaging is no less than that contained within the standard buffer prior to averaging.

(Ord. No. 2011-029, § 1, 12-5-2011)

Except as otherwise specified, all buffers shall be retained in their natural condition. Where buffer disturbance may or has occurred during construction, revegetation with native vegetation will be required.

(Ord. No. 2011-029, § 1, 12-5-2011)

A building setback of fifteen feet is required from the edge of any critical area buffer, as defined in subsequent sections of this chapter. Minor structural intrusions into the area of the building setback may be allowed if the permit-issuing authority determines that such intrusions will not negatively impact the environmentally critical area or cause the buffer vegetation to be trimmed or removed. The setback shall be identified on the site plan.

(Ord. No. 2011-029, § 1, 12-5-2011)

Except for cases of discontinuance as part of normal agricultural practices, non-conforming uses shall be governed by Part VI of this chapter and AMC Chapter 20.32 (Nonconforming Situations).

(Ord. No. 2011-029, § 1, 12-5-2011)

The Snohomish County Assessor's office considers environmentally critical area regulations in determining the fair market value of land. Any owner of an undeveloped critical area who has dedicated an easement or entered into a perpetual conservation restriction with the city of Arlington or a qualified nonprofit organization to permanently control some or all regulated activities in that portion of land assessed consistent with these restrictions shall be considered for exemption from special assessments to defray the cost of municipal improvements such as sanitary sewers, storm sewers, and water mains.

(Ord. No. 2011-029, § 1, 12-5-2011)

In the event that mitigation is required, the applicant shall be required to provide a mitigation plan for approval by the community and economic development director. The plan shall provide information on land acquisition, construction, maintenance, and monitoring of the replaced critical area. All mitigation plans shall include the following submitted by the applicant or a qualified biologist, civil or geotechnical engineer:

(1)

Specific goals and objectives describing site function, target species and selection criteria;

(2)

Performance standards that shall include criteria for assessing goals and objectives;

(3)

Contingency plans that clearly define course of action or corrective measures needed if performance standards are not met;

(4)

A legal description and a survey prepared by a licensed surveyor of the proposed development site and location of the critical area(s) on the site;

(5)

The need for performance or maintenance securities.

(6)

A scaled plot plan that indicates the proposed construction in relation to zoning setback requirements and sequence of construction location in relation to zoning setback requirements and sequence of construction phases including cross-sectional details, topographic survey data (including percent slope, existing and finished grade elevations) and other technical information as required in sufficient detail to explain, illustrate and provide for:

(A)

Soil and substrate conditions, topographic elevations, scope of grading and excavation proposal, erosion and sediment treatment and source controls needed for critical area construction and maintenance;

(B)

Planting plans specifying plant species, types, quantities, location, size spacing, or density. The planting season or timing, watering schedule, and nutrient requirements for planting, and where appropriate, measures to protect plants from destruction; and

(C)

Contingency or mid-course corrections plan and a minimum five-year monitoring and replacement plan establishing responsibility for removal of exotic and nuisance vegetation and permanent establishment of the critical area and all component parts.

(7)

A clearly defined approach to assess progress of the project.

(8)

The plan must indicate ownership, size, type, and complete ecological assessment including flora, fauna, hydrology, functions, etc., of the critical area being restored or created; and

(9)

The plan must also provide information on the natural suitability of the proposed site for establishing the replaced critical area, including water source and drainage patterns, topographic position, wildlife habitat opportunities, value of existing area to be converted, etc.

(10)

Once the plan is implemented, as-builts shall also be submitted pursuant to department of public works requirements.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

Fish and wildlife conservation areas include:

(1)

Lands containing priority habitats and species, including plant and/or animal species listed on federal or state threatened or endangered species lists.

(2)

Ponds and their submerged aquatic beds that provide fish or wildlife habitat.

(A)

"Type S" waters of the state as defined in WAC 222-16-030, which includes all waters, within their ordinary high-water mark, as inventoried as "shorelines of the state" under Chapter 90.58 RCW and the rules promulgated pursuant to Chapter 90.58 RCW, but not including those waters' associated wetlands as defined in Chapter 90.58 RCW.

(3)

Segments of natural waters and periodically inundated areas of their associated wetlands that are used by salmonids for off-channel habitat. These areas are critical to the maintenance of optimum survival of juvenile salmonids. This habitat shall be identified based on the following criteria:

(A)

The site must be connected to a stream bearing salmonids and accessible during some period of the year; and

(B)

The off-channel water must be accessible to juvenile salmonids through drainage with less than a five percent gradient.

(4)

Lakes, ponds, and streams planted with game fish (defined at RCW 77.09.020), including those planted under the auspices of a federal, state, local, or tribal programs, or which support priority fish species as identified by the department of fish and wildlife.

(5)

State natural area preserves and natural resource conservation areas.

(6)

Habitats or species of local importance. Such habitats or species may be locally listed per the process elucidated in Section 20.93.420 (Species/habitats of local importance).

(Ord. No. 2011-029, § 1, 12-5-2011)

The community and economic development director shall determine the boundaries of fish and wildlife conservation areas. In doing so he may rely on information from qualified federal, state, county, or tribal agencies or on a biological resources survey prepared by a qualified wildlife biologist per the department's biological resources survey guidelines. Such reports or information may be required to be provided by an applicant for an activity or permit at the request of the city. In the location of shoreline jurisdiction the adopted shoreline designation maps establish the boundary. When a project is at or below OHWM and within shoreline setbacks, the OHWM shall be determined by a site-specific investigation using field indicators.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

(a)

Species or habitats may be listed as a species or habitat of local importance by the city council according to the following process:

(1)

An individual or organization must:

(A)

Demonstrate a need for special consideration based on:

(i)

Declining populations,

(ii)

Sensitivity to habitat manipulation; or

(iii)

Commercial or game value, or other special value, such as flood refugia or public appeal.

(B)

Propose relevant management strategies considered effective and within the scope of this chapter.

(C)

Provide species habitat location(s) on a map.

