HomeMy WebLinkAbout2011-029 ORDINANCE NO. 2011-029
AN ORDINANCE OF THE CITY OF ARLINGTON, WASHINGTON, ADDING A NEW
CHAPTER 20.93 OF THE ARLINGTON MUNICIPAL CODE RELATING TO
ENVIRONMENTALLY CRITICAL AREAS, AND REPEALING CHAPTER 20.92
WHEREAS, the City of Arlington has the authority to regulate land uses within the City;
and
WHEREAS, the City of Arlington has adopted a Shoreline Master Plan; and
WHEREAS, the city wishes to amend provisions of the land use code relating to
shoreline management and critical areas; and
WHEREAS, environmental review has been completed as required by SEPA and
consistent with the requirements of the State Growth Management Act;
WHEREAS, the City Planning Commission considered these amendments at their
October 4, 2011 public hearing and the City Council considered the same, along with the
Planning Commission recommendations, at a public hearing conducted on November 7, 2011
and determined approving the amendments was in the best interest of the City and its citizens;
NOW, THEREFORE, the City Council of the City of Arlington do hereby ordain as
follows:
Section 1. A new Chapter 20.93 of the Arlington Municipal Code is hereby adopted to
read as follows:
CHAPTER 20.93 ENVIRONMENTALLY CRITICAL AREAS
Sections:
Part I. Purpose and Intent
20.93.010 Purpose and Intent.
Part II. Definitions
20.93.100 Definitions.
Part III. General Provisions
20.93.200 Applicability.
20.93.210 Regulated Activities.
20.93.220 Allowed Activities.
20,93.230 Compliance.
20.93.240 Classification as an Environmentally Critical Area.
20.93.250 Procedures.
20.93.260 Submittal Requirements.
20.93.270 Site/Resource Specific Reports,
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20.93.280 Maps and Inventory.
20.93.290 Dedication of Environmentally Critical Area Easements.
20.93.300 Dedication of Land and/or Easements in Lieu of Required Parks or Open Space.
20.93.310 Increased Buffer Widths
20.93.320 Buffer Width Averaging.
20,93.330 Buffers to be Retained in Natural Condition
20.93.340 Building Setbacks from Buffers
20.93.350 Special Conditions for Possible Reductions in Buffer Width
20.93.370 Non-Conforming Activities.
20.93.380 Assessment Relief.
20.93.390 Mitigation Plan Requirements.
Part IV. Fish and Wildlife Conservation Areas
20.93.400 Classification.
20.93.410 Determination of Boundary.
20.93.420 Species/Habitats of Local Importance.
20.93.430 Allowed Activities.
20.93.440 Requirements.
20.93.450 Mitigation.
Part V. Frequently Flooded Areas
20.93.500 Classification.
20.93.510 Determination of Boundary.
20.93.520 Allowed Activities.
20.93.530 Requirements.
20.93.540 Mitigation.
Part VI. Geologically Hazardous Areas
20.93.600 Classification.
20.93.610 Determination of Boundary.
20.93.620 Allowed Activities.
20.93.630 Requirements.
20.93.640 Mitigation.
Part VII. Streams, Creeks, Rivers, Lakes and Other Surface Water
20.93.700 Classification,
20.93.710 Determination of Boundary.
20.93.720 Allowed Activities.
20.93.730 Requirements.
20,93.740 Mitigation.
Part VIII. Wetlands
20.93.800 Classification.
20,93.810 Determination of Boundary.
20.93.820 Allowed Activities.
20.93.830 Requirements.
20.93.840 Mitigation.
Part IX. Aquifer Recharge Areas
20.93.900 Purpose and Objectives.
20.93.910 Applicability.
20.93.920 Information Required Upon Application.
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20.93.930 Hydrogeologic Site Evaluations.
20.93.940 Best Management Practices (BMP) Plans.
20.93.950 Mitigation Plans
20.93.960 Imposition of Conditions on Projects
Part X. Adoption of Plans
20.93.970 Shoreline Master Plan and Maps Adopted
Part I. Purpose and Intent
20.93.010 Purpose and Intent.
This Chapter establishes regulations for the protection of environmentally critical areas (ECAs)
within the City's shoreline jurisdiction, including critical areas, natural resource lands, and
protective buffers. While it is intended that this Chapter fulfill the mandates of the Washington
State Shoreline Management Act, that is not its sole purpose: Its primary purpose is to fulfill the
legislative intent of the City of Arlington, which is to protect the public health, safety, and
welfare of the citizens of Arlington 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:
(a) If at all possible, avoid impacts to environmentally critical areas. If this is not practicable,
then:
1. 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.
2. Mitigate any impacts by repairing, rehabilitating, or restoring the affected
environment.
3. Reduce or eliminate any impacts over time by preservation and maintenance
operations during the life of the action.
4. Compensate for unavoidable impacts by replacing, enhancing or providing substitute
resources or environments through monitoring of specific and cumulative impacts.
