HomeMy WebLinkAboutOrd 2625 - TMC Title 18 Chapters - Critical Areas RegulationsCover page to Ordinance 2625
The full text of the ordinance follows this cover page.
Ordinance2625was amended or repealedby the following ordinances.
AMENDEDREPEALED
Section(s) AmendedAmended by Ord#Section(s) RepealedRepealed by Ord#
481-12, 21-662741
2661, 2678
58, 66
2678
AN ORDINANCE OF THE CITY COUNCIL OF THE CITY OF TUKWILA,
WASHINGTON, ADDING, REPEALING AND AMENDING VARIOUS
DEFINITIONS AS CODIFIED IN TUKWILA MUNICIPAL CODE (TMC)
CHAPTER 18.06, "DEFINITIONS," AS IDENTIFIED HEREIN; AMENDING
AND RECODIFYING VARIOUS ORDINANCES AS CODIFIED IN
MULTIPLE SECTIONS OF TMC CHAPTER 18.52, "LANDSCAPE
REQUIREMENTS;" AMENDING ORDINANCE NO. 2443 §25, AS
CODIFIED AT TMC SECTION 18.28.240.C; AMENDING ORDINANCE NO.
2570 §3, §4, §5, §6, §7, §9, §12, §17 AND §20, AND ORDINANCE NO.
1758 §1 (PART), AS CODIFIED AT MULTIPLE SECTIONS OF TMC
CHAPTER 18.54, "URBAN FORESTRY AND TREE REGULATIONS;"
AMENDING ORDINANCE NO. 2518 §15 AND ORDINANCE NO. 1819 §1
(PART), AS CODIFIED AT TMC SECTION 18.70.050; REPEALING
ORDINANCE NOS. 2175 AND 2077, AS CODIFIED AT TMC SECTION
18.70.050; REPEALING ORDINANCE NO. 2301, AS CODIFIED IN
MULTIPLE SECTIONS OF TMC CHAPTER 18.45, "ENVIRONMENTALLY
SENSITIVE AREAS;" REPEALING ORDINANCE NO. 2368 §47, §48, §49
AND §50, AS CODIFIED AT VARIOUS SECTIONS OF TMC CHAPTER
18.45 AS IDENTIFIED HEREIN; REENACTING TMC CHAPTER 18.45,
"ENVIRONMENTALLY SENSITIVE AREAS," TO AMEND AND
ESTABLISH NEW REGULATIONS RELATED TO CRITICAL AREAS;
PROVIDING FOR SEVERABILITY; AND ESTABLISHING AN EFFECTIVE
DATE.
WHEREAS, the City of Tukwila adopted new regulations governing development on
sensitive areas and buffers in 2010 based on State Growth Management Act (GMA)
requirements to adopt development regulations that protect the functions of sensitive
areas, including wetlands, watercourse, fish and habitat conservation areas, and areas
of potential geological instability; and
WHEREAS, the City's critical area regulations should be consistent with the
Washington State Department of Ecology wetland classification system, which is based
on best available science; and
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WHEREAS, the City's critical area regulations should be consistent with the
Washington State Department of Natural Resources' stream classification system; and
WHEREAS, the City is conducting a required periodic update of its critical areas
regulations per RCW 36.70A.130; and
WHEREAS, after administering the critical area regulations for the past nine years
the City has determined there are certain clarifications and refinements needed to
improve the effectiveness of the ordinance; and
WHEREAS, the City Council adopted a Public Outreach Plan that incorporated a
variety of methods to notify the general public and property owners including an open
house, mailings to property owners and tenants, notice in a stormwater bill, postings on
the City's web site, creation of a broadcast e-mail group that received updates of the
critical areas review process, and articles in the City's newsletter "The Hazelnut;" and
WHEREAS, after receiving public input and administering the recently adopted tree
and landscaping regulations, the City has determined there are certain clarifications and
refinements needed to the "Urban Forestry and Tree Regulations" chapter and the
"Landscape Requirements" chapter of the Tukwila Municipal Code to improve the
effectiveness of those ordinances; and
WHEREAS, the Planning Commission reviewed a public review Draft Critical Areas
Regulations, held a public hearing on April 11, 2019, and recommended adoption of
revised regulations to the City Council on June 27, 2019; and
WHEREAS, an environmental checklist was prepared for the Draft Critical Areas
Regulations as recommended by the Planning Commission and a Determination of Non -
Significance was issued September 9, 2019; and
WHEREAS, the City Council held a public hearing on September 23, 2019, to review
the Planning Commission recommended Draft Critical Areas Regulations; and
WHEREAS, the City Council reviewed written and verbal testimony and approved
revisions to the Planning Commission recommended Draft Critical Areas Regulations to
address issues raised by interested parties, individual councilmembers, staff and the
Department of Ecology; and
WHEREAS, notice has been provided to the Washington State Department of
Commerce pursuant to RCW 36.70A.106;
NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF TUKWILA,
WASHINGTON, HEREBY ORDAINS AS FOLLOWS:
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Section 1. TMC Chapter 18.06, "Definitions," Amended. Ordinance No. 2075 §1
(part), as codified in Tukwila Municipal Code (TMC) Chapter 18.06, "Definitions," under
the subparagraph entitled "Adaptive Management," is hereby amended to read as follows:
Adaptive Management
"Adaptive management" means the use of scientific methods to evaluate how well
regulatory and non -regulatory actions protect a critical area.
Section 2. New Definition Adopted. A new section is hereby added to TMC
Chapter 18.06, "Definitions," as follows:
Alteration
"Alteration" means any human -induced change in an existing condition of a critical
area or its buffer. Alterations include, but are not limited to, grading, filling, channelizing,
dredging, clearing of vegetation, construction, compaction, excavation, or any other
activity that changes the character of the critical area.
Section 3. TMC Chapter 18.06, "Definitions," Amended. Ordinance No. 2075 §1
(part), as codified in TMC Chapter 18.06, "Definitions," under the subparagraph entitled
"Best Available Science," is hereby amended to read as follows:
Best Available Science
"Best Available Science" means that scientific information applicable to the critical
area prepared by appropriate local, state or federal agencies, a qualified scientist or team
of qualified scientists, which will be consistent with the criteria established in WAG 365-
195-900 through WAC 365-195-925. Characteristics of a valid scientific process will be
considered to determine whether information received during the permit review process
is reliable scientific information. A valid scientific process includes some or all of the
following characteristics:
1. Peer reviewed research or background information.
2. Study methods clearly stated.
3. Conclusions based on logical assumptions.
4. Quantitative analysis.
5. Proper context is established.
6. References are included that cite relevant, credible literature and other
pertinent information.
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Section 4. TMC Chapter 18.06, "Definitions," Amended. Ordinance No. 1758 §1
(part), as codified in TMC Chapter 18.06, "Definitions," under the subparagraph entitled
"Essential Street, Road, Right of Way or Utility," is hereby amended to read as follows:
Essential Street, Road, or Right -of -Way
"Essential street, road, or right-of-way" means a street, road or right-of-way where no
feasible alternative location exists based on an analysis of technology and system
efficiency.
Section 5. New Definition Adopted. A new section is hereby added to TMC
Chapter 18.06, "Definitions," as follows:
Essential Utility
"Essential utility" means a utility facility or utility system where no feasible alternative
location exists based on an analysis of technology and system efficiency.
Section 6. TMC Chapter 18.06, "Definitions," Amended. Ordinance Nos. 2075 §1
(part) and 1758 §1 (part), as codified in TMC Chapter 18.06, "Definitions," under the
subparagraph entitled "Mitigation," are hereby amended to read as follows:
Mitigation
"Mitigation" means replacing project induced critical area and buffer losses or
impacts, and includes but is not limited to the following:
1. Restoration: Actions performed to reestablish critical area and its buffer
functional characteristics and processes that have been lost by alterations, activities or
catastrophic events within an area that no longer meets the definition of a critical area;
2. Creation: Actions performed to intentionally establish a critical area and its
buffer at a site where it did not formerly exist;
3. Enhancement: Actions performed to improve the condition of an existing
degraded critical area or its buffer so that the functions it provides are of higher quality.
Section 7. TMC Chapter 18.06, "Definitions," Amended. Ordinance No. 1758 §1
(part), as codified in TMC Chapter 18.06, "Definitions," under the subparagraph entitled
"Sensitive Area Buffer," is hereby amended to read as follows:
Critical Area Buffer
"Critical area buffer" means an area lying adjacent to but outside a critical area as
defined by this Title, whose function is to protect critical areas from the potential adverse
impacts of development, land use, or other activities. A wetland or watercourse critical
area buffer also provides critical habitat value, bank stabilization, or water overflow area
functions.
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Section 8. TMC Chapter 18.06, "Definitions," Amended. Ordinance No. 1758 §1
(part), as codified in TMC Chapter 18.06, "Definitions," under the subparagraph entitled
"Sensitive Area Regulated Activities," is hereby amended to read as follows:
Critical Area Regulated Activities
"Critical area regulated activities" means any of the following activities that are directly
undertaken or originate in a regulated wetland or watercourse or their buffers:
1. Removal, excavation, grading or dredging of soil, sand, gravel, minerals,
organic matter or material of any kind;
2. Dumping, discharging or filling with any material;
3. Draining, flooding or disturbing the water level or water table;
4. Driving of pilings;
5. Placing of obstructions;
6. Construction, reconstruction, demolition or expansion of any structure;
7. Destruction or alteration of wetlands, watercourses or their buffers through
clearing, harvesting, shading, intentional burning or planting of vegetation that would alter
the character of a regulated wetland, watercourse or buffer, provided that these activities
are not part of a forest practice governed under RCW 76.09 and its rules; or
8. Activities that result in a significant change to the water sources of wetlands
or watercourses. These alterations include a significant change in water temperature,
physical or chemical characteristics, including quantity; and the introduction of pollutants.
Section 9. TMC Chapter 18.06, "Definitions," Amended. Ordinance Nos. 2075 §1
(part) and 1758 §1 (part), as codified in TMC Chapter 18.06, "Definitions," under the
subparagraph entitled "Sensitive Areas," are hereby amended to read as follows:
Critical Areas
"Critical areas" means wetlands, watercourses, areas of potential geologic instability
(other than Class I areas), abandoned coal mine areas, fish and wildlife habitat
conservation areas, and special hazard flood areas.
Section 10. TMC Chapter 18.06, "Definitions," Amended. Ordinance Nos. 2075 §1
(part) and 1758 §1 (part), as codified in TMC Chapter 1.8.06, "Definitions," under the
subparagraph entitled "Sensitive Areas Ordinance," are hereby amended to read as
follows:
Critical Areas Ordinance
"Critical Areas Ordinance" means the Environmentally Critical Areas chapter of this
title or as amended hereafter which establishes standards for land development on lots
with critical areas (e.g. steep slopes, wetlands, watercourses, etc.).
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Section 11. TMC Chapter 18.06, "Definitions," Amended. Ordinance Nos. 2075 §1
(part) and 1758 §1 (part), as codified in TMC Chapter 18.06, "Definitions," under the
subparagraph entitled "Sensitive Areas Tract or Easement," are hereby amended to read
as follows:
Critical Area Tract or Easement
"Critical area tract or easement" means a tract or portion of a parcel that is created
to protect the critical area and its buffer, whose maintenance is assured, and which is
recorded on all documents of title of record for all affected lots and subsequent owners.
Section 12. TMC Chapter 18.06, "Definitions," Amended. Ordinance Nos. 2368 §3
and 1758 §1 (part), as codified in TMC Chapter 18.06, "Definitions," under the
subparagraph entitled "Wetland Edge," are hereby amended to read as follows:
Wetland Edge
"Wetland edge" means the delineated boundary of a wetland performed in
accordance with approved federal wetland delineation manual and current applicable
regional supplements.
Section 13. Section Numbers within TMC Chapter 18.06, "Definitions," Amended.
As a result of amendments contained herein, the section number for some definitions
in TMC Chapter 18.06, "Definitions," may be changed as part of codification of this
ordinance including, but not limited to, the following:
Current Section Number Definition
18.06.017 Adaptive Management
18.06.064 Best Available Science
18.06.285
Essential Street, Road or Right -of -Way
18.06.581
Mitigation
18.06.710
Critical Area Buffer
18.06.715
Critical Area Regulated Activities
18.06.720
Critical Areas
18.06.725
Critical Areas Ordinance
18.06.730
Critical Area Tract or Easement
18.06.924
Wetland Edge
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Section 14. Repealer. Ordinance No. 1758 §1 (part), as codified in TMC Chapter
18.06, "Definitions," under the subparagraph entitled "Wetlands or Watercourses
Constructed," is hereby repealed.
Section 15. Repealer. Ordinance No. 1758 §1 (part), as codified in TMC Chapter
18.06, "Definitions," under the subparagraph entitled "Wetland, Emergent," is hereby
repealed.
Section 16. Repealer. Ordinance Nos. 2075 §1 (part) and 1758 §1 (part), as codified
in TMC Chapter 18.06, "Definitions," under the subparagraph entitled "Wetland,
Forested," are hereby repealed.
Section 17. Repealer. Ordinance No. 2301, as codified in multiple sections of
TMC Chapter 18.45, "Environmentally Sensitive Areas," is hereby repealed in its entirety.
Section 18. Repealer. Ordinance No. 2368 §47, §48, §49 and §50, as codified at
TMC Sections 18.45.040, 18.45.080, 18.45.120 and 18.45.180 respectively, are hereby
repealed.
Section 19. Repealer. Ordinance Nos. 2175 and 2077, as codified at TMC Section
18.70.050, "Nonconforming Structures," are hereby repealed.
Section 20. Chapter Title. Tukwila Municipal Code Chapter 18.45 is hereby retitled
to read as follows:
CHAPTER 18.45
ENVIRONMENTALLY CRITICAL AREAS
Sections:
18.45.010 Purpose
18.45.020 Best Available Science
18.45.030 Critical Area Applicability, Maps and Inventories
18.45.040 Critical Areas Special Studies
18.45.070 Critical Area Permitted Activities
18.45.075 Mitigation Sequencing
18.45.080 Wetlands Designations, Ratings and Buffers
18.45.090 Wetlands Uses, Alterations and Mitigation
18.45.100 Watercourse Designations, Ratings and Buffers
18.45.110 Watercourse Alterations and Mitigation
18.45.120 Areas of Potential Geologic Instability Designations, Ratings and
Buffers
18.45.130 Areas of Potential Geologic Instability Uses, Exemptions,
Alterations and Mitigation
18.45.140 Coal Mine Hazard Areas
18.45.150 Fish and Wildlife Habitat Conservation Areas — Designation,
Mapping, Uses and Standards
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18.45.155
Special Hazard Flood Areas
18.45.158
Vegetation Protection and Management
18.45.160
Critical Area Master Plan Overlay
18.45.170
Critical Areas Tracts and Easements
18.45.180
Exceptions
18.45.190
Time Limitation, Appeals and Vesting
18.45.195
Violations
18.45.197
Enforcement
18.45.200
Recording Required
18.45.210
Assurance Device
18.45.220
Assessment Relief
Section 21. TMC Section 18.45.010 is hereby reenacted to read as follows:
18.45.010 Purpose
A. The purpose of TMC Chapter 18.45 is to protect the environment, human life and
property; to designate and classify ecologically critical areas including but not limited to
regulated wetlands and watercourses and geologically hazardous areas and to protect
these critical areas and their functions while also allowing for reasonable use of public
and private property. These regulations are prepared to comply with the Growth
Management Act, RCW 36.70A, to apply best available science according to WAC 365-
195-900 through 925 and to protect critical areas as defined by WAC 365-190-080.
B. Standards are hereby established to meet the following goals of protecting
environmentally critical areas:
1. Minimize developmental impacts on the natural functions of these areas.
2. Protect quantity and quality of water resources.
3. Minimize turbidity and pollution of wetlands and fish -bearing waters and
maintain wildlife habitat.
4. Prevent erosion and the loss of slope and soil stability caused by the removal
of trees, shrubs, and root systems of vegetative cover.
5. Protect the public against avoidable losses, public emergency rescue and
relief operations cost, and subsidy cost of public mitigation from landslide, subsidence,
erosion and flooding.
6. Protect the community's aesthetic resources and distinctive features of
natural lands and wooded hillsides.
7. Balance the private rights of individual property owners with the preservation
of environmentally critical areas.
8. Prevent the loss of wetland and watercourse function and acreage, and
strive for a gain over present conditions.
9. Give special consideration to conservation or protection measures
necessary to protect or enhance anadromous fisheries.
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10. Incorporate the use of best available science in the regulation and protection
of critical areas as required by the State Growth Management Act, according to WAC
365-195-900 through 365-195-925 and WAC 365-190-080.
Section 22. TMC Section 18.45.020 is hereby reenacted to read as follows:
18.45.020 Best Available Science
A. Policies, regulations and decisions concerning critical areas shall rely on best
available science to protect the functions of these areas and must give special
consideration to conservation or protection measures necessary to preserve or enhance
anadromous fish and their habitats.
B. Nonscientific information may supplement scientific information, but is not an
adequate substitution for valid and available scientific information.
C. Incomplete or unavailable scientific information leading to uncertainty for
permitting critical area impacts may require application of effective adaptive
management on a case by case basis. Adaptive management relies on scientific
methods to evaluate how well regulatory or non -regulatory actions protect critical areas
or replace their functions.
Section 23. TMC Section 18.45.030 is hereby reenacted to read as follows:
18.45.030 Critical Area Applicability, Maps, and Inventories
A. APPLICABILITY. The provisions of TMC Chapter 18.45 shall apply to all land
uses and all development activities in a critical area or a critical area buffer as defined in
the "Definitions" chapter of this title. The provisions of TMC Chapter 18.45 apply whether
or not a permit or authorization is required within the City of Tukwila. No person, company,
agency, or applicant shall alter a critical area or buffer except as consistent with the
purposes and requirements of TMC Chapter 18.45. The following are critical areas
regulated by TMC Chapter 18.45:
Coal Mine Hazard Areas;
2. Areas of potential geologic instability: Class 2, 3, 4 areas (as defined in the
Definitions chapter of this title and TMC Section 18.45.120.A);
3. Wetlands;
4. Watercourses;
5. Fish and Wildlife Habitat Conservation Areas; and
6. Special Hazard Flood Areas (see TMC Chapter 16.52 for additional
regulations).
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B. Areas of seismic instability are identified as critical areas by the Growth
Management Act and are defined and regulated through the Washington State Building
Code.
C. In the event of a conflict between this TMC Chapter 18.45 and any other laws,
regulations, ordinances or restrictive covenants, the provision that imposes greater
restrictions or higher standards upon the development or use of land shall prevail.
D. CRITICAL AREAS MAPS AND INVENTORIES.
1. The distribution of many critical areas and potential critical areas in Tukwila
is displayed on the Critical Areas Maps, on file with the Department of Community
Development (DCD). These maps are based on site assessment of current conditions and
review of the best available scientific data and are hereby adopted by reference. Not all
critical areas are shown on the map. Thus it is the responsibility of property owners and
applicants to verify actual presence or absence of a critical area or critical area buffer
based on the definitions in this code. Applicant is also responsible for delineation and
categorization of potential wetland based on methodology required under TMC Section
18.45.080 and verifying that watercourse typing and location is consistent with TMC
Section 18.45.100.
2. Studies, preliminary inventories and ratings of potential critical areas are on
file with the Department of Community Development.
3. As new environmental information related to critical areas becomes
available, the Director is hereby designated to periodically add, remove, or alter new
information to the Critical Areas Maps. Removal of any information from the Critical Areas
Maps is a Type 1 decision as described in TMC Chapter 18.108.
Section 24. TMC Section 18.45.040 is hereby reenacted to read as follows:
18.45.040 Critical Area Special Studies
A. Application Required. An applicant for a development proposal within a
parcel that may include a critical area and/or its buffer shall submit those studies as
required by the City and specified within this section to adequately identify and evaluate
the critical area and its buffers.
1. A required critical area study shall be prepared by a person with experience
and training in the scientific discipline appropriate for the relevant critical area as outlined
within this section and in accordance with WAC 365-195-905(4). A qualified
professional must have obtained a B.S. or B.A. or equivalent degree in ecology or
related science, environmental studies, fisheries, geotechnical or related field, and two
years of related work experience.
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a. A qualified professional for Fish and Wildlife Habitat Conservation
Areas must have a degree in ecology or related sciences and professional experience
related to the subject species.
b. A qualified professional for wetland critical area studies must be a
certified Professional Wetland Scientist or a Wetland Scientist with at least two years of
full-time work experience as a wetlands professional, including delineating wetlands
using the approved federal manual and applicable regional supplements, preparing
wetland reports, conducting functional assessments, and developing and implementing
mitigation plans.
c. A qualified professional for a geological hazard study must be a
professional geotechnical engineer as defined in the Definitions chapter of this title,
licensed in the state of Washington.
d. A qualified professional for watercourses and frequently flooded areas
means a hydrologist, fisheries biologist, engineer or other scientist with experience in
preparing watercourse assessments.
2. The critical area study shall use scientifically valid methods and studies in
the analysis of critical area data and shall use field reconnaissance and reference the
source of science used. The critical area study shall evaluate the proposal and all
probable impacts to critical areas.
B. Wetland and Watercourse Critical Area Studies. Wetland and watercourse
special studies are valid for five years following the date of the study, unless otherwise
determined by the Director. The critical area study shall contain the following
information, as applicable:
1. The name and contact information of the applicant, a description of the
proposal, and identification of the permit requested;
2. A copy of the site plan for the development proposal showing: critical areas
and buffers and the development proposal with dimensions, clearing limits, proposed
storm water management plan, and mitigation plan for impacts due to drainage
alterations;
3. The dates, names and qualifications of the persons preparing the study and
documentation of any fieldwork performed on the site;
4. Identification and characterization of all critical areas, water bodies, and
buffers on or adjacent to the proposed project area or potentially impacted by the
proposed project as described in the following sections:
a. Characterization of wetlands must include:
(1) A wetland delineation report that includes methods used, field
indicators evaluated and the results. Wetland delineation must be performed in
accordance with approved federal wetland delineation manual and current applicable
regional supplements. Field data forms are to be included in the report. Data collection
points are to be shown on the site plan with their corresponding numbers indicated. After
the City of Tukwila confirms the boundaries, they are to be professionally surveyed to the
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nearest square foot and the site plan modified as necessary to incorporate the survey
data. Exact wetland acreage will be calculated after the boundaries have been surveyed.
Applicant must submit electronic survey data in Autocad, GIS or similar format at the time
of as -built submittal.
(2) Cowardin (Classification of Wetlands and Deepwater Habitats of the
U.S. — U.S. Department of Interior) classification of the wetland(s).
(3) Hydrogeomorphic classification of the wetland(s).
(4) Hydroperiod.