(2)

Submitted proposals will be reviewed by the community and economic development director and forwarded to the departments of fish and wildlife and natural resources, and/or other local, state, federal, or tribal agencies or experts for comment and recommendation regarding accuracy of data and effectiveness of proposed management strategies.

(3)

The city council will hold a public hearing for proposals found to be complete, accurate, potentially effective, and within the scope of this chapter. Approved nominations will become designated a "species or habitat of local importance" and will be subject to the provisions of this chapter.

(b)

Species or habitats of local importance include:

(1)

None adopted as of December 5, 2011.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

Except where regulated by other sections of this or any other title or law, the following uses shall be allowed within fish and wildlife conservation areas when the requirements of Section 20.93.440 (Fish and wildlife conservation areas—Requirements) have been met and mitigation adequate to alleviate any other impacts has been proposed:

(1)

Those activities listed in Section 20.93.220 (General provisions—Allowed activities).

(2)

Activities consistent with the species located there and all applicable state and federal regulations regarding the species, as determined by the community and economic development director, who will consult with other resource agencies including tribes as to their recommendations based on adopted standards or guidance.

(3)

Within the fifty-foot management zone of the buffer required pursuant to Section 20.93.440 (Fish and wildlife conservation areas—Requirements) the following uses are allowed as long as sixty-five percent of native tree cover is established and maintained and the total effective impervious area (TIA) remains below three percent:

(A)

When the fifty-foot management zone is in an already developed state including buildings, parking lots, lawn or ornamental landscaping stormwater management systems designed to blend into the natural landscape allowing full mature growth of native trees and shrubs, and provide the same or greater functional habitat that would occur in a naturally vegetated buffer. Specifically, this does not include buried vaults, ecology block or grass-lined ponds or swales (though ponds or swales planted with native vegetation may be allowed). Such systems are required to provide diffuse effluent point(s) to the immediate edge of the no-touch buffer to allow infiltration and polishing. Walkways and trails, provided that those pathways are limited to minor crossings having no adverse impact on water quality. They should be generally parallel to the perimeter of the wetland, located only in the outer twenty-five percent of the wetland buffer area, and located to avoid removal of significant trees. They should be limited to pervious surfaces no more than five feet in width for pedestrian use only. Raised boardwalks utilizing non-treated pilings may be acceptable.

(B)

Utility easements and access routes that are built so as to not affect the lateral or vertical hydrology of the system, and are compatible with full maturity of native tree and shrub species.

(C)

Other uses as may be approved by the city's natural resources manager as recommended in a local, state or federal watershed management plan or low impact development regulations.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

(a)

Except as provided in Subsections (b) and (c):

(1)

For endangered or threatened salmonid fish and wildlife conservation areas, a one hundred fifty-foot buffer shall be required for all regulated activities adjacent to the fish and wildlife conservation areas. This buffer shall consist of a one-hundred-foot area closest to the stream or river being designated a native growth protection easement in which no human activities may be allowed (except as provided by Section 20.93.430 (Fish and wildlife conservation areas—Allowed activities), and the remaining fifty-foot zone being designated a management zone, in which vegetation may be managed solely for public health and safety reasons that may threaten structures or public infrastructure. The natural resource may require a landowner to have an assessment performed by a professional arborist to determine if a tree is hazardous. If found hazardous the methods of removal will utilize options that will result in some level of habitat function (i.e., snag, nurse log, etc.). Buffers for salmonid fish and wildlife conservation areas shall be measured pursuant to Section 20.93.730 (Streams, creeks, lakes, and other surface water—Requirements).

(2)

For all other fish and wildlife conservation areas, the applicant shall have a habitat protection plan prepared by a qualified biologist, in which appropriate buffers and other protection shall be identified based on the best available science and/or standards promulgated by the state or federal agency with jurisdiction for the identified species being protected. Buffers shall be measured from the fish and wildlife conservation areas boundary as surveyed in the field.

(b)

Buffer widths may be increased based on recommendations by the state or federal agency with jurisdiction.

(c)

Buffer widths from fish and wildlife conservation areas may be decreased in areas where specific project recommendations can be found in Section 20.93.320 of this chapter, local watershed recovery plans, the Shoreline Master Program has identified allowed uses, a habitat protection plan, or either a property-specific or programmatic biological assessment showing that the proposal would have negligible adverse impact on the protected species or habitat (with or without mitigation) has been approved by the state or federal agency with jurisdiction. Said biological assessments would be prepared by the applicant in a format approved by the agency with jurisdiction. The width of the buffer would be determined through this biological assessment approval process but could in no case be reduced to less than that required for the underlying environmentally critical areas by other sections of this chapter.

(d)

For streams upstream from an endangered or threatened salmonid fish and wildlife conservation area, if requested by the city, applicants shall have prepared a report analyzing potential downstream impacts to the FWCA and propose appropriate measures to mitigate any identified significant impacts. Such reports shall be prepared by a qualified biologist.

(e)

The applicant shall dedicate a functionally exclusive environmentally critical area easement for the protection of wildlife and/or habitat over the fish and wildlife conservation areas and its buffer, as determined above. Where such requirement leads to, or would in the opinion of the permit-issuing authority lead to, a court finding of a taking mitigation as described in Section 20.93.450 (Fish and wildlife conservation areas—Mitigation) may be considered.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

In order to avoid significant environmental impacts and, if in the opinion of the permit-issuing authority the requirements listed in Section 20.93.440 (Fish and Wildlife Conservation Areas—Requirements) do not adequately mitigate impacts, the applicant for a land use activity or development permit may consider performing the following actions, listed in order of preference. What is considered adequate mitigation will depend on the nature and magnitude of the potential impact. Specific mitigation requirements are outlined in the Shoreline Master Program regulations.