(b) Protect the public from personal injury, loss of life, or property damage due to flooding,
erosion, landslides, seismic events, or soil subsidence. (c) Protect against publicly financed
expenditures due to the misuse of environmentally critical areas that cause:
1. Unnecessary maintenance and replacement of public facilities;
2. Publicly funded mitigation of avoidable impacts;
3. Cost for public emergency rescue and relief operations where the causes are avoidable;
4. Degradation of the natural environment.
(d) Protect aquatic resources.
(e) Protect unique, fragile, and valuable elements of the environment, including wildlife and its
habitat.
(f) Alert appraisers, assessors, owners, potential buyers, or lessees to the development limitations
of environmentally critical areas;
(g) Provide City officials with sufficient information to adequately protect environmentally
critical areas when approving, conditioning, or denying applications for public or private
development proposals.
(h) Give guidance to the development of Comprehensive Plan policies in regard to the natural
systems and environment of the Arlington Watershed(s);
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(i) 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.
Part II. Definitions
20.93.100 Definitions.
For the purposes of this Chapter, the following definitions shall apply:
Alteration(s). A change or rearrangement of the structural parts of existing facilities or an
enlargement by extending the side or increasing the height or depth or the moving from one
location to another.
AMC. The Arlington Municipal Code.
Applicant. 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.
Classes. Taxonomic classification system of the United States Fish and Wildlife Service
(Cowardin, et al 1978).
Commercial. Activity with goods, merchandise, or services for sale or rent.
Compensation. 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)
Critical Areas. Fish and wildlife habitat conservation areas, Streams, Wetlands, areas with a
critical recharging effect on aquifers used for potable water, fish and wildlife habitat
conservation areas, frequently flooded areas; and geologically hazardous areas.
Dedication. 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. A wetland in which the vegetation, soils, and/or hydrology have been
adversely altered, resulting in lost or reduced functions and values.
Developable Area. Land outside of critical areas and environmentally critical area setbacks and
buffers.
Development Permit. Any permit or approval under this code or the AMC that must be issued
before initiating a use or development activity.
Ditch. A long narrow excavation dug in the earth for drainage with its top width less than 10 feet
at design flow and that does not meet the definition of a stream. A ditch may be regulated if it
conveys stream flow.
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Easement. 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. The boundary of a wetland as delineated based on the criteria contained in this Chapter.
Emergent Wetland. A wetland with at least thirty percent of its surface covered by erect, rooted,
herbaceous vegetation at the uppermost vegetative strata.
Enhancement. Alteration of an existing resource to improve or increase its characteristics and
processes without degrading other existing functions. Enhancements are to be distinguished
from resource creation or restoration projects.
Erosion Hazard Area. A landform or soil type subject to being worn away by the action of water,
wind, freeze-thaw or ice.
Exotic Species. Plants or animals that are not native to the Puget Sound Lowlands region.
Extraordinary Hardship. 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). 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. Wetlands with at least thirty percent of the surface area covered by woody
vegetation greater than twenty feet in height or> 3-inch diameter at breast_height.
Forest Land. 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.
Frequently Flooded Areas. Lands indicated on the most current FEMA map to be within the 100-
year flood plain. These areas include, but are not limited to, streams, lakes, coastal areas, and
wetlands. Local areas not identified on FEMA maps that experience frequent periods of
inundation.
Functions. The beneficial roles served by critical areas including, but not limited to, water
quality protection and enhancement, fish and wildlife habitat, food chain support, flood storage,
conveyance and attenuation, groundwater recharge and discharge, erosion control, wave
attenuation, and aesthetic value protection, and recreation. These roles are not listed in order of
priority.
Geologically Hazardous Areas. 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. The physical manipulation of the earth's surface and/or drainage pattern in preparation
of an intended use or activity.
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;
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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. 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. 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.
Improvement. Any structure or manmade feature.
Isolated 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. Are outside of and not contiguous to any wetland system of one acre or more, or the
100-year floodplain of a lake, river, creek, or stream; and,
2. Have no contiguous hydric soil or hydrophytic vegetation between the wetland and
contiguous wetlands of one acre or more or any surface water.
Landslide Hazard Areas. Areas potentially subject to risk of mass movement due to a
combination of factors, including historic failures.
Land Uses, High Intensity. a zone classification allowing more than one dwelling unit per acre.
Land Uses, Low Intensity. 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 §20.93.220 (Allowed Activities).
Land Uses, Medium Intensity. 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.
Mineral Resource Lands. Lands primarily devoted to the extraction of gravel, sand, other
construction materials, or valuable metallic or mineral substances.
Native Vegetation. Plant species that are indigenous to the Puget Sound Lowlands region.
Natural Condition. Lands that retain native vegetation, forest duff and naturally occurring
contours and drainage patterns not modified by human activity.
Natural Resource Lands. Agriculture, forest, and mineral resource lands as defined in this
section.
Constructed Stormwater Wetland. 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.
Nonconforming. 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
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provisions of this code or that was not approved by the city through the appropriate decision-
making process required under this code.
Open Space. Land not covered by buildings, roadways, parking areas, or other surfaces through
which water cannot percolate into the underlying soils.
Ordinary high water mark. As defined by RCW 90.58.030(2)(b), as now or hereafter amended.
Palustrine Wetland. Freshwater with open water, emergent herbaceous vegetation, scrub-shrub
vegetation, and/or trees .