(5) Brief landscape assessment of the wetland (identify hydrologic
basin/sub-basin; inlets, outlets; surrounding land use; habitat quality and connectivity;
ultimate point of discharge; presence of culverts or other constraints to flow; relationship
to other wetlands/watercourses adjacent to or potentially impacted by the proposed
project).
(6) Description of buffer size per this chapter, conditions (topographic
considerations, existing vegetation types and density, habitat features, watercourse
edges, presence of invasive species, etc.) and functions.
(7) Assessment. For proposed wetland filling or proposed projects
that will impact buffers, the most current Washington Wetland Classification System shall
be used as a functional assessment.
b. Characterization of the watercourses on site, adjacent to or potentially
impacted by the proposed project must include:
(1) Description of: flow regime, physical characteristics of streambed,
banks, dimensions and bank -full width, stream gradient, stream and buffer vegetation
conditions, habitat conditions, and existing modifications.
(2) Brief landscape assessment of the watercourse (identify hydrologic
basin/sub-basin, and contributing basin area acreage, outlets, surrounding land use,
habitat quality and connectivity, ultimate point of discharge, presence of culverts or other
constraints to flow, presence of man-made or natural barriers to fish passage, relationship
to wetlands or other watercourses adjacent to or potentially impacted by the proposed
project, flow regime).
(3) Classification of the watercourse under Tukwila's rating system.
(4) Description of buffer size per this chapter, conditions (topographic
considerations, existing vegetation types and density, habitat features, watercourse
edges, presence of invasive species, etc.) and functions.
(5) Description of habitat conditions, wildlife/fish use of the
watercourse, including sensitive, threatened or endangered species.
c. Citation of any literature or other resources utilized in preparation of
the report.
5. A statement specifying the accuracy of the study and assumptions used in
the study.
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6. Determination of the degree of hazard and risk from the proposal both on
the site and on adjacent properties.
7. An assessment of the probable cumulative impacts to critical areas, their
buffers and other properties resulting from the proposal.
8. A description of reasonable efforts made to apply mitigation sequencing to
avoid, minimize and mitigate impacts to critical areas.
9. Plans for adequate mitigation to offset any impacts.
10. Recommendations for maintenance, short-term and long-term monitoring,
contingency plans and bonding measures.
11. Any technical information required by the Director to assist in determining
compliance with this chapter.
C. Geotechnical Report.
1. A geotechnical report appropriate both to the site conditions and the
proposed development shall be required for development in Class 2, Class 3, Class 4
areas, and any areas identified as Coal Mine Hazard Areas.
2. Geotechnical reports for Class 2 areas shall include at a minimum a site
evaluation review of available information regarding the site and a surface
reconnaissance of the site and adjacent areas potentially impacted by the proposed
project. Subsurface exploration of site conditions is at the discretion of the geotechnical
consultant.
3. Geotechnical reports for Class 3, Class 4 and Coal Mine Hazard Areas
shall include a site evaluation review of available information about the site, a surface
reconnaissance of the site and adjacent areas potentially impacted by the proposed
project, a feasibility analysis for the use of infiltration on -site and a subsurface
exploration of soils and hydrology conditions. Detailed slope stability analysis shall be
done if the geotechnical engineer recommends it in Class 3 or Coal Mine Hazard Areas,
and must be done in Class 4 areas.
4. Applicants shall retain a geotechnical engineer to prepare the reports and
evaluations required in this subsection. The geotechnical report and completed site
evaluation checklist shall be prepared in accordance with the generally accepted
geotechnical practices, under the supervision of and signed and stamped by the
geotechnical engineer. The report shall be prepared in consultation with the Community
Development and Public Works Departments.
5. The opinions and recommendations contained in the report shall be
supported by field observations and, where appropriate or applicable, by literature
review conducted by the geotechnical engineer, which shall include appropriate
explorations, such as borings or test pits, and an analysis of soil characteristics
conducted by or under the supervision of the engineer in accordance with standards of
the American Society of Testing and Materials or other applicable standards. If the
evaluation involves geologic evaluations or interpretations, the report shall be reviewed
and approved by a geotechnical engineer.
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D. Critical Area Study — Modifications to Requirements.
1. The Director may limit the required geographic area of the critical area study
as appropriate if the applicant, with assistance from the City, cannot obtain permission to
access properties adjacent to the project area.
2. The Director may allow modifications to the required contents of the study
where, in the judgment of a qualified professional, more or less information is required to
adequately address the potential critical area impacts and required mitigation.
E. Review of Studies. The Department of Community Development will review
and verify the information submitted in the critical area study to confirm the nature and
type of the critical area. The Public Works Department shall seek a peer review of the
geotechnical report on Class 3 and 4 slopes; and peer review on Class 2 slopes may be
required at the discretion of the Public Works Director. Peer review of the geotechnical
reports shall be at the expense of the applicants. For all other critical areas and at the
discretion of the Director, critical area studies may undergo peer review, at the expense
of the applicant.
Section 25. TMC Section 18.45.070 is hereby reenacted to read as follows:
18.45.070 Critical Area Permitted Activities
A. Outright Permitted Activities. T
subject to the provisions of TMC Chapter 21
chapter, if applicable:
ie following activities are outright permitted
04 and of the mitigation requirements of this
1. Maintenance and repair of existing facilities provided no alteration or
additional fill materials will be placed or heavy construction equipment used in the critical
area or buffer.
2. Site exploration or research that does not include use of heavy equipment
or native vegetation removal.
3. Maintenance and repair of essential streets, roads, rights -of -way, or utilities,
and placement, maintenance, and repair of new fiberoptic utilities within existing improved
and paved roads.
4. Actions to remedy the effects of emergencies that threaten the public health,
safety or welfare.
5. Maintenance activities of existing landscaping and gardens in a critical area
buffer including, but not limited, to mowing lawns, weeding, harvesting and replanting of
garden crops and pruning and planting of vegetation. This provision does not apply to
removal of established native trees and shrubs, or to the excavation, filling, and
construction of new landscaping features, such as concrete work, berms and walls.
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6. Voluntary native revegetation and/or removal of invasive species that does
not include use of heavy equipment. The use of herbicide by a licensed contractor with
certification as needed from the Washington Department of Ecology and the Washington
Department of Agriculture is permitted but requires notification prior to application to the
City and shall comply with TMC Section 18.45.158.E.3
B. Permitted Activities Subject to Administrative Review. The following uses
may be permitted only after administrative review and approval of a Type 2 Special
Permission application by the Director:
1. Maintenance and repair of existing uses and facilities where alteration or
additional fill materials will be placed or heavy construction equipment used in the critical
area or buffer.
2. New surface water discharges to critical areas or their buffers from detention
facilities, pre -settlement ponds or other surface water management structures may be
allowed provided that the discharge meets the clean water standards of RCW 90.48 and
WAC 173-200 and 173-201A as amended, and does not adversely affect wetland
hydrology or watercourse flow. Water quality monitoring may be required as a condition
of use.
3. Construction of bioswales and
facilities allowed in wetland or watercourE
required as a condition of use.
dispersion trenches are the only stormwater
buffers. Water quality monitoring may be
4. Enhancement or other mitigation including landscaping with native plants
that requires heavy equipment.
5. Construction or maintenance of essential utilities if designed to protect the
critical area and its buffer against erosion, uncontrolled storm water, restriction of
groundwater movement, slides, pollution, habitat disturbance, any loss of flood carrying
capacity and storage capacity, and excavation or fill detrimental to the environment.
6. Construction or maintenance of essential public streets, roads and rights -of -
way as defined by TMC Section 18.06.285, provided the following criteria are met:
a. Are designed and maintained to prevent erosion and avoid restricting
the natural movement of groundwater.
b. Are located to conform to the topography so that minimum alteration of
natural conditions is necessary. The number of crossings shall be limited to those
necessary to provide essential access.
c. Are constructed in a way that does not adversely affect the hydrologic
quality of the wetland or watercourse and/or its buffer. Where feasible, crossings must
allow for combination with other essential utilities.
7. Public/Private Use and Access,
a. Public and private access shall be limited to trails, boardwalks, covered
or uncovered viewing and seating areas, footbridges only if necessary for access to other
areas of the property, and displays (such as interpretive signage or kiosks), and must be
located in areas that have the lowest sensitivity to human disturbance or alteration.
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Access features shall be the minimum dimensions necessary to avoid adverse impacts
to the critical area. Trails shall be no wider than 5 feet and are only allowed in the outer
25 percent of the buffer, except for allowed wetland or stream crossings. Crossings and
trails must be designed to avoid adverse impacts to critical area functions. The Director
may require mechanisms to limit or control public access when environmental conditions
warrant (such as temporary trail closures during wildlife breeding season or migration
season).
b. Public access must be specifically developed for interpretive,
educational or research purposes by, or in cooperation with, the City or as part of the
adopted Tukwila Parks and Open Space Plan. Private footbridges are allowed only for
access across a critical area that bisects the property.
c. No motorized vehicle is allowed within a critical area or its buffer except
as required for necessary maintenance, agricultural management or security.
d. Any public access or interpretive displays developed along a critical area
and its buffer must, to the extent possible, be connected with a park, recreation or open -
space area.
e. Vegetative edges, structural barriers, signs or other measures must be
provided wherever necessary to protect critical areas and their buffers by limiting access
to designated public use or interpretive areas.
f. Access trails and footbridges must incorporate design features and
materials that protect water quality and allow adequate surface water and groundwater
movement. Trails must be built of permeable materials.
g. Access trails and footbridges must be located where they do not disturb
nesting, breeding and rearing areas and must be designed so that sensitive plant and
critical wildlife species are protected. Trails and footbridges must be placed so as to not
cause erosion or sedimentation, destabilization of watercourse banks, interference with
fish passage or significant removal of native vegetation. Footbridges must be anchored
to prevent their movement due to water level or flow fluctuations. Any work in the wetland
or stream below the OHWM will require additional federal and state permits.
8. Dredging, digging or filling may occur within a critical area or its buffer only
with the permission of the Director provided it meets mitigation sequencing requirements
and is permitted under TMC, Section 18.45.090 (alteration of wetland), TMC Section
18.45.110 (alteration of watercourse), or TMC Sections 18.45.120 and 18.45.130 (areas
of geologic instability). Dredging, digging or filling shall only be permitted for flood control,
improving water quality and habitat enhancement unless otherwise permitted by this
chapter.
Section 26. Regulations Established. TMC Section 18.45.075, "Mitigation
Sequencing," is hereby established to read as follows:
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18.45.075 Mitigation Sequencing
Applicants shall demonstrate that reasonable efforts have been examined with the
intent to avoid and minimize impacts to critical areas and critical area buffers. When an
alteration to a critical area or its required buffer is proposed, such alteration shall be
avoided, minimized or compensated for in the following order of preference:
1. Avoiding the impact altogether by not taking a certain action or parts of an
action;
2. Minimizing critical area or critical area buffer impacts by limiting the degree
or magnitude of the action and its implementation, by using appropriate technology, or by
taking affirmative steps to avoid or reduce impacts;
3. Rectifying the impact by repairing, rehabilitating or restoring the affected
environment;
4. Reducing or eliminating the impact over time by preservation and
maintenance operations during the life of the action;
5. Compensating for the impact by replacing, enhancing, or providing substitute
resources or environments; and/or
6. Monitoring the impact and taking appropriate corrective measures.
Section 27. TMC Section 18.45.080 is hereby reenacted to read as follows:
18.45.080 Wetlands Designations, Ratings and Buffers
A. WETLAND DESIGNATIONS.
1. For the purposes of TMC Chapter 18.45, "wetlands" are defined in the
Definitions chapter of this title. A wetland boundary is the line delineating the outer edge
of a wetland established in accordance with the approved federal wetland delineation
manual and applicable regional supplement.
2. Wetland determinations and delineation of wetland boundaries shall be
made by a qualified professional, as described in TMC Section 18.45.040.
3. Wetland determinations and delineation or wetland boundaries must be
conducted within no more than five years prior to the date of permit application.
B. WETLAND RATINGS.
Wetlands shall be designated in accordance with the Washington State Wetlands
Rating System for Western Washington (Washington State Department of Ecology, 2014,
Publication # 14-06-029); or as otherwise amended by Ecology, as Category I, Il, III, or
IV.
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C. WETLAND BUFFERS. The purpose of the buffer area shall be to protect the
integrity and functions of the wetland area. Any land alteration must be located out of the
buffer areas as required by this section. Wetland buffers are intended in general to:
1. Minimize long-term impacts of development on properties containing
wetlands;
2. Protect wetlands from adverse impacts during development;
3. Preserve the edge of the wetland and its buffer for its critical habitat value;
4. Provide an area to stabilize banks, to absorb overflow during high water
events and to allow for slight variation of aquatic system boundaries over time due to
hydrologic or climatic effects;
5. Reduce erosion and increased surface water runoff,
6. Reduce loss of or damage to property;
7. Intercept fine sediments from surface water runoff and serve to minimize
water quality impacts; and
8. Protect the critical area from human and domestic animal disturbances.
Buffer widths in Table 18.45.080-1 have been established in accordance with the
best available science. They are based on the category of wetland and the habitat score.
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Table 18.45.080-1 — Wetland Buffer Widths
Wetland buffer width (feet), Ecology 2014, high -intensity land use impact
Habitat
Habitat
Habitat
Habitat
Habitat
Habitat
score
score
score
score
score
score
Category
<6
<6
6=7
6=7
8_9
8_9
Standard
Alternate
Standard
Alternate Buffer
Standard
Alternate Buffer
Buffer
Buffer if
Buffer
if impact
Buffer
if impact
impact
minimization
minimization
minimization
measures taken
measures taken
measures
AND buffer is
AND buffer is
taken AND
replanted. Also,
replanted.
buffer is
100 feet
Also, 100 feet
replanted
vegetated
vegetated
corridor between
corridor between
wetland and any
wetland and any
nearby Priority
nearby Priority
Habitats is
Habitats is
maintained (see
maintained.
footnote')
(see footnote')
1
100
75
150
110
300
225
11
100
75
150
110
300
225
111
80
60
150
110
300
225
IV
50
40
50
40
50
40
(1) A relatively undisturbed, vegetated corridor at least 100 feet wide is protected between the wetland
and any nearby Priority Habitats as defined by the Washington State Department of Fish and Wildlife. The
corridor must be protected for the entire distance between the wetland and the Priority Habitat by some
type of legal protection such as a conservation easement. Presence or absence of a nearby habitat must
be confirmed by a qualified biologist. If no option for providing a corridor is available, Table 18.45.080-1
may be used with the required measures in Table 18.45.080-2 alone.
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Table 18.45.080-2 — Required Measures to Minimize Impacts to Wetlands
Disturbance
Required Measures to Minimize Impacts
Lights
. Direct lights away from wetland
Noise
. Locate activity that generates noise away from wetland
• If warranted, enhance existing buffer with native vegetation plantings
adjacent to noise source
• For activities that generate relatively continuous, potentially disruptive
noise, such as certain heavy industry or mining, establish an additional
10-foot heavily vegetated buffer strip immediately adjacent to the outer
edge of wetland buffer
Toxic runoff
. Route all new, untreated runoff away from wetland while ensuring
wetland is not dewatered
Establish covenants limiting use of pesticides within 150 feet of wetland
• Apply integrated pest management
Stormwater runoff
. Retrofit stormwater detention and treatment for roads and existing
adjacent development
• Prevent channelized flow from lawns that directly enters the buffer
• Use Low Intensity Development (LID) techniques where appropriate
(for more information refer to the drainage ordinance and manual)
Change in water regime
. Infiltrate or treat, detain, and disperse into buffer new runoff from
impervious surfaces and new lawns
Pets and human
. Use privacy fencing OR plant dense vegetation to delineate buffer edge
disturbance
and to discourage disturbance using vegetation appropriate for the
ecoregion
Place wetland and its buffer in a separate tract or protect with a
conservation easement
Dust
. Use best management practices to control dust
E. BUFFER SETBACKS.
1. All commercial and industrial buildings shall be set back 15 feet and all other
development shall be set back 10 feet from the buffer's edge. The building setbacks shall
be measured from the foundation to the buffer's edge. Building plans shall also identify a
20-foot area beyond the buffer setback within which the impacts of development will be
reviewed.
2. The Director may waive setback requirements when a site plan
demonstrates there will be no impacts to the buffer from construction or occasional
maintenance activities.
F. VARIATION OF STANDARD WETLAND BUFFER WIDTH.
1. Buffer averaging may be allowed by the Director as a Type 2 permit if the
total area of the buffer after averaging is equal to the area required without averaging and
the buffer at its narrowest point is never less than either 3/4 of the required width or 75
feet for Category I and II, 50 feet for Category III, and 25 feet for Category IV, whichever
is greater, and so long as the following criteria is met:
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a. The wetland has significant differences in characteristics that affect its
habitat functions, and the buffer is increased adjacent to the higher -functioning area of
habitat or more -sensitive portion of the wetland and decreased adjacent to the lower -
functioning or less -sensitive portion as demonstrated by a critical areas report.
b. There are no feasible alternatives to the site design that could be
accomplished without buffer averaging, and the averaged buffer will not result in
degradation of the wetland's functions and values as demonstrated by a critical areas
report.
c. Compliance with mitigation sequencing requirements (TMC Section
18.45.075).
d. Compliance with TMC Chapter 18.45, "Vegetation Protection and
Management" section.
e. Submittal of buffer enhancement plan, mitigation monitoring and
maintenance plan along with financial guarantee in accordance with this chapter.
2. Interrupted Buffer. Waiver for interrupted buffer may be allowed by the
Director as a Type 2 permit if it complies with the following:
a. The buffer is interrupted by a paved public or private road; existing or
future levee legally constructed adjacent to an off -channel habitat, legally constructed
buildings or parking lots. This waiver does not apply to accessory structures such as
sheds and garages;
b. The existing legal improvement creates a substantial barrier to the buffer
function;
c. The interrupted buffer does not provide additional protection of the
critical area from the proposed development; and
d. The interrupted buffer does not provide significant hydrological, water
quality and wildlife functions. This waiver does not apply if large trees or other significant
native vegetation exists.
e. Enhancement of remaining buffer is required if feasible.
3. Buffers for all types of wetlands will be increased when they are determined
to be particularly sensitive to disturbance or the proposed development will create
unusually adverse impacts. Any increase in the width of the buffer shall be required only
after completion of a wetland study by a qualified wetlands professional or expert that
documents the basis for such increased width. An increase in buffer width may be
appropriate when:
a. The development proposal has the demonstrated potential for significant
adverse impacts upon the wetland that can be mitigated by an increased buffer width; or;
b. The area serves as a habitat for endangered, threatened, sensitive or
monitor species listed by the federal government or the State.
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Section 28. TMC Section 18.45.090 is hereby reenacted to read as follows:
18.45.090 Wetlands Uses, Alterations and Mitigation
A. No use or development may occur in a wetland or its buffer except as specifically
allowed by TMC Chapter 18.45. Any use or development allowed is subject to review and
approval by the Director. Where required, a mitigation plan must be developed and must
comply with the standards of mitigation required in this chapter. Where unauthorized
alterations occur within a critical area or its buffer, the City will require the applicant to
submit a critical area study, that includes mitigation, subject to approval. The applicant
shall be responsible for implementing the mitigation and for additional penalties as
determined by the Director. In addition, federal and/or state authorization is required for
direct impacts to waters of the United States or the State of Washington.
B. ALTERATIONS.
1. Alterations to wetlands are discouraged and are limited to the minimum
necessary for project feasibility. Requests for alterations must be accompanied by a
mitigation plan, are subject to Director approval, and may be approved only if the following
findings are made:
a. The alteration complies with mitigation sequencing requirements (TMC
Section 18.45.075);
b. The alteration will not adversely affect water quality;
c. The alteration will not adversely affect fish, wildlife, or their habitat;
d. The alteration will not have an adverse effect on drainage and/or storm
water detention capabilities;
e. The alteration will not lead to unstable earth conditions or create an
erosion hazard or contribute to scouring actions;
f. The alteration will not be materially detrimental to any other property;
g. The alteration will not have adverse effects on any other critical areas;
and
h. Complies with the maintenance and monitoring requirements listed
within this section.
2. Alterations are not permitted to Category I and II wetlands unless specifically
exempted under the provisions of this chapter.
3. Alterations to Category III and IV wetlands are allowed only where
unavoidable and adequate mitigation is carried out in accordance with the standards of
this section.
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4. Alterations to isolated Category IV wetlands less than 1,000 square feet in
size that meet all of the following conditions are allowed where adequate mitigation is
carried out in accordance with the standards of this section.
a. They are not associated with a riparian corridor;
buffers,
b. They are not associated with Shorelines of the State or their associated
c. They are not part of a wetland mosaic;
d. They do not contain habitat identified as essential for local populations
of priority species identified by the Washington State Department of Fish and Wildlife;
and
e. They do not score 6 points or greater for habitat in the Western
Washington Wetland Rating System.
C. MITIGATION STANDARDS.
1. Types of Wetland Mitigation:
a. Mitigation for wetlands shall follow the mitigation sequencing steps in
this chapter and may include the following types of actions in order of decreasing
preference:
(1) Restoration:
(a) Re-establishment. The manipulation of the physical, chemical
or biological characteristics of a site with the goal of restoring wetland functions to a
former wetland, resulting in a net increase in wetland acres and functions.
(b) Rehabilitation. The manipulation of the physical, chemical or
biological characteristics of a site with the goal of repairing historic functions and
processes of a degraded wetland, resulting in a gain in wetland functions but not acreage.
(2) Creation (establishment). The manipulation of the physical,
chemical or biological characteristics to develop a wetland on an upland or deepwater
site, where a biological wetland did not previously exist.
(3) Enhancement. The manipulation of the physical, chemical or
biological characteristics to heighten, intensify, or improve specific functions (such as
vegetation) or to change the growth stage or composition of the vegetation present,
resulting in a change in wetland functions but not in a gain in wetland acreage.
(4) A combination of the three types of actions listed above.
b. Required mitigation ratios are described in TMC Section
18.45.090.C.1.b.(1)-(4) (below). Alternate mitigation ratios may be accepted by the
Director upon presentation of justification based on best available science that shows the
proposed compensation represents a roughly proportional exchange for the proposed
impacts.
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(1) Alterations are not permitted to Category I or II wetlands unless
specifically exempted under the provisions of this program. When alterations are allowed,
mitigation ratios for Category I wetlands shall be at a 4:1 for creation or re- establishment,
8:1 for rehabilitation, and 16:1 for enhancement. Mitigation ratios for Category II wetlands
shall be at 3:1 for creation or re-establishment, 6:1 for rehabilitation and 12:1 for
enhancement. Creation or re-establishment shall be contiguous to the wetland, unless an
exception is authorized by the Director. For Category II estuarine wetlands, re-
establishment, creation and enhancement ratios will be decided on a case -by -case basis.