(1)

Where on-site protection is not possible, dedicate a functionally exclusive easement for the protection of equivalent (in type and value) wildlife and/or habitat over fish and wildlife conservation areas and a one hundred fifty-foot buffer on off-site fish and wildlife conservation areas at a minimum two to one ratio (two offsite areas for every one onsite area impacted) on property that would likely not be required to dedicate such an easement were it to undergo a permitting process. If functionally equivalent habitat is not available, then a higher ratio may be considered to compensate. The location of any off-site fish and wildlife conservation areas shall be located as near to the site as possible, following this preferred order:

(A)

Hydrologically connected to the impacted fish and wildlife conservation areas or via an intact habitat corridor,

(B)

Elsewhere within the city,

(C)

Within the Arlington UGA,

(D)

Within the sub-basin, and

(E)

Watershed.

(Ord. No. 2011-029, § 1, 12-5-2011)

(a)

Geologically hazardous areas include areas susceptible to erosion, sliding, earthquakes, liquefaction, or other geological events. Geologically hazardous areas shall be classified based upon the history or existence of landslides, unstable soils, steep slopes, high erosion potential or seismic hazards. In determining the significance of a geologically hazardous area the following criteria shall be used:

(1)

Potential economic, health, safety, and environmental impact related to construction in the area;

(2)

Soil type, slope, vegetative cover, and climate of the area;

(3)

Available documentation of history of soil movement, the presence of mass wastage, debris flow, rapid stream incision, stream bank erosion or undercutting by wave action, or the presence of an alluvial fan which may be subject to inundation, debris flows, or deposition of stream-transported sediments.

(b)

The different types of geologically hazardous areas are defined as follows:

(1)

Erosion hazard areas are as defined by the USDA Soil Conservation Service, United States Geologic Survey, or by the Department of Ecology Coastal Zone Atlas. The following classes are high erosion hazard areas.

(A)

Class 3, class U (unstable) includes severe erosion hazards and rapid surface runoff areas;

(B)

Class 4, class UOS (unstable old slides) includes areas having severe limitations due to slope; and,

(C)

Class 5, class URS (unstable recent slides).

(2)

Landslide hazard areas shall include areas subject to severe risk of landslide based on a combination of geologic, topographic and hydrologic factors. Some of these areas may be identified in the Department of Ecology Coastal Zone Atlas, or through site-specific criteria. Landslide hazard areas include any of the following:

(A)

Areas characterized by slopes greater than fifteen percent and impermeable soils (typically silt and clay) frequently interbedded with permeable granular soils (predominantly sand and gravel) or impermeable soils overlain with permeable soils or springs or groundwater seepage;

(B)

Any area that has exhibited movement during the Holocene epoch (from ten thousand years ago to present) or which is underlain by mass wastage debris of that epoch;

(C)

Any area potentially unstable due to rapid stream incision, stream bank erosion or undercutting by wave action;

(D)

Any area located on an alluvial fan presently subject to or potentially subject to inundation by debris flows or deposition of steam-transported sediments;

(E)

Any area with a slope of thirty-three percent or greater and with a vertical relief of ten or more feet except areas composed of consolidated rock;

(F)

Any area with slope defined by the United States Department of Agriculture Soil Conservation Service as having a severe limitation for building site development; and

(G)

Any shoreline designated or mapped as class U, UOS, or URS by the Department of Ecology Coastal Zone Atlas.

(3)

Slopes.

(A)

Moderate slopes shall include any slope greater than or equal to fifteen percent and less than thirty-three percent.

(B)

Steep slopes shall include any slope greater than or equal to thirty-three percent.

(4)

Seismic hazard areas shall include areas subject to severe risk of earthquake damage as a result of seismic induced settlement, shaking, slope failure or soil liquefaction. These conditions occur in areas underlain by cohesion less soils of low density usually in association with a shallow groundwater table.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

The community and economic development director, relying on a geotechnical or similar technical report and other information where available and pertinent, shall make determination of a boundary of a geologically hazardous area. Such reports or information shall be provided by an applicant for an activity or permit at the request of the city.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

Except where regulated by other sections of this or any other title or law, the following uses shall be allowed within geologically hazardous areas when the requirementsof Section 20.93.630 (Geologically hazardous areas—Requirements) have been met and mitigation adequate to alleviate any other impacts has been proposed:

(1)

Those activities allowed per Section 20.93.220 (General provisions—Allowed activities).

(2)

Any other use allowed per the zone, provided that it meets the requirements of Section 20.93.630 (Geologically hazardous areas—Requirements) and will not have a detrimental impact on the health, safety, and welfare of the public, or will not negatively impact neighboring properties.

(3)

Recontouring of land to eliminate geologically hazardous areas, including steep slopes, is expressly prohibited unless otherwise approved through the land use permit process (not the construction plan review process). The permit issuing authority may approve recontouring to eliminate geological hazardous areas only upon finding that such action would serve the health, safety, and welfare of the general public and not just a particular development proposal.

(Ord. No. 2011-029, § 1, 12-5-2011; Ord. No. 2016-013, § 8, 7-18-2016)

(a)

Erosion Hazard Areas. All development proposals on sites containing erosion hazard areas shall comply with the following requirements:

(1)

Erosion Control Plan. The applicant shall submit an erosion control plan prior to the approval of any permit. Plans shall be consistent with the guidelines set forth in the International Building Code (IBC) grading section and the department of public works' construction standards and specifications.

(2)

Alteration. All authorized clearing for roads, utilities, etc., shall be limited to the minimum necessary to accomplish the engineering design. Alterations of erosion hazard sites shall meet the requirements of Chapter 20.44, Part II (Land clearing, grading, filling, and excavation).

(b)

Landslide hazard areas. All development proposals on sites containing landslide hazard areas shall comply with the following requirements:

(1)

Alterations. Landslide hazard areas located on slopes thirty-three percent or greater shall be altered only as allowed under standards for steep slopes set forth in this section. Landslide hazard areas and land adjacent to such a hazard area located on slopes less than thirty-three percent may be altered if:

(A)

The proposal will not increase surface water discharge or sedimentation and will not decrease adjacent property slope stability; and

(B)

It can be demonstrated through geotechnical analysis that there is no significant risk to the development proposal or adjacent properties or that the proposal can be designed so that the landslide hazard is significantly eliminated or mitigated such that the site and adjacent property are rendered as safe as an area without landslide hazards.

