HomeMy WebLinkAboutOrd 2626 - DOCUMENT A - Shoreline Master Program (Adopted on 3/2/2020)Adopted by Ord 2626
TUKWILA SHORELINE MASTER PROGRAM
Adopted by the Tukwila City Council March 2, 2020
Prepared by Tukwila Department of Community Development
with the assistance of ESA Adolfson and The Watershed Company
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This report was funded in part through a grant, G0600234, from the Washington State
Department of Ecology.
TABLE OF CONTENTS
1. INTRODUCTION 1
1.1 Purpose and Background 1
1.2 Shoreline Jurisdiction 1
2. SHORELINE MASTER PROGRAM 5
2.1 SMP Components 5
2.2 SMP Elements 6
2.3 History of SMP Planning in Tukwila 6
2.4 Current SMP Update Process 7
3. DEFINITIONS 8
4. SHORELINE INVENTORY AND CHARACTERIZATION—SUMMARY .8
4.1 Watershed Context and Shoreline Modifications 9
4.2 Biological Resources and Shoreline Functions 10
4.3 Land Use 11
4.4 Restoration Opportunities and Potential Use Conflicts 13
4.5 Conclusions 15
5. SHORELINE RESTORATION PLAN - SUMMARY 17
5.1 Background 17
5.2 Assessment of Shoreline Functions 17
5.3 Plans, Programs, and Completed Projects 19
5.4 Restoration Opportunities 19
5.5 Potential Projects and Priorities 20
6. SHORELINE GOALS AND POLICIES 21
7. SHORELINE ENVIRONMENT DESIGNATIONS 21
7.1 Pre 2009 Regulatory Framework 21
7.2 Key Findings of the Shoreline Inventory / 22
Characterization Report and Restoration Plan
i
7.3 State Environment Designation System 23
7.4 Environment Designations 26
7.5 Determination of Shoreline Buffers 31
7.6 Shoreline Residential Environment 36
7.7 Urban Conservancy Environment 38
7.8 High Intensity Environment 42
7.9 Aquatic Environment 44
8. SHORELINE USE REGULATIONS AND 44
DEVELOPMENT STANDARDS
9. ENVIRONMENTALLY CRITICAL AREAS WITHIN THE
SHORELINE JURISDICTION. 45
9.1 Applicable Critical Areas Regulations 45
9.2 Purpose 46
10. PUBLIC ACCESS TO THE SHORELINE 49
11. SHORELINE DESIGN GUIDELINES 51
12. SHORELINE RESTORATION 51
13. ADMINISTRATION 52
13.1 Applicability of Shoreline Master Program and
Substantial Development Permit 52
13.2 Relationship to Other Codes and Regulations 53
14. APPEALS 53
15. MASTER PROGRAM REVIEW AND AMENDMENTS 54
16. LIABILITY 54
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LIST OF FIGURES
Figure 1. Pre 2009 Tukwila SMP Shoreline Management Zones (1974 SMP; TMC 18.44) 22
Figure 2. Briscoe Levee Profile 35
Figure 3. Schematic of Shoreline Residential Environment and Buffer 38
Figure 4. Schematic of Shoreline Jurisdiction and Buffers for the
Urban Conservancy Environment in Areas without Levees 40
Figure 5. Schematic of Shoreline Jurisdiction and Buffers for the
Urban Conservancy Environment in Areas with Levees 41
Figure 6. Schematic of Buffer Reduction Through Placement of Fill on
Levee Back Slope 42
Figure 7. Schematic Showing the Proposed Shoreline Jurisdiction and Buffer
for the High Intensity Environment 43
LIST OF TABLES
Table 1. General Restoration Potential within the Shorelines of Tukwila 18
Table 2. State Recommended Environment Designation System —
WAC 173-26-211 (5) 25
Table 3. Summary of Buffer Widths for Land Use Zones and Shoreline 27
Ecological Conditions
LIST OF MAPS
Map 1. Annexation History and Potential Annexation Areas 4
Map 2. Duwamish River Transition Zone .16
Map 3. Shoreline Environments .30
Map 4. Critical Areas in the Shoreline ..48
Map 5. Shoreline Public Access 50
APPENDICES
A. Shoreline Inventory and Characterization Report
B. Shoreline Restoration Plan
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1. INTRODUCTION
1.1 Purpose and Background
This document presents the Shoreline Master Program (SMP) for the City of Tukwila. It is
an update to Tukwila's existing SMP, originally adopted in 1974. The SMP is intended to
guide new shoreline development, redevelopment and promote reestablishment of natural
shoreline functions, where possible. It was prepared in conformance with the Washington
State Shoreline Management Act (Chapter 90.58 RCW) and its implementing regulations
(WAC 173-26).
This Shoreline Master Program reflects changes in local conditions and priorities and the
evolving State regulatory environment.
This Shoreline Master Program presents background information on the Shoreline
Management Act, describes shoreline jurisdiction in Tukwila, summarizes the amendment
process carried out to date, presents a summary of the Shoreline Inventory and
Characterization, presents a summary of the Shoreline Restoration Plan, proposes shoreline
environments, and establishes goals, policies and regulations, which apply to all activities on
all affected lands and waters within the shoreline jurisdiction. In addition, there is a chapter
that establishes design guidelines. Maps are provided to illustrate shoreline jurisdiction and
environments. The Shoreline Inventory and Characterization Report is provided in Appendix
A. The Restoration Plan is provided in Appendix B. A Cumulative Impacts Analysis is
provided as a stand-alone document.
1.2 Shoreline Jurisdiction
A. Jurisdiction under the Shoreline Management Act
The Shoreline Management Act, or SMA (RCW 90.58), establishes regulations for the
management and protection of the state's shoreline resources and requires planning for
reasonable and appropriate uses. The Act calls for a joint planning effort between state and
local jurisdictions, requiring local government to develop its own Shoreline Master Program
based on state guidelines.
The SMA requires that local governments establish shoreline jurisdiction for those bodies
of water and lands that are considered to be "shorelines of the state" or "shorelines of
statewide significance." Shorelines of the state include rivers with a mean annual flow of
at least 20 cubic feet per second (cfs). Shorelines of statewide significance in western
Washington include rivers with a mean annual flow of at least 1,000 cubic feet per second
(cfs). The minimum shoreline environment required by the SMA includes all lands 200
feet from the "ordinary high water mark" or floodway of a state shoreline, whichever is
greater, and all wetlands associated with these state shorelines and located within the 100 -
year floodplain. The following graphic illustrates the jurisdiction of the Shoreline
Management Act.