(2) Alterations to Category III wetlands are prohibited except where
unavoidable and mitigation sequencing in accordance with this chapter has been utilized
and where mitigation is carried out in accordance with the standards in the section.
Mitigation for any alteration to a Category III wetland must be provided at a ratio of 2:1 for
creation or re-establishment, 4:1 for rehabilitation and 8:1 for enhancement alone.
(3) Mitigation for alteration to a Category IV wetland will be 1.5:1 for
creation or re-establishment, 3:1 for rehabilitation or 6:1 for enhancement. Where only a
portion of a Category IV wetland is filled, the potential functionality of the remaining
reduced wetland must be considered in mitigation planning.
(4) Mitigation for alteration to wetland buffers will be 1:1.
2. The following shall be considered the minimum performance standards for
approved wetland alterations:
a. Wetland functions improved over those of the original conditions.
b. Hydrologic conditions and hydroperiods are improved over existing
conditions and the specific hydrologic performance standards specified in the approved
mitigation plan are achieved.
c. Square feet requirements for creation, reestablishment, rehabilitation or
enhancement and for proposed wetland classes are met.
d. Vegetation native to the Pacific Northwest is installed and vegetation
survival and coverage standards over time are met and maintained.
improved.
e. Habitat features are installed, if habitat is one of the functions to be
Buffer and bank conditions and functions exceed the original state.
3. Maintenance and monitoring of mitigation shall be done by the property
owner for a period of no less than five years and for ten years when the mitigation plan
includes establishing forested wetland and/or buffers. Maintenance shall be carried out in
accordance with the approved mitigation plan. Monitoring reports must be submitted to
the City for review with the frequency specified in the approved mitigation plan.
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D. WETLAND AND BUFFER MITIGATION LOCATION.
1. In instances where portions of a wetland or wetland buffer impacted by
development remain after buffer averaging, mitigation for buffer impacts shall be provided
on -site, if feasible. Where an essential public road, street or right-of-way or essential
public utility cannot avoid buffer alterations, buffer enhancement must be carried out at
other locations around the impacted wetland.
2. On -site mitigation for wetland impacts shall be provided, except where the
applicant can demonstrate that:
a. On -site wetland mitigation is not scientifically feasible due to problems
with hydrology, soils, waves or other factors; or
b. Mitigation is not practical due to potentially adverse impact from
surrounding land uses; or
c. Existing functions created at the site of the proposed restoration are
significantly greater than lost wetland functions; or
d. Regional goals for flood storage, flood conveyance, habitat or other
wetland functions have been established and strongly justify location of mitigation at
another site, and where off -site mitigation is demonstrated to provide a greater ecological
benefit to the watershed. Refer to 2005 WRIA 9 Salmon Habitat Plan as it now reads and
hereafter updated or amended, for potential offsite mitigation locations.
3. Purchase of mitigation credits through mitigation banks and in lieu fee
programs is preferred over permittee responsible offsite mitigation.
4. The Community Development Director may approve, through a Type 2
decision, the transfer of wetland mitigation to a wetland mitigation bank or in -lieu fee
program using the criteria in 4.a. through 4.f. below. Wetland mitigation bank credits shall
be determined by the certified mitigation banking or in -lieu fee instrument.
a. Off -site mitigation is proposed in a wetland mitigation bank that has been
approved by all appropriate agencies, including the Department of Ecology, Corps of
Engineers, EPA and certified under state rules; and
b. The proposed wetland alteration is within the designated service area of
the wetland bank; and
c. The applicant provides a justification for the number of credits proposed;
and
d. The mitigation achieved through the number of credits required meets
the intent of TMC Chapter 18.45; and
e. The Director bases the decision on a written staff report, evaluating the
equivalence of the lost wetland functions with the number of wetland credits required; and
f. The applicant provides a copy of the wetland bank ledger demonstrating
that the approved number of credits has been removed from the bank.
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5. Where off -site mitigation location is proposed it shall comply with the
following criteria:
a. Mitigation sites located within the Tukwila City limits are preferred.
b. Mitigation bank or in -lieu fee option is not feasible.
c. The proposed mitigation will not alter or increase buffers on adjacent
properties without their permission.
6. The Director may approve permittee-responsible offsite mitigation sites
outside the city upon finding that:
a. Adequate measures have been taken to ensure the non -development
and long-term viability of the mitigation site; and
b. Adequate coordination with the other affected local jurisdiction has
occurred.
c. The applicant has selected a site in a location where the targeted
functions can reasonably be performed and sustained and has pursued sites in the
following order of preference:
(1) Sites within the immediate drainage sub -basin;
(2) Sites within the next higher drainage sub -basin; and
(3) Sites within Green/Duwamish River basin.
7. Wetland creation for restoration projects may only be approved if the
applicant can show: (1) that the adjoining property owners are amenable to having
wetland buffers extend onto or across their property; or (2) that the on -site wetland buffers
are sufficient to protect the functions and values of the wetland and the project as a whole
results in net environmental benefit.
E. MITIGATION TIMING. Mitigation projects shall be completed prior to activities
that will permanently disturb wetlands and either prior to or immediately after activities
that will temporarily disturb wetlands. Construction of mitigation projects shall be timed
to reduce impacts to existing wildlife, flora and water quality, and shall be completed prior
to use or occupancy of the activity or development. The Director may allow activities that
permanently disturb wetlands prior to implementation of the mitigation plan under the
following circumstances:
1. To allow planting or re -vegetation to occur during optimal weather
conditions;
2. To avoid disturbance during critical wildlife periods; or
3. To account for unique site constraints that dictate construction timing or
phasing.
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F. WETLAND MITIGATION PLAN CONTENT.
1. The mitigation plan shall be developed as part of a critical area study by a
qualified professional. Wetland and/or buffer alteration or relocation may be allowed only
when a mitigation plan clearly demonstrates that the changes would be an improvement
of wetland and buffer quantitative and qualitative functions. The plan shall show how
water quality, habitat, and hydrology would be improved.
2. The scope and content of a mitigation plan shall be decided on a case -by -
case basis taking into account the degree of impact and the extent of the mitigation
measures needed. As the impacts to the critical area increase, the mitigation measures
to offset these impacts will increase in number and complexity.
3. For wetlands, the format of the mitigation plan should follow that established
in Wetland Mitigation in Washington State, Part 2 — Developing Mitigation Plans
(Washington Department of Ecology, Corps of Engineers, EPA, March 2006 or as
amended).
4. The components of a complete mitigation plan are as follows:
a. Baseline information of quantitative data collection or a review and
synthesis of existing data for both the project impact zone and the proposed mitigation
site.
b. Environmental goals and objectives that describe the purposes of the
mitigation measures. This should include a description of site selection criteria,
identification of target evaluation species and resource functions.
c. Performance standards of the specific criteria for fulfilling environmental
goals and for beginning remedial action or contingency measures. They may include
water quality standards, species richness and diversity targets, habitat diversity indices,
or other ecological, geological or hydrological criteria.
d. A detailed construction plan of the written specifications and
descriptions of mitigation techniques. This plan should include the proposed construction
sequence, construction management and tree protection and be accompanied by detailed
site diagrams and blueprints that are an integral requirement of any development
proposal.
e. A monitoring and/or evaluation program that outlines the performance
standards and methods for assessing whether those performance standards are
achieved during the specified monitoring period, at least 5 years. At a minimum, the
monitoring plan should address vegetative cover, survival, and species diversity. Any
project that alters the dimensions of a wetland or creates a new wetland shall also monitor
wetland hydrology. An outline shall be included that spells out how the monitoring data
will be evaluated by agencies that are tracking the mitigation project's progress.
f. Contingency plan identifying potential courses of action and any
corrective measures to be taken when monitoring or evaluation indicates project
performance standards have not been met.
g. Performance security or other assurance devices as described in TMC
Section 18.45.210.
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Section 29. TMC Section 18.45.100 is hereby reenacted to read as follows:
18.45.100 Watercourse Designations, Ratings and Buffers
A. WATERCOURSE RATINGS. Watercourse ratings are consistent with the
Washington Department of Natural Resources water typing categories (WAC 222-16-
030) or as amended, which are based on the existing habitat functions and classified as
follows:
1. Type S Watercourse: Watercourses inventoried as Shorelines of the State,
under RCW 90.58. These watercourses shall be regulated under TMC Chapter 18.44,
Shoreline Overlay.
2. Type F Watercourse: Those watercourses that are known to be used by
fish or meet the physical criteria to be potentially used by fish (as established in WAC
222-16-031(3) or as amended) and that have perennial (year-round) or seasonal flows.
3. Type Np Watercourse: Those watercourses that have perennial flows and
do not meet the criteria of a Type F stream or have been proven not to contain fish using
methods described in the Forest Practices Board Manual Section 13.
4. Type Ns Watercourse: Those watercourses that have intermittent flows
(do not have surface flow during at least some portion of the year); do not meet the
physical criteria of a Type F watercourse; or have been proven to not support fish using
methods described in the Forest Practices Board Manual Section 13.
B. WATERCOURSE BUFFERS. Any land alteration must be located out of the
buffer areas as required by this section. Watercourse buffers are intended in general to:
1. Minimize long-term impacts of development on properties containing
watercourses;
2. Protect the watercourse from adverse impacts during development;
3. Preserve the edge of the watercourse and its buffer for its critical habitat
value;
4. Provide shading to maintain stable water temperatures and vegetative cover
for additional wildlife habitat;
5. Provide input of organic debris and uptake of nutrients;
6. Provide an area to stabilize banks, to absorb overflow during high water
events and to allow for slight variation of aquatic system boundaries over time due to
hydrologic or climatic effects;
7. Reduce erosion and increased surface water runoff;
8. Reduce loss of, or damage to, property;
9. Intercept fine sediments from surface water runoff and serve to minimize
water quality impacts; and
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10. Protect the critical area from human and domestic animal disturbance.
An undisturbed and high quality critical area or buffer may substitute for the yard
setback and landscape requirements of TMC Chapter 18.50 and 18.52.
C. WATERCOURSE BUFFER WIDTHS. The following buffer widths, measured
from the Ordinary High Water Mark (OHWM), apply to each side of a watercourse. If the
OHWM cannot be determined, then the buffer will be measured from the top of bank:
Overlay.
1. Type S Watercourse: Regulated under TMC Chapter 18.44, Shoreline
2. Type F Watercourse: 100-foot-wide buffer.
3. Type Np Watercourse: Standard 80-foot-wide buffer; alternate buffer in the
50-65 range allowed with buffer enhancement.
4. Type Ns Watercourse: 50-foot-wide buffer.
D. BUFFER SETBACKS.
1. All commercial and industrial buildings shall be set back 15 feet and all other
development shall be set back 10 feet. Building setbacks shall be measured from the
foundation to the buffer's edge. Building plans shall also identify a 20-foot area beyond
the buffer setback within which the impacts of development will be reviewed.
2. The Director may waive setback requirements when a site plan
demonstrates there will be no impacts to the buffer from construction or occasional
maintenance activities.
E. VARIATION OF STANDARD WATERCOURSE BUFFER WIDTH.
1. Buffer averaging may be allowed by the Director as a Type 2 decision if the
total area of the buffer after averaging is equal to the area required without averaging and
the buffer at its narrowest point is never less than either 3/4 of the required width; and the
following criteria is met:
a. The watercourse has significant differences in characteristics that affect
its habitat functions, and the buffer is increased adjacent to the higher -functioning area of
habitat or more -sensitive portion of the watercourse and decreased adjacent to the lower -
functioning or less -sensitive portion as demonstrated by a critical areas report from a
qualified professional.
b. There are no feasible alternatives to the site design that could be
accomplished without buffer averaging, and the averaged buffer will not result in
degradation of the watercourse's functions and values as demonstrated by a critical areas
report.
c. Compliance with mitigation sequencing requirements (TMC Section
18.45.075).
d. Compliance with TMC Chapter 18.45.158, "Vegetation Protection and
Management."
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e. Submittal of buffer enhancement plan, mitigation monitoring and
maintenance plan, along with financial guarantee in accordance with this chapter.
Buffer averaging shall not adversely affect water quality.
g. No adverse affect to water temperature or shade potential will occur to
the watercourse using methodology per 2011 Washington State Department of Ecology's
Green River Temperature Total Maximum Daily Load (TMDL) assessment or as
amended.
2. Interrupted Buffer. Waiver for interrupted buffer may be allowed by the
Director as a Type 2 permit if it complies with the following:
a. The buffer is interrupted by a paved public or private road; legally
constructed buildings or parking lots. This waiver does not apply to accessory structures
such as sheds and garages;
b. The existing legal improvement creates a substantial barrier to the buffer
function;
c. The interrupted buffer does not provide additional protection of the
critical area from the proposed development; and
d. The interrupted buffer does not provide significant hydrological, water
quality and wildlife functions. This waiver does not apply if large trees or other significant
native vegetation exists.
e. Enhancement of remaining buffer is required if feasible.
3. Buffers for all types of watercourses will be increased when they are
determined to be particularly sensitive to disturbance or the proposed development will
create unusually adverse impacts. Any increase in the width of the buffer shall be required
only after completion of a watercourse study by a qualified professional or expert that
documents the basis for such increased width. An increase in buffer width may be
appropriate when:
a. The development proposal has the demonstrated potential for significant
adverse impacts upon the watercourse that can be mitigated by an increased buffer width;
or
b. The area serves as habitat for endangered, threatened, sensitive or
monitor species listed by the federal government or the State.
Section 30. TMC Section 18.45.110 is hereby reenacted to read as follows:
18.45.110 Watercourse Alterations and Mitigation
A. WATERCOURSE ALTERATIONS. No use or development may occur in a
watercourse or its buffer except as specifically allowed by this chapter. Any use or
development allowed is subject to the standards of this chapter.
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B. ALTERATIONS. Daylighting and meandering of watercourses is encouraged.
Culvert replacement is required where applicable, and upgrades are required to meet
State standards. Piping, dredging, diverting or rerouting is discouraged. Culverts are
piped segments of streams that flow under a road, trail or driveway. Daylighting of a
stream refers to taking a stream out of a pipe that is flowing underground, but not
necessarily under a road. All watercourse alterations shall be carried out as specified by
the State Department of Fish and Wildlife in accordance with an approved Hydraulic
Project Approval (HPA).
1. The City encourages daylighting of a watercourse that is located in a pipe or
meandering of a previously altered watercourse to restore the stream to a more natural
and open condition. As an incentive for daylighting, the Director may approve reduced
buffers or setbacks. Daylighting or meandering of a watercourse is only permitted if the
following criteria are met:
a. The values and functions of the watercourse are improved, including
reducing stream flow during storm and flood events, and providing fish and wildlife habitat.
b. No adverse impact to fish are expected to occur.
c. Water quality is equal or better than existing condition.
d. Hydraulic capacity is maintained within the new channel.
e. The watercourse design complies with the Washington Department of
Fish and Wildlife Water Crossing Design Guidelines Manual 2013 as it now reads and
hereafter updated or amended.
2. On properties with culverts that are being developed or re -developed, or
when stream crossings in public or private rights -of -way are being replaced, existing
culverts that carry fish -bearing watercourses or those that could bear fish (based on the
criteria in WAC 222-16-031, Washington Forest Practices Rules and Regulations) shall
be upgraded to meet the standards in the Washington Department of Fish and Wildlife
Water Crossing Design Guidelines Manual 2013, or as amended, if technically feasible.
Any culvert replacement shall comply with the following criteria:
a. The values and functions of the watercourse are improved including
reducing stream flow during storm and flood events, and providing fish and wildlife habitat.
b. No adverse impact to fish are expected to occur.
c. Water quality is equal or better than existing condition.
d. Hydraulic capacity is maintained within the new channel.
e. The watercourse design complies with the Washington Department of
Fish and Wildlife Water Crossing Design Guidelines manual 2013 as it now reads and
hereafter updated or amended.
3. Piping, dredging, diverting or rerouting of any watercourse shall be avoided,
if possible. Relocation of a watercourse or installation of a bridge is preferred to piping. If
piping occurs in a watercourse, it shall be limited to the degree necessary for stream
crossings for access. Additionally, these alterations may only occur with the permission
of the Director as a Type 2 decision and subject to mitigation sequencing and an approved
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mitigation plan, and shall meet the following criteria:
a. The watercourse alteration shall comply with the standards in current
use and the standards of the Washington Department of Fish and Wildlife Water Crossing
Design Guidelines Manual 2013 or as amended.
b. The watercourse alteration shall not cause adverse impacts to fish,
confine the channel or floodplain, or adversely affect riparian habitat (including
downstream habitat).
c. Maintenance dredging of watercourses shall be allowed only when
necessary to protect public safety, structures and fish passage and shall be done as
infrequently as possible. Long-term solutions such as stormwater retrofits are preferred
over ongoing maintenance dredging.
d. Stormwater runoff shall be detained and infiltrated to preserve the
existing hydrology of the watercourse.
e. All construction shall be designed to have the least adverse impact on
the watercourse, buffer and surrounding environment. Construction shall minimize
sedimentation through implementation of best management practices for erosion control.
f. As a condition of approval, the Director may require water quality
monitoring for stormwater discharges to streams, and additional treatment of stormwater
if water quality standards are not being met.
g. Where allowed, piping shall be limited to the shortest length possible as
determined by the Director to allow access onto a property.
h. Where water is piped for an access point, those driveways or entrances
shall be consolidated to serve multiple properties where possible, and to minimize the
length of piping.
i. Piping shall not create an entry point for road runoff, create downstream
scour, or cause erosion or sedimentation.
j. Water quality must be as good or better for any water exiting the pipe as
for the water entering the pipe, and flow must be comparable.
C. MITIGATION STANDARDS.
1. The following shall be considered the minimum standards for approved
mitigation projects:
a. Maintenance or improvement of stream channel habitat and dimensions
such that the fisheries habitat functions of the compensatory stream meet or exceed that
of the original stream;
b. Bank and buffer configuration restored to an enhanced state;
c. Channel, bank and buffer areas replanted with native vegetation that
improves upon the original condition in species diversity and density;
d. Stream channel bed and biofiltration systems equivalent to or better than
in the original stream;
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e. Original fish and wildlife habitat enhanced unless technically not
feasible; and
f. If onsite mitigation is not possible and to ensure there is no net loss of
watercourse functions including, but not limited to, shading, the applicants may pay into
an in -lieu fund, if available, to ensure that projects are fully mitigated.
2. Relocation of a watercourse shall not result in the new critical area or buffer
extending beyond the development site and onto adjacent property without the written
agreement of the affected property owners.
D. MITIGATION TIMING. Department of Community Development -approved plans
are Type 2 decisions and must have the mitigation construction completed before the
existing watercourse can be modified. The Director may allow activities that permanently
disturb a watercourse prior to implementation of the mitigation plan under the following
circumstances:
1. To allow planting or re -vegetation to occur during optimal weather
conditions; or
2. To avoid disturbance during critical wildlife periods; or
3. To account for unique site constraints that dictate construction timing or
phasing.
E. MITIGATION PLAN CONTENT. All impacts to a watercourse that degrade the
functions of the watercourse or its buffer shall be avoided. If alteration to the watercourse
or buffer is unavoidable, all adverse impacts resulting from a development proposal or
alteration shall be mitigated in accordance with an approved mitigation plan as described
below.
1. Mitigation plans shall be completed for any proposals of dredging, filling,
diverting, piping and rerouting of watercourses or buffer impacts and shall be developed
as part of a critical area study by a qualified professional. The plan must show how water
quality, treatment, erosion control, pollution reduction, wildlife and fish habitat, and
general watercourse quality would be improved.
2. The scope and content of a mitigation plan shall be decided on a case -by -
case basis taking into account the degree of impact and extent of mitigation measures
needed. As the impacts to the watercourse or its buffer increase, the mitigation plan to
offset these impacts will increase in extent and complexity.
3. The components of a complete mitigation plan are as follows:
a. Baseline information including existing watercourse conditions such as
hydrologic patterns/flow rates, stream gradient, bank full width, stream bed conditions,
bank conditions, fish and other wildlife use, in -stream structures, riparian conditions,
buffer characteristics, water quality, fish barriers and other relevant information.
b. Environmental goals and objectives that describe the purposes of the
mitigation measures. This should include a description of site selection criteria,
identification of target evaluation species and functions.
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c. Performance standards for fulfilling environmental goals and objectives
and for triggering remedial action or contingency measures. Performance standards may
include water quality standards, species richness and diversity targets, habitat diversity
indices, creation of fish habitat, or other ecological, geological or hydrological criteria.
d. Detailed construction plan of the written specifications and descriptions
of mitigation techniques. This plan should include the proposed construction sequence
and construction management, and be accompanied by detailed site diagrams and
blueprints that are an integral requirement of any development proposal.
e. Monitoring and/or evaluation program that outlines the approach for
assessing a completed project. At least five years of monitoring is required. An outline
shall be included that spells out how the monitoring data will be evaluated by agencies
that are tracking the mitigation project's process. For projects that discharge stormwater
to a stream, the Director may require water quality monitoring.
f. Contingency plan identifi
corrective measures to be taken when
performance standards have not been met.
,ing potential courses of action and any
monitoring or evaluation indicates project
g. Performance security or other assurance devices as described in TMC
Section 18.45.210.
Section 31. TMC Section 18.45.120 is hereby reenacted to read as follows:
18.45.120 Areas of Potential Geologic Instability Designations, Ratings and Buffers
A. DESIGNATION. Potential areas of geologic instability include areas of potential
erosion and landslide hazards. Areas of potential geologic instability are classified as
follows:
Class 1 areas, which have a slope of less than 15%;
2. Class 2 areas, which have a slope between 15% and 40%, and which are
underlain by relatively permeable soils;
3. Class 3 areas, which include areas sloping between 15% and 40%, and
which are underlain by relatively impermeable soils or by bedrock, and which also include
all areas sloping more steeply than 40%;
4. Class 4 areas, which include sloping areas with mappable zones of
groundwater seepage, and which also include existing mappable landslide deposits
regardless of slope.
1. The approximate location, extent, and designation of areas of potential
geologic instability are depicted in the City's Critical Areas Map. Actual boundaries and
designations shall be determined by a qualified professional on a site -specific basis.
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2. In addition to the City's Critical Areas Map, the following publicly available
mapping information may be used to determine appropriate designations:
a. For historic landslides, areas designated as quaternary slumps,
earthflows, mudflows, or landslides on maps published by the U.S. Geological Survey or
the WDNR Division of Geology and Earth Resources,
b. For potential or historic landslides, those areas mapped by the WDNR
(slope stability mapping) as unstable (U or Class 3), unstable old slides (UOS or Class
4), or unstable recent slides (URS or Class 5);
c. For soil characteristics, the U.S. Department of Agriculture's Natural
Resources Conservation Service (NRCS) Official Soil Survey Data; and
d. For general instability, those areas mapped by the NRCS as having a
significant limitation for building site development.