(2)

Buffers. Unless the alteration is approved under the provisions in Subsection (1) (Alterations), a minimum buffer of fifty feet shall be provided from the edges of all landslide hazard areas regardless of slope. The buffer may be extended beyond these limits to mitigate erosion hazards.

(3)

Building setback lines. All buildings are required to be set back a minimum of fifteen feet from the buffer or landslide hazard area.

(c)

Slopes. Grading, vegetation removal, and other site disturbances on slopes can lead to erosion or landslides. If the amount of the slope disturbed is decreased, then the risk of erosion and landslides decreases. The risk is also less on slopes that are less steep. Therefore, all site disturbances on moderate and steep slopes and their buffers shall be reviewed and certain standards are required to be met depending on the percent of slope.

(1)

The maximum slope and buffer disturbance allowed, unless restricted for other reasons, is:

(2)

Development on moderate and steep slopes shall meet the following standards:

(A)

Development must be located to minimize disturbance and removal of vegetation and also to protect most critical areas and retain open space.

(B)

Structures must be located or clustered where possible to reduce disturbance and maintain natural topographic character.

(C)

Grading shall be minimized;

(D)

Structures should conform to the natural contour of the slope, with foundations tiered where possible to conform to existing topography of site.

(E)

Natural surface or sub-surface drainage courses shall be preserved.

(F)

All development proposals shall be designed to minimize the footprint of building and other disturbed areas. Common access drives and utility corridors are encouraged.

(G)

All development shall be designed to minimize impervious lot coverage and should incorporate under- or over-structure parking and multi-level structures.

(H)

Roads, walkways and parking areas should be designed to parallel the natural contours.

(I)

Access shall be in the least critical area of the site.

(3)

Additional standards for steep slopes: All proposed development on steep slopes shall be avoided if possible. Alterations are allowed in only the following instances provided that the standards in Subsections (1) and (2), can be met; and, where it has been demonstrated through a soils report prepared by a geotechnical engineer that no adverse impact will result from the proposal and where approved surface water conveyance will result in minimum slope and vegetation disturbance:

(A)

The construction of approved public or private trails provided they are constructed in a manner that is not detrimental to surface water runoff control (e.g., cable lift access); and

(B)

The construction of public or private utility corridors in accordance with Chapter 20.93 regulations provided it has been demonstrated that such alterations will not increase landslide or erosion risks.

(4)

In all other cases, no disturbance is allowed on a steep slope and a minimum fifteens-foot vegetated buffer shall be established from the top, toe and along all sides of the slope. The buffer may be extended beyond these limits on a case-by-case basis to mitigate landslide and erosion hazards.

(d)

Seismic Hazard Areas. Standards for development in seismic hazard areas shall be in accordance with the provisions in the IBC, as adopted by the city.

(e)

For all geological hazardous areas on which development is not permitted by the above regulations, the applicant shall dedicate to the city an exclusive environmentally critical area easement for the protection of geological hazardous areas over the environmentally critical area and a buffer consistent with the standards listed above.

(Ord. No. 2011-029, § 1, 12-5-2011; Ord. No. 2016-013, §§ 9, 10, 7-18-2016)

If potential geologic impacts cannot be avoided by adhering to the above requirements, other forms of mitigation may be considered. Applicants must provide mitigation plans exploring and analyzing any proposed mitigation measures. What is considered adequate mitigation will depend on the nature and magnitude of the potential impact. For example, some potential risk due to construction in geologically hazardous areas may be reduced through retention of existing vegetation.

(Ord. No. 2011-029, § 1, 12-5-2011; Ord. No. 2016-013, § 11, 7-18-2016)

(a)

The city hereby adopts the stream classification system of the state, as specified in WAC 222-16-030, as may be amended. Briefly, these are as follows (see WAC 222-16-030 for complete definitions of types):

(1)

Type S water means all the waters, within their ordinary high-water mark, as inventoried as "shorelines of the state" under Chapter 90.58 RCW and the rules promulgated pursuant to Chapter 90.58 RCW, but not including those waters' associated wetlands as defined in Chapter 90.58 RCW.

(2)

Type F-ESA water means all the waters meeting the criteria of Type F stream, but has been identified as having presumed use by ESA listed fish species.

(b)

"Type F water" shall mean segments of natural waters that are not classified as Type 1 water and have a substantial fish, wildlife, or human use. These are segments of natural waters and periodically inundated areas of their associated wetlands, which:

(1)

Are diverted for domestic use by more than one hundred residential or camping units or by a public accommodation facility licensed by the state to serve more than one hundred persons, where such diversion is determined by the Washington State Department of Ecology to be a valid appropriation of water and the only practical water source for such users. Such waters shall be considered to be Type 2 water upstream from the point of such diversion for one thousand five hundred feet or until the drainage area is reduced by fifty percent, whichever is less;

(2)

Are within a federal, state, local, or private campground having more than thirty camping units: Provided, that the water shall not be considered to enter a campground until it reaches the boundary of the park lands available for public use and comes within one hundred feet of a camping unit, trail or other park improvement;

(3)

Are used by substantial numbers of anadromous or resident game fish for spawning, rearing or migration. Waters having the following characteristics are presumed to have highly significant fish populations:

(A)

Stream segments having a defined channel twenty feet or greater in width between the ordinary high-water marks and having a gradient of less than four percent.

(B)

Lakes, ponds, or impoundments having a surface area of one acre or greater at seasonal low water; or

(4)

Are used by salmonids for off-channel habitat. These areas are critical to the maintenance of optimum survival of juvenile salmonids. This habitat shall be identified based on the following criteria:

(A)

The site must be connected to a stream bearing salmonids and accessible during some period of the year; and

(B)

The off-channel water must be accessible to juvenile salmonids through drainage with less than a five percent gradient.