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Ordinary high
water mark
(OHWM)
Wetland in 100 year
Flood plain
1111
1111
1111-1111-
1111 1111 1111
1111 -1111 -III -1111-1111-1111-11
—IIII—IIII—IIII-1111-1111—III —111
= 1111 - 1111 - 1111 - 1111 — 1111 — 1111 — IIII
1 200' J
MIL
_1111-1111— 111_1111— —1111_1111_1111=
1111=1111=1111
111 =1111=1111=1111=1111=1111:
1111 -IIII - 1111 - 11 - 1111 —IIII —IIII —IIII — 11 —
k 2001
Flood way
100 Year Flood Plain
200' from OHWM or flood way and
all marshes, bogs, and swamps in
100 year flood plain
200' from OHWM and 100 year flood plain
Figure 1.1 Lands and waters under the jurisdiction of the Shoreline Management Act
B. Shoreline Jurisdiction in Tukwila
The Green/Duwamish River is the only "shoreline of statewide significance" in the city
(RCW 98.58.030). A small portion of the Black River, a shoreline of the state, is also
located in Tukwila. Throughout the SMP document, the term "Shoreline Jurisdiction" is
used to describe the water and land areas subject to shoreline jurisdiction in Tukwila.
Based on SMA guidelines for shoreline jurisdiction, Tukwila's Shoreline Jurisdiction is
defined as follows:
The Tukwila Shoreline Jurisdiction includes the channel of the
Green/Duwamish River and the Black River, its banks, the upland
area which extends from the ordinary high water mark landward for
200 feet on each side of the river, floodways and all associated
wetlands within its floodplain. For the purpose of determining
shoreline jurisdiction only, the floodway shall not include those
lands that have historically been protected by flood control devices
and, therefore, have not been subject to flooding with reasonable
regularity.
The Tukwila SMP applies to all development activity occurring within the Shoreline
Jurisdiction, which corresponds to the Shoreline Overlay District as established by Chapter
18.44 of the Tukwila Municipal Code.
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All proposed uses and activities under its jurisdiction must be reviewed for compliance with
the goals, policies and regulations referenced herein. All proposed uses and development
occurring within shoreline jurisdiction must conform to chapter 90.58 RCW, the Shoreline
Management Act and this Master Program whether or not a permit is required.
This Master Program includes the two proposed annexation areas indicated in the
Comprehensive Plan (Map 1). The north annexation area is located between the
Green/Duwamish River on the east, Military Road to the west, and from S. 128th Street north
to S. 96th Street. The south annexation area is located between I-5 and the Green River, south
of the City limits to S. 204th Street. Adoption of shoreline policies and environment
designations for newly annexed areas would require an amendment to the Shoreline Master
Program. To avoid having to amend the SMP later, these potential annexation areas are
considered here and the environmental designations and regulations will apply upon
annexation.
In response to regional policies of the King County Growth Management Planning Council,
Tukwila designated two key areas as its Urban Center and its Manufacturing Industrial Center
(MIC). The Southcenter area, from I-405 south to S. 180th Street was designated the "Urban
Center;" and the Duwamish Corridor, an area where existing industrial employment is
concentrated, was designated as Tukwila's "Manufacturing Industrial Center." Both of these
areas have lands adjacent to the Green River and are identified on Map 1.
The City Council adopted a Strategic Implementation Plan for the MIC on November 2, 1998.
The Plan includes an analysis of existing conditions along the shoreline, narratives of various
habitats, current regulations, proposed requirements and prototypes for future development
along the shoreline in the MIC. The Strategic Plan was prepared in conjunction with a
Planned Action Environmental Impact Statement that analyzed development alternatives in
the MIC area and streamlined SEPA review for development in that corridor for the past 20
years. Where changed circumstances dictate, the SMP will provide updated guidance and
regulations for the MIC area. The MIC area has significant potential for redevelopment.
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Map 1
Annexation
History and
Potential
Annexation
Areas
Manufacturing/Industrial
Center Boundary
Legend
-� ▪ Tukwila City Limits
Tukwila Urban Center
— — ▪ Manufacting /Industrial Center
Potential Annexation Areas
jGreen 1 Duwamish River
1 Shoreline Annexed After 1974
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sates: 141:44
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2. TUKWILA'S SHORELINE MASTER PROGRAM
2.1 SMP Components
This SMP document contains the SMA overview and background related to the development
of the SMP Comprehensive Update in 2011 as updated through the 2019 Periodic Review
process. To comply with the SMA, Tukwila has included the following components in this
Shoreline Master Program (SMP):
• Outreach including a citizen participation process, and coordination with state
agencies, Indian tribes, and other local governments (see Section 2.4)
• Inventory, analysis and characterization of shoreline conditions, environmental
functions and ecosystem -wide processes
• Analysis of potential shoreline restoration opportunities
• Establishment of shoreline environments
• Shoreline Design Guidelines that have been codified in TMC Chapter 18.44
• Evaluation and consideration of cumulative impacts
The Shoreline Element of the Comprehensive Plan:
• Contains the SMP goals and policies that have been adopted in the Shoreline
Element of the Comprehensive Plan (Ordinance No. 2413, October 21, 2013)
The Shoreline Regulations:
• Development regulations that have been codified in TMC Chapter 18.44
(Ordinance No. 2627, March 2, 2020)
• Development regulations that have been codified in TMC Chapter 18.45
(Ordinance No. 2625, March 2, 2020)
• Shoreline Design Guidelines that have been codified in TMC Chapter 18.44
(Ordinance No. 2627, March 2, 2020)
• Board of Architectural Review Shoreline Design Criteria found in TMC Section
18.60.050 (Ordinance No. 2627, March 2, 2020)
• Shoreline Landscape Requirements that have been codified in TMC Chapter
18.52 (Ordinance Nos. 2625 and 2627, March 2, 2020)
• Definitions provided in TMC Chapter 18.06 (Ordinance Nos. 2625 and 2627,
March 2, 2020)
• Portions of the Critical Areas Protection Provisions that have been codified in
TMC Chapter 18.45 (Ordinance No. 2625, March 2, 2020) with exclusions
identified in Subsection 9 of this document and within TMC Chapter 18.44.
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2.2 SMP Elements
The SMA includes eight main issues, or "elements," to be addressed in each local shoreline
master program (RCW 90.58.100). To implement these elements, shoreline policies and
regulations are to be developed for each. The policies are found in the Shoreline Element of
the Comprehensive Plan and the regulations in Chapters 18.44 and 18.45 of the City's Zoning
Code. The elements required by the SMA are:
Economic Development
Public Access
Recreation
Circulation
Shoreline Uses
Conservation
Historical, cultural, educational and scientific element
Preventing or minimizing flood damage
Consistent with the Growth Management Act requirement to integrate the SMP and the
Comprehensive Plan, the City incorporated the required elements of a SMP noted above into
its Plan. Further direction for implementation of the required elements of SMPs is provided
through Zoning Code and Design Review requirements.
2.3 History of SMP Planning in Tukwila
Tukwila's Shoreline Master Program (SMP) was first adopted in 1974, in response to the
passage of the Shoreline Management Act (RCW 90.58). The SMP was later updated through
minor amendments in 1982 and 1987, none of which required the adoption of a new SMP.
In 1992-1993, as part of the preparation for a major revision to the City's Comprehensive
Plan, the City completed a Shorelines Background Report (1993), with the participation of
the Tukwila Tomorrow Citizen's Committee. This report established the basis for the
shoreline comprehensive plan goals and policies adopted in 1995.
Staff began the process to prepare a new SMP in 1999, based on the draft shoreline
guidelines that were in the process of adoption by the Department of Ecology at the time.
A grant from the Washington State Department of Ecology provided funding for a
Shoreline Inventory of all parcels within the 200 foot shoreline jurisdiction and a Shoreline
Design Manual.
New shoreline regulations approved by Ecology in 2000 were immediately appealed and
ultimately invalidated by the Shoreline Hearings Board in 2001. As a result, the City opted
to defer completing its SMP update process until new guidelines were issued by Ecology,
which occurred in 2003.
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In 2005, Tukwila received a grant (SMA Grant No. 0600234) to complete a comprehensive
update, including new technical analyses of shoreline conditions, restoration planning, and
the preparation of revised SMP goals, policies, and regulations.
In order to capitalize on previous citizens' involvement in the planning process, the City
decided to start the SMP update with the work begun in 1999, with revisions to address new
Ecology regulations and guidance, as well as changed conditions in the City's shoreline area.
The development of any SMP, as required by new shoreline regulations, involves three
specific steps:
• Shoreline inventory and characterization, preparation of a restoration plan,
preparation of a cumulative impacts analysis;
• Citizen involvement in development of policies and regulations; and
• Review by interested parties, including adjacent jurisdictions.
As part of this 2009 SMP update process, the City:
• Continued the previously started citizen involvement program utilizing the
Planning Commission, which serves as the City's permanent citizen advisory
body for land use issues, holding open houses and public hearings
• Coordinated and shared information with neighboring jurisdictions
• Updated and expanded the Shoreline Inventory and mapping (included as
Appendix A to this document)
• Prepared a Shoreline Restoration Plan (Appendix B)
• Proposed shoreline environment designations
• Proposed shoreline development policies
• Proposed shoreline development regulations
• Prepared a draft Cumulative Impacts Analysis
• Coordinated with Department of Ecology, submitting a staff draft SMP for review
and comment and meeting with Ecology staff
2.4 Current SMP Update Process
The City of Tukwila completed a comprehensive update to its Shoreline Master Program
in 2009, with additional revisions made in 2011. Washington State law requires
jurisdictions to periodically review and update their SMPs every eight years in accordance
with the SMA and its current guidelines and legislative rules to attain state approval. The
City of Tukwila's update started with an open house in the fall of 2018 and will be complete
in 2019.
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This periodic update is focused on:
• Reviewing relevant legislative updates since 2009 and incorporating any applicable
amendments.
• Ensuring consistency with recently adopted regulations for critical areas and flood
hazard areas.
• Streamlining and eliminating duplication in the documents.
• Addressing a limited number of policy questions such as a required levee profile,
use of flood walls and incentives for public access.
This periodic update will not:
• Re-evaluate the ecological baseline which was established as part of the 2009
comprehensive update.
• Extensively assess no net loss criteria other than to ensure that proposed
amendments do not result in degradation of the baseline condition.
• Change shoreline jurisdiction or environment designations.
3. DEFINITIONS
Definitions used in the administration of the Shoreline Master Program are incorporated
into the Definitions Chapter of the Zoning Code, TMC Chapter 18.06. In addition to the
definitions provided in TMC Chapter 18.06, Chapter 90.58 RCW, Chapter 173-26 WAC,
and Chapter 173-27 WAC apply within the shoreline jurisdiction. Where definitions in the
Tukwila Municipal Code conflict with state definitions, the definitions provided in RCW
or WAC shall control.
4. SHORELINE INVENTORY AND CHARACTERIZATION -
SUMMARY
Local jurisdictions updating their Shoreline Master Program (SMP) are required to prepare
an inventory and characterization of the shoreline resources within their boundaries. As
part of the City's prior SMP update, a Draft Inventory and Characterization Report and
Map Folio was prepared in December 2006, and finalized in the spring of 2007 following
technical review by Ecology and King County. The final report and map folio are included
as Appendix A to this SMP. While the report has been finalized, the City continues to
utilize the most recent information available, such as the recently updated FEMA (Federal
Emergency Management Agency) Revised Preliminary Digital Flood Insurance Rate Maps
(DFIRM), which were issued after the completion of the Inventory and Characterization
report.
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The purpose of the Inventory and Characterization Report was to conduct a baseline
inventory of conditions for water bodies regulated as "shorelines of the state" located in
the City of Tukwila. The area regulated under Tukwila's SMP is approximately 12.5 linear
miles along the banks of the Green/Duwamish River.
For the baseline inventory, the river shoreline was divided into four reaches:
1) Reach G1 -PAA (southern Potential Annexation Area);
2) Reach G1 (from the southern City boundary downstream to the Black
River/Green River confluence);
3) Reach G2 (from the Black River/Green River confluence downstream to the
northern City limits); and
4) Reach G2 -PAA (the northern Potential Annexation Area).
The reaches are depicted on Map 3.
The shoreline characterization identifies existing conditions, identifies current uses and
public access, evaluates functions and values of resources in the shoreline jurisdiction, and
explores opportunities for conservation and restoration of ecological functions. The
findings are intended to provide a framework for updates to the City's shoreline
management goals, policies, and development regulations. Key findings of the inventory
and characterization are summarized below.
4.1 Watershed Context and Shoreline Modifications
The City of Tukwila includes approximately 12.5 miles of the Green/Duwamish River and
is situated in the Puget Sound Lowlands at the transition from the fresh water Green River
to the tidally influenced Duwamish estuary ecosystem. The Green River basin is part of
the Green/Duwamish Water Resource Inventory Area (WRIA 9).
Historically, the Green/Duwamish River drained a significantly larger area than it does
today. The Green/Duwamish River has undergone extensive modifications in the past to
reduce channel migration and limit the extent and duration of valley flooding. The
modifications include both natural river course changes and major engineering projects in
the early part of the 20th Century that diverted the White, Black and Cedar Rivers to
neighboring basins. As a result, the overall freshwater discharge in the Green/Duwamish
River has been reduced to around a third of the pre -diversion era.
Seven pump stations also modify flows into the Green and Duwamish Rivers. Three of the
pump stations, Black River, P-17, and Segale, are operated by the Green River Flood
Control District, and four stations, Lift Stations 15, 17, 18, and 19 are operated by the City
of Tukwila. The Black River pump station is the largest station discharging flows to the
Duwamish River. This station is approximately 1,000 feet upstream of the Green—Black
River confluence, and is intended to both block floodwaters from the Green from
inundating the Black River and Springbrook Creek in the City of Renton, and also regulates
flows from Springbrook Creek into the Duwamish River. The P-17 pump station drains
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the P-17 Pond that collects surface water from a majority of the Urban Center. The Segale
pump station was installed to regulate soil saturation and piping during high river events
but does not add new flows to the river. The remaining City pump stations only operate
when gravity discharge to the river is prevented by high river events.
Levees and/or revetments were constructed along much of the Green/Duwamish River
through the City of Tukwila to increase bank strength and reduce flooding. In addition,
flows within the Green/Duwamish River were greatly modified by the construction of the
Howard A. Hanson Dam and installation of water diversions. These modifications
significantly reduced the severity of floods that historically covered much of the valley
bottom. The condition of the current system of levees and revetments is a growing source
of concern for King County and the cities involved, as many of the levees are aging and
do not meet current standards for either flood conveyance or stability. The Tukwila 205
levee on the left bank of the river in the Urban Center is not certified and areas protected
by this levee have been designated as "secluded" and regulated as outside of the 100 -year
Special Flood Hazard on the proposed 9/15/2017 FEMA Revised Preliminary Digital
Flood Hazard Insurance Rate Maps (DFIRM). Other levees in the City also do not meet
Corps of Engineers standards and are mapped as floodplain. These include portions of the
Tukwila South area and levees along the right bank of the river.
4.2 Biological Resources and Shoreline Functions
The Green/Duwamish River within the City of Tukwila provides important habitat for
several fish and some wildlife species, such as osprey. The aquatic environment within the
channel is an important corridor located at the transition from the freshwater riverine
environment to tidal estuarine environment of Elliott Bay. Almost every species of
anadromous fish migrates through this Transition Zone. The entire length of the
Green/Duwamish River within the City of Tukwila has been declared "critical habitat" for
Chinook salmon, Steelhead trout and bull trout. These species are listed as threatened
under the Federal Endangered Species Act.
One particularly important feature of Tukwila's shorelines is the habitat functions provided
by the Transition Zone between fresh and salt water associated with the Duwamish estuary.
In Tukwila, this area generally extends from the East Marginal Way bridge to the city's
northern limits. The Transition Zone between fresh and salt water has effectively been
pushed upstream from its historic location due to: (1) a significant reduction (70%) of
fresh water flowing into the Duwamish estuary (owing to the diversion of the White and
Cedar/Black Rivers); (2) channel dredging; and (3) reduction of flows as a result of the
construction of the Howard A. Hanson Dam. The establishment of heavy industrial uses
in the Transition Zone has replaced wetlands with impervious surfaces, and the stream
banks have been replaced by levees and other armoring, eliminating edge habitat which
slows flows and creating unrestrained rapid downstream flows. Spatial structure, residence
time, and the habitat available for fish refugia and rearing functions in the Duwamish
estuary have therefore been reduced and constrained. High densities of fish have been
observed utilizing what is left of this specific habitat. At the watershed scale, overall
increases in salmonid survival rates are dependent on the availability of sufficient
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Transition Zone habitat to accommodate fish while they adjust from fresh to salt water
(WRIA 9 Steering Committee, 2005).
Modifications to the river system have resulted over time in reduced levels of ecosystem
functioning, including hydrology, water quality, riparian habitat, and in -stream habitat.
Changes to hydrology are the result of modified flow regime due to dam construction,
diversion, and urban development. River management, piping of streams including the use
of tide -gates, pumped storm discharges, and levees have reduced the connection between
the rivers and their floodplains, changing the spatial extent of habitats, and increasing the
potential for negative water quality impacts. Disturbances to the channel banks have
resulted in areas that are dominated by non-native invasive species and generally devoid
of sufficient riparian vegetation. Wood, in the form of riparian trees and in -channel wood,
is generally lacking throughout the system, which negatively impacts riparian and aquatic
habitats as well as river temperatures that periodically exceed state standards and create
lethal and sublethal conditions for adult salmon.
4.3 Land Use
A. A History of the Green/Duwamish River and Tukwila's Shoreline: Origins of Land
Development Patterns
The Green River drains 492 square miles extending from the western Cascade Mountains to
Elliott Bay. The City of Tukwila lies at the lower 1/4 of the overall watershed. As the Green
River flows into the southern boundary of the City of Tukwila, it has drained approximately
440 square miles, or about 78 percent of its total drainage basin. Approximately 12.5 river
miles of the Green/Duwamish River are included within the City of Tukwila, from about River
Mile (RM) 16 to RM 3.7.
The Green/Duwamish River channel has been highly modified during the last 150 years.
Modifications range from the installation of levees and revetments to straightening and
dredging for navigation purposes. In general, the level of physical modification to the system
increases with distance downstream, culminating at the artificial Harbor Island that supports
industrial activities at the Port of Seattle. Several turning basins are maintained by periodic
dredging throughout the straightened reach. The highly modified portion of the
Green/Duwamish has also been the location of significant discharge of pollutants, resulting in
portions of the river being designated as Federal Superfund sites. Remediation, source control
and disposal activities are ongoing throughout the area.
Prior to European settlement of the Lower Green River Valley, the floodplain likely consisted
of a highly interspersed pattern of active and temporarily abandoned meandering channels,
secondary channels, logjams, riparian forest, and scrub -shrub wetlands. The proportion of
open channel to forest in the floodplain appears to have varied depending on the severity and
timing of floods. High flows resulted in wider channels and the creation of new channels
across the floodplain. Accounts of the channel systems indicate that major floods resulted in
channel avulsion (abrupt change in the course of a river), rerouting around logjams, and the
formation of new logjams. The area presently occupied by the City of Tukwila appeared
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historically to contain oxbow channels, secondary and backwater channels, and extensive
floodplain wetlands.
As part of regional flood control and river management efforts, significant watershed -scale
changes occurred to the major river drainages south of Elliott Bay, including changes to the
alignments and discharge points of the Cedar, Black, Green and White Rivers. In general,
these changes have reduced the amount of water flowing through the Green/Duwamish River
to approximately one third of historic conditions and have impacted fish habitat.
Land use changes between European settlement and the current day have occurred in two
general phases. From the mid 1800s to World War II, agriculture and timber harvesting
dominated the Lower Green River Valley. Population densities in the Lower Green River
Valley remained low until the Howard A. Hanson Dam project was completed in 1962,
providing flood protection for the valley. Levees have also been constructed along the banks
of the Green/Duwamish River, ranging from federally -certified levees to non -engineered
agricultural berms. Since the dam and levee systems have significantly decreased the extent
of flooding within the Lower Green River Valley, land development and urbanization have
occurred. For more discussion on the character of the Green/Duwamish River and an
inventory of river conditions, see the Shoreline Inventory and Characterization Report
prepared by ESA/Adolfson, May 2007, found in Appendix A.
Historically, the Green/Duwamish River Valley was known for its farmland. Farming was
established in the early 1900's after forested areas were cleared and transportation to the area
was improved. In 1906, construction of the Lake Washington Ship Canal eliminated flows
of the Black River into the valley, reducing valley flooding. As a result, the river valley
developed into highly productive farmland for the region.
In the early 1950's, the Port of Seattle proposed to convert much of the Green/Duwamish
River Valley to intensive industrial uses. These plans included converting the river into a
shipping canal, possibly reaching as far south as the City of Auburn. Valley landowners
countered this proposal by annexing large tracts of land into Tukwila to retain more control
over future land use decisions. With the construction of the Howard A. Hanson Dam in 1962
on the upper Green River, flooding in the valley was further reduced. Much of the river is
now contained within levees and surrounded by commercial and industrial development.
The Port's actions in the northern part of the River and drastic reduction in river flooding have
had a major influence on the development of the river valley. Today, Tukwila's portion of the
Green/Duwamish River is known as a center for retail, commercial and industrial uses. The
river remains inaccessible to shipping activity south of the Turning Basin, where it can be
accessed primarily by small watercraft, kayaks and canoes only. Land uses along the river
are mostly commercial and industrial activities, with a few residential areas. With the
designation of the Southcenter area as an Urban Center and the Duwamish Corridor as a
Manufacturing Industrial Center (MIC), this development pattern is expected to continue, and
to intensify as redevelopment occurs.
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B. Riverbank Vegetation
The natural environment along the river has been significantly altered from its original
riparian corridor by intense urban development and riverbank modification due to the
construction of levees, revetments or other shoreline armoring. Most native stands of trees
are gone, but have been replaced by new trees and plants in some areas. Landscaping with
native and non-native plantings have also been completed in conjunction with new
development along the corridor. Birds and small mammals are supported in both habitats.
While more natural habitat is found upstream, redevelopment of the shoreline has the potential
to provide appropriate landscaping and restoration of habitat that are more attractive to
wildlife and people and a more environmentally sensitive form of development
C. Public Access
The regional Green River Trail provides public access to existing shoreline amenities and
plans anticipate future linkages to Seattle's system. As redevelopment occurs, there will be
opportunities to provide other types of public access, including viewing platforms, boat ramps
and fishing areas.
4.4 Restoration Opportunities and Potential Use Conflicts
Past restoration work focused on the Green\Duwamish River (in Water Resource Inventory
Area 9) has resulted in good data collection and identification of potential restoration
opportunities. Significant restoration activities along the Green\Duwamish River are
already underway in the form of the multi -agency Green River Ecosystem Restoration
Project. Several opportunities have been identified on the river as part of the recently
adopted King County Flood Hazard Management Plan. Restoration opportunities focus on
several key elements:
• Removing non-native, invasive plant species and re -vegetating with native riparian
forest species;
• Removing artificial debris and walls that harden channel banks;
• Integrating the reconnection of floodplains, levee setbacks, and other ecosystem
restoration techniques with future flood and river management efforts; and
• Property acquisition to allow for levee setbacks, side channel reconnection, and
channel migration.
Two key issues illustrate constraints to implementing restoration and potential use conflicts
in Tukwila:
1) levee maintenance and management; and
2) existing development patterns and anticipated redevelopment.
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Discussion of shoreline planning for the Green River in Tukwila must acknowledge the
fact that, in light of the existing system of levees (including the federally authorized "205"
levees) and revetments, the City cannot act alone. There are a variety of regulatory
jurisdictions outside of the City with different responsibilities for maintenance,
management, and regulating of the levee system, including the U.S. Army Corps of
Engineers (the Corps), the Federal Emergency Management Agency (FEMA), King
County Flood Control District (KCFCD), and private property owners. The City of
Tukwila Public Works Department has overall responsibility for maintenance of all levees,
including the federally authorized Tukwila 205 levee, which extends from about the I-405
crossing to approximately S. 196th Street. The actual maintenance work on public levees
is performed by KCFCD.
The restoration of native tree and shrub species along the levees would increase riparian
habitat ecological functioning of this reach of the Green/Duwamish River, benefiting
salmonids as well as other species. However, the Corps of Engineers (responsible for
certifying the federal levee) believes that the root system of these trees could destabilize
levees, resulting in water piping (e.g., water infiltrating into and through levees along root
pathways at higher rates than it could through root -free soil) at high flows, and potential
levee failure if trees fall. For the Vegetation Free Zone of the levee, current Corps guidance
only allows grass as vegetative cover on the levees (USACOE, Engineering Manual 1110-
2-301). Current guidance also specifies a root -free zone where plantings can occur, but
roots will generally not penetrate this structural zone. Therefore, under current regulations,
to meet the requirements for federal levee certification, some vegetation was recently
removed and ongoing vegetation management will be required to maintain the levee
certification.
Under the SMA, removing trees and vegetation from the riparian zone of shorelines of the
state is in conflict with policies for vegetation conservation and enhancement. A possible
solution is to step back and re -slope the levees to create mid -slope benches where
vegetation can be planted that will not interfere with the levee prism as the levee system is
reconstructed to improve its stability. This would require additional easement area beyond
the existing maintenance easements that have been acquired along the length of the system.
The existing development pattern also represents constraints to implementing restoration
projects, including levee setbacks, off -channel habitat restoration, wetland and stream
restoration, and riparian zone enhancements. Most of Tukwila is fully developed, with
portions having a dense, urbanized land use pattern. The City's first SMP, in place since
1974, established a 40 -foot setback from the mean high water line. In places that have not
been redeveloped under current regulations there is little more than this 40 -foot zone that
is not intensely developed. Some places have somewhat more open space and less
development and thus have greater flexibility to accommodate potential habitat restoration
actions. The City's vision for future land use, based on its Comprehensive Plan, includes
maintenance and further development of its urban character, particularly its identity as a
regionally significant center for manufacturing, industrial, and commercial development.
A challenge lies ahead in determining how best to accommodate new and redevelopment
near the shoreline in a manner consistent with both the Comprehensive Plan and the
Shoreline Master Program in order to achieve "no net loss" of shoreline function.
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4.5 Conclusions
Like many rivers in the Puget Sound region, the course and dynamics of the
Green/Duwamish River have changed significantly as a result of development and
alteration of its watershed over the past century or so. Characteristic of many cities in the
region, Tukwila has grown and become highly urbanized. Continued growth is anticipated
and the City is planning for that growth. To a significant degree, the City has envisioned
and maintained a development pattern that preserved public access to the Green River and
assured setbacks of new buildings from the shoreline. Issues of concern today are focused
on reconstructing existing levees and revetments to protect existing development from
flood hazards and restore habitat, an effort that will take place over a number of years in
coordination with the King County Flood Control Zone District, King County and state
and federal agencies. There are many opportunities for conservation and restoration
actions in the City to restore or replace habitat while managing natural hazard areas.
SMP Public Review Draft Clean 15 2/20/2020
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2/20/2020
5. SHORELINE RESTORATION PLAN -SUMMARY
5.1 Background
The state guidelines require that local governments develop SMP policies that promote
"restoration" of impaired shoreline ecological functions and a "real and meaningful"
strategy to implement restoration objectives. The City's Shoreline Inventory and
Characterization Report identifies which shoreline ecological functions and ecosystem
processes have been impaired. Local governments are further encouraged to contribute to
restoration by planning for and supporting restoration through the SMP and other
regulatory and non -regulatory programs. As part of the SMP update process, the City
developed a Draft Shoreline Restoration Plan in February 2007. The draft plan was
finalized in May 2008 following technical review by King County and Ecology, and has
since been updated to include additional potential projects, address Ecology comments and
refocus priorities to projects within the Transition Zone. The Shoreline Restoration Plan
is included as Appendix B to the SMP.
The restoration plan builds on the Inventory and Characterization Report and provides a
framework to:
• Identify primary goals for ecological restoration of the Green/Duwamish
ecosystem;
• Identify how restoration of ecological function can be accomplished;
• Suggest how the SMP update process may accomplish the restoration of impaired
shoreline functions associated with the Green/Duwamish ecosystem; and
• Prioritize restoration projects so that the highest value restoration actions may be
accomplished first.
5.2 Assessment of Shoreline Functions
As summarized in the previous section, the shoreline inventory and characterization
analysis examined riverine and estuarine ecosystem processes that maintain shoreline
ecological functions, and identified impaired ecological functions. The inventory report
identified key ecosystem processes, and provided a qualitative assessment of their levels
of functioning at both a watershed and city reach scale. Key ecosystem functions identified
in the inventory, their level of alteration, and potential restoration actions are summarized
in Table 1.
As noted in the Shoreline Inventory and Characterization Report and summarized in the
Shoreline Inventory and Characterization Summary Section, many of the alterations to
shoreline functions and ecosystem processes in the Green/Duwamish River are due to
watershed scale issues within the upper watershed that cannot be fully restored or addressed
in the lower river section through Tukwila. However, hydrologic, water quality, and
habitat restoration measures in the City do have the potential to improve the overall
functioning of this important section of the Green/Duwamish River ecosystem that includes
the Transition Zone from fresh to salt water.
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Table 1. General Restoration Potential within the Shorelines of Tukwila
Function
Category
Function
Alterations to natural functioning
Potential Restoration Action within the
City
Hydrologic
Channel -Floodplain
Interaction
Presence of flood protection structures
(e.g., levees, riverbank revetments,
flood gates) and significant fill and
development along the shoreline limit
channel -floodplain interactions in
Tukwila.
1. Modify current levees and revetments to
increase channel and floodplain
interaction;
2. Excavate back or side channels.
Hydrologic
Upland sediment
generation
Fine sediment contribution to the river is
increased due to build-up and wash -off
from surrounding urban land uses.
Implement enhanced stormwater Best
Management Practices for fine sediment
removal in stormwater runoff.
Water
Quality
Retention of
particulates and
contaminants
Levees and revetments are virtually
continuous along the riverbanks,
limiting the potential to retain
particulates or contaminants contained
in stormwater sheet flows in the fluvially
dominated reaches. Particulates,
including sediment, are retained in the
tidally dominated reaches, as evidenced
by the need to dredge the estuary turning
basin.
1. Modify current levees and revetments to
increase channel and floodplain area;
2. Install native riparian species to increase
bank roughness.
Water
Quality
Nutrient cycling
As channel -floodplain interaction was
reduced, the channel became a conduit
for nutrients, offering little opportunity
for contact time with soils.
1. Increase riverine wetland area;
2. Install native riparian plant species;
3. Set back banks (revetments and levees).
Large Woody
Debris
(LWD) and
Organics
Maintain
characteristic plant
community
The majority of the shoreline within the
City of Tukwila is currently dominated
by non-native invasive weed species
(Himalayan blackberry, reed canary-
grass, and Japanese knotweed ) Some
higher quality areas of cottonwood,
alder, and willow exist in riparian areas
bordering open space, parkland, and
residential zones.
1. Remove invasive plants and install native
riparian species;
2. Incorporate LWD into bank stabilization
and restoration projects;
3. Institute programmatic weed control
activities along shoreline.
4. Promote bioengineering techniques for
shoreline stabilization projects.
LWD and
Organics:
Source of LWD
Despite the lack of many sources for
LWD, there are some large cottonwoods
and big leaf maples that occur along the
levees and revetment system.
1. Install native riparian species;
2. Incorporate LWD into bank stabilization
and restoration projects.
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5.3 Plans, Programs, and Completed Projects
The importance of the Green/Duwamish ecosystem within the Puget Sound has resulted in
significant focus on this area in terms of restoration potential. With the federal listing of
Chinook and bull trout as endangered species, watershed planning in the region (e.g.,
WRIA 9) has focused on developing a Salmon Habitat Plan (WRIA 9, 2005), to which the
City of Tukwila is a party. The plan establishes goals, objectives, and programmatic and
site specific actions to address restoration of habitat critical to salmon species in the
Green/Duwamish watershed.
Tukwila has already engaged in the greater regional restoration effort for the
Green/Duwamish River. The City Council has ratified the WRIA 9 Plan and contributes
resources to maintain operating staff. Tukwila has worked within the larger
Green/Duwamish River ecosystem restoration project to acquire or donate properties for
restoration (Cecil B. Moses Park, Codiga Farm, North Winds Weir, Duwamish Gardens).
WRIA 9 and other regional partners are currently working together to monitor baseline
conditions. Several projects from the WRIA 9 Plan are included on the City's Capital
Improvement Program (CIP) list; other projects will be added as CIP projects are
completed and funds are identified for new projects.
The restoration plan identifies several projects that have already been completed in the
Green/Duwamish River. These projects provide an excellent opportunity to learn about
what river restoration measures are the most effective. For example, it appears that the
back channel that was excavated at Codiga Farm provides important habitat for migrating
juvenile fish.
5.4 Restoration Opportunities
Based on the key ecosystem functions that are currently altered, there appear to be five
specific types of restoration actions that will most benefit the Green/Duwamish ecosystem
in Tukwila. These actions are intended to boost the levels of ecosystem functioning as part
of a self-sustaining ecosystem that will limit the need for future manipulation. While these
projects are intended to restore many ecosystem functions, the restoration activities will
occur in the highly urban valley bottom, and as a result, cannot fully achieve pre -
disturbance channel conditions. In addition, some restoration actions must occur at the
watershed scale, which will restore ecosystem functions that cannot be addressed solely
within Tukwila or as part of the SMP.
• Enlarging channel cross-sectional area. This action could include setting back
levees and re -sloping banks to reduce steepness. These actions will increase flood
storage, allow for more stable levees, restore some floodplain area, provide a
larger intertidal zone in this important transitional area, and provide a more
natural transition from aquatic to upland habitats. The Transition Zone is
identified in Map 2.
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• Enhancing existing habitats. These actions could include the removal of non-
native invasive vegetation, installation of native riparian vegetation, and
installation of LWD below Ordinary High Water. This action will improve the
functioning of the aquatic, riverine wetland, and riparian habitats that currently
exist along the Green/Duwamish River.
• Creating off -channel habitat areas. This action would create off channel areas
through the excavation of historic fill or floodplain materials to create back
channels as fish foraging and refugia areas.
• Reconnecting wetland habitat to the river. This action would reconnect an old
oxbow wetland to the river, allowing for off -channel habitat (Nelson Side
Channel).
• Removing fish barriers where tributary streams discharge to the river. This
action would remove flap gates and install fish -friendly flap gates at the mouths
of Tukwila's three major streams (Gilliam, Southgate and Riverton) and possibly
restore habitat area at these locations in the shoreline jurisdiction.
5.5 Potential Projects and Priorities
The restoration plan summarizes 26 potential projects as specific restoration projects within
the shorelines of Tukwila. Most of the restoration projects are part of ongoing restoration
planning through the WRIA 9 watershed planning process. Additionally, opportunities
exist to enhance riparian vegetation along the majority of the Green/Duwamish River.
The restoration plan provides a preliminary qualitative (high, medium, low) project ranking
system. Within this ranking system, the highest priority location for restoration projects is
within the Transition Zone. The Transition Zone is identified in Map 2.
High priority projects will typically:
• Address both hydrologic and habitat ecosystem functions;
• Have opportunity for multiple funding sources;
• Include freshwater tributary channels; and/or
• Not require additional property acquisition.
Medium priority projects will typically:
• Address limited ecosystem functions; and
• Be eligible for multiple funding sources, and/or require property acquisition.
Low priority projects will typically:
• Only focus on habitat enhancement;
• Will be used as mitigation to offset impacts elsewhere; or
• Not be eligible for multiple funding sources.
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6. SHORELINE GOALS AND POLICIES
The goals and policies that lead and inspire Tukwila's shoreline actions are found in the
Shoreline Element of the City's 2015 Comprehensive Plan. These, along with the narrative
in that Chapter, were updated based on the 2009 SMP and 2011 revisions approved by the
Department of Ecology.
7. SHORELINE ENVIRONMENT DESIGNATIONS
The City of Tukwila's Shoreline Master Program (SMP) establishes a system to classify
shoreline areas into specific "environment designations." This system of classifying
shorelines is established by the Shoreline Management Act (RCW 90.58) and Master
Program Guidelines (WAC 173-26-211). The purpose of shoreline environment
designations is to provide a uniform basis for applying policies and use regulations within
similar shoreline areas. Generally, shoreline designations should be based on existing and
planned development patterns, biological and physical capabilities and limitations of the
shoreline, and a community's vision or objectives for its future development.
7.1 Pre 2009 Regulatory Framework
Tukwila's first SMP, adopted in 1974, designated all shorelines as "Urban." At the time
the 1974 SMP was developed, all of the land in Tukwila's shoreline jurisdiction was either
zoned commercial/industrial or was developed with urban uses. The SMP defined the
Urban Environment as "areas to be managed in high intensive land uses, including
residential, commercial, and industrial development and accessory uses, while providing
for restoration and preservation to ensure long-term protection of natural and cultural
resources within the shoreline" (Tukwila, 1974). The SMP further stated that the
management objectives for the shoreline "are directed at minimizing adverse impacts on
the river and shoreline ecology, maximizing the aesthetic quality and recreational
opportunities of the river shore, and recognizing the rights and privileges of property
owners" (Tukwila, 1974). Within the Urban Environment, Tukwila's SMP employed a
tiered system of regulations based on the distance from the Green/Duwamish River mean
high water mark (MHWM). These tiered management zones are generally described below
and illustrated on Figure 1:
• River Environment/Zone: A 40 -foot wide zone extending landward from
MHWM and having the most environmentally protective regulations;
• Low -Impact Environment/Zone: The area between the River Environment and
100 feet from the MHWM; and
• High -Impact Environment/Zone: The area between 100 and 200 feet from the
MHWM.
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The City also administered the King County Shoreline Master Program for the areas which
had been annexed since the adoption of the City's SMP in 1974. These areas were
designated Urban and the setbacks from Ordinary High Water Mark varied from 20 feet to
50 feet depending on whether the use was water dependent, single family or
commercial/industrial. See Annexation History (Map 1) for an identification of the areas
where the City administered the County's SMP.
ir
200'
URBAN ENVIRONMENT
100'
HIGH
IMPACT
ZONE
60' 40'
( ,
LOW
IMPACT
ZONE
RIVER
ZONE
RIVER
ii
200'
40'
F-,
RIVER
ZONE
URBAN ENVIRONMENT
60'
LOW
IMPACT
ZONE
100'
HIGH
IMPACT
ZONE
4 -MEAN HIGH WATER LINE
Figure 1. Pre 2009 Tukwila SMP Shoreline Management Zones
(1974 SMP; TMC Chapter 18.44)
7.2 Key Findings of the Shoreline Inventory / Characterization Report and
Restoration Plan
This section summarizes findings from the Inventory and Characterization Report and
Restoration Plan elements of the SMP update (Appendices A and B). These findings
inform the goals, policies, regulations, and the development and application of
environment designations. In this context, the key findings can be summarized as follows:
• The Green/Duwamish River throughout Tukwila is a critical resource for salmonids
and other species. Adult salmon heading upstream to spawn require cool water; and
juveniles heading downstream require food and refuge from high flows. The
Transition Zone, which extends from river mile 10 downstream through the
northern City limits (see Map 2), where juvenile salmon adjust from fresh to salt
water habitat (osmoregulate), is of critical importance because of significant habitat
losses over the years. Additionally, the river provides migratory habitat for
numerous fish species, as well as riparian habitat for a variety of wildlife.
• The entire Green/Duwamish River and its tributaries are a critical resource for
federally protected Muckleshoot Indian Tribe fishing.
• The river is a critical resource for some water dependent uses north of the Turning
Basin.
• The river is an important recreational resource for sport fishing, small watercraft
and Green River Trail users.
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• At an ecosystem scale, the habitat is largely homogenous throughout the city. In
addition, many ecosystem processes are largely controlled by up -river
characteristics, particularly the Howard A. Hanson Dam and are little affected by
actions in the City, except for such functions as water quality (especially fine
sediment capture and filtering of contaminants in stormwater), local surface
hydrology (stormwater from increasing amounts of impervious surfaces and
contribution to peak flows of the river), riparian habitat, and temperature control
(shading from riparian habitat). With the exception of the functions provided by
the transitional mixing zone from salt to fresh water, habitat conditions and
functions are relatively similar throughout the shoreline. The Transition Zone
needs greater protection and restoration focus than other sections of the shoreline
in the city.
• Restoration opportunities are numerous and spatially distributed throughout
Tukwila's shoreline. Activities that provide restoration of both floodplain
functions and habitat functions should be prioritized, particularly those projects in
the Transition Zone. Policies should promote and regulations should enable the
City to accomplish restoration goals and actions.
7.3 State Environment Designation System
State Master Program Guidelines (WAC 173-26-211) establish the environment
designation system for shorelines regulated by the Shoreline Management Act. The
guidelines (WAC 173-26-150 and 176-26-160) give local jurisdictions the option to plan
for shorelines in designated Urban Growth Areas (UGA) and Potential Annexation Areas
(PAA) as well. The City can "pre -designate" shoreline environments in its designated PAA
as part of this planning process. However, shorelines in the PAA would continue to be
regulated under the provisions of the King County SMP until the City annexes those areas.
The County's SMP designates the City's North PAA and the South PAA as High Intensity.
The guidelines (WAC 173-26-211(4)(b)) recommend six basic environment designations:
High-intensity
Shoreline residential
Urban conservancy
Rural conservancy
Natural
Aquatic
Local governments may establish a different designation system, retain their current
environment designations and/or establish parallel environments provided the designations
are consistent with the purposes and policies of the guidelines (WAC 173-26-211(4)(c)).
The guidelines also note that local shoreline environment designations should be consistent
with the local comprehensive plan (WAC 173-26-211(3)).
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For each environment designation, jurisdictions must provide a purpose statement,
classification criteria, management policies and environment specific regulations. Table 2
describes the purpose for each of the recommended designations in the state guidelines.
For each designation, the potential applicability to Tukwila is noted.
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Table 2. State Recommended Environment Designation System - WAC 173-26-211 (5)
Environment
Designation
Purpose
Applicability to Tukwila
Aquatic
The purpose of the "aquatic" environment is to
protect, restore, and manage the unique
characteristics and resources of the areas
waterward of the ordinary high-water mark.
This designation will be used for the area
waterward of the ordinary high water mark
which includes the water surface along
with the underlying lands and the water
column.
Natural
The purpose of the "natural" environment is to
protect those shoreline areas that are relatively
free of human influence or that include intact
or minimally degraded shoreline functions
intolerant of human use.
While the Green River shorelines in
Tukwila provide some important
ecological functions, the river and
adjacent uplands throughout Tukwila have
been significantly altered by dense urban
development and are generally armored or
otherwise modified.
Rural
Conservancy
The purpose of the "rural conservancy"
environment is to protect ecological functions,
conserve existing natural resources and
valuable historic and cultural areas in order to
provide for sustained resource use, achieve
natural floodplain processes, and provide
recreational opportunities.
Not applicable to Tukwila. All of the
City's shorelines are urbanized. Potential
annexation areas are either urbanized or
proposed for intensive development.
Urban
Conservancy
The purpose of the "urban conservancy"
environment is to protect and restore
ecological functions of open space, floodplain
and other critical areas where they exist in
urban and developed settings, while allowing
a variety of compatible uses.
This designation is applicable in that the
Green River is an important natural
resource. The most significant shoreline
function provided in Tukwila is related to
fish and wildlife habitat. Open space is
limited by the existing development
pattern and floodplains are largely
disconnected by a