C. BUFFERS. The buffers for areas of potential geologic instability are intended to:
areas;
Minimize long-term impacts of development on properties containing critical
2. Protect critical areas from adverse impacts during development;
3. Prevent loading of potentially unstable slope formations;
4. Protect slope stability;
5. Provide erosion control and attenuation of precipitation surface water and
stormwater runoff; and
6. Reduce loss of or damage to property.
D. Each development proposal containing or threatened by an area of potential
geologic instability Class 2 or higher shall be subject to a geotechnical report pursuant to
the requirements of TMC Chapter 18.45.040.C. The geotechnical report shall analyze and
make recommendations on the need for and width of any setbacks or buffers necessary
to achieve the goals and requirements of this chapter. Development proposals shall then
include the buffer distances as defined within the geotechnical report.
Section 32. TMC Section 18.45.130 is hereby reenacted to read as follows:
18.45.130 Areas of Potential Geologic Instability Uses, Exemptions, Alterations
and Mitigation
A. GENERAL. The uses permitted in the underlying zoning district may be
undertaken on sites that contain areas of potential geologic instability subject to the
standards of this section and the recommendations of a geotechnical study.
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B. EXEMPTIONS. The following areas are exempt from regulation as geologically
hazardous areas:
1. Temporary stockpiles of topsoil, gravel, beauty bark or other similar
landscaping or construction materials;
pad;
2. Slopes related to materials used as an engineered pre -load for a building
3. Roadway embankments within right-of-way or road easements; and
4. Slopes retained by approved engineered structures.
C. ALTERATIONS.
1. Prior to permitting alteration of an area of potential geologic instability, the
applicant must demonstrate one of the following:
a. There is no evidence of past instability or earth movement in the vicinity
of the proposed development, and, where appropriate, quantitative analysis of slope
stability indicates no significant risk to the proposed development or surrounding
properties; or
b. The area of potential geologic instability can be modified or the project
can be designed so that any potential impact to the project and surrounding properties is
eliminated, slope stability is not decreased, and the increase in surface water discharge
or sedimentation shall not decrease slope stability.
2. Where any portion of an area of potential geologic instability is cleared for
development, a landscaping plan for the site shall include replanting of preferably native
trees (an equal mix of evergreen and deciduous), shrubs and groundcover. The
landscaping plan must be approved by the Director. Replacement vegetation shall be
sufficient to provide erosion and stabilization protection.
3. Critical facilities shall not be sited within or below an area of potential
geologic instability unless there is no practical alternative (demonstrated by the applicant).
4. Land disturbing activities in an area of potential geologic instability shall
provide for storm water quality and quantity control, including preparation of a TESC and
permanent drainage plan prepared by a professional engineer licensed in Washington.
5. Unless otherwise provided or as part of an approved alteration, removal of
vegetation from an area of potential geologic instability or its buffer shall be prohibited.
When permitted as part of an approved alteration, vegetation removal shall be minimized
to the extent practicable.
6. Surface drainage, including downspouts, shall not be directed across the
face of an area of potential geologic instability; if drainage must be discharged from the
top of a hazard to its toe, it shall be collected above the top and directed to the toe by
tight line drain, and provided with an energy dissipative device at the toe for discharge to
a swale or other acceptable natural drainage areas.
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7. Structures and improvements shall minimize alterations to the natural
contour of the slope, and foundations shall be tiered where possible to conform to existing
topography (minimize grading/cut and fill to amount necessary).
8. The proposed development shall not result in greater risk or a need for
increased buffers on neighboring properties.
D. DISCLOSURES, DECLARATIONS AND COVENANTS.
1. It shall be the responsibility of the applicant to submit, consistent with the
findings of the geotechnical report, structural plans that were prepared and stamped by a
structural engineer. The plans and specifications shall be accompanied by a letter from
the geotechnical engineer who prepared the geotechnical report stating that in his/her
judgment the plans and specifications conform to the recommendations in the
geotechnical report, the risk of damage to the proposed development site from soil
instability will be minimal subject to the conditions set forth in the report, and the proposed
development will not increase the potential for soil movement.
2. Further recommendations signed and sealed by the geotechnical engineer
shall be provided should there be additions or exceptions to the original recommendations
based on the plans, site conditions or other supporting data. If the geotechnical engineer
who reviews the plans and specifications is not the same engineer who prepared the
geotechnical report, the new engineer shall, in a letter to the City accompanying the plans
and specifications, express his or her agreement or disagreement with the
recommendations in the geotechnical report and state that the plans and specifications
conform to his or her recommendations.
3. The architect or structural engineer shall submit to the City, with the plans
and specifications, a letter or notation on the design drawings at the time of permit
application stating that he or she has reviewed the geotechnical report, understands its
recommendations, has explained or has had explained to the owner the risks of loss due
to slides on the site, and has incorporated into the design the recommendations of the
report and established measures to reduce the potential risk of injury or damage that
might be caused by any earth movement predicted in the report.
4. The owner shall execute a Critical Areas Covenant and Hold Harmless
Agreement running with the land on a form provided by the City. The City will file the
completed covenant with the King County Department of Records and Licensing Services
at the expense of the applicant or owner. A copy of the recorded covenant will be
forwarded to the owner.
E. ASSURANCE DEVICES. Whenever the City determines that the public interest
would not be served by the issuance of a permit in an area of potential geologic instability
without assurance of a means of providing for restoration of areas disturbed by, and repair
of property damage caused by, slides arising out of or occurring during construction, the
Director may require assurance devices pursuant to TMC Section 18.45.210.
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F. CONSTRUCTION MONITORING.
1. Where recommended by the geotechnical report, the applicant shall retain a
geotechnical engineer to monitor the site during construction. The applicant shall
preferably retain the geotechnical engineer who prepared the final geotechnical
recommendations and reviewed the plans and specifications. If a different geotechnical
engineer is retained by the owner, the new geotechnical engineer shall submit a letter to
the City stating whether or not he/she agrees with the opinions and recommendations of
the original geotechnical engineer. Further recommendations, signed and sealed by the
geotechnical engineer, and supporting data shall be provided should there be exceptions
to the original recommendations.
2. The geotechnical engineer shall monitor, during construction, compliance
with the recommendations in the geotechnical report, particularly site excavation, shoring,
soil support for foundations including piles, subdrainage installations, soil compaction and
any other geotechnical aspects of the construction. Unless otherwise approved by the
City, the specific recommendations contained in the soils report must be implemented by
the owner. The geotechnical engineer shall make written, dated monitoring reports on the
progress of the construction to the City at such timely intervals as shall be specified.
Omissions or deviations from the approved plans and specifications shall be
immediately reported to the City. The final construction monitoring report shall contain a
statement from the geotechnical engineer that based upon his or her professional opinion,
site observations and testing during the monitoring of the construction, the completed
development substantially complies with the recommendations in the geotechnical report
and with all geotechnical-related permit requirements. Occupancy of the project will not
be approved until the report has been reviewed and accepted by the Director.
G. CONDITIONING AND DENIAL OF USE OR DEVELOPMENTS.
1. Substantial weight shall be given to ensuring continued slope stability and
the resulting public health, safety and welfare in determining whether a development
should be allowed.
2. The City may impose conditions that address site -work problems which
could include, but are not limited to, limiting all excavation and drainage installation to the
dryer season, or sequencing activities such as installing erosion control and drainage
systems well in advance of construction. A permit will be denied if it is determined by the
Director that the development will increase the potential of soil movement that results in
an unacceptable risk of damage to the proposed development, its site or adjacent
properties.
Section 33. TMC Section 18.45.140 is hereby reenacted to read as follows:
18.45.140 Coal Mine Hazard Areas
A. Development of a site containing an abandoned mine area may be permitted
when a geotechnical report shows that significant risks associated with the abandoned
mine workings can be eliminated or mitigated so that the site is safe. Approval shall be
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obtained from the Director before any building or land -altering permit processes begin.
B. Any building setback or land alteration shall be based on the geotechnical report.
C. The City may impose conditions that address site -work problems which could
include, but are not limited to, limiting all excavation and drainage installation to the dryer
season, or sequencing activities such as installing drainage systems or erosion controls
well in advance of construction. A permit will be denied if it is determined that the
development will increase the potential of soil movement or result in an unacceptable risk
of damage to the proposed development or adjacent properties.
D. The owner shall execute a Critical Areas Covenant and Hold Harmless
Agreement running with the land on a form provided by the City. The City will file the
completed covenant with the King County Division of Records and Licensing Services at
the expense of the applicant or owner. A copy of the recorded covenant will be forwarded
to the owner.
Section 34. TMC Section 18.45.150 is hereby reenacted to read as follows:
18.45.150 Fish and Wildlife Habitat Conservation Areas Designation, Mapping,
Uses and Standards
A. DESIGNATION.
1. Fish and wildlife habitat conservation areas include the habitats listed below:
a. Areas with which endangered, threatened, and sensitive species have a
primary association;
b. Habitats and species of local importance, including but not limited to bald
eagle habitat, heron rookeries, mudflats and marshes, and areas critical for habitat
connectivity;
c. Naturally occurring ponds under 20 acres and their submerged aquatic
beds that provide fish or wildlife habitat;
d. Waters of the State;
e. State natural area preserves and natural resource conservation areas;
and
f. Lakes, ponds, streams, and rivers planted with game fish by a
governmental or tribal entity.
2. Type S watercourses, including the Green/Duwamish River, are regulated
under TMC Chapter 18.44 and not under this chapter.
3. Wetlands and watercourses are addressed under TMC Sections 18.45.080,
18.45.090, 18.45.100 and 18.45.110, and not under this section.
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1. The approximate location and extent of known fish and wildlife habitat
conservation areas are identified by the City's Critical Areas Maps, inventories, open
space zones, and Natural Environment Background Report.
2. In addition to the Critical Areas Maps, the following maps are to be used as
a guide for the City, but do not provide a final habitat area designation:
a. Washington State Department of Fish and Wildlife Priority Habitat and
Species Maps;
b. Anadromous and resident salmonid distribution maps contained in the
Habitat Limiting Factors report for the Green/Duwamish and Central Puget Sound
Watersheds published by King County and the Washington Conservation Commission;
and
c. NOAA Digital Coast for Washington State.
C. BUFFERS.
1. Each development proposal on, adjacent to, or with the potential to impact a
Fish and Wildlife Habitat Conservation Area other than wetlands and watercourses shall
be subject to a habitat assessment report pursuant to the requirements of TMC Sections
18.45.040.B. The habitat assessment shall analyze and make recommendations on the
need for and width of any setbacks or buffers necessary to achieve the goals and
requirements of this chapter, with specific consideration of Priority Habitats and Species
Management Recommendations from the Washington Department of Fish and Wildlife.
Recommended buffers shall be no less than 100 feet in width.
2. Buffers may be increased by the Director when an area is determined to be
particularly sensitive to the disturbance created by a development. Such a decision will
be based on a City review of the report as prepared by a qualified biologist and by a site
visit.
D. USES AND STANDARDS. Each development proposal on, adjacent, or
with the potential to impact a Fish and Wildlife Habitat Conservation Area that is not fully
addressed under TMC Sections 18.45.080, 18.45.090, 18.45.100 and 18.45.110 shall be
subject to a habitat assessment report pursuant to the requirements of TMC Sections
18.45.040.B. The habitat assessment shall analyze potential impacts to Fish and Wildlife
Habitat Conservation Areas and make recommendations to minimize such impacts, with
specific consideration of Priority Habitats and Species Management Recommendations
from the Washington Department of Fish and Wildlife.
Section 35. Regulations Established. TMC Section 18.45.155, "Special Hazard
Flood Areas," is hereby established to read as follows:
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18.45.155 Special Hazard Flood Areas
A. Regulations governing Special Hazard Flood Areas are found in TMC Chapter
16.52, "Flood Plain Management," and TMC Section 18.45.155.13.
B. Floodplain Habitat Assessment.
1. When development is proposed within a Special Hazard Flood area, a
floodplain habitat assessment shall be prepared pursuant to the requirements of TMC
Sections 18.45.040.13.
2. The floodplain habitat assessment shall address the effects of the
development on federally listed salmon, including, but not limited to the following:
a. Impervious surfaces,
b. Floodplain storage and conveyance,
c. Floodplain and riparian vegetation, and
d. Stormwater drainage.
3. If the floodplain habitat assessment concludes that the project is expected
to have an adverse effect on listed species as evaluated under the guidance issued for
ESA compliance under the National Flood Insurance Program in Puget Sound, the
applicant shall mitigate those impacts. Such mitigation shall be consistent with, or in
addition to, any mitigation required by this chapter and shall be incorporated into the
approved project plans.
4. Activities Exempt from Floodplain Habitat Assessment. A floodplain
habitat assessment is not required under the following circumstances:
a. Projects that are undergoing or have undergone consultation with the
National Marine Fisheries Service under the Endangered Species Act.
b. Repair or remodeling of an existing structure, if the repair or remodeling
is not a substantial improvement.
c. Expansion of an existing structure that is no greater than 10 percent
beyond its existing footprint; provided that the repairs or remodeling are not a substantial
improvement, or a repair of substantial damage. This measurement is counted
cumulatively from September 22, 2011. If the structure is in the floodway, there shall be
no change in the dimensions perpendicular to flow.
d. Activities with the sole purpose of creating, restoring, or enhancing
natural functions provided the activities do not include construction of structures, grading,
fill, or impervious surfaces.
e. Development of open space and recreational facilities, such as parks
and trails, that do not include structures, fill, impervious surfaces or removal of more than
5 percent of the native vegetation on that portion of the property in the regulatory
floodplain.
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f. Repair to on -site septic systems provided the ground disturbance is the
minimum necessary.
g. Other minor activities considered to have no effect on listed species, as
interpreted using ESA guidance issued by the National Flood Insurance Program in Puget
Sound and confirmed through City review of the development proposal.
Section 36. Regulations Established. TMC Section 18.45.158, "Vegetation
Protection and Management," is hereby established to read as follows:
18.45.158 Vegetation Protection and Management
A. Purpose. The purpose of this section is to:
1. Regulate the protection of existing trees and native vegetation in the critical
areas and their buffers;
2. Establish requirements for removal of invasive plants at the time of
development or re -development of sites;
3. Establish requirements for the long-term maintenance of native vegetation
to prevent establishment of invasive species and promote ecosystem processes.
B. Applicability. This chapter sets forth rules and regulations to control
maintenance and clearing of trees within the City of Tukwila for properties located within
a critical area or its associated buffer. For properties located within the Shoreline
jurisdiction, the maintenance and removal of vegetation shall be governed by TMC
Chapter 18.44, "Shoreline Overlay." TMC Chapter 18.54, "Urban Forestry and Tree
Regulations," shall govern tree removal on any undeveloped land and any land zoned
Low Density Residential (LDR) that is developed with a single-family residence. TMC
Chapter 18.52, "Landscape Requirements," shall govern the maintenance and removal
of landscaping on developed properties zoned commercial, industrial, or multifamily, and
on properties located in the LDR zone that are developed with a non -single family
residential use. The most stringent regulations shall apply in case of a conflict.
C. Vegetation Retention and Replacement.
Retention.
a. Native vegetation in critical areas and their buffers must be protected
and maintained. No removal of native vegetation is allowed without prior approval by the
City except in cases of emergency where an imminent hazard to public life, safety or
property exists. Vegetation may be removed from the buffer as part of an enhancement
plan approved by the Director. Enhancements will ensure that slope stability and wetland
quality will be maintained or improved. Any temporary disturbance of the buffers shall be
replanted with a diverse plant community of native northwest species.
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b. Invasive vegetation (blackberry, ivy, laurel, etc.) may be removed from
a critical area or its buffer except steep slopes without a permit if removal does not utilize
heavy equipment. The use of herbicide by a licensed contractor with certifications as
needed from the Washington Department of Ecology and the Washington Department of
Agriculture is permitted but requires notification prior to application to the City and shall
comply with TMC Section 18.45.158.E.3. Invasive vegetation removal on steep slopes
requires prior City approval.
c. Hazardous or defective trees, as defined in TMC Chapter 18.06, may be
removed from a critical area if threat posed by the tree is imminent. If the hazard is not
obvious, an assessment by a certified professional, as defined in Chapter TMC 18.06,
may be required by the Director. Dead and hazardous trees should remain standing or
be cut and placed within the critical area to the extent practicable to maximize habitat.
Tree replacement in accordance with this chapter is required for any hazardous tree
removed from a critical area.
d. In the case of development or re -development, as many significant trees
and as much native vegetation as possible are to be retained on a site, taking into
account the condition and age of the trees. As part of a land use application including,
but not limited to, subdivision or short plat, design review or building permit review, the
Director of Community Development or the Board of Architectural Review may require
alterations in the arrangement of buildings, parking or other elements of proposed
development in order to retain significant vegetation.
2. Permit Requirements. Prior to any tree removal or site clearing, unless it
is part of Special Permission approval for interrupted buffer, buffer averaging or other
critical areas deviation, a Type 2 Critical Area Tree Removal and Vegetation Clearing
Permit application must be submitted to the Department of Community Development
(DCD) containing the following information:
a. A vegetation survey on a site plan that shows the diameter, species and
location of all significant trees and all existing native vegetation.
b. A site plan that shows trees and native vegetation to be retained and
trees to be removed and provides a table showing the number of significant trees to be
removed and the number of replacement trees required.
c. Tree protection zones and other measures to protect any trees or native
vegetation that are to be retained for sites undergoing development or re -development.
d. Location of the OHWM, stream buffer, wetland, wetland buffer, steep
slope or any other critical areas with their buffers.
e. A landscape plan that shows diameter, species name, spacing and
planting location for any required replacement trees and other proposed vegetation.
f. An arborist evaluation justifying the removal of hazardous trees if
required by DCD.
g. An application fee in accordance with the Consolidated Permit Fee
Schedule adopted by resolution of the City Council.
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3. Criteria for Tree Removal in a Critical Area or its Buffer. A Type 2 Critical
Area Tree Removal and Vegetation Clearing Permit shall only be approved if the proposal
complies with the following criteria as applicable:
a. The site is undergoing development or redevelopment.
b. Tree poses a risk to structures.
c. There is imminent potential for root or canopy interference with utilities.
d. Tree interferes with the access and passage on public trails.
e. Tree condition and health is poor; the City may require an evaluation by
an International Society of Arborists (ISA) certified arborist.
f. Trees present an imminent hazard to the public. If the hazard is not
readily apparent, the City may require an evaluation by an International Society of
Arborists (ISA) certified arborist.
g. The proposal complies with tree retention, replacement, maintenance
and monitoring requirements of this chapter.
4. Tree Replacement Requirements. Where permitted, significant trees that
are removed, illegally topped, or pruned by more than 25% within a critical area shall be
replaced pursuant to the Tree Replacement Requirements Table (below), up to a density
of 100 trees per acre (including existing trees). Significant trees that are part of an
approved landscape plan on the developed portion of the site are subject to replacement
per TMC Chapter 18.52. Dead or dying trees removed that are part of an approved
landscape plan on the developed portion of the site shall be replaced at a 1:1 ratio in the
next appropriate planting season. Dead or dying trees located within the critical area or
its buffer shall be left in place as wildlife snags, unless they present a hazard to structures,
facilities or the public. Removal of dead, dying or otherwise hazardous trees in non -
developed areas are subject to the replacement requirements listed in the "Tree
Replacement Requirements" Table below. The Director may require additional trees or
shrubs to be installed to mitigate any potential impact from the loss of this vegetation as
a result of new development.
Table 18.45.158-1 — Tree Replacement Requirements
Diameter* of Tree Removed
(*measured at height of 4.5 feet
from the ground)
Number of Replacement
Trees Required
4 - 6 inches (single trunk);
2 inches (any trunk of a multi -trunk tree)
3
Over 6 - 8 inches
4
Over 8 - 20 inches
6
Over 20 inches
8
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5. If all required replacement trees cannot be reasonably accommodated on
the site, the applicant shall pay into a tree replacement fund in accordance with the
Consolidated Permit Fee Schedule adopted by resolution of the City Council.
6. Topping of trees is prohibited and will be regulated as removal subject to the
Tree Replacement Requirements Table listed above.
7. Pruning of trees shall not exceed 25% of canopy in a 36-month period.
Pruning in excess of 25% canopy shall be regulated as removal with tree replacement
required per the Tree Replacement Requirements Table listed above. Trees may only
be pruned to lower their height to prevent interference with an overhead utility line with
prior approval by the Director as part of Type 2 Critical Area Tree Permit. The pruning
must be carried out under the direction of a Qualified Tree Professional or performed by
the utility provider under the direction of a Qualified Tree Professional. The crown shall
be maintained to at least 2/3 the height of the tree prior to pruning.
D. Tree Protection.
All trees not proposed for removal as part of a project or development shall be
protected using Best Management Practices and the standards below.
1. The Critical Root Zones (CRZ) for all trees designated for retention, on site
or on adjacent property as applicable, shall be identified on all construction plans,
including demolition, grading, civil and landscape site plans.
2. Any roots within the CRZ exposed during construction shall be covered
immediately and kept moist with appropriate materials. The City may require a third -party
Qualified Tree Professional to review long-term viability of the tree.
3. Physical barriers, such as 6-foot chain link fence or plywood
or other approved equivalent, shall be placed around each individual tree or grouping at
the CRZ.
4. Minimum distances from the trunk for the physical barriers shall be based on
the approximate age of the tree (height and canopy) as follows:
a. Young trees (trees which have reached less than 20% of life
expectancy): 0.75 per inch of trunk diameter.
b. Mature trees (trees which have reached 20-80% of life expectancy):
1 foot per inch of trunk diameter.
c. Over mature trees (trees which have reached greater than 80% of life
expectancy): 1.5 feet per inch of trunk diameter.
5. Alternative protection methods may be used that provide equal or greater
tree protection if approved by the Director.
6. A weatherproof sign shall be installed on the fence or barrier that reads:
"TREE PROTECTION ZONE — THIS FENCE SHALL NOT BE REMOVED
OR ENCROACHED UPON. No soil disturbance, parking, storage, dumping
or burning of materials is allowed within the Critical Root Zone. The value of
this tree is $ [insert value of tree as determined by a Qualified Tree
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Professional here]. Damage to this tree due to construction activity that
results in the death or necessary removal of the tree is subject to the
Violations section of TMC Chapter 18.45."
7. All tree protection measures installed shall be inspected by the City and, if
deemed necessary a Qualified Tree Professional, prior to beginning construction or earth
moving.
8. Any branches or limbs that are outside of the CRZ and might be damaged
by machinery shall be pruned prior to construction by a Qualified Tree Professional.