Pond. Any inland body of water, either naturally or artificially formed or increased, that has a
surface area of 1,000 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. 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.
Priority Habitats. 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. Wildlife species of concern due to their population status and their sensitivity to
habitat alteration.
Riparian Habitat. An ecosystem that occurs in the transition zone between aquatic and upland
environments.
Scrub-shrub Wetlands. A wetland with at least thirty percent of its surface area covered with
woody vegetation less than twenty feet in height or< 3-inch diameter at breast height.
Seismic Hazard Areas. 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.
Slope. See §20.93.600 (Geological Hazardous Areas—Classification).
Sphagnum. 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. 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 §20.93.600 (Geological Hazardous Areas—Classification).
Structure. 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.
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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 that remain after a person proposing to alter environmentally critical areas
has demonstrated that no practicable alternative exists for the proposed project.
Use. "Development" 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. A use for which the use of surface water would be essential in fulfilling the
purpose of the proposed project.
Wetlands. "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.
Part III. General Provisions
20.93.200 Applicability.
This Chapter applies to environmentally critical areas within the City's shoreline jurisdiction.
The maps adopted in AMC 20.93.970 show the general location of the City's shoreline
jurisdiction; however, whether an environmentally critical area is within shoreline jurisdiction
shall be determined by the Shoreline Administrator. 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.
20,93.210 Regulated Activities.
(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 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.
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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.
20.93.220 Allowed Activities.
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 20.93
(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.
20.93.230 Compliance.
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.
20.93.240 Classification as an Environmentally Critical Area.
Criteria for classification as an environmentally critical area will be listed under the pertinent
sections of this Chapter.
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20.93.250 Procedures.
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 Development Director is authorized to adopt administrative procedures
for the purpose of carrying out the provisions of this Chapter.
20.93.260 Submittal Requirements.
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 §20.93.270 (General Provisions—Site/Resource
Specific Reports), and any other pertinent information requested by the Department of
Community Development. The Community Development Director may waive any of these
submittal requirements if it is deemed unnecessary to make a compliance determination.
20.93.270 Site/Resource Specific Reports.
Unless waived per §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 Development, which is hereby authorized to do so.
20.93.280 Maps and Inventory.
The approximate location and extent of environmentally critical areas in the City are displayed
on various inventory maps available at the Department of Community 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 (AMC 20,93.970). 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.
20.93.290 Dedication of Environmentally Critical Area Easements.
(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.
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(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 protect <<<
insert 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 Planning and Community Development."
20.93.300 Dedication of Land and/or Easements in Lieu of Required Parks or Open Space.
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 & Open
Space).
20.93.310 Increased Buffer Widths
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:
(a) A larger buffer is necessary to maintain viable populations of existing species; or
(b) 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
(c) The adjacent land has minimal vegetative cover or slopes greater than 15 percent and
is therefore susceptible to severe erosion, and erosion control measures will not
effectively prevent adverse environmentally critical area impacts.
(d) 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.
20.93.320 Buffer Width Averaging.
Buffer widths may be modified by averaging. In no instance shall the buffer width be reduced by
more than 25% of the standard buffer unless specifically identified in other sections of the 20.93.
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Buffer width averaging shall be allowed only where the applicant demonstrates all of the
following:
(a) 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;
(b) That the least impactive aspects of the proposed land use would be located adjacent to
areas where the buffer width is reduced;
(c) That width averaging will not adversely impact the environmentally critical area
functional values; and
(d) That the total area contained within the buffer after averaging is no less than that
contained within the standard buffer prior to averaging.
20.93.330 Buffers to be Retained in Natural Condition
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.
20.93.340 Building Setbacks from Buffers
A building setback of 15 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.
20.93.360. Reserved
20.93.370 Non-Conforming Activities.
Except for cases of discontinuance as part of normal agricultural practices, non-conforming uses
shall be governed by Part VI of this Chapter 20.93 and AMC Chapter 20.32 (Nonconforming
Situations).
20.93.380 Assessment Relief.
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.
20.93.390 Mitigation Plan Requirements.
In the event that mitigation is required, the applicant shall be required to provide a mitigation
plan for approval by the Community 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:
ORDINANCE NO. 2011-029 12
(a) Specific goals and objectives describing site function, target species and selection
criteria;
(b) Performance standards that shall include criteria for assessing goals and objectives;
(c) Contingency plans that clearly define course of action or corrective measures needed
if performance standards are not met;
(d) 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.
(e) The need for performance or maintenance securities.
(f) 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:
1. 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;
2. 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
3. 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.
(g) A clearly defined approach to assess progress of the project.
(h) 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
(i) 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.
0) Once the plan is implemented, as-builts shall also be submitted pursuant to
Department of Public Works requirements.
Part IV. Fish and Wildlife Conservation Areas
20.93.400 Classification.
Fish and Wildlife Conservation Areas include:
(a) Lands containing priority habitats and species, including plant and/or animal species listed on
Federal or State threatened or endangered species lists.
(b) Ponds and their submerged aquatic beds that provide fish or wildlife habitat.
1. "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
ORDINANCE NO. 2011-029 13
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.