(C)

Ponds or impoundments having a surface area of less than one-half acre at seasonal low water and having an outlet to an anadromous fish stream.

(5)

Are highly significant for protection of downstream water quality. Tributaries which contribute greater than twenty percent of the flow to a Type S or F water are presumed to be significant for one thousand five hundred feet from their confluence with the Type S or F water or until their drainage area is less than fifty percent of their drainage area at the point of confluence, whichever is less.

(c)

Type Np water. Segments of natural waters within the bankfull width of defined channels that are perennial nonfish habitat streams. Perennial streams are waters that do not go dry any time of the year of normal rainfall. However, for the purpose of water typing, Type Np waters include the intermittent dry portions of the perennial channel below the uppermost point of perennial flow. Np waters begin downstream of the point along the channel where the contributing basin area is at least fifty-two acres in size.

(d)

Type Ns water shall be segments of natural waters within the bankfull width of the defined channels that are not Type S, F, or Np waters. These are seasonal, nonfish habitat streams in which surface flow is not present for at least some portion of a year of normal rainfall and are not located downstream from any stream reach that is a Type Np water. Ns waters must be physically connected by an above-ground channel system to Type S, F, or Np waters.

(e)

Non-natural water course means constructed vegetated swales and ditches that are designed and installed for the express purpose of periodically moving storm water not associated with naturally occurring streams.

(Ord. No. 2011-029, § 1, 12-5-2011)

The community and economic development director, relying on delineation by a licensed engineer or other comparable expert, shall determine the boundary of the creek, stream, river, lake, or other surface water. For ravines with banks greater than ten feet in depth the boundary shall be contiguous with the top of the bank. Where there is no ravine or the bank is less than ten feet in depth, the boundary shall be contiguous with the ordinary high water mark. In case of disagreement as to its location, the ultimate decision on the OHWM shall rest with ecology.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

Except where regulated by other sections of this, Shoreline Master Program or any other title or law (e.g., see Part IV of this chapter, Fish and Wildlife Conservation Areas), the following uses shall be allowed within streams, creeks, rivers, lakes, and other surface waters when the requirements of Section 20.93.730 have been met and mitigation adequate to alleviate any other impacts has been proposed:

(1)

Those activities allowed under Section 20.93.220 (General provisions—Allowed activities).

(2)

Bridges and other crossings for public and private rights-of-way where no other feasible means on ingress and egress to a parcel is available.

(Ord. No. 2011-029, § 1, 12-5-2011)

(a)

To retain the natural functions of streams and stream corridors, and unless modified by Part IV (Fish and Wildlife Conservation Areas), the streamside buffers listed in Table 20.93-3: Stream Buffer Widths shall be maintained on both sides of the environmentally critical area. All existing native vegetation within these buffers shall be preserved. (Note also that buffer averaging may be allowed pursuant to Section 20.93.320 (General provisions—Buffer width averaging.)

(b)

To protect the natural functions and aesthetic qualities of a stream and stream buffer, a detailed temporary erosion control plan that identifies the specific mitigating measures to be implemented during construction to protect the water from vegetation removal, erosion, siltation, landslides and hazardous construction materials shall be required. The City of Arlington shall review and approve the plan with the appropriate state, federal and tribal agencies, and any adjacent jurisdiction.

(c)

In accordance with the Shoreline Master Plan the buffer set-back in the historic shoreline business district is thirty feet landward from the OHWM or top of slope whichever is most protective of the shoreline, and those activities that are allowed under AMC 20.64 Floodplains.

(d)

The applicant shall dedicate to the city an exclusive environmentally critical area easement for the protection of creeks, streams, rivers, lakes, or other surface water over the environmentally critical area and a buffer consistent with the standards listed in Subsection (a).

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

(a)

In order to avoid significant environmental impacts for those activities not regulated by the Shoreline Master Program and allowed pursuant to Section 20.93.720 (Streams, creeks, rivers, lakes, and other surface water—Allowed activities), the applicant for a land use or development permit will select one or more of the following mitigation actions, listed in order of preference. What is considered adequate mitigation will depend on the nature and magnitude of the potential impact.

(1)

On-site environmentally critical area restoration/improvement—Restoration or improvement in functional value of degraded on-site waterways and/or their buffers at a two to one ratio (two square feet for every one square foot impacted).

(2)

On-site ECA/Creation—Creation of on-site waterways and their buffers at a two to one ratio (two square feet for every one square foot impacted).

(3)

On-site ECA buffer restoration—Restoration or improvement in functional value of degraded on-site waterway buffers at a ratio of six to one.

(b)

All ECA restoration, creation and/or enhancement projects required pursuant to this chapter either as a permit condition or as the result of an enforcement action shall follow a mitigation plan prepared in conformance to the requirements of Section 20.93.390 (Mitigation plan requirements).

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

(a)

Wetlands shall be rated according to the Washington State Wetland Rating System for Western Washington, Ecology Publication #14-06-029 or as revised by ecology. Wetland rating categories shall be applied as the wetland exists at the time of the adoption of this title or as it exists at the time of an associated permit application. Wetland rating categories shall not change due to illegal modifications. Wetlands identified as having local significance in hydrologic and habitat functions may be rated higher based on importance.

(b)

Wetland Types.

(1)

Category I. Category I wetlands are those that 1) represent a unique or rare wetland type; or 2) are more sensitive to disturbance than most wetlands; or 3) are relatively undisturbed and contain ecological attributes that are impossible to replace within a human lifetime; or 4) provide a high level of functions. In western Washington the following types of wetlands are Category I:

(A)

Relatively undisturbed estuarine wetlands larger than one acre;

(B)

Wetlands that are identified by scientists of the Washington Natural Heritage Program/DNR as wetlands of high conservation value;

(C)

Bogs;

(D)

Mature and old-growth forested wetlands larger than one acre;

(E)

Wetlands in coastal lagoons;

(F)

Interdunal wetlands larger than one acre and score high for habitat; or

(G)

Wetlands that perform functions at high levels.