9. The CRZ shall be covered with 4 to 6 inches of wood chip mulch. Mulch shall
not be placed directly against the trunk. A 6-inch area around the trunk shall be free of
mulch. Additional measures, such as fertilization or supplemental water, shall be carried
out prior to the start of construction if deemed necessary by the Qualified Tree
Professional's report to prepare the trees for the stress of construction activities.
10. No storage of equipment or refuse, parking of vehicles, dumping of materials
or chemicals, or placement of permanent heavy structures or items shall occur within the
CRZ.
11. No grade changes or soil disturbance, including trenching, shall be allowed
within the CRZ. Grade changes within 10 feet of the CRZ shall be approved by the City
prior to implementation.
12. The applicant is responsible for ensuring that the CRZ of trees on adjacent
properties are not impacted by the proposed development.
13. A pre -construction inspection shall be conducted by the City to finalize tree
protection actions.
14. Post -construction inspection of protected trees shall be conducted by the
City and, if deemed necessary by the City, a Qualified Tree Professional. All corrective or
reparative pruning will be conducted by a Qualified Tree Professional.
E. Plant Materials Standards.
For any new development, redevelopment or restoration in a Critical Area, invasive
vegetation must be removed, and native vegetation planted and maintained in the Critical
Area and its buffer.
1. A planting plan prepared by a qualified biologist shall be submitted to the
City for approval that shows plant species, size, number, spacing, soil preparation
irrigation, and invasive species removal. The requirement for a biologist may be waived
by the Director for single family property owners when the mitigation area is less than
1,500 square feet.
2. Invasive vegetation must be removed as part of site preparation and native
vegetation planted in the Critical Area and its buffer where impacts occur.
3. Removal of invasive species shall be done by hand or with hand-held power
tools. The use of herbicide by a licensed contractor with certifications as needed from the
Washington Department of Ecology and the Washington Department of Agriculture is
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permitted but requires notification prior to application to the City and shall comply with this
TMC Section 18.45.158.E.3. Where removal is not feasible by hand or with hand-held
power tools and mechanized equipment is needed, the applicant must obtain a Type 2
permit prior to work being conducted. Removal of invasive vegetation must be conducted
so that the slope stability, if applicable, will be maintained and native vegetation is
protected. A plan must be submitted indicating how the work will be done and what
erosion control and tree protection features will be utilized. Federal and State permits may
be required for vegetation removal with mechanized equipment.
4. Removal of invasive vegetation may be phased over several years prior to
planting, if such phasing is provided for by a plan approved by the Director to allow for
alternative approaches, such as sheet mulching and goat grazing. The method selected
shall not destabilize the bank or cause erosion.
5. A combination of native trees, shrubs and groundcovers (including but not
limited to grasses, sedges, rushes and vines) shall be planted. Site conditions, such as
topography, exposure, and hydrology shall be taken into account for plant selection. Other
species may be approved if there is adequate justification.
6. Non-native trees may be used as street trees in cases where conditions are
not appropriate for native trees (for example where there are space or height limitations
or conflicts with utilities).
7. Plants shall meet the current American Standard for Nursery Stock
(American Nursery and Landscape Association — ANLA).
8. Smaller plant sizes (generally one gallon, bareroot, plugs, or stakes,
depending on plant species) are preferred for buffer plantings. Willow stakes must be at
least 1/2-inch in diameter. For existing developed areas refer to TMC Chapter 18.52,
"Landscape Requirements," for plant sizes in required landscape areas.
9. Site preparation and planting of vegetation shall be in accordance with Best
Management Practices for ensuring the vegetation's long-term health and survival.
Irrigation is required for all plantings for the first three years as approved by the Director.
10. Plants may be selected and placed to allow for public and private view
corridors with approval by Director.
11. Native vegetation in critical areas and their buffers installed in accordance
with the preceding standards shall be maintained by the property owner to promote
healthy growth and prevent establishment of invasive species. Invasive plants (such as
blackberry, ivy, knotweed, bindweed) shall be removed on a regular basis, according to
the approved maintenance plan.
12. Critical areas, including steep slopes disturbed by removal of invasive plants
or development, shall be replanted with native vegetation where necessary to maintain
the density shown in the Critical Area Buffer Vegetation Planting Densities Table below,
and must be replanted in a timely manner except where a long-term removal and re -
vegetation plan, as approved by the City, is being implemented.
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Table 18.45.158-2 —
Critical Area Buffer Vegetation Planting Densities Table
Plant Material Type
Planting Density
Stakes/cuttings along streambank
1 - 2 feet on center or per
willows, red osier dogwood)
bioengineering method
Shrubs
3 - 5 feet on center, depending on
species
Trees
15 — 20 feet on center, depending
on species
Groundcovers, grasses, sedges,
1 — 1.5 feet on center, depending
rushes, other herbaceous plants
on species
Native seed mixes
5 — 25 lbs. per acre, depending on
species
13. The Department Director, in consultation with the City's environmentalist,
may approve the use of shrub planting and installation of willow stakes to be counted
toward the tree replacement standard in the buffer if proposed as a measure to control
invasive plants and increase buffer function.
F. Vegetation Management in Critical Areas. The requirements of this section
apply to all existing and new development within critical areas.
1. Trees and shrubs may only be pruned for safety, to maintain access
corridors and trails by pruning up or on the sides of trees, to maintain clearance for utility
lines, and/or for improving critical area ecological function. No more than 25% may be
pruned from a tree within a 36-month period without prior City review. This type of pruning
is exempt from any permit requirements.
2. Plant debris from removal of invasive plants or pruning shall be removed
from the site and disposed of properly unless on -site storage is approved by the Director.
Per King County Noxious Weed Control Program guidelines, regulated noxious weeds
shall be disposed of in the landfill/trash and non -regulated noxious weeks may be
disposed of in green waste or composted on site.
3. Use of pesticides.
a. Pesticides (including herbicides, insecticides, and fungicides) shall not
be used in the critical area or its buffer except where:
(1) Alternatives such as manual removal, biological control, and cultural
control are not feasible given the size of the infestation, site characteristics, or the
characteristics of the invasive plant species and herbicide is determined to be least
ecologically impactful,
(2) The use of pesticides has been approved by the City through a
comprehensive vegetation or pest management and monitoring plan, or a King County
Noxious Weed Control Program Best Management Practices document;
(3) The pesticide is applied in accordance with state regulations,
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(4) The proposed herbicide is approved for aquatic use by the U.S.
Environmental Protection Agency; and
(5) The use of pesticides in the critical area jurisdiction is approved by
the City and the applicant presents a copy of the Aquatic Pesticide Permit issued by the
Department of Ecology or Washington Department of Agriculture, if required.
b. Self-contained rodent bait boxes designed to prevent access by other
animals are allowed.
c. Sports fields, parks, golf courses and other outdoor recreational uses
that involve maintenance of extensive areas of turf shall implement an integrated turf
management program or integrated pest management plan designed to ensure that water
quality in the critical area is not adversely impacted.
4. Restoration Project Plantings. Restoration projects may overplant the site
as a way to discourage the re-establishment of invasive species. Thinning of vegetation
without a separate Type 2 Special Permission or critical area tree permit may be permitted
five to ten years after planting if this approach is approved as part of the restoration
project's maintenance and monitoring plan and with approval by the City prior to thinning
work.
G. Maintenance and Monitoring.
The property owner is required to ensure the viability and long-term health of
vegetation planted for replacement or mitigation through proper care and maintenance
for the life of the project subject to permit requirements as follows:
Tree Replacement and Vegetation Clearing Permit Requirements.
a. Schedule an inspection with the City of Tukwila's Urban
Environmentalist to document planting of the correct number and type of plants.
years.
b. Submit annual documentation of tree and vegetation health for three
2. Restoration and Mitigation Project Requirements.
a. A five-year monitoring and maintenance plan must be approved by the
City prior to permit issuance. The monitoring period will begin when the restoration is
accepted by the City and as -built plans have been submitted.
b. Monitoring reports shall be submitted annually for City review up until
the end of the monitoring period. Reports shall measure survival rates against project
goals and present contingency plans to meet project goals.
c. Mitigation will be complete after project goals have been met and
accepted by the City of Tukwila's Urban Environmentalist.
d. A performance bond or financial security equal to 150% of the cost of
labor and materials required for implementation of the planting, maintenance and
monitoring shall be submitted prior to City acceptance of project.
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Section 37. TMC Section 18.45.160 is hereby reenacted to read as follows:
18.45.160 Critical Area Master Plan Overlay
A. The purpose of this section is to provide an alternative to preservation of existing
individual wetlands, watercourses and their buffers in situations where an area -wide plan
for alteration and mitigation will result in improvements to water quality, fish and wildlife
habitat and hydrology beyond those that would occur through the strict application of the
provisions of TMC Chapter 18.45.
B. The City Council may designate certain areas as Critical Area Master Plan
Overlay Districts for the purpose of allowing and encouraging a comprehensive approach
to critical area protection, restoration, enhancement and creation in appropriate
circumstances utilizing best available science. Designation of Critical Area Master Plan
Overlay Districts shall occur through the Type 5 decision process established by TMC
Chapter 18.104.
C. Criteria for designating a Critical Area Master Plan Overlay District shall be as
follows:
The overlay area shall be at least 10 acres.
2. The City Council shall find that preparation and implementation of a Critical
Area Master Plan is likely to result in net improvements in critical area functions when
compared to development under the general provisions of TMC Chapter 18.45.
D. Within a Critical Area Master Plan Overlay District, only those uses permitted
under TMC Sections 18.45.070, 18.45.090 and 18.45.110 shall be allowed within a
Category I wetland or its buffer.
E. Within a Critical Area Master Plan Overlay District, the uses permitted under TMC
Sections 18.45.070, 18.45.090 and 18.45.110 and other uses as identified by an
approved Critical Area Master Plan shall be permitted within Category III and Category
IV wetlands and their buffers; and within Type F, Np and Ns watercourses and their
buffers, provided that such uses are allowed by the underlying zoning designation.
F. A Critical Area Master Plan shall be prepared under the direction of the Director
of Community Development. Consistent with subsection A, the Director may approve
development activity within a Critical Area Overlay District for the purpose of allowing and
encouraging a comprehensive approach to critical areas protection, creation, and
enhancement that results in environmental benefits that may not be otherwise achieved
through the application of the requirements of TMC Chapter 18.45.
G. The Director shall consider the following factors when determining whether a
proposed Critical Areas Overlay and Master Plan results in an overall net benefit to the
environment and is consistent with best available science:
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1. Whether the Master Plan is consistent with the goals and policies of the
Natural Environment Element and the Shorelines Element (if applicable) of the Tukwila
Comprehensive Plan.
2. Whether the Master Plan is consistent with the purposes of TMC Chapter
18.45 as stated in TMC Section 18.45.010.
3. Whether the Master Plan includes a Mitigation Plan that incorporates stream
or wetland restoration, enhancement or creation meeting or exceeding the requirements
of TMC Section 18.45.090 and/or TMC Section 18.45.110, as appropriate.
4. Whether proposed alterations or modifications to critical areas and their
buffers and/or alternative mitigation results in an overall net benefit to the natural
environment and improves critical area functions.
5. Whether the Mitigation Plan gives special consideration to conservation and
protection measures necessary to preserve or enhance anadromous fisheries.
6. Mitigation shall occur on -site unless otherwise approved by the Director. The
Director may approve off -site mitigation only upon determining that greater protection,
restoration or enhancement of critical areas could be achieved at an alternative location
within the same watershed.
7. Where feasible, mitigation shall occur prior to grading, filling or relocation of
wetlands or watercourses.
8. At the discretion of the Director, a proposed Master Plan may undergo peer
review, at the expense of the applicant. Peer review, if utilized, shall serve as one source
of input to be utilized by the Director in making a final decision on the proposed action.
H. A Critical Area Master Plan shall be subject to approval by the Director of
Community Development. Such approval shall not be granted until the Master Plan has
been evaluated through preparation of an Environmental Impact Statement (EIS) under
the requirements of TMC Chapter 21.04. The EIS shall compare the environmental
impacts of development under the proposed Master Plan relative to the impacts of
development under the standard requirements of TMC Chapter 18.45. The Director shall
approve the Critical Area Master Plan only if the evaluation clearly demonstrates overall
environmental benefits, giving special consideration to conservation or protection
measures necessary to preserve or enhance anadromous fisheries.
I. The critical area buffer widths for those areas that were altered, created or
restored as mitigation (Wetland 10, 1, Johnson Creek and the Green River off -channel
habitat), at the time of approval of the Sensitive Area Master Plan (SAMP) Permit No.
L10-014 shall be vested as shown on Map A to be codified as Figure 18-59; provided the
adjacent land was cleared and graded pursuant to a City -approved grading permit; and
provided further that those mitigation measures required by the SAMP were performed
and meet the ecological goals, in accordance with the terms of the SAMP.
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Section 38. TMC Section 18.45.170 is hereby reenacted to read as follows:
18.45.170 Critical Area Tracts and Easements
A. In development proposals for planned residential or mixed use developments,
short subdivisions or subdivisions, and boundary line adjustments and binding site plans,
applicants shall create critical areas tracts or easements, in lieu of an open space tract,
per the standards of the Planned Residential Development District chapter of this title.
B. Applicants proposing development involving uses other than those listed in TMC
Section 18.45.170.A, on parcels containing critical areas or their buffers, may elect to
establish a critical areas tract or easement which shall be:
1. If under one ownership, owned and maintained by the owner;
2. If held in common ownership by multiple owners, maintained collectively; or
3. Dedicated for public use if acceptable to the City or other appropriate public
agency.
C. A notice shall be placed on the property title or plat map that critical area tracts
or easements shall remain undeveloped in perpetuity.
Section 39. TMC Section 18.45.180 is hereby reenacted to read as follows:
18.45.180 Exceptions
A. REASONABLE USE EXCEPTIONS.
1. If application of TMC Chapter 18.45 would deny all reasonable use of the
property containing designated critical areas or their buffers, the property owner or the
proponent of a development proposal may apply for a reasonable use exception.
2. Applications for a reasonable use exception shall be a Type 3 decision and
shall be processed pursuant to TMC Chapter 18.104.
3. If the applicant demonstrates to the satisfaction of the Hearing Examiner that
application of the provisions of TMC Chapter 18.45 would deny all reasonable use of the
property, development may be allowed that is consistent with the general purposes of
TMC Chapter 18.45 and the public interest.
4. The Hearing Examiner, in granting approval of the reasonable use
exception, must determine that:
a. There is no feasible on -site alternative to the proposed activities,
including reduction in size or density, modifications of setbacks, buffers or other land use
restrictions or requirements, phasing of project implementation, change in timing of
activities, revision of road and lot layout, and/or related site planning that would allow a
reasonable economic use with fewer adverse impacts to the critical area.
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b. As a result of the proposed development there will be no unreasonable
threat to the public health, safety or welfare on or off the development proposal site.
c. Alterations permitted shall be the minimum necessary to allow for
reasonable use of the property.
d. The proposed development is compatible in design, scale and use with
other development with similar site constraints in the immediate vicinity of the subject
property if such similar sites exist.
e. Disturbance of critical areas and their buffers has been minimized to the
greatest extent possible.
f. All unavoidable impacts are fully mitigated.
g. The inability to derive reasonable use of the property is not the result of:
(1) a segregation or division of a larger parcel on which a reasonable
use was permittable after the effective date of Sensitive Areas Ordinance No. 1599, June
10, 1991;
(2) actions by the owner of the property (or the owner's agents,
contractors or others under the owner's control) that occurred after the effective date of
the critical areas ordinance provisions that prevents or interferes with the reasonable use
of the property; or
(3) a violation of the critical areas ordinance.
h. The Hearing Examiner, when approving a reasonable use exception,
may impose conditions, including but not limited to a requirement for submission and
implementation of an approved mitigation plan designed to ensure that the development:
(1) complies with the standards and policies of this chapter to the extent
feasible; and
(2) does not create a risk of damage to other property or to the public
health, safety and welfare.
i. Approval of a reasonable use exception shall not eliminate the need for
any other permit or approval otherwise required for a project, including but not limited to
design review.
B. EMERGENCIES. Alterations in response to an emergency that poses an
immediate threat to public health, safety or welfare, or that poses an immediate risk of
damage to private property may be excepted. Any alteration undertaken as an emergency
shall be reported within one business day to the Community Development Department.
The Director shall confirm that an emergency exists and determine what, if any, mitigation
and conditions shall be required to protect the health, safety, welfare and environment
and to repair any damage to the critical area and its required buffers. Emergency work
must be approved by the City. If the Director determines that the action taken, or any part
thereof, was beyond the scope of an allowed emergency action, then the enforcement
provisions of TMC Section 18.45.195 shall apply.
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Section 40. TMC Section 18.45.190 is hereby reenacted to read as follows:
18.45.190 Time Limitation, Appeals and Vesting
A. Time Limitation. Type 2 Special Permission decisions for interrupted buffer,
buffer averaging or other alterations shall expire one year after the decision unless an
extension is granted by the Director. Type 1 tree permits for tree removal within critical
areas or their buffers shall expire one year after the permit is issued, unless an extension
is granted by the Director. Extensions of a Type 2 Special Permission or Type 1 tree
permit may be granted if:
Unforeseen circumstances or conditions necessitate the extension of the
permit; and
2. Termination of the permit would result in unreasonable hardship to the
applicant; and the applicant is not responsible for the delay; and
3. The extension of the permit will not cause substantial detriment to existing
uses, critical areas, or critical area buffers in the immediate vicinity of the subject property.
B. Appeals. Any appeal of a final decision made by the Community Development
Department, pursuant to TMC Chapter 18.45, shall be an appeal of the underlying permit
or approval. Any such appeal shall be processed pursuant to TMC Section 18.108.020
and TMC Chapter 18.116.
C. In considering appeals of decisions or conditions, the following shall be
considered:
The intent and purposes of this chapter;
2. Technical information and reports considered by the Community
Development Department; and
3. Findings of the Director, which shall be given substantial weight.
D. Vesting. Projects are vested to the critical areas ordinance in effect at the time
a complete building permit is submitted except for short plats, subdivisions, binding site
plans and shoreline permits. Short plats or subdivisions or binding site plans are vested
to the critical area ordinance in effect at the time complete application is submitted for
preliminary plats or for the binding site plan. The final plat and all future building permits
on the lots remain vested to that same critical areas ordinance in effect for the preliminary
plat or preliminary binding site plan application, so long as building permits are applied
for within five years of the final plat. For single-family residential short plats and
subdivisions that received preliminary plat approval prior to the adoption of this ordinance,
building permits on the lots shall be considered under the critical areas ordinance in effect
on the date of the preliminary plat application provided complete building or construction
permits are submitted within five years of the final plat approval. Vesting provisions for
shoreline permits are provided in TMC Chapter 18.44.
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Section 41. TMC Section 18.45.195 is hereby reenacted to read as follows:
18.45.195 Violations
A. VIOLATIONS. Failure to comply with any requirement of this chapter shall be
deemed a violation subject to enforcement pursuant to this chapter and TMC Chapter
8.45. The following actions shall be considered a violation of this chapter:
1. To use, construct or demolish a structure or to conduct clearing, earth -
moving, construction or other development not authorized under a Special Permission,
Reasonable Use or other permit where such permit is required by this chapter.
2. Any work that is not conducted in accordance with the plans, conditions, or
other requirements in a permit approved pursuant to this chapter, provided the terms or
conditions are stated in the permit or the approved plans.
3. To remove or deface any sign, notice, complaint or order required by or
posted in accordance with this chapter.
4. To misrepresent any material fact in any application, plans or other
information submitted to obtain any critical area use, buffer reduction or development
authorization.
5. To fail to comply with the requirements of this chapter.
B. PENALTIES.
1. Except as provided otherwise in this section, any violation of any provision
of this chapter, or failure to comply with any of the requirements of this chapter, shall be
subject to the penalties prescribed in TMC Chapter 8.45, "Enforcement".
2. It shall not be a defense to the prosecution for failure to obtain a permit
required by this chapter that a contractor, subcontractor, person with responsibility on the
site, or person authorizing or directing the work erroneously believed a permit had been
issued to the property owner or any other person.
3. Penalties for Tree Removal.
a. In addition to any other penalties or other enforcement allowed by law,
any person who fails to comply with the provisions of this chapter also shall be subject to
a civil penalty assessed against the property owner as set forth herein. Each unlawfully
removed or damaged tree shall constitute a separate violation.
b. Removal or damage of tree(s) without applying for and obtaining
required City approval is subject to a fine of $1,000 per tree, or up to the marketable value
of each tree removed or damaged as determined by a Qualified Tree Professional,
whichever is greater.
c. Any fines paid as a result of violations of this chapter shall be allocated
as follows: 75% paid into the City's Tree Fund; 25% into the General Fund.
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d. The Director may elect not to seek penalties or may reduce the penalties
if he/she determines the circumstances do not warrant imposition of any or all of the civil
penalties.
e. Penalties are in addition to the restoration of removed trees through the
remedial measures listed in TMC Section 18.54.200.
f. It shall not be a defense to the prosecution for a failure to obtain a permit
required by this chapter that a contractor, subcontractor, person with responsibility on the
site or person authorizing or directing the work erroneously believes a permit was issued
to the property owner or any other person.
C. REMEDIAL MEASURES REQUIRED. In addition to penalties assessed, the
Director shall require any person conducting work in violation of this chapter to mitigate
the impacts of unauthorized work by carrying out remedial measures.
1. Any illegal removal of required trees shall be subject to obtaining a Tree
Permit and replacement with trees that meet or exceed the functional value of the
removed trees.
2. To replace the tree canopy lost due to the tree removal, additional trees must
be planted on -site. Payment shall be made into the City's Tree Fund if the number of
replacement trees cannot be accommodated on -site. The number of replacement trees
required will be based on the size of the tree(s) removed as stated in Table 18.45.158-1,
Tree Replacement Requirements.
3. The applicant shall satisfy the permit provisions as specified in this chapter.
4. Remedial measures must conform to the purposes and intent of this chapter.
In addition, remedial measures must meet the standards specified in this chapter.
5. Remedial measures must be completed to the satisfaction of the Director
within 6 months of the date a Notice of Violation and Order is issued pursuant to TMC
Chapter 8.45, or within the time period otherwise specified by the Director.
6. The cost of any remedial measures necessary to correct violation(s) of this
chapter shall be borne by the property owner and/or applicant. Upon the applicant's failure
to implement required remedial measures, the Director may redeem all or any portion of
any security submitted by the applicant to implement such remedial measures, pursuant
to the provisions of this chapter.
Section 42. Regulations Established. TMC Section 18.45.197, "Enforcement," is
hereby established to read as follows:
18.45.197 Enforcement
A. General. In addition to the Notice of Violatio
in TMC Chapter 8.45, the Director may take any o
prescribed in this chapter to ensure compliance with,
chapter; and/or when immediate danger exists to th
determined by the Director.
n
e
and Order measures prescribed
r all of the enforcement actions
and/or remedy a violation of this
public or adjacent property, as
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Page 56 of 87
1. The Director may post the site with a "Stop Work" order directing that all
vegetation clearing not authorized under a Tree Permit cease immediately. The issuance
of a "Stop Work" order may include conditions or other requirements which must be
fulfilled before clearing may resume.