(c) 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:
1. The site must be connected to a stream bearing salmonids and accessible during some
period of the year; and
2. The off-channel water must be accessible to juvenile salmonids through drainage with
less than a 5% gradient.
(d) 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.
(e) State natural area preserves and natural resource conservation areas.
(f) Habitats or species of local importance. Such habitats or species may be locally listed per the
process elucidated in §20.93.420 (Species/Habitats of Local Importance).
20.93.410 Determination of Boundary.
The Community 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.
20.93.420 Species/Habitats of Local Importance.
(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 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:
ORDINANCE NO. 2011-029 14
1. None adopted as of December 5, 2012.
20.93.430 Allowed Activities.
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
§20.93.440 (Fish and Wildlife Conservation Areas—Requirements) have been met and
mitigation adequate to alleviate any other impacts has been proposed:
(a) Those activities listed in §20.93.220 (General Provisions—Allowed Activities)
(b)Activities consistent with the species located there and all applicable state and federal
regulations regarding the species, as determined by the Community Development
Director, who will consult with other resource agencies including Tribes as to their
recommendations based on adopted standards or guidance.
(c) Within the 50-foot management zone of the buffer required pursuant to §20.93.440
(Fish & Wildlife Conservation Areas--Requirements) the following uses are allowed as
long as 65% of native tree cover is established and maintained and the Total Effective
Impervious Area(TIA) remains below 3%:
1. When the 50-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(25%) of the wetland buffer area, and
located to avoid removal of significant trees. They should be limited to pervious
surfaces no more than five (5) feet in width for pedestrian use only. Raised
boardwalks utilizing non-treated pilings may be acceptable.
2. 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.
3. 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.
20.93.440 Requirements.
(a) Except as provided in Subsections (b) and (c):
1. For endangered or threatened salmonid Fish and Wildlife Conservation Areas, a 150-
foot buffer shall be required for all regulated activities adjacent to the Fish and Wildlife
Conservation Areas. This buffer shall consist of a 100-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 §20.93.430 (Fish and Wildlife
Conservation Areas—Allowed Activities), and the remaining 50-foot zone being
ORDINANCE NO. 2011-029 15
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 §20.93.730 (Streams, Creeks, Lakes, & 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 §20.93.450
(Fish and Wildlife Conservation Areas—Mitigation) may be considered.
20.93.450 Mitigation.
In order to avoid significant environmental impacts and, if in the opinion of the permit-issuing
authority the requirements listed in §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.
(a) 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
ORDINANCE NO. 2011-029 16
Conservation Areas and a 150-foot buffer on off-site Fish and Wildlife Conservation Areas at a
minimum 2:1 ratio (2 offsite areas for every 1 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: i) hydrologically connected to the
impacted Fish and Wildlife Conservation Areas or via an intact habitat corridor, ii) elsewhere
within the City, iii) within the Arlington UGA, iv) within the sub-basin, and v) watershed.
Part V. Frequently Flooded Areas
20,93.500 Classification.
Classification for Flood Zones shall be consistent with the 100-year floodway and floodplain
designations as adopted by the City, or where the City has not adopted such a designation, by the
100-year flood zone designation of the Federal Emergency Management Agency and the
National Flood Insurance Program. Any such designations adopted by the City shall consider the
following criteria if and when designating and classifying these areas:
(a) Flooding impact to human health, safety, and welfare and to public facilities and services;
and,
(b) Documentation including federal, state and local laws, regulations and programs, local maps
and federally subsidized flood insurance programs; and,
(c) The future floodplain defined as a channel of the stream and that portion of the adjoining
floodplain which is necessary to contain and discharge the base flood flow at build-out without
any measurable increase in flood heights.
20.93.510 Determination of Boundary.
The boundary of a Flood Zone shall be contiguous with the 100-year floodway and floodplain
designations as adopted by the City, or where such a designation has not been adopted by the
City, the 100-year floodplain designation of the Federal Emergency Management Agency
(FEMA) and the National Flood Insurance Program where it has been delineated (shown on
Flood Insurance Rate Maps (FIRM). Where this information does not exist, the boundary
determination shall be made by a licensed engineer and based upon the same criteria used by
FEMA including the consideration of the Channel Migration Zone. The Flood Plain
Administrator shall confirm this determination.
20.93.520 Allowed Activities.
Except where regulated by other sections of this or any other Title or law, the following uses
shall be allowed within floodways or flood plains when the requirements of§20.93.530
(Frequently Flooded Areas—Requirements) have been met and mitigation adequate to alleviate
any other impacts has been proposed:
(a) Floodways
1. Those activities allowed per the Shoreline Master Program regulations and §20.93.220
(General Provisions—Allowed Activities).
2. Outdoor recreational activities (including fishing, bird watching, hiking, boating,
swimming, canoeing, bicycling, etc.) and aquatic recreation facilities authorized by this
20.93.
ORDINANCE NO. 2011-029 17
3. Those uses allowed by §20.64.150 (Permissible Uses Within Floodways).
(b) Floodplains
1. All those activities allowed in floodways
2. Recreational Fields
3. Those uses allowed by and consistent with the regulations of Chapter 20.64
(Floodways, Floodplains, Drainage, and Erosion).