We cannot afford the risk of any degradation to these wetlands because their functions and values are too difficult to replace. Generally, these wetlands are not common and make up a small percentage of the wetlands in the region.

(2)

Category II. Category II wetlands are difficult, though not impossible, to replace, and provide high levels of some functions. These wetlands occur more commonly than Category I wetlands, but still need a relatively high level of protection. Category II wetlands in western Washington include:

(A)

Estuarine wetlands smaller than one acre, or disturbed estuarine wetlands larger than one acre;

(B)

Wetlands with a moderately high level of functions; or

(C)

Interdunal wetlands larger than one acre or those in a mosaic.

(3)

Category III. Category III wetlands are 1) wetlands with a moderate level of functions, 2) can often be adequately replaced with a well-planned mitigation project, and 3) interdunal wetlands between one-tenth and one acre in size. Category III wetlands generally have been disturbed in some ways and are often less diverse or more isolated from other natural resources in the landscape than Category II wetlands.

(4)

Category IV. Category IV wetlands have the lowest levels of functions and are often heavily disturbed. These are wetlands that should be able to replace, and in some cases be able to improve. However, experience has shown that replacement cannot be guaranteed in any specific case. These wetlands may provide some important functions and also need to be protected.

(Ord. No. 2011-029, § 1, 12-5-2011; Ord. No. 2016-013, § 12, 7-18-2016;Ord. No. 2022-030, § 1, 10-17-2022)

(a)

The community and economic development director, relying on a field investigation supplied by an applicant, and applying the wetland definition provided in this chapter shall determine the location of the wetland boundary. Qualified professional and technical scientists shall perform wetland delineations. Identification of wetlands and delineation of their boundaries pursuant to this chapter shall be done in accordance with the approved federal wetland delineation manual and applicable regional supplements. All areas within the city meeting the wetland designation criteria in that procedure are hereby designated critical areas and are subject to the provisions of this chapter. Criteria to be included in required wetland identification reports may be found in Section 20.93.390 (Mitigation plan requirements). The applicant is required to show the location of the wetland boundary on a scaled drawing as a part of the permit application.

(1)

Designating, defining, and identifying wetlands. Wetlands are those areas, identified in accordance with RCW 90.58.030: "Wetlands" means areas that are inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas. Wetlands do not include those artificial wetlands intentionally created from non-wetland sites, including, but not limited to, irrigation and drainage ditches, grass-lined swales, canals, detention facilities, wastewater treatment facilities, farm ponds, and landscape amenities, or those wetlands created after July 1, 1990, that were unintentionally created as a result of the construction of a road, street, or highway. Wetlands may include those artificial wetlands intentionally created from nonwetland areas to mitigate the conversion of wetlands. All areas within the [city/county] meeting the criteria in the wetland definition regardless of whether these areas have previously been identified or mapped, are hereby designated critical areas and are subject to the provisions of this title.

(2)

Mapping.

(A)

The approximate location and extent of wetlands are shown on the critical area(s) maps adopted in the city of Arlington Comprehensive Plan. Additionally, soil maps produced by U.S. Department of Agriculture Natural Resources Conservation Service may be useful in helping to identify potential wetland areas. These maps are to be used as a guide for the city, project applicants, and/or property owners to identify potential wetland areas that may be subject to the provisions of this title.

(B)

It is the actual presence of wetlands on a parcel, as delineated by the requirements of the methods in the approved federal wetland delineation manual and applicable regional supplements in accordance with WAC 173-22-035, that establishes duties under this chapter. The exact location of a wetland's boundary shall be determined through the performance of a field delineation by a qualified wetlands professional, applying the approved federal wetland delineation manual and applicable regional supplements in accordance with WAC 173-22-035.

(b)

Where the applicant has provided a delineation of the wetland boundary, the community and economic development director shall verify the accuracy of, and may render adjustments to, the boundary delineation. In the event the applicant contests the adjusted boundary delineation, the community and economic development director shall, at the applicant's expense, obtain expert services to render a final delineation.

(c)

When agreed to by the applicant, the community and economic development director may waive the requirement that the applicant provide the delineation of boundary and rely on staff delineation. The community and economic development director shall consult with qualified professional scientists and technical experts or other experts as needed to perform the delineation. The applicant will be charged for the costs incurred. Where the community and economic development director performs a wetland delineation at the request of the applicant, such delineation shall be considered a final determination.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

Except where regulated by other sections of this or any other title or law, and provided they are conducted using best management practices, the following uses shall be allowed within wetlands and their buffers when the requirements of Sections 20.93.830 (Wetlands—Requirements) and 20.93.840 (Wetlands—Mitigation) have been met, state and federal approvals have been granted when required, and mitigation adequate to alleviate any other impacts has been proposed:

Generally, uses will be required to avoid and minimize impacts, and compensate for the impact that may reduce the functions of the wetland or its buffers:

(1)

Those uses listed in Section 20.93.220 (General provisions—Allowed activities).

(2)

In Class III and Class IV wetlands only, access to developable portions of legal lots where:

(A)

There is no other feasible method of accessing the property,

(B)

Altering the terrain would not cause drainage impacts to neighboring properties, and

(C)

Not more than two thousand five hundred square feet of wetland is impacted, and mitigated.

(3)

Permitted uses in a wetland buffer—Regulated activities shall not be allowed in a buffer except for the following:

(A)

Activities having minimal adverse impacts on buffers and no adverse impacts on regulated wetlands. These may include low intensity, passive recreational activities such as low impact trails in the outer twenty-five percent, non-permanent wildlife watching blinds, short-term scientific or educational activities, and sports fishing;

(B)

With respect to Category III and IV wetlands, stormwater management facilities having no reasonable alternative on-site location; or

(C)

With respect to Category III and IV wetlands, development having no feasible alternative location when the following conditions have been met: Impacts are the minimum necessary; Buffer impacts are mitigated through buffer averaging.