2. The Director may, after written notice is given to the applicant, or after the
site has been posted with a "Stop Work" order, suspend or revoke any Tree Permit issued
by the City.
3. No person shall continue clearing in an area covered by a "Stop Work" order,
or during the suspension or revocation of a Tree Permit, except work required to correct
an imminent safety hazard as prescribed by the Director.
B. Injunctive Relief. Whenever the Director has reasonable cause to believe that
any person is violating or threatening to violate this chapter or any provision of an
approved Special Permission or Tree Permit, the Director may institute a civil action in
the name of the City for injunctive relief to restrain the violation or threatened violation.
Such civil action may be instituted either before or after, and in addition to, any other
action, proceeding or penalty authorized by this chapter or TMC Chapter 8.45.
C. Inspection Access.
1. The Director may inspect a property to ensure compliance with the
provisions of a Tree Permit or this chapter, consistent with TMC Chapter 8.45.
2. The Director may require a final inspection as a condition of a Special
Permission or Tree Permit issuance to ensure compliance with this chapter. The permit
process is complete upon final approval by the Director.
Section 43. TMC Section 18.45.200 is hereby reenacted to read as follows:
18.45.200 Recording Required
The property owner receiving approval of a use or development permit pursuant to
TMC Chapter 18.45 shall record the City -approved site plan, clearly delineating the
wetland, watercourse, areas of potential geologic instability or abandoned mine and their
buffers designated by TMC Sections 18.45.080, 18.45.090, 18.45.100, 18.45.120,
18.45.140 and 18.45.150 with the King County Division of Records and Licensing
Services. The face of the site plan must include a statement that the provisions of TMC
Chapter 18.45, as of the effective date of the ordinance from which TMC Chapter 18.45
derives or is thereafter amended, control use and development of the subject property,
and provide for any responsibility of the property owner for the maintenance or correction
of any latent defects or deficiencies. Additionally, the applicant shall provide data (GPS
or survey data) for updating the City's critical area maps.
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Section 44. TMC Section 18.45.210 is hereby reenacted to read as follows:
18.45.210 Assurance Device
A. In appropriate circumstances, such as when mitigation is not completed in
advance of the project, the Director may require a letter of credit or other security device
acceptable to the City to guarantee performance and maintenance requirements of TMC
Chapter 18.45. All assurances shall be on a form approved by the City Attorney and be
equal to 150% of the cost of the labor and materials for implementation of the approved
mitigation plan.
B. When alteration of a critical area is approved, the Director may require an
assurance device, on a form approved by the City Attorney, to cover the cost of monitoring
and maintenance costs and correction of possible deficiencies for five years. If at the end
of five years performance standards are not being achieved, an increase in the security
device may be required by the Director. When another agency requires monitoring
beyond the City's time period, copies of those monitoring reports shall be provided to the
City.
C. The assurance device shall be released by the Director upon receipt of written
confirmation submitted to the Department from the applicant's qualified professional, and
confirmed by the City, that the mitigation or restoration has met its performance standards
and is successfully established. Should the mitigation or restoration meet performance
standards and be successfully established in the third or fourth year of monitoring, the
City may release the assurance device early. The assurance device may be held for a
longer period, if at the end of the monitoring period, the performance standards have not
been met or the mitigation has not been successfully established. In such cases, the
monitoring period will be extended and the bond held until the standards have been met.
D. Release of the security does not absolve the property owner of responsibility for
maintenance or correcting latent defects or deficiencies or other duties under law.
Section 45. TMC Section 18.45.220 is hereby reenacted to read as follows:
18.45.220 Assessment Relief
A. Fair Market Value. The King County Assessor considers critical area
regulations in determining the fair market value of land under RCW 84.34.
B. Current Use Assessment. Established critical area tracts or easements, as
defined in the Definitions chapter of this title and provided for in TMC Section 18.45.170,
may be classified as open space and owners thereof may qualify for current use taxation
under RCW 18.34; provided, such landowners have not received density credits, or
setback or lot size adjustments as provided in the Planned Residential Development
District chapter of this title.
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C. Special Assessments. Landowners who qualify under TMC Section
18.45.220.13 shall also be exempted from special assessments on the critical area tract
or easement to defray the cost of municipal improvements such as sanitary sewers, storm
sewers and water mains.
Section 46. Regulations Established. TMC Section 18.52.020, "Applicability,"
is hereby established to read as follows:
18.52.020 Applicability
This chapter sets forth rules and regulations to control maintenance, clearing and
planting of landscaping and vegetation within the City of Tukwila on any developed
properties that are zoned commercial, industrial, or multifamily; and on properties that are
zoned LDR and developed with a non -single-family residential use. For properties
located within the Shoreline jurisdiction, the maintenance and removal of vegetation shall
be governed by TMC Chapter 18.44, "Shoreline Overlay." For properties located within
a critical area or its associated buffer, the maintenance and removal of vegetation shall
be governed by TMC Chapter 18.45, "Critical Areas." Clearing and removal of trees on
undeveloped land and any land zoned LDR that is developed with a single-family
residence is regulated by TMC Chapter 18.54, "Urban Forestry and Tree Regulations."
In case of conflict the most stringent regulations apply.
Section 47. TMC Section 18.52.020 Amended and Recodified to TMC 18.52.030.
Ordinance Nos. 2523 §7, 2518 §11, 2251 §62 and 1872 §14 (part), as codified at TMC
Section 18.52.020, "Landscaping Types," are hereby amended to recodify this section as
TMC Section 18.52.030, which shall read as follows:
18.52.030 Landscaping Types
A. General Standards for All Landscaping Types.
1. Trees.
a. Trees shall be spaced based on the stature tree selected (small, medium
or large stature of tree), excluding curb cuts and spaced regularly, except where there
are conflicts with utilities.
b. Large and medium stature tree species are required, per the Tukwila
Approved Tree List, except where there is insufficient planting area (due to proximity to a
building, street light, above or below ground utility, etc.) or the planned tree location does
not permit this size tree at maturity.
2. Shrubs. Shrubs shall be spaced based on the mature size of the plant
material selected and shall achieve a continuous vertical layer within 3 years. The shrubs
will provide 4 feet clearance when mature when adjacent to any fire hydrant or fire
department connection.
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3. Groundcover.
a. Sufficient live groundcovers of varying heights, colors and textures to
cover, within 3 years, 100% of the yard area not needed for trees and shrubs.
b. If grass is being used as the groundcover, a 4-foot diameter ring of bark
mulch is required around each tree.
B. Type I — Light Perimeter Screening.
1. The purpose of Type I landscaping is to enhance Tukwila's streetscapes,
provide a light visual separation between uses and zoning districts, screen parking areas,
and allow views to building entryways and signage.
2. Plant materials shall consist of the following:
a. Trees: A mix of deciduous and evergreen trees.
b. One shrub per 7 linear feet.
c. Groundcover.
C. Type II — Moderate Perimeter Screening.
1. The purpose of Type II landscaping is to enhance Tukwila's streetscapes,
provide a moderate visual separation between uses and zoning districts, screen blank
building walls and parking areas, and allow views to building entryways and signage.
2. Plant materials shall consist of the following:
a. Trees: A mix of deciduous and evergreen trees.
b. One shrub per 4 linear feet, excluding curb cuts.
c. Groundcover.
D. Type III — Heavy Perimeter Screening.
1. The purpose of Type III landscaping is to provide extensive visual separation
along property lines between highly incompatible development, such as warehousing and
residential uses.
2. Plant materials shall consist of the following:
a. Trees consisting of at least 50% evergreen along the applicable property
line (75% along property line adjacent to residential uses).
b. Privacy screen utilizing evergreen shrubs, screening walls or fences (up
to 7 feet tall).
c. Groundcover.
E. Parking Lot Landscaping. This landscaping is required to mitigate adverse
impacts created by parking lots such as noise, glare, stormwater run-off, and increased
heat and to improve their physical appearance.
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1. Trees shall be evenly distributed throughout the parking lot. Planting in
continuous, landscaped planting strips between rows of parking is encouraged. Surface
water management design may also be combined with landscaping in parking lots. In
industrial districts (C/LI, LI, HI, MIC/L, MIC/H), clustering of interior parking lot landscaping
may be permitted to accommodate site usage.
2. Landscape islands.
a. Landscape islands must be a minimum of 6 feet wide, exclusive of
overhang, and a minimum of 100 square feet in area. All landscaped areas must be
protected from damage by vehicles through the use of curbs, tire stops, or other protection
techniques.
b. Landscape islands shall be placed at the ends of each row of parking to
protect parked vehicles from turning movements of other vehicles.
c. The number and stature of trees shall be based on the area available in
the landscape island. A minimum of one large stature evergreen or deciduous tree or two
medium stature trees are required for every 100 square feet of landscaped island, with
the remaining area to contain a combination of shrubs, living groundcover, and mulch.
d. For parking lots adjacent to public or private streets, the islands must be
placed at minimum spacing of 1 for every 10 parking spaces. For parking areas located
behind buildings or otherwise screened from public or private streets or public spaces, if
landscape islands are used, islands shall be placed at a minimum of 1 for every 15 parking
stalls.
3. Bioretention, which includes trees, shrubs and groundcover, may be used to
meet interior parking lot landscaping requirements. The bioretention facility must be
designed by a professional trained or certified in low impact development techniques as
set forth in TMC Chapter 14.30. All bioretention facilities must be protected by curbing to
prevent vehicle damage to the facility and for public safety.
4. Vehicular Overhang.
a. Vehicle overhang into any landscaping area shall not exceed two feet.
b. No plant material greater than 12 inches in height shall be located within
two feet of the curb or other protective barrier in landscape areas adjacent to parking
spaces and vehicle use areas.
c. Raised curbs or curb stops shall be used around the landscape islands
or bioretention facilities to prevent plant material from being struck by automobiles.
Where bioretention is used, curb cuts shall be placed to allow stormwater runoff from
adjacent pavements to enter the bioretention system.
5. Pervious pavement shall be used, where feasible, including parking spaces
and pedestrian paths.
6. Parking lot landscape design shall accommodate pedestrian circulation.
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F. Street Trees in the Public Frontage.
1. Street tree spacing.
a. Street tree spacing in the public frontage shall be as specified in TMC
Section 18.52.080.B.2. based on the stature size of the tree.
b. Spacing must also consider sight distance at intersections, driveway
locations, and utility conflicts as specified in TMC Section 18.52.080.B.3.
c. Street trees in the public frontage shall be planted using the following
general spacing standards:
(1) At least 3-1/2 feet back from the face of the curb.
(2) At least 5 feet from underground utility lines.
front for access).
(3) At least 10 feet from utility poles.
(4) At least 7-1/2 feet from driveways.
(5) At least 3 feet from pad -mounted transformers (except 10 feet in
(6) At least 4 feet from fire hydrants and connections.
d. Planting and lighting plans shall be coordinated so that trees are not
planted in locations where they will obstruct existing or planned street or site lighting,
while maintaining appropriate spacing and allowing for their size and spread at maturity.
e. Planting plans shall consider the location of existing or planned signage
to avoid future conflicts with mature trees and landscaping.
2. Tree grates.
a. Tree grates are not encouraged, but when used, shall be designed so
that sections of grate can be removed incrementally as the tree matures and shall be
designed to avoid accumulation of trash.
b. When used, tree grates and landscaped tree wells shall be a minimum
36 square feet in size (6' x 6'). Tree well size may be adjusted to comply with ADA
standards on narrower sidewalks. See TMC Section 18.52.090.A.1., "Soil Preparation
and Planting," for structural soil requirements. Root barriers may be installed at the curb
face if structural soils are not used.
3. Maintenance and Pruning.
a. Street trees are subject to the planting, maintenance, and removal
standards and Best Management Practices (BMPs) as adopted by the International
Society of Arboriculture, as it now reads and as hereafter amended. Street trees planted
prior to the adoption of the most current tree planting standards shall be exempt from
these planting standards but are still subject to current removal and maintenance
standards.
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b. The following standards apply to street tree maintenance:
(1) Street trees shall be maintained consistent with International
Society of Arboriculture BMPs.
(2) Street trees shall be maintained in a manner that does not impede
public street or sidewalk traffic, consistent with the specifications in the Public Works
Infrastructure Design Manual, including:
streets.
(a) 8 feet of clearance above public sidewalks.
(b) 13 feet of clearance above public local and neighborhood
(c) 15 feet of clearance above public collector streets.
(d) 18 feet of clearance above public arterial streets.
(3) Street trees shall be maintained so as not to become a defective
tree as per the definition in TMC Chapter 18.06.
4. Trees planted in a median shall be appropriate for the planting environment
and meet the following requirements:
a. Trees shall be consistent with previously approved median tree plans,
given space constraints for roots and branches at maturity.
b. Median plantings shall provide adequate species diversity Citywide and
reasonable resistance to pests and diseases.
c. Columnar trees may be considered for median plantings to avoid
conflicts with vehicles and utilities.
d. Structural soils shall be used to avoid the need for root barriers and to
ensure the success of the median plantings.
e. Any median tree that is removed must be replaced within the same
median unless spacing constraints exist. Replacement trees shall be of the same stature
or greater at maturity as the removed tree, consistent with other space considerations.
Section 48. TMC Section 18.52.030 Amended and Recodified to TMC 18.52.040.
Ordinance Nos. 2580 §6, 2523 §8, 2442 §1, 2251 §61, 2235 §13 and 1872 §14, as
codified at TMC Section 18.52.030, "Perimeter and Parking Lot Landscaping
Requirements by Zone District," are hereby amended to recodify this section as TMC
Section 18.52.040, and to amend the "Notes" in TABLE A to read as follows:
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TABLE A — Perimeter and Parking Lot Landscaping Requirements by Zone District
FRONT
ZONING
YARD
LANDSCAPE
LANDSCAPE
LANDSCAPE
LANDSCAPE
LANDSCAPING FOR
DISTRICTS
(SECOND
TYPE FOR
FOR SIDE
FOR REAR
TYPE FOR
PARKING LOTS
FRONT)
FRONTS
YARD
YARD
SIDE/REAR
(square feet)
(linear feet)
(linear feet)
(linear feet)
LDR
152
Type I
10
10
Type I
20 per stall for
(for uses other
non-residential
than residential)
uses; 15 per stall if
parking is placed
behind building
MDR
151 2,11
Type I
10
10
Type I
Same as LDR
HDR
151.2.11
Type 1
10
10
Type I
Same as LDR
ZONING DISTRICTS
FRONT
LANDSCAPE
LANDSCAPE
LANDSCAPE
LANDSCAPE
LANDSCANG FOR
YARD
TYPE FOR
FOR SIDE
FOR REAR
TYPE FOR
PARKING LOTS
(SECOND
FRONTS
YARD
YARD
SIDE/REAR
(square feet)
FRONT)
(linear feet)
(linear feet)
(linear feet)
MUO
15 (12.5)2.11
Type 17
64
64.11
Type I'
20 per stall adjacent
to street; 15 per stall
if parking is placed
behind building
O
15 (12.5)2
Type 17
64
64
Type 17
Same as MUO
RCC
20 (10)2.3
Type 17
64
loll
Type II
Same as MUO
NCC
104.11
Type 17.13
04
04.11
Type II
Same as MUO
RC
10
Type 113
64
04
Type 116
Same as MUO
RCM
10
Type]
64
04
Type 11'
Same as MUO
C/LI
15
Type 16
65,12
05,12
Type 118
15 per stall;
10 per stall for parking
placed behind building
LI
152
Type 11
04,12
04.12
Type III
15 per stall;
10 per stall for
parking placed
behind building
HI
152
Type 11
04.12
04.12
Type 111
15 per stall
MIC/L
105
Type II
05,12
05,12
Type 111
10 per stall
MIC/H
105
Type 11
05.12
05.12
Type 111
10 per stall
TUC — See TMC Chapter 18.28
TVs
152, 3
Type 11
04
04
Type III
Same as C/LI
TSO
152.9
Type I
010,
010
Type III
Same as C/LI for
non-residential uses.
Same as LDR for
residential uses.
Notes:
1. Minimum required front yard landscaped areas in the MDR and HDR zones may have up to 20%
of their required landscape area developed for pedestrian and transit facilities subject to the approval criteria
in TMC Section 18.52.120.C.
2. In order to provide flexibility of the site design while still providing the full amount of landscaping
required by code, the front yard landscape width may be divided into a perimeter strip and one or more
other landscape areas between the building and the front property line if the perimeter strip is a minimum
of 10 feet and the landscape materials are sufficient to provide landscaping along the perimeter and
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screening of the building mass.
3. Required landscaping may include a mix of plant materials, pedestrian amenities and features,
outdoor cafe -type seating and similar features, subject to the approval criteria in TMC Section 18.52.120.C.
Bioretention may also be used as required landscaping subject to the approval criteria in TMC Section
18.52.120.E. Required plant materials will be reduced in proportion to the amount of perimeter area
devoted to pedestrian -oriented space.
4. Increased to 10 feet if any portion of the yard is within 50 feet of LDR, MDR or HDR.
5. Increased to 15 feet if any portion of the yard is within 50 feet of LDR, MDR or HDR.
6. Increased to Type II if the front yard contains truck loading bays, service areas or outdoor storage.
7. Increased to Type II if any portion of the yard is within 50 feet of LDR, MDR or HDR.
8. Increased to Type III if any portion of the yard is within 50 feet of LDR, MDR or HDR.
9. Only required along public streets.
10. Increased to 10 feet for residential uses; or if adjacent to residential uses or non-TSO zoning.
11. In the MDR and HDR districts and other districts where multifamily development is permitted, a
community garden may be substituted for some or all of the landscaping. In order to qualify, a partnership
with a nonprofit (501(c)(3)) with community garden expertise is required to provide training, tools and
assistance to apartment residents. Partnership with the nonprofit with gardening expertise is required
throughout the life of the garden. If the community garden is abandoned, the required landscaping must be
installed. If the garden is located in the front landscaping, a minimum of 5 feet of landscaping must be
placed between the garden and the street.
12. To accommodate the types of uses found in the C/Ll, LI, HI and MIC districts, landscaping may
be clustered to permit truck movements or to accommodate other uses commonly found in these districts
if the criteria in TMC Section 18.52.120.D are met.
13. For NCC and RC zoned parcels in the Tukwila International Boulevard District, the front
landscaping may be reduced or eliminated if buildings are brought out to the street edge to form a
continuous building wall, and if a primary entrance from the front sidewalk as well as from off-street parking
areas is provided.
Section 49. TMC Section 18.52.050 Amended and Recodified to TMC 18.52.060.
Ordinance No. 2523 §10, as codified at TMC Section 18.52.050, "Significant Tree
Retention," is hereby amended to recodify this section as TMC Section 18.52.060, which
shall read as follows:
18.52.060 Significant Tree Retention
A. All significant trees located within any required landscape area that are not dead,
dying, diseased, or a nuisance species, as identified in the Tukwila Approved Tree List,
and that do not pose a safety hazard or conflict with overhead utility lines as determined
by the City or an ISA certified arborist, shall be retained and protected during construction
with temporary fencing or other enclosure, as appropriate to the site and following Best
Management Practices for tree protection (see TMC Chapter 18.54).
B. Topping of trees is prohibited and is subject to replacement. Additionally, pruning
of more than 25% of canopy in a 36-month period is prohibited and is subject to
replacement per TMC Section 18.52.130, Table C.
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C. Retained significant trees may be counted towards required landscaping.
Additionally, the required landscaping may be reduced in exchange for retaining
significant trees subject to Director approval and per TMC Section 18.52.120.F.
D. The area designated for protection will vary based on the tree's diameter,
species, age, and the characteristics of the planted area, and Best Management Practices
for protection shall be utilized (see TMC Chapter 18.54). Property owners may be
required to furnish a report by an ISA certified arborist to document a tree's condition if a
tree is to be retained. The Director may require that an ISA certified arborist be retained
to supervise tree protection during construction. Grade changes around existing trees
within the critical root zone are not allowed.
Section 50. Regulations Established. TMC Section 18.52.070, "Tree Protection
Standards," is hereby established to read as follows:
18.52.070 Tree Protection Standards
All trees not proposed for removal as part of a project or development shall be
protected using Best Management Practices and the standards below.
1. The Critical Root Zones (CRZ) for all trees designated for retention, on site
or on adjacent property as applicable, shall be identified on all construction plans,
including demolition, grading, civil and landscape site plans.
2. Any roots within the CRZ exposed during construction shall be covered
immediately and kept moist with appropriate materials. The City may require a third party
Qualified Tree Professional to review long-term viability of the tree.
3. Physical barriers, such as 6-foot chain link fence or plywood or other
approved equivalent, shall be placed around each individual tree or grouping at the CRZ.
4. Minimum distances from the trunk for the physical barriers shall be based on
the approximate age of the tree (height and canopy) as follows:
a. Young trees (trees which have reached less than 20% of life
expectancy): 0.75 per inch of trunk diameter.
b. Mature trees (trees which have reached 20-80% of life expectancy):
1 foot per inch of trunk diameter.
c. Over mature trees (trees which have reached greater than 80% of life
expectancy): 1.5 feet per inch of trunk diameter.
5. Alternative protection methods maybe used that provide equal or greater tree
protection if approved by the Director.
6. A weatherproof sign shall be installed on the fence or barrier that reads:
"TREE PROTECTION ZONE — THIS FENCE SHALL NOT BE REMOVED OR
ENCROACHED UPON. No soil disturbance, parking, storage, dumping or
burning of materials is allowed within the Critical Root Zone. The value of this
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tree is $ [insert value of tree as determined by a Qualified Tree Professional
here]. Damage to this tree due to construction activity that results in the death
or necessary removal of the tree is subject to the Violations section of TMC
Chapter 18.54."
7. All tree protection measures installed shall be inspected by the City and, if
deemed necessary, a Qualified Tree Professional, prior to beginning construction or earth
moving.
8. Any branches or limbs that are outside of the CRZ and might be damaged
by machinery shall be pruned prior to construction by a Qualified Tree Professional. No
construction personnel shall prune affected limbs except under the direct supervision of
a Qualified Tree Professional.
9. The CRZ shall be covered with 4 to 6 inches of wood chip mulch. Mulch
shall not be placed directly against the trunk. A 6-inch area around the trunk shall be free
of mulch. Additional measures, such as fertilization or supplemental water, shall be
carried out prior to the start of construction if deemed necessary by the Qualified Tree
Professional's report to prepare the trees for the stress of construction activities.