20.93.530 Requirements.
All land uses and development proposals shall comply with the regulations for general and
specific flood hazard protection(see Chapter 20.64, Floodways, Floodplains, Drainage, and
Erosion). Development shall not reduce the effective base flood storage volume. Reduction of
the floodwater storage volume effectiveness due to grading, construction, or other regulated
activities shall be compensated for by creating on- or off-site detention and/or retention ponds.
Effective storage capacity must be maintained. Base flood data and flood hazard notes shall be
on the face of any recorded plat or site plan including, but not limited to, base flood elevations,
flood protection elevation, boundary of floodplain and zero rise floodway.
20.93.540 Mitigation.
If potential flooding impacts cannot be avoided by design or by providing on- or off-site
detention and/or retention ponds, other forms of mitigation may be considered in order to avoid
significant environmental impacts. Applicants must provide mitigation plans exploring and
analyzing any proposed mitigation measures, which must be consistent with the Shoreline
Master Program and the regulations of AMC Chapter 20.64 (Floodways, Floodplains, Drainage,
and Erosion).
Part VI. Geologically Hazardous Areas
20.93.600 Classification.
(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;
ORDINANCE NO. 2011-029 18
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 15 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 10,000
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 33 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 15 percent and
less than 33 percent.
b. Steep slopes shall include any slope greater than or equal to 33 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.
20.93.610 Determination of Boundary.
The Community 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.
20,93.620 Allowed Activities.
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 requirements of§20.93.630
(Geologically Hazardous Areas—Requirements) have been met and mitigation adequate to
alleviate any other impacts has been proposed:
(a) Those activities allowed per §20.93.220 (General Provisions—Allowed Activities).
ORDINANCE NO. 2011-029 19
(b) Any other use allowed per the zone and Shoreline Master Program, provided that it meets the
requirements of§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.
(c) 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.
20.93.630 Requirements.
(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
Uniform Building Code (UBC) 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 AMC 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 33 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
33 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 above
(Alterations), a minimum buffer of 50 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 15 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.
ORDINANCE NO. 2011-029 20
1. The maximum slope and buffer disturbance allowed, unless restricted for other
reasons, is:
Table 20.93-2: Slope Disturbance
Disturbance Allowed Allowed
Slope
1 - 14% 100%
15 - 24% 60%
25 —32% 45%
33% or greater 0%
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 1 and 2, above, 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 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 15-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 of Arlington.
ORDINANCE NO. 2011-029 21
(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.
20.93.640 Mitigation.
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 to the Shoreline and an ecological
function. For example, some potential risk due to construction in geologically hazardous areas
may be reduced through retention of existing vegetation.
Part VII. Streams, Creeks, Rivers, Lakes and Other Surface Water
20.93,700 Classification.
(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):
a. Type S Water means all the waters, within their ordinary high-water mark, as inventoried
as —shorelines of the statell 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.
b. 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 100 residential or camping units or by a
public accommodation facility licensed by the State to serve more than 100 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 1,500 feet or until the drainage area is reduced by 50 percent, whichever is less;
2. Are within a federal, state, local, or private campground having more than 30 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 100 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 20 feet or greater in width between
the ordinary high-water marks and having a gradient of less than 4 percent.
b. Lakes, ponds, or impoundments having a surface area of 1 acre or greater at
seasonal low water; or
ORDINANCE NO. 2011-029 22
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 5% gradient.
c. Ponds or impoundments having a surface area of less than 0.5 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 20 percent of the flow to a Type S or F Water are presumed to be
significant for 1,500 feet from their confluence with the Type S or F Water or until their
drainage area is less than 50 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 52 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.
20.93.710 Determination of Boundary.
The Community 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 (10) 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 (10)
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.
20.93.720 Allowed Activities.
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§20.93.730 (Streams, Creeks, Rivers, Lakes and Other Surface Water—
Requirements) have been met and mitigation adequate to alleviate any other impacts has been
proposed:
ORDINANCE NO. 2011-029 23
(a) Those activities allowed under §20.93.220 (General Provisions—Allowed Activities).
(b) 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.
20.93.730 Requirements.
(a) To retain the natural functions of streams and stream corridors, and unless modified by Part
IV (Fish & Wildlife Habitat), the streamside buffers listed in Table 20.93-3: Non-ESA Stream
Buffer Width 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 §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 30 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.
Table 20.93-3: Non-ESA Stream Buffer Width Stream
Type Standard Buffer
S 150 feet
F-ESA 150 feet
F 100 feet
Np 50 feet
Ns 50 feet
Non- None
natural
c. 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).
20.93.740 Mitigation.
(a) In order to avoid significant environmental impacts for those activities not regulated by the
Shoreline Master Program and allowed pursuant to §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 action, listed in order of preference.
ORDINANCE NO. 2011-029 24
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
2:1 ratio (2 square feet for every 1 square foot impacted).
2. On-Site ECA/ Creation—Creation of on-site waterways and their buffers at a 2:1 ratio
(2 square feet for every 1 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 6:1.
(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§20.93.390 (Mitigation Plan Requirements).