(4)

Those activities and uses conducted pursuant to the Washington State Forest Practices Act and its rules and regulations, WAC 222-12-030, where state law specifically exempts local authority, except those developments requiring local approval for Class 4—General Forest Practice Permits (conversions) as defined in RCW 76.09 and WAC 222-12:

(A)

Conservation or preservation of soil, water, vegetation, fish, shellfish, and/or other wildlife that does not entail changing the structure or functions of the existing wetland.

(B)

The harvesting of wild crops in a manner that is not injurious to natural reproduction of such crops and provided the harvesting does not require tilling of soil, planting of crops, chemical applications, or alteration of the wetland by changing existing topography, water conditions, or water sources.

(C)

Drilling for utilities/utility corridors under a wetland, with entrance/exit portals located completely outside of the wetland buffer, provided that the drilling does not interrupt the ground water connection to the wetland or percolation of surface water down through the soil column. Specific studies by a hydrologist are necessary to determine whether the ground water connection to the wetland or percolation of surface water down through the soil column will be disturbed.

(D)

Enhancement of a wetland through the removal of non-native invasive plant species. Removal of invasive plant species shall be restricted to hand removal unless permits from the appropriate regulatory agencies have been obtained for approved biological or chemical treatments. All removed plant material shall be taken away from the site and appropriately disposed of. Plants that appear on the Washington State Noxious Weed Control Board list of noxious weeds must be handled and disposed of according to a noxious weed control plan appropriate to that species. Re-vegetation with appropriate native species at natural densities is allowed in conjunction with removal of invasive plant species.

(E)

Educational and scientific research activities.

(F)

Normal and routine maintenance and repair of any existing public or private facilities within an existing right-of-way, provided that the maintenance or repair does not expand the footprint of the facility or right-of-way and impacts are mitigated.

(G)

Stormwater Management Facilities. Stormwater management facilities are limited to stormwater dispersion outfalls and bioswales. They may be allowed within the outer twenty-five percent of category II, III or IV wetland buffers when in an already developed state including buildings, parking lots, lawn or ornamental landscaping stormwater management systems designed to blend into the natural landscape allowing full mature growth of native trees and shrubs, and provide the same or greater functional habitat that would occur in a naturally vegetated buffer. Specifically, this does not include buried vaults, ecology block or grass-lined ponds or swales (though ponds or swales planted with native vegetation may be allowed). Such systems are required to provide diffuse effluent point(s) to the immediate edge of the no-touch buffer to allow infiltration and polishing, provided that:

(i)

No other location is feasible; and

(ii)

The location of such facilities will not degrade the functions or values of the wetland; and

(iii)

Stormwater management facilities are not allowed in intact buffers of category I wetlands.

(H)

Nonconforming uses. Repair and maintenance of nonconforming uses or structures, where legally established within the buffer, provided they do not increase the degree of nonconformity.

(Ord. No. 2011-029, § 1, 12-5-2011; Ord. No. 2016-013, §§ 13, 14, 7-18-2016;Ord. No. 2022-030, § 1, 10-17-2022)

(a)

Buffer Requirements. The following buffer widths have been established in accordance with the best available science. They are based on the category of wetland and the habitat score as determined by a qualified wetland professional using the Washington State Wetland Rating System for Western Washington: 2014 Update (Ecology Publication #14-06-029, or as revised and approved by ecology). The adjacent land use intensity is assumed to be high.

(1)

For wetlands that score six points or more for habitat function, the buffers in Table 20.93-4 can be used only if all of the following criteria are met:

(A)

A relatively undisturbed, vegetated corridor at least one hundred feet wide is protected between the wetland:

i.

A legally protected, relatively undisturbed and vegetated area (e.g., priority habitats, compensatory mitigation sites, wildlife areas/refuges, national, county, and state parks where they have management plans with identified areas designated as natural, natural forest, or natural area preserve, or

ii.

An area that is the site of a watershed project identified within, and fully consistent with, a watershed plan as defined by Chapter 89.08.460 RCW, or

iii.

An area where development is prohibited according to the provisions of the local shoreline master program, or

iv.

An area with equivalent habitat quality that has conservation status in perpetuity, in consultation with WDFW.

(B)

The corridor is permanently protected for the entire distance between the wetland and the shoreline or legally protected area by a conservation easement, deed restriction, or other legal site protection mechanisms.

(C)

Presence or absence of the shoreline or priority habitat must be confirmed by a qualified biologist or shoreline administrator.

(D)

The measures in Table 20.93-5 are implemented, as applicable, to minimize the impacts of the adjacent land uses.

(2)

For wetlands that score five or fewer habitat points, only the measures in Table 20.93-5 are required for the use of the buffers in Table 20.93-4.

(3)

If an applicant does not apply the mitigation measures in Table 20.93-5 or is unable to provide a protected corridor, then the buffers in Table 20.93-6 shall be used.

(4)

The buffer widths in Tables 20.93-4 and 20.93-6 assume that the buffer is vegetated with a native plant community appropriate for the ecoregion. If the existing buffer is unvegetated, sparsely vegetated, or vegetated with invasive species that do not perform needed functions, the buffer must either be planted to create the appropriate native plant community or be widened to ensure that the buffer provides adequate functions to protect the wetland.

(Ord. No. 2011-029, § 1, 12-5-2011; Ord. No. 2016-013, § 15, 7-18-2016;Ord. No. 2022-030, § 1, 10-17-2022)

(a)

In order to avoid significant environmental impacts, the applicant for a land use or development permit shall compensate for unavoidable wetland impacts, listed in order of preference. What is considered adequate mitigation will depend on the nature and magnitude of the potential impact.

(1)

On-site wetlands restoration/improvement—Restoration or improvement in functional value of degraded on-site wetlands and/or their buffers at the ratio listed in Table 20.93-7 according to the wetland type.

(2)

On-site wetlands creation—Creation of on-site wetlands and their buffers at the ratio listed in Table 20.93-7 according to the wetland type.

(3)

On-site wetlands buffer restoration—Restoration or improvement in functional value of degraded on-site wetland buffers at the ratio listed in Table 20.93-7 according to the wetland type.