10. No storage of equipment or refuse, parking of vehicles, dumping of materials
or chemicals, or placement of permanent heavy structures or items shall occur within the
CRZ.
11. No grade changes or soil disturbance, including trenching, shall be allowed
within the CRZ. Grade changes within 10 feet of the CRZ shall be approved by the City
prior to implementation.
12. The applicant is responsible for ensuring that the CRZ of trees on adjacent
properties are not impacted by the proposed development.
13. A pre -construction inspection shall be conducted by the City to finalize tree
protection actions.
14. Post -construction inspection of protected trees shall be conducted by the
City and, if deemed necessary by the City, a Qualified Tree Professional. All corrective
or reparative pruning will be conducted by a Qualified Tree Professional.
Section 51. TMC Section 18.52.070 Amended and Recodified to TMC 18.52.090.
Ordinance No. 2523 §12, as codified at TMC Section 18.52.070, "Soil Preparation,
Planting and Irrigation," is hereby amended to recodify this section as TMC Section
18.52.090, which shall read as follows:
18.52.090 Soil Preparation, Planting and Irrigation
A. Soil Preparation and Planting.
1. For landscaping in sidewalks and parking lots, or in limited areas of soil
volume, structural soils (Cornell University product or similar) must be used to a preferred
depth of 36 inches to promote tree root growth and provide structural support to the paved
area. Minimum soil volumes for tree roots shall be 750 cubic feet per tree (see
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specifications and sample plans for CU-Structural Soils). Trees and other landscape
materials shall be planted according to specifications in "CU Structural Soils — A
Comprehensive Guide," as it now reads and as hereafter amended, or using current Best
Management Practices (BMPs) as approved by the Director. Suspended pavement
systems (Silva Cells or similar) may also be used if approved by the Director.
2. For soil preparation in bioretention areas, existing soils must be protected
from compaction. Bioretention soil media must be prepared in accordance with standard
specifications of the Surface Water Design Manual, adopted in accordance with TMC
Chapter 14.30, to promote a proper functioning bioretention system. These specifications
shall be adhered to regardless of whether a stormwater permit is required from the City.
3. For all other plantings (such as large planting areas where soil volumes are
adequate for healthy root growth with a minimum volume of 750 cubic feet per tree), soils
must be prepared for planting in accordance with BMP T5.13, "Post Construction Soil
Quality and Depth," from the Washington Department of Ecology Stormwater
Management Manual for Western Washington (as it now reads and as hereafter
amended), regardless of whether a stormwater permit is required by the City.
4. The applicant will be required to schedule an inspection by the City of the
planting areas prior to planting to ensure soils are properly prepared. Soil must be
amended, tilled and prepped to a depth of at least 12 inches.
5. Installation of landscape plants must comply with BMPs including:
a. Planting holes that are the same depth as the size of the root ball and
two to three times wider than the root ball.
b. Root balls of potted and balled and burlapped (B&B) plants must be
loosened and pruned as necessary to ensure there are no encircling roots prior to
planting. All burlap and all straps or wire baskets must be removed from B&B plants prior
to planting.
c. The top of the root flare, where the roots and the trunk begin, should be
placed at grade. The root ball shall not extend above the soil surface and the flare shall
not be covered by soil or mulch.
d. If using mulch around trees and shrubs, maintain at least a 6-inch mulch -
free ring around the base of the tree trunks and woody stems of shrubs. If using mulch
around groundcovers until they become established, mulch shall not be placed over the
crowns of perennial plants.
B. Irrigation.
1. The intent of this standard is to ensure that plants will survive the critical
establishment period when they are most vulnerable due to lack of watering and to ensure
their long term viability.
2. All required plantings must be served by a permanent automatic irrigation
system, unless approved by the Director.
a. Irrigation shall be designed to conserve water by using the best practical
management techniques available, including BMPs, for daily timing of irrigation to
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optimize water infiltration and conservation. These techniques may include, but not be
limited to: drip irrigation (where appropriate) to minimize evaporation loss, moisture
sensors to prevent irrigation during rainy periods, automatic controllers to ensure proper
duration of watering, sprinkler head selection and spacing designed to minimize
overspray, and separate zones for turf and other landscaping and for full sun exposure
and shady areas to meet watering needs of different sections of the landscape.
b. Exceptions to the irrigation requirement may be approved by the
Director, such as xeriscaping (i.e., low water usage plantings), plantings approved for low
impact development techniques, established indigenous plant material, or landscapes
where natural appearance is acceptable or desirable to the City. However, those
exceptions will require temporary irrigation until established.
3. All temporary irrigation must be removed at the end of the 3-year plant
establishment period.
Section 52. TMC Section 18.52.080 Amended and Recodified to TMC 18.52.100.
Ordinance No. 2523 §13, as codified at TMC Section 18.52.080, "Maintenance and
Pruning," is hereby amended to recodify this section as TMC Section 18.52.100, which
shall read as follows:
18.52.100 Maintenance and Pruning
A. Any landscaping required by this chapter shall be retained and maintained by the
property owner for the life of the development in conformance with the intent of the
approved landscape plan and this chapter. Maintenance shall also include keeping all
planting areas free of weeds and trash and replacing any unhealthy or dead plant
materials.
B. Green roofs or rooftop gardens shall be maintained to industry standards and
any dead or dying plant material replaced.
C. Pruning of trees and shrubs is only allowed for the health of the plant material, to
maintain sight distances or sight lines, or if interfering with overhead utilities. All pruning
must be done in accordance with American National Standards Institute (ANSI) A-300
specifications, as it now reads and as hereafter amended.
D. No tree planted by a property owner or the City to fulfill landscape requirements,
or any existing tree, may be topped or removed without prior approval from the City. Any
tree topped or removed without approval shall be subject to code enforcement action per
TMC Chapter 8.45 in addition to the requirements of TMC Section 18.52.130, "Violations."
E. Private property owners shall collect and properly dispose of all landscaping
debris. Private property landscaping debris shall not be placed or blown into the public
right-of-way for City collection. Violations will be subject to code enforcement action per
TMC Chapter 8.45.
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F. As trees along the street frontages mature, they shall be limbed up, using proper
ISA pruning techniques, to a minimum height of 8 to 18 feet depending on location of tree
(over sidewalk, adjacent to road, etc.) to allow adequate visibility and clearance for
vehicles. Trees may be pruned to improve views of signage and entryways by using such
techniques as windowing, thinning, and limbing up; however, no more than 1/4 of the
canopy may be removed within any 2-year period. All pruning shall be done in
accordance with ANSI Standard A-300 specifications, as it now reads and as hereafter
amended.
G. Trees may only be pruned to lower their height to prevent interference with an
overhead utility line with prior approval by the Director. The pruning must be carried out
under the direction of an ISA certified arborist. The crown shall be maintained to at least
2/3 the height of the tree prior to pruning. Otherwise, trees shall not be topped. Illegal
topping is subject to replacement. Additionally, pruning of more than 25% of canopy in a
36-month period is prohibited and is subject to replacement per TMC Section 18.52.130,
Table C.
Section 53. TMC Section 18.52.100 Amended and Recodified to TMC 18.52.120.
Ordinance No. 2523 §15, as codified at TMC Section 18.52.100, "Request for Landscape
Modifications," is hereby amended to recodify this section as TMC Section 18.52.120,
which shall read as follows:
18.52.120 Request for Landscape Modifications
A. Revisions to existing landscaping may be approved only if the following criteria
are met:
1. The revision does not reduce the landscaping to the point that activities on
the site become a nuisance to adjacent properties.
2. Proposed vegetation removal, replacement, and any mitigation measures
proposed are consistent with the purpose and intent of this chapter and bring landscaping
into conformance with standards of TMC Chapter 18.52.
3. Proposed revision will not be detrimental to the public health, safety or
welfare or injurious to other property in the vicinity.
4. Any trees proposed to be removed shall be replaced with trees of similar or
larger size at a minimum ratio of 1:1.
B. The following deviations to the requirements of this chapter may be considered
either as a Type 2, Special Permission Director decision, or through design review if the
project is subject to that process.
1. Deviation from the requirements of Type I, II, or III landscaping, including
but not limited to the use of the landscape area for pedestrian and transit facilities,
landscape planters, rooftop gardens or green roofs, terraced planters or green walls, or
revisions to existing landscaping. The amount of landscaping on commercially -zoned
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properties may be reduced by 15% if buildings are moved to the front of the site with no
parking between the building and the front landscaping, to create a more pedestrian -
friendly site design.
2. Clustering and/or averaging of required landscaping. The landscape
perimeter may be clustered if the total required square footage is achieved, unless the
landscaping requirement has been increased due to proximity to LDR, MDR or HDR. In
addition, up to 50% of the perimeter landscaping may be relocated to the interior parking
to provide more flexibility for site organization.
3. Substitution of bioretention facility for required landscaping for Type I or II
landscaping. Landscaping in a bioretention facility that includes trees, shrubs and
groundcover may be counted up to 100% towards required landscaping depending on
the location, type of bioretention facility proposed and proposed use.
4. Credit for retained significant trees towards landscaping requirement.
C. The following criteria apply to requests for deviation from any required
landscaping standards.
1. The deviation does not reduce the landscaping to the point that activities on
the site become a nuisance to neighbors; and
2. The modification or revision does not diminish the quality of the site
landscape as a whole; and
3. One or more of the following are met:
a. The modification or revision more effectively screens parking areas and
blank building walls; or
b. The modification or revision enables significant trees or existing built
features to be retained; or
c. The modification or revision is used to reduce the number of driveways
and curb cuts and allow joint use of parking facilities between neighboring businesses; or
d. The modification or revision is used to incorporate pedestrian or transit
facilities; or
e. The modification is for properties in the NCC or RC districts along
Tukwila International Boulevard, where the buildings are brought out to the street edge
and a primary entrance from the front sidewalk as well as from off-street parking areas is
provided; or
f. The modification is to incorporate alternative forms of landscaping such
as landscape planters, rooftop gardens, green roof, terraced planters or green walls; or
g. The modification is to incorporate a community garden, subject to the
provisions of TMC Section 18.52.040, Note 11.
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D. Clustering or perimeter averaging of landscaping may be considered if:
1. It does not diminish the quality of the site landscape as a whole; and
2. It does not create a nuisance to adjacent properties; and
3. If adjacent to residential development, the impacts from clustering are
minimized; and
4. One or more of the following criteria are met:
a. Clustering or perimeter averaging of plant material allows more effective
use of the industrial property; or
b. Clustering or perimeter averaging of landscaping enables significant
trees to be retained; or
c. Clustering or perimeter averaging is used to reduce the number of
driveways and curb cuts and/or allow joint use of parking facilities between neighboring
businesses; or
d. Clustering or perimeter averaging avoids future conflicts with signage.
E. Landscaping in a bioretention facility that includes trees, shrubs, and
groundcovers as identified on the City's approved Bioretention Plant List and as regulated
in TMC Chapter 14.30, may be counted up to 100% towards required Type I or Type II
landscaping. Bioretention facilities shall not be counted towards required Type III
landscaping. All of the following criteria must be met:
1. The bioretention facility has been designed by a professional trained or
certified in low impact development techniques; and
2. The landscaping meets the screening requirements of the specified
landscape type; and
3. Public safety concerns have been addressed; and
4. The number of trees required by the landscape type are provided.
F. Credit for Significant Trees.
1. Credit for retained significant trees may be counted towards required
landscaping if the following criteria are met:
a. Assessment of trees by an ISA certified arborist as to tree health, value
of the trees and the likelihood of survivability during and after construction is provided;
and
b. Retention of tree(s) supports the Tukwila Comprehensive Plan urban
tree canopy goals and policies; and
c. A financial assurance is posted based on 150% of the value of the
retained tree(s) to ensure tree replacement should the retained trees be damaged or die
as a result of construction impacts. The financial assurance shall be retained for three
years.
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2. The value of the significant tree(s) to be retained, as determined by an ISA
certified arborist, shall be posted on the tree prior to site preparation and retained
throughout the construction of the project.
Section 54. TMC Section 18.52.110 Amended and Recodified to TMC 18.52.130.
Ordinance No. 2523 §16, as codified at TMC Section 18.52.110, "Violations," is hereby
amended to recodify this section as TMC Section 18.52.130, which shall read as follows:
18.52.130 Violations
A. Violations. The following actions shall be considered a violation of this chapter:
Any removal or damage of landscaping that is required by this chapter.
2. Topping or excessive pruning of trees or shrubs, except as explicitly allowed
by this chapter.
3. Failure to replace dead landscaping materials.
B. Penalties. In addition to any other penalties or other enforcement actions, any
person who fails to comply with the provisions of this chapter also shall be subject to a
civil penalty assessed against the violator as set forth herein. Each unlawfully removed
or damaged tree shall constitute a separate violation.
1. The amount of the penalty shall be assessed based on Table B below. The
Director may elect not to seek penalties or may reduce the penalties if he/she determines
the circumstances do not warrant imposition of any or all of the civil penalties.
2. Penalties are in addition to the restoration of removed plant materials
through the remedial measures listed in TMC Section 18.52.130.C.
3. It shall not be a defense to the prosecution for a failure to obtain a permit
required by this chapter that a contractor, subcontractor, person with responsibility on the
site or person authorizing or directing the work erroneously believes a permit was issued
to the property owner or any other person.
TABLE B — Fines
Type of Violation
I Allowable Fines per Violation
Removal or damage of trees or
specimen shrubs without applying for
and obtaining required City approval
$1,000 per tree, or up to the marketable value
of each tree removed or damaged as determined
by an ISA certified arborist.
C. Remedial Measures. In addition to the penalties provided in TMC Section
18.52.130.13, the Director shall require any person conducting work in violation of this
chapter to mitigate the impacts of unauthorized work by carrying out remedial measures.
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1. Any illegal removal of required trees shall be subject to obtaining a tree
permit and replacement with trees that meet or exceed the functional value of the
removed trees. In addition, any shrubs and groundcover removed without City approval
shall be replaced.
2. To replace the tree canopy lost due to the tree removal, additional trees must
be planted on -site. Payment may be made into the City's Tree Fund if the number of
replacement trees cannot be accommodated on -site. The number of replacement trees
required will be based on the size of the tree(s) removed as stated in Table C.
TABLE C — Tree Replacement Requirements
Diameter* of Tree Removed (*measured at
height of 4.5 feet from the ground)
Number of Replacement
Trees Required
4-6 inches (single trunk) OR
2 inches (any trunk of a multi -trunk tree)
3
Over 6-8 inches
4
Over 8-20 inches
6
Over 20 inches
8
D. Enforcement. It shall be the duty of the Community Development Director to
enforce this chapter pursuant to the terms and conditions of TMC Chapter 8.45 or as
otherwise allowed by law.
E. Inspection Access.
1. For the purposes of inspection for compliance with the provisions of a permit
or this chapter, authorized representatives of the Community Development Director may
enter all sites for which a permit has been issued.
2. Upon completion of all requirements of a permit, the applicant shall request
a final inspection by contacting the planner of record. The permit process is complete
upon final approval by an authorized representative of the Community Development
Director.
Section 55. TMC Sections Recodified. The following sections in TMC Chapter
18.52 are hereby renumbered to be codified as follows:
Old Section # New Section #
18.52.060
18.52.090
18.52.050
18.52.110
Section Name
Screening and Visibility
Plant Material Requirements and Tree Standards
Landscape Plan Requirements
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Section 56. TMC Section 18.28.240 Amended. Ordinance No. 2443 §25, as
codified at TMC Section 18.28.240, "General Landscaping," subparagraph C, is hereby
amended to correct a section reference and shall read as follows:
C. General Landscaping Considerations.
Plant Materials.
a. Drought resistant species are encouraged in order to minimize irrigation
requirements, except where site conditions within the required landscape areas ensure
adequate moisture for growth.
b. The mature size of selected tree species should be suitable to lot size,
the scale of adjacent structures, and the proximity to utility lines.
c. In general, deciduous trees with open branching structures are
recommended to ensure visibility to retail establishments. More substantial shade trees
are recommended in front of private residences.
d. All trees should be selected and located so they will not obstruct views
to showroom windows and building signage as they mature.
e. Evergreen landscaping (Figure 18-48) is appropriate for screening utility
vaults, loading docks and some storage areas. (Also see TMC Section 18.52.050 for
screening outdoor storage areas.)
f. Species selection is very important in grouped plantings (Figure 18-49).
Drought tolerant species are strongly recommended and monoculture plantings are
discouraged. Low maintenance cost and low replacement costs are two advantages of
planting drought tolerant species in grouped configurations. Low (24-30 inches) shrubs,
perennial or groundcover plantings that provide a superior degree of separation between
the sidewalk and street at reduced maintenance costs may be used.
2. Design.
a. Shade trees should be planted to shade buildings' east and west -facing
windows to provide a balance between summer cooling and winter heating through solar
gain.
b. All landscaped areas should be designed to allow aquifer filtration and
minimize stormwater run-off utilizing bio-swales, filtration strips, and bio-retention ponds
where appropriate.
Section 57. TMC Section 18.54.020 Amended. Ordinance Nos. 2570 §3 and 1758
§1 (part), as codified at TMC Section 18.54.020, are hereby amended to read as follows:
18.54.020 Applicability
This chapter sets forth rules and regulations to control maintenance and clearing of
trees within the City of Tukwila on any undeveloped land and any land zoned Low Density
Residential (LDR) that is developed with a single family residence. For properties located
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within the Shoreline jurisdiction, maintenance and removal of vegetation shall be
governed by TMC Chapter 18.44, "Shoreline Overlay." For properties located within a
critical area or its associated buffer, the maintenance and removal of vegetation shall be
governed by TMC Chapter 18.45, "Environmentally Critical Areas". TMC Chapter 18.52,
"Landscape Requirements," shall govern the maintenance and removal of landscaping
on developed properties that are zoned commercial, industrial, or multifamily; and on
properties located in the LDR zone that are developed with a non -single family residential
use. The most stringent regulations shall apply in case of a conflict.
Section 58. TMC Section 18.54.030 Amended. Ordinance Nos. 2570 §4 and 1758
§1 (part), as codified at TMC Section 18.54.030, are hereby amended to read as follows:
18.54.030 Tree Permit Required
A. Permit Required.
1. A Tree Permit is required prior to work within the Critical Root Zone of any
Significant, Exceptional or Heritage Tree or prior to the removal or destruction of any of
these trees within the City, unless the action is exempt from this chapter.
2. A Tree Permit is required when any person wishes to prune a Heritage Tree
in excess of 20% of the existing crown in a two-year period.
3. A request for an exception to the requirements of the chapter shall be
processed under a Tree Exception Permit.
B. Tree Removal Exemptions. The following activities are exempt from the permit
requirements of this chapter except as noted below:
1. The removal of trees that are less than 6 inches in Diameter at Breast Height
(DBH) on a property zoned Low Density Residential and improved with a single-family
dwelling.
2. Removal of no more than four trees that are 6-8" DBH on a property zoned
Low Density Residential and improved with a single-family dwelling in any 36-month
period, as long as the property owner submits a tree inventory survey that includes the
following:
a. Number of and size of trees to be removed;
b. The location of any affected utility lines within the overhead "fall zone"
or other built infrastructure;
c. Photos of the tree(s) to be removed;
d. The method of removal and identification of contractor; and
e. Time schedule of tree removal.
3. The removal of Dead Trees outside of the shoreline jurisdiction or a sensitive
area or its buffer.
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4. Routine maintenance of trees necessary to maintain the health of cultivated
plants, or to contain noxious weeds or invasive species as defined by the City of Tukwila
or King County, and routine maintenance within rights -of -way related to Interference,
Sight Distance, Emergencies or Topping, as codified in TMC Chapter 11.20. Routine
maintenance includes the removal of up to 25% of the existing tree crown in a 36-month
period.
5. Emergency actions necessary to remedy an immediate threat to people or
property, or public health, safety or welfare by a high -risk or extreme -risk tree may be
undertaken in advance of receiving a permit. Any person, utility or public entity
undertaking such an action shall submit a Tree Permit application within one week of the
emergency action and replace tree(s) if required by this chapter. Additional time to apply
for a Tree Permit may be granted at the discretion of the Director.
6. The removal of trees in the right-of-way related to a capital project that has
a landscaping component that includes trees, where there is adequate room in the right-
of-way.
7. Removal of trees as allowed with a Class I -IV forest practices permit issued
by the Washington State Department of Natural Resources.
Section 59. TMC Section 18.54.040 Amended. Ordinance No. 2570 §5, as codified
at TMC Section 18.54.040, is hereby amended to read as follows:
18.54.040 Permit Submittal Requirements
A. Permit Application. Prior to any tree removal, site clearing or work within the
Critical Root Zone, a Tree Permit application must be submitted to the Department of
Community Development containing the following information:
1. Site Plan of the proposal showing:
a. Diameter, species name, location and canopy of existing Significant
Trees in relation to proposed and existing structures, utility lines, and construction limit
line;
b. Identification of all Significant Trees to be removed and/or relocated;
c. Existing and proposed topography of the site at 2-foot contour intervals;
and
d. Limits of any critical area and critical area buffer and/or shoreline
jurisdiction.
2. Landscape Plan for the proposal showing:
a. Diameter, species name, spacing and location of replacement trees to
be planted;
b. Diameter, species name and location of all Significant Trees to be
retained; and
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c. Vegetation protection measures consistent with the criteria in TMC
Section 18.54.060.
3. Professional review or recommendation for removal of Heritage Trees or as
otherwise required. A Qualified Tree Professional report is not required for the permitted
removal of trees, other than Heritage Trees, on a lot zoned Low Density Residential and
improved with a single-family dwelling. The Director may require a report from a Qualified
Tree Professional if replacement trees are required or when the Director determines that
tree removal, site clearing, or work within the Critical Root Zone may result in adverse
impacts requiring remedial measures. Third party review of the report or recommendation
may be required. The report or recommendation shall address the following:
a. The anticipated effects of proposed construction or tree removal on the
viability of Significant Trees to remain on -site;
b. Recommendations on replacement trees, spacing and maintenance of
proposed replacement trees once installed;
c. Post -construction site inspection and evaluation; and
d. Estimated cost of maintenance of replacement trees for the purposes of
calculation of financial assurance, if required.
4. A photo of the tree(s) to be impacted or removed.
5. Time schedule. Proposed time schedule of vegetation removal, relocation
and/or replacement, and other construction activities that may affect on -site vegetation,
sensitive area, sensitive area buffer, and/or shoreline zone.
B. Permit Materials Waiver. The Director may waive the requirement for any or all
plans or permit items specified in this section upon finding that the information on the
application is sufficient to demonstrate that the proposed work will meet the approval
criteria detailed in this chapter and other City ordinances. Such waiver of a requirement
shall not be construed as waiving any other requirements of this chapter or related
regulations.
C. Permit Application Fee. A Tree Permit fee shall be paid at the time an
application or request is filed with the department, pursuant to TMC Section 18.88.010,
except as otherwise noted in this chapter. All fees shall be paid according to the Land
Use Fee Schedule in effect at the time of application. There is no permit fee for submittal
of the Tree Inventory Survey.
Section 60. TMC Section 18.54.050 Amended. Ordinance Nos. 2570 §6 and 1758
§1 (part), as codified at TMC Section 18.54.050, are hereby amended to read as follows:
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18.54.050 Permit Approval Criteria, General
All Tree Permit applications shall meet the criteria outlined below for approval.
1. Existing trees will be retained on -site to the maximum extent possible as
required by TMC Section 18.54.060 and as recommended in the Qualified Tree
Professional report, if applicable.
2. Tree protection will be implemented as required in TMC Section 18.54.070.
3. Tree replacement will be implemented as required in TMC Section
18.54.080; unless no replacement is required per TMC Section 18.54.080, Table A.
4. Tree replacement funds will be deposited into the City of Tukwila Tree Fund,
as described in TMC Section 18.54.100, if required.
5. A performance assurance will be submitted as required in TMC Section
18.54.110.
Section 61. TMC Section 18.54.060 Amended. Ordinance Nos. 2570 §7 and 1758
§1 (part), as codified at TMC Section 18.54.060, are hereby amended to read as follows:
18.54.060 Tree Retention Standards
A. As many Significant, Exceptional and Heritage Trees as possible are to be
retained on a site proposed for development or re -development, particularly to provide a
buffer between development, taking into account the condition and age of the trees. As
part of a land use application such as, but not limited to, subdivision or short plat review,
design review or building permit review, the Director of Community Development or the
Board of Architectural Review may require reasonable alterations to the arrangement of
buildings, parking or other elements of the proposed development in order to retain
Significant, Exceptional or Heritage non-invasive Trees.
B. Topping and pruning of more than 25% of the canopy of trees is prohibited and
considered removal and subject to replacement requirements of TMC Section 18.54.080.
C. Removal or topping of trees located on undeveloped properties is prohibited
except:
1. Those that interfere with access and/or passage on public trails; or
2. When trees, including alders and cottonwoods, have been determined to be
one of the following by a Tree Risk Assessment prepared by a Tree Risk Assessor, and
where the risk cannot be reduced to Low with mitigation, such as pruning:
a. Moderate risk with significant consequences;
b. Moderate risk with severe consequences;
c. High risk with a Target or Risk Target; or
d. Extreme risk.
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3. Factors that will be considered
are not limited to, tree condition and health,
for root or canopy interference with utilities.
in approving such tree removal include, but
age, risks to life or structures, and potential
D. Protection of trees shall be a major factor in the location, design, construction
and maintenance of streets and utilities. Removal or significant damage that could lead
to tree death of Significant, Exceptional or Heritage Trees shall be mitigated with on- or
off -site tree replacement as required by this chapter.
E. A Qualified Tree Professional shall provide an assessment of any tree proposed
for retention in a proposed development to ensure its survivability during construction.
F. The Department shall conduct a tree canopy assessment every five years from
the date of the adoption of this chapter to ensure the tree canopy goals of the
Comprehensive Plan are being met.
Section 62. TMC Section 18.54.080 Amended. Ordinance Nos. 2570 §9 and 1758
§1 (part), as codified at TMC Section 18.54.080, are hereby amended to read as follows:
18.54.080 Tree Replacement
A. Replacement Exemption for Single -Family Tree Removal. Except for
Heritage Trees, the removal of Significant Trees, depending on the size within any 36-
month period on a property zoned Low Density Residential and improved with a single-
family dwelling, is permitted, subject to the requirements of Table A below.
TABLE A —
Single Family Tree Removal without Replacement Limits
Trees (DBH)
# of Trees in 36 month period that
can be removed without
replacement
>6-8"
4
>8-18"
2
>18"
1 and no other trees
(') A combination of trees of different sizes may be removed without
replacement so long as the total number of trees removed does not
exceed the number allowed for the largest tree removed in a 36-month
period. See Tree Permit Application for additional details.
B. Replacement Standards.
1. Each existing Significant Tree removed, including removal of trees in
easements and rights -of -way for the purposes of constructing public streets and utilities,
shall be replaced with new tree(s), based on the size of the existing tree as shown below,
up to a maximum density of 100 new trees per acre, generally 12-15 feet apart. If the
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number of required replacement trees exceeds site capacity, payment is required into the
City's Tree Fund.
2. Tree Replacement Ratios. Table B (below) establishes tree replacement
ratios when Significant, Exceptional or Heritage Trees are removed. For properties zoned
Low Density Residential and improved with a single-family dwelling, when the number of
trees permitted to be removed in a 36-month period, as shown in Table A, has been
exceeded, the replacement ratios set forth in Table B apply. Trees damaged due to
natural disasters, such as wind storms, hail, ice or snow storms, and earthquakes, are
not required to be replaced. Trees determined to be Defective by the City or a Qualified
Tree Professional, are not required to be replaced. Any tree removal on undeveloped
properties is subject to replacement ratios in Table B. Illegal topping and pruning more
than 25% in a 36-month period is subject to replacement ratios in Table B.
3. The property owner is required to ensure the viability and long-term health
of trees planted for replacement through proper care and maintenance for the life of the
site's improvement. Replaced trees that do not survive must be replanted in the next
appropriate season for planting.
4. If all required replacement trees cannot be accommodated reasonably on
the site, the applicant shall pay into the Tree Fund in accordance with the Consolidated
Permit Fee Schedule adopted by resolution of the City Council.
TABLE B — Tree Replacement Requirements
Replacement
Trees
ratio for trees
(DBH)
that are subject
to re lacement
6-8"
1:1
>8-18"
1:2
>18"
1:3
5. Tree replacement shall also meet the standards in TMC Section 18.54.160.
Section 63. TMC Section 18.54.110 Amended. Ordinance Nos. 2570 §12 and
1758 §1 (part), as codified at TMC Section 18.54.110, are hereby amended to read as
follows:
18.54.110 Performance Assurance
To mitigate potential damages that may result from unauthorized tree removal or
maintenance, the Director may require the applicant to submit a bond, letter of credit, or
other means of assurance acceptable to the City prior to issuance of a Tree Permit,
subject to the following provision:
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1. Tree Protection Assurance. The applicant may be required to post a three
year performance bond or other acceptable security device to ensure the installation,
maintenance and adequate performance of tree protection measures during the
construction process. The amount of this bond shall equal 150 percent of the City's
estimated cost of replacing each replacement tree. The estimated cost per tree shall be
the fair market value of the tree. Prior to DCD final inspection, any protected tree found
to be irreparably damaged, severely stressed or dying shall be replaced according to the
standards identified in this chapter. The City may release all or part of the bond prior to
the conclusion of the bonding period if the applicant demonstrates that the requirements
of this section have been satisfied and there is evidence that the protected trees will
survive. If trees designated for retention are damaged, they shall be subject to
replacement.
2. Tree Maintenance Assurance. Where replacement trees are required, the
applicant may be required to post a one-year replacement tree maintenance bond or other
acceptable security device to ensure the survival of replacement trees. The amount of
the maintenance bond shall equal 150 percent of the cost of plant material, periodic
fertilizing and pruning, and labor until tree survival is ensured. In the event a required
replacement tree becomes irreparably damaged, severely stressed or dies, the tree shall
be replaced according to the standards in this chapter. The City may release all or part
of the bond prior to the conclusion of the bonding period if the applicant demonstrates
that the requirements of this section have been satisfied and there is evidence that the
protected trees will survive. Submission of annual photos for three years documenting
that the tree is in good health will satisfy this requirement for properties zoned Low Density
Residential and improved with a single-family dwelling. Trees that do not survive the
three-year maintenance period shall be replanted and the three year maintenance period
shall restart at the time of replanting.
3. The applicant shall provide an estimate of the costs associated with the
required performance bond or other security as described above. In lieu of an applicant's
estimate, the performance assurance shall be equal to City staff's best estimate of
possible costs to meet the above requirements. In no case shall the performance -
assurance exceed an amount equal to two and one-half times the current cost of replacing
the plants in accordance with the tree replacement provisions of this chapter.
4. The performance assurances shall not be fully released without final
inspection and approval of completed work by the City, submittal of any post -construction
evaluations or following any prescribed trial maintenance period required in the permit.
5. Performance assurances provided in accordance with this chapter may be
enforced in whole or in part by the City upon determination by the Director that the
applicant has failed to fully comply with approved plans and/or conditions.
Section 64. TMC Section 18.54.160 Amended. Ordinance Nos. 2570 §17 and
1758 §1 (part), as codified at TMC Section 18.54.160, are hereby amended to read as
follows:
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18.54.160 Soil Preparation, Plant Material and Maintenance Standards
A. Soil Preparation.
1. Soils must be prepared for planting by incorporating compost and/or topsoil
to a depth of 12 inches throughout the planting area.
2. An inspection of the planting areas prior to planting may be required to
ensure soils are properly prepared.
3. Installation of plants must comply with Best Management Practices
including, but not limited to:
a. Planting holes that are the same depth as the size of the root ball and
two to three times wider than the root ball.
b. Root balls of potted and balled and burlapped (B&B) plants must be
loosened and pruned as necessary to ensure there are no encircling roots prior to
planting. All burlap and all straps or wire baskets must be removed from B&B plants prior
to planting.
c. The top of the root flare, where the roots and the trunk begin, should be
placed at grade. The root ball shall not extend above the soil surface and the flare shall
not be covered by soil or mulch. For bare root plants, ensure soil beneath roots is stable
enough to ensure correct height of the tree.
d. If using mulch around trees and shrubs, maintain at least a 4-inch mulch -
free ring around the base of the tree trunks and woody stems of shrubs. If using mulch
around groundcovers until they become established, mulch shall not be placed over the
crowns of perennial plants.
B. Plant Material Standards.
1. Plant material shall be healthy, vigorous and well -formed, with well -
developed, fibrous root systems, free from dead branches or roots. Plants shall be free
from damage caused by temperature extremes, pre -planting or on -site storage, lack of or
excess moisture, insects, disease, and mechanical injury. Plants in leaf shall show a full
crown and be of good color. Plants shall be habituated to outdoor environmental
conditions (i.e. hardened -off).
2. Evergreen trees shall be a minimum of 6 feet in height at time of planting.
3. Deciduous trees shall have at least a 2-inch caliper at time of planting as
measured 4.5 feet from the ground, determined according to the American Standard for
Nursery Stock as it now reads and as hereafter amended.
4. Smaller plant stock may be substituted on a case -by -case basis with
approval of the City's environmental specialist.
5. Tree spacing shall take into account the location of existing and new trees
as well as site conditions.
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6. Where there are overhead utility lines, the tree species selected shall be of
a type which, at full maturity, will not interfere with the lines or require pruning to maintain
necessary clearances.
C. Tree Maintenance and Pruning.
1. Pruning of trees should be (1) for the health of the plant material, (2) to
maintain sight distances or sight lines, or (3) if interfering with overhead utilities. All
pruning must be done in accordance with American National Standards Institute (ANSI)
A300 specifications, as it now reads and as hereafter amended. No more than 25% of
the tree canopy shall be pruned in any two-year period, except for fruit trees that are being
pruned to increase harvest potential. Any tree pruned in excess of 25% of the canopy
shall be subject to replacement ratios listed under TMC Section 18.54.080.
2. All protected and replacement trees and vegetation shown in approved Tree
Permit shall be maintained in a healthy condition by the property owner throughout the
life of the project, unless otherwise approved by the Director in a subsequent Tree Permit.
3. Trees may only be pruned to lower their height to prevent interference with
an overhead utility line with prior approval by the Director. The pruning must be carried
out under the direction of a Qualified Tree Professional or performed by the utility provider
under the direction of a Qualified Tree Professional. The crown shall be maintained to at
least 2/3 the height of the tree prior to pruning.
Section 65. TMC Section 18.54.190 Amended. Ordinance Nos. 2570 §20 and
1758 §1 (part), as codified at TMC Section 18.54.190, are hereby amended to read as
follows:
18.54.190 Violations
A. Failure to comply with any requirement of this chapter shall be deemed a violation
subject to enforcement pursuant to this chapter and TMC Chapter 8.45.
B. Penalties.
1. In addition to any other penalties or other enforcement allowed by law, any
person who fails to comply with the provisions of this chapter also shall be subject to a
civil penalty assessed against the property owner as set forth herein. Each unlawfully
removed or damaged tree shall constitute a separate violation.
2. Removal or damage of tree(s) without applying for and obtaining required
City approval is subject to a fine of $1,000 per tree, or up to the marketable value of each
tree removed or damaged as determined by a Qualified Tree Professional, whichever is
greater.
3. Any fines paid as a result of violations of this chapter shall be allocated as
follows: 75% paid into the City's Tree Fund; 25% into the General Fund.
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4. The Director may elect not to seek penalties or may reduce the penalties if
he/she determines the circumstances do not warrant imposition of any or all of the civil
penalties.
5. Penalties are in addition to the restoration of removed trees through the
remedial measures listed in TMC Section 18.54.200.
6. It shall not be a defense to the prosecution for a failure to obtain a permit
required by this chapter that a contractor, subcontractor, person with responsibility on the
site or person authorizing or directing the work erroneously believes a permit was issued
to the property owner or any other person.
Section 66. TMC Section 18.70.050 Amended. Ordinance Nos. 2518 §15 and
1819 §1 (part), as codified at TMC Section 18.70.050, are hereby amended to read as
follows:
18.70.050 Nonconforming Structures
Where a lawful structure exists at the effective date of adoption of this title that could
not be built under the terms of this title by reason of restrictions on area, development
area, height, yards or other characteristics of the structure, it may be continued so long
as the structure remains otherwise lawful subject to the following provisions:
1. No such structure may be enlarged or altered in such a way that increases
its degree of nonconformity. Ordinary maintenance of a nonconforming structure is
permitted, pursuant to TMC Section 18.70.060, including but not limited to painting, roof
repair and replacement, plumbing, wiring, mechanical equipment repair/replacement and
weatherization. These and other alterations, additions or enlargements may be allowed
as long as the work done does not extend further into any required yard or violate any
other portion of this title. Complete plans shall be required of all work contemplated under
this section.
2. Should such structure be destroyed by any means to an extent of more than
50% of its replacement cost at time of destruction, in the judgment of the City's Building
Official, it shall not be reconstructed except in conformity with provisions of this title,
except that in the LDR zone, structures that are nonconforming in regard to yard setbacks
or sensitive area buffers, but were in conformance at the time of construction may be
reconstructed to their original dimensions and location on the lot.
3. Should such structure be moved for any reason or any distance whatsoever,
it shall thereafter conform to the regulations for the zone in which it is located after it is
moved.
4. When a nonconforming structure, or structure and premises in combination,
is vacated or abandoned for 24 consecutive months, the structure, or structure and
premises in combination, shall thereafter be required to be in conformance with the
regulations of the zone in which it is located. Upon request of the owner, the City Council
may grant an extension of time beyond the 24 consecutive months.
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5. Residential structures and uses located in any single-family or multiple -
family residential zoning district and in existence at the time of adoption of this title shall
not be deemed nonconforming in terms of bulk, use, or density provisions of this title.
Such buildings may be rebuilt after a fire or other natural disaster to their original
dimensions and bulk, but may not be changed except as provided in the non -conforming
uses section of this chapter.
6. Single-family structures in single- or multiple -family residential zone districts
that have legally nonconforming building setbacks, shall be allowed to expand the ground
floor only along the existing building line(s), so long as the existing distance from the
nearest point of the structure to the property line is not reduced, and the square footage
of new intrusion into the setback does not exceed 50% of the square footage of the current
intrusion.
7. In wetlands, watercourses and their buffers, existing structures that do not
meet the requirements of the Critical Areas Overlay District chapter of this title may be
remodeled, reconstructed or replaced, provided that:
a. The new construction does not further intrude into or adversely impact
an undeveloped critical area or the required buffer, except where an interrupted buffer
waiver has been granted by the Director. However, legally constructed buildings, other
than accessory structures, may:
(1) Expand vertically to add upper stories in exchange for buffer
enhancement, provided no significant tree is removed.
(2) Expand laterally along the building side that is opposite of critical
area up to a maximum of 1,000 square feet, provided that expansion is outside 75 percent
of the required buffer; buffer enhancement is proposed; and no significant tree is
removed.
(3) Expand laterally along the existing building lines in exchange for
buffer enhancement, provided the expansion into the buffer is less than 50 percent of the
current encroachment or 500 square feet, whichever is less; expansion is outside 75
percent of the required buffer; and no significant tree is removed.
(4) Enclose within existing footprint in exchange for buffer
enhancement, provided no significant tree is removed.
welfare.
b. The new construction does not threaten the public health, safety or
c. The structure otherwise meets the requirements of this chapter.
8. In areas of potential geologic instability, coal mine hazard areas, and buffers,
as defined in the Critical Areas Overlay District chapter of this title, existing structures
may be remodeled, reconstructed or replaced, provided that:
a. The new construction is subject to the geotechnical report requirements
and standards of TMC Sections 18.45.120.13 and 18.45.120.C;
b. The new construction does not threaten the public health, safety or
welfare;
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c. The new construction does not increase the potential for soil erosion or
result in unacceptable risk or damage to existing or potential development or to
neighboring properties; and
d. The structure otherwise meets the requirements of this chapter.
Section 67. Corrections by City Clerk or Code Reviser. Upon approval of the
City Attorney, the City Clerk and the code reviser are authorized to make necessary
corrections to this ordinance, including the correction of clerical errors; references to other
local, state or federal laws, codes, rules, or regulations; or ordinance numbering and
section/subsection numbering.
Section 68. Severability. If any section, subsection, paragraph, sentence, clause
or phrase of this ordinance or its application to any person or situation should be held to
be invalid or unconstitutional for any reason by a court of competent jurisdiction, such
invalidity or unconstitutionality shall not affect the validity or constitutionality of the
remaining portions of this ordinance or its application to any other person or situation.
Section 69. Effective Date. This ordinance or a summary thereof shall be published
in the official newspaper of the City, and shall take effect and be in full force upon approval
of the Shoreline Master Program by the Washington State Department of Ecology and
publication as provided by law.
PASSED BY THE CITY COUNCIL OF THE CITY OF TUKWILA, WASHINGTON, at
a Regular Meeting thereof this ZK day of tAO�v'C.�,.- , 2020.
ATTEST/AUTH ENTICATED:
hristy O'Flaherty, MMC, City Clerk
APPROVED AST O FORM BY:
Office of the City Attorney
Allan Ekbeg, Mayor
Filed with the City Clerk:
Passed by the City Council: 3 -2- -2
Published: 3 -'5 -2'9
Effective Date: W✓ Sec6vvk. 6`�
Ordinance Number: 2421;_
Attachment: Map A — Critical Area Tracts in Tukwila South
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Page 87 of 87
Figure 18-59
Critical Area Tracts in Tukwila South
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City of Tukwila Public Notice of Ordinance Adoption for Ordinance 2625-2627.
On March 2, 2020 the City Council of the City of Tukwila, Washington, adopted the
following ordinances, the main points of which are summarized by title as follows:
Ordinance 2625: AN ORDINANCE OF THE CITY COUNCIL OF THE CITY OF TUKWILA,
WASHINGTON, ADDING, REPEALING AND AMENDING VARIOUS DEFINITIONS AS CODIFIED IN
TUKWILA MUNICIPAL CODE (TMC) CHAPTER 18.06, "DEFINITIONS," AS IDENTIFIED HEREIN;
AMENDING AND RECODIFYING VARIOUS ORDINANCES AS CODIFIED IN MULTIPLE SECTIONS OF
TMC CHAPTER 18.52, "LANDSCAPE REQUIREMENTS;" AMENDING ORDINANCE NO. 2443 §25, AS
CODIFIED AT TMC SECTION 18.28.240.C; AMENDING ORDINANCE NO. 2570 §3, §4, §5, §6, §7, §9,
§12, §17 AND §20, AND ORDINANCE NO. 1758 §1 (PART), AS CODIFIED AT MULTIPLE SECTIONS OF
TMC CHAPTER 18.54, "URBAN FORESTRY AND TREE REGULATIONS;" AMENDING ORDINANCE NO.
2518 §15 AND ORDINANCE NO. 1819 §1 (PART), AS CODIFIED AT TMC SECTION 18.70.050;
REPEALING ORDINANCE NOS. 2175 AND 2077, AS CODIFIED AT TMC SECTION 18.70.050;
REPEALING ORDINANCE NO. 2301, AS CODIFIED IN MULTIPLE SECTIONS OF TMC CHAPTER
18.45, "ENVIRONMENTALLY SENSITIVE AREAS;" REPEALING ORDINANCE NO. 2368 §47, §48, §49
AND §50, AS CODIFIED AT VARIOUS SECTIONS OF TMC CHAPTER 18.45 AS IDENTIFIED HEREIN;
REENACTING TMC CHAPTER 18.45, "ENVIRONMENTALLY SENSITIVE AREAS," TO AMEND AND
ESTABLISH NEW REGULATIONS RELATED TO CRITICAL AREAS; PROVIDING FOR SEVERABILITY;
AND ESTABLISHING AN EFFECTIVE DATE.
Ordinance 2626: AN ORDINANCE OF THE CITY COUNCIL OF THE CITY OF TUKWILA,
WASHINGTON, REPEALING ORDINANCE NO. 2344; REPEALING THE 2011 SHORELINE MASTER
PROGRAM; APPROVING AND ADOPTING A NEW SHORELINE MASTER PROGRAM UPDATE FOR
THE CITY OF TUKWILA TO INCORPORATE NEW STATE REQUIREMENTS; PROVIDING FOR
SEVERABILITY; AND ESTABLISHING AN EFFECTIVE DATE.
Ordinance 2627: AN ORDINANCE OF THE CITY COUNCIL OF THE CITY OF TUKWILA,
WASHINGTON; REPEALING VARIOUS DEFINITIONS AS CODIFIED IN TUKWILA MUNICIPAL CODE
(TMC) CHAPTER 18.06, "DEFINITIONS"; REPEALING ORDINANCE NO. 2346 AND 2549 §23;
REENACTING TMC CHAPTER 18.44, "SHORELINE OVERLAY," TO ESTABLISH NEW REGULATIONS
RELATED TO SHORELINE USES; AMENDING VARIOUS ORDINANCES AS CODIFIED IN TMC
SECTIONS 18.52.030, 18.60.050 AND 18.104.010 TO UPDATE ZONING REGULATIONS RELATED TO
SHORELINE USES; PROVIDING FOR SEVERABILITY; AND ESTABLISHING AN EFFECTIVE DATE.
The full text of this ordinance will be provided upon request.
Christy O'Flaherty, MMC, City Clerk
Published Seattle Times: March 5, 2020