Part VIII. Wetlands
20.93.800 Classification.
(a) Wetlands shall be rated according to the Washington State wetland rating system for;
Washington State Wetland Rating System for Western Washington - Revised, Ecology
Publication 404-06-025) 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: 1) relatively undisturbed estuarine wetlands
larger than 1 acre; 2)wetlands that are identified by scientists of the Washington Natural
Heritage Program/DNR as high quality wetlands; 3) bogs; 4) mature and old-growth
forested wetlands larger than 1 acre; 5) wetlands in coastal lagoons; or 6) wetlands that
perform many functions well and score 70 or above.
Category I wetlands represent a unique or rare wetland type, are more sensitive to
disturbance than most wetlands, are relatively undisturbed and contain some ecological
attributes that are impossible to replace within a human lifetime, or provide a very high
level of functions.
2. Category II. Category II wetlands are: 1) estuarine wetlands smaller than 1 acre, or
disturbed estuarine wetlands larger than 1 acre; 2) a wetland identified by the Washington
State Department of Natural Resources as containing "sensitive" plant species; 3) a bog
between '/a and '/z acre in size; 4) an interdunal wetland larger than 1 acre; or 5) wetlands
with a moderately high level of functions. Wetland scoring between 51 and 69 points.
Wetlands identified as having local significance in reducing flooding or providing
habitat.
ORDINANCE NO. 2011-029 25
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 they still need a relatively high level of protection.
3. Category III. Category III wetlands are: 1) wetlands with a moderate level of
functions scoring between 30 and 50 points; or 2) interdunal wetlands between 0.1 and 1
acre in size. Generally, wetlands in this category may have been disturbed in some way
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 scoring less
than 30 points and are often heavily disturbed. These are wetlands that should be
replaceable, and in some cases may be improved. However, experience has shown that
replacement cannot be guaranteed in any specific case. These wetlands may provide
some important functions and should be protected to some degree.
20,93.810 Determination of Boundary.
(a) The Community 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 §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
ORDINANCE NO. 2011-029 26
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
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 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 Development Director may waive the
requirement that the applicant provide the delineation of boundary and rely on staff delineation.
The Community 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 Development Director performs a wetland
delineation at the request of the applicant, such delineation shall be considered a final
determination.
20.93.820 Allowed Activities.
Except where regulated by other sections of this, Shoreline Master Program 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§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:
(a) Those uses listed in §20.93.220 (General Provisions—Allowed Activities).
(b) In Class III and Class IV wetlands only, access to developable portions of legal lots where:
1. there is no other feasible method of accessing the property,
2. altering the terrain would not cause drainage impacts to neighboring properties, and
3. not more than 2,500 square feet of wetland is impacted, and mitigated.
(c) Permitted Uses in a Wetland Buffer—Regulated activities shall not be allowed in a buffer
except for the following:
1. 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 25%, non-permanent wildlife watching blinds, short-term
scientific or educational activities, and sports fishing;
2. With respect to category III and IV wetlands, stormwater management facilities having
no reasonable alternative on-site location; or
ORDINANCE NO. 2011-029 27
3. 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.
(d) 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:
1. 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.
2. 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.
3. 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.
4. 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.
5. Educational and scientific research activities.
6. 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.
7. Stormwater management facilities. Stormwater management facilities are limited to
stormwater dispersion outfalls and bioswales. They may be allowed within the outer
twenty-five percent (25%) of 50-foot management zone, whichever is most protective, of
Category 11, 111 or IV wetlands buffer when the 50-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, provided that:
a. No other location is feasible; and
ORDINANCE NO. 2011-029 28
b. The location of such facilities will not degrade the functions or values of the
wetland; and
c. Stormwater management facilities are not allowed in intact buffers of Category
I wetlands.
8. Non-Conforming Uses. Repair and maintenance of non-conforming uses or structures,
where legally established within the buffer, provided they do not increase the degree of
nonconformity.
20.93.830 Requirements.
(a) Buffers—ECA buffers shall be required for all regulated activities adjacent to regulated
wetlands as provided in Table 20.93-4, below, unless modified per Subsection (b). Any
wetland created, restored, or enhanced as compensation for approved wetland alterations
shall also include the standard buffer required for the category of the created, restored, or
enhanced wetland. All buffers shall be measured from the wetland boundary as
determined pursuant to §20.93.810 (Wetlands—Determination of Boundary). The width
of the wetland buffer zone shall be determined according to wetland category and the
proposed land use. These buffers have been established to reflect the impact of land use
intensity on wetland functions and values.
(b) The standard buffer widths in Table 20.93-4 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.
1. The use of the standard buffer width requires the implementation of the measures in
Table 20.93-5, where applicable, to minimize the impacts of the adjacent land uses.
2. If an applicant chooses not to apply the mitigation measures in Table 20.93-5 or
other sections of this document, then a 33% increase in the width of all buffers is
required. For example, a 75-foot buffer with the mitigation measures would be a 100-
foot buffer without them.
3. The standard buffer widths 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 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.
4. Additional buffer widths are added to the standard buffer widths as indicated in Table
20.93 —4.
(c) The applicant shall dedicate to the City an exclusive Environmentally Critical Area
easement for the protection of wetlands over the Environmentally Critical Area and a
buffer consistent with the standards listed in Subsection (a).
Table 20.93-4 —Wetland Buffer Requirements for Western Washington
Wetland Category Standard Additional Additional Additional
Buffer buffer width if buffer width if buffer width if
Width wetland scores wetland scores wetland scores
21 —25 habitat 26—29 habitat 30— 36 habitat
ORDINANCE NO. 2011-029 29
points oints points
Category I: based on total 75 ft Add 30 ft Add 90 ft Add 150 ft
score
Category 1: Bogs 190 ft NA NA Add 35 ft
Category 1: Natural Heritage 190 ft NA NA Add 35 ft
Wetlands
Category 1: Forested 75 ft Add 30 ft Add 90 ft Add 150 ft
Category II: Based on Score 75 ft Add 30 ft Add 90 ft Add 150 ft
Category III: (all) 60 ft Add 45 ft Add 105 ft NA
Category IV: (all) 40 ft NA NA NA
Table 20.93-5. Examples of Required Measures to Minimize Impacts (This is not a complete
list of measures.
Examples of Activities and Uses that Examples of Measures to Minimize Impacts
Disturbance Cause Disturbances
Lights • Parking lots • Direct lights away from critical areas and buffers
• Warehouses • Day use only regulations preventing the need for
• Manufacturing lights
• Residential • Timer on lights
-Parks
Noise • Manufacturing • Locate activity that generates noise away from
• Residential wetlands
• Seasonal limitations on hours of operation
Toxic runoff* • Parking lots • Route all new, untreated runoff away from
• Roads wetland while ensuring wetland is not
• Manufacturing dewatered
• Residential areas • Establish covenants limiting use of pesticides
• Application of within 150 ft of critical area or buffer
agricultural • Apply integrated pest management
pesticides
• Landscaping
Stormwater • Parking lots • Retrofit stormwater detention and treatment
runoff • Roads for roads and existing adjacent development
• Manufacturing • Prevent channelized flow from lawns that
• Residential areas directly enters the buffer
• Commercial
• Landscaping
Change in • Impermeable surfaces • Infiltrate or treat, detain, and disperse into
water regime • Lawns buffer new runoff from impervious surfaces
ORDINANCE NO. 2011-029 30
• Tilling and new lawns
-Forest and forest duff -Retain minimum forest and forest duff
removal
Pets and • Residential areas • Use privacy fencing; plant dense vegetation to
human -Parks delineate buffer edge and to discourage
disturbance disturbance using vegetation appropriate for
the ecoregion; place wetland and its buffer in
a separate tract
Dust • Construction sites • Use best management practices to control dust
Disruption of •Roads_ -Maintain connection to offsite areas that are
corridors or -Residential undisturbed
connections -Commercial -Restore corridors or connections to offsite
•Manufacturing habitats by replanting
-Landscaping
•Stormwater
* These examples are not necessarily adequate for minimizing toxic runoff if threatened or
endangered species are present at the site.
20.93.840 Mitigation.
(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 and in accordance with section 4.2 of the Shoreline Master Plan. What is considered
adequate mitigation will depend on the nature and magnitude of the potential impact, or
specifically identified in the Shoreline Master Program as required mitigation.
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 20.93-6 according to the wetland type.
2. On-Site Wetlands Creation—Creation of on-site wetlands and their buffers at the ratio
listed in Table 20.93-6 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 20.93-6 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 20.93-6 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: (i) contiguous to the impacted wetland, (ii) within the same drainage
basin where it would best provide the same function as the impacted wetland, and (iii)
elsewhere within the City.
ORDINANCE NO. 2011-029 31
(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§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 utilizing Selecting Wetland Mitigation Sites Using a Watershed
Approach (Western Washington) (Publication#09-06-3 2).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))
(c) Mitigation ratios for the replacement of impacted wetlands shall be as listed in Table 20.93-6.
Table 20.93 - 6
Category and Creation or Re- Rehabilitation Enhancement Preservation
Type of Wetland establishment
Category 1: Bog, Not considered 6:1 Case by case 10:1
Natural Heritage possible
site
Category 1: 6:1 12:1 24:1 24:1
Mature Forested
Category 1: 4:1 8:1 16:1 20:1
Based on
functions
Category II 1 3:1 6:1 1 12:1 20:1
Category III 2:1 4:1 8:1 15:1
CategoryIV 1.5:1 3:1 6:1 10:1
20.93 850 Monitoring
1. For projects that include native vegetation, a detailed five-year or ten-year vegetation
maintenance and monitoring program to include the following:
(a) Goals and objectives of the shoreline stabilization plan;
(b) Success criteria by which the implemented plan will be assessed;
(c) A Ten (10) year maintenance and monitoring plan for wetland projects with trees
and shrubs , consisting of site visits done in years 1, 2, 5, 7 and 10 by a qualified
professional, with progress reports submitted to the Shoreline Administrator and all other
agencies with jurisdiction following the site visits ; and,
ORDINANCE NO. 2011-029 32
a maintenance and monitoring plan for Compensatory mitigation projects which shall be
monitored for a minimum of five years with monitoring plans submitted for 0, 1 , 2, 3 and
5 years.
(d) A contingency plan in case of failure.
2. Monitoring of Fish and Wildlife populations may be required.
Part IX. Aquifer Recharge Areas
20.93.900 Purpose and Objectives.
(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
3 6.70A.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.
20.93.910 Applicability.
(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.
20.93.920 Information Required Upon Application.
All land use permit applications for development subject to these regulations shall include the
information specified in Table 20.93-6, Groundwater Protection Administration Guidance Chart.
20.93.930 Hydrogeologic Site Evaluations.
Hydrogeologic site evaluations shall address the following:
(a) Soil texture, permeability, and contaminant attenuation properties;
(b) Characteristics of the unsaturated top layer of soil, the vadose zone, and geologic material,
including permeability and attenuation properties;
(c) Depth to groundwater and/or impermeable soil layer;
(d) Aquifer properties such as hydraulic conductivity and gradients.
(e) Potential impacts to the aquifer or groundwater.
20.93.940 Best Management Practices (BMP) Plans.
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.
20.93.950 Mitigation Plans
ORDINANCE NO. 2011-029 33
(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.
20.93.960 Imposition of Conditions on Projects
Based on available information, including that provided by the applicant pursuant to the
requirements of Sections 20.93.920 (Aquifer Recharge Areas—Information Required Upon
Application), 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.
Table 20.93-6: Groundwater Protection Administration Guidance Chart Project
Use Type Information Required with
Application
1. A Best Management Practices
Underground Storage Tanks (USTs) as defined by Plan is required, as is proof of
Chapter173-360 WAC compliance with Department of
Ecology regulations and the
license number of the installer. A
mitigation plan may be required.
2. A Best Management Practices
Commercial, industrial, institutional, or other facilities that Plan is required. A mitigation plan
store, use, handle, or produce hazardous substances or may be required.
waste products as defined by WAC 173-303-101
3. Proof of compliance with
On-site sewage disposal systems serving large Department of Ecology and/or
developments, or any single use generating sufficient Snohomish County Health District
effluent over three thousand five hundred (3,500) gallons requirements. A mitigation plan
per day, require approval of their plans by the Department may be required.
of Health under Chapter 246-272 WAC or the Department
of Ecology under Chapter 173-240 WAC
4. Petroleum pipelines Both a Hydrologic Site Evaluation
and a Best Management Practices
Plan are required. A mitigation
plan may be required.
5. Solid waste facilities Both a Hydrologic Site Evaluation
and a Best Management Practices
Plan are required. A mitigation
plan may be required.
ORDINANCE NO. 2011-029 34
6. Land application of sewage sludge from sewage Both a Hydrologic Site Evaluation
treatment works which combine industrial waste and/or and a Best Management Practices
commercial waste with domestic waste or any sewage Plan are required. These studies
sludge application exceeding two (2) acres in size shall determine the application
rate. A mitigation plan may be
required.
7. All other development. Determination of whether the
project lies within a public
groundwater recharge area or
whether any wells are located
within 100 feet of the project. If
either of these criteria is met, the
applicant must show how all
applicable regulations, including
but not limited to those of the
Department of Ecology and/or
Snohomish County Health
District, are met. A mitigation
plan may be required.
Part X. Adoption of Plans
20.93.970 Shoreline Master Plan and Maps Adopted.
The City hereby adopts and incorporates by reference herein the "City of Arlington Shoreline
Master Program", September 2011 draft, prepared by the Watershed Company, as its Shoreline
Master Plan, including the Maps reflecting Environment Designations contained in Appendix A
thereto.
Section 2. Chapter 20.92 of the Arlington Municipal Code shall be and hereby is
repealed.
Section 3. Severability. If any provision, section, or part of this ordinance shall be
adjudged to be invalid or unconstitutional, such adjudication shall not affect the validity of the
ordinance as a whole or any section, provision or part thereof not adjudged invalid or
unconstitutional.
Section 4. Effective Date. The title of this Ordinance, which summarizes the
contents of this ordinance, shall be published in the official newspaper of the City. The
Ordinance shall take effect and be in full force five (5) days after the date of publication.
PASSED BY the City Council and APPROVED by the Mayor this rj "day of
December, 2011.
ORDINANCE NO. 2011-029 35
CITY OF ARLINGTON
Marg Larson, Mayor
Attest:
1
Kristi anfield, City Clerk
Approved as to form:
St en J. ei e
Cky-Atforney
ORDINANCE NO. 2011-029 36
CERTIFICATION OF ORDINANCE
I, Kristin Banfield, being the duly appointed and acting Clerk of the City of Arlington,
Washington, a municipal corporation, do hereby certify that the following Ordinance #2011-029
was approved at the December 5, 2011 City Council meeting.
ORDINANCE#2011-029
"AN ORDINANCE OF THE CITY OF ARLINGTON, WASHINGTON, ADDING A NEW
CHAPTER 20.93 OF THE ARLINGTON MUNICIPAL CODE RELATING TO
ENVIRONMENTALLY CRITICAL AREAS, AND REPEALING CHAPTER 20.92"
A true and correct copy of the original ordinance is attached.
Dated this 61h day of December, 2011.
Kristin anfield
City Clerk for the City of Arlington