(4)

Off-site wetlands protection—Where on-site protection is not possible, dedicate an exclusive easement for the protection of equivalent (in ecological type and function) wetland and its buffer on an off-site wetland at the ratio listed in Table 20.93-7 according to the wetland type. The location of any off-site wetland mitigation area shall be located within the same watershed as the impact and as near to the site as possible, following this preferred order:

(A)

Contiguous to the impacted wetland,

(B)

Within the same drainage basin where it would best provide the same function as the impacted wetland, and

(C)

Elsewhere within the city.

(b)

All wetland restoration, creation and/or enhancement projects required pursuant to this chapter either as a permit condition or as the result of an enforcement action shall follow a mitigation plan prepared in conformance to the requirements of Section 20.93.390 (Mitigation plan requirements).

(c)

Location of mitigation. When compensatory measures are appropriate pursuant to the mitigation priority sequence above, preferential consideration shall be given to measures that replace the impacted functions directly and in the immediate vicinity of the impact. However, alternative compensatory mitigation within the watershed sub-basin that addresses limiting factors or identified critical needs for shoreline resource conservation based on watershed or comprehensive resource management plans applicable to the area of impact may be authorized. If there are no previously identified mitigation opportunities in the impacted sub-basin identified in local watershed or comprehensive plans the applicant will use a watershed approach in selecting mitigation sites utilizingSelecting Wetland Mitigation Sites Using a Watershed Approach (Western Washington) (Publication #09-06-32). Authorization of compensatory mitigation measures may require appropriate safeguards, terms, or conditions as necessary to ensure no net loss of ecological functions (WAC 173-26-201(2)(e)(ii)(B)).

(d)

Mitigation ratios for the replacement of impacted wetlands shall be as listed in Table 20.93-7.

(Ord. No. 2011-029, § 1, 12-5-2011; Ord. No. 2016-013, § 16, 7-18-2016;Ord. No. 2022-030, § 1, 10-17-2022)

(a)

For projects that include native vegetation, a detailed five-year or ten-year vegetation maintenance and monitoring program to include the following:

(1)

Goals and objectives of the shoreline stabilization plan;

(2)

Success criteria by which the implemented plan will be assessed;

(3)

A ten-year maintenance and monitoring plan for wetland projects with trees and shrubs, consisting of site visits done in years one, two, five, seven and ten by a qualified professional, with progress reports submitted to the shoreline administrator and all other agencies with jurisdiction following the site visits; and, a maintenance and monitoring plan for compensatory mitigation projects which shall be monitored for a minimum of five years with monitoring plans submitted for zero, one, two, three and five years.

(4)

A contingency plan in case of failure.

(b)

Monitoring of fish and wildlife populations may be required.

(Ord. No. 2011-029, § 1, 12-5-2011)

(a)

The purpose of this part is to protect public aquifer recharge areas. Additionally, it is the intent of this part to adopt development regulations, as required in RCW 36.70A.060, that preclude land uses or development that is incompatible with critical areas designated under RCW 36.70A.170.

(b)

The objectives of this part are to:

(1)

Protect human life and health;

(2)

Assure the long-term conservation of resources;

(3)

Protect groundwater; and,

(4)

Further the public interest in the conservation and wise use of lands.

(Ord. No. 2011-029, § 1, 12-5-2011)

(a)

All development except those exempted in Subsection (b) is subject to the regulations of this part.

(b)

The following uses are exempt from this part:

(1)

Uses legally existing on any parcel prior to these regulations' adoption.

(Ord. No. 2011-029, § 1, 12-5-2011)

Editor's note— Ord. No. 2016-013, § 17, adopted July 18, 2016, repealed § 20.93.920 in its entirety. Former § 20.93.920 pertained to "Information required upon application," and was derived from Ord. No. 2011-029, § 1, adopted December 5, 2011.

Hydrogeologic site evaluations shall address the following:

(1)

Soil texture, permeability, and contaminant attenuation properties;

(2)

Characteristics of the unsaturated top layer of soil, the vadose zone, and geologic material, including permeability and attenuation properties;

(3)

Depth to groundwater and/or impermeable soil layer;

(4)

Aquifer properties such as hydraulic conductivity and gradients.

(5)

Potential impacts to the aquifer or groundwater.

(Ord. No. 2011-029, § 1, 12-5-2011)

Best management practices (BMP) plans shall detail what actions or operations may harm the aquifer if not performed or managed properly and how such actions or operations shall be performed or managed so as to avoid impacts. Permit applications may be conditioned on on-going adherence to the BMP plan.

(Ord. No. 2011-029, § 1, 12-5-2011)

(a)

If the evaluation identifies significant impacts to critical public aquifer storage recharge areas, the project applicant is required to document potential impacts and provide a discussion of alternatives by which such impacts could be avoided or prevented.

(b)

The applicant shall provide a detailed mitigation plan for avoiding potential impacts. The city may require that the mitigation plan include preventative measures, monitoring, process control, and remediation, as appropriate. the mitigation plan must be approved by the city and be implemented as a condition of project approval.

(Ord. No. 2011-029, § 1, 12-5-2011)

Based on available information, including that provided by the applicant pursuant to the requirements of Sections 20.93.930 (Aquifer recharge areas—Hydrogeologic site evaluations), the permit-issuing authority shall impose conditions designed to prevent degradation of groundwater quality or quantity. Such conditions may include determining background water quality and quantity prior to development, determining groundwater levels, monitoring of those levels, mitigation plans including prevention, and development of groundwater quality or quantity management plans. All conditions on permits shall be based on known, available, and reasonable methods of prevention, control, and treatment.

(Ord. No. 2011-029, § 1, 12-5-2011;Ord. No. 2022-030, § 1, 10-17-2022)

Editor's note— Ord. No. 2016-013, § 17, adopted July 18, 2016, repealed § 20.93.970 in its entirety. Former § 20.93.970 pertained to "Shoreline master plan and maps adopted," and was derived from adopted December 5, 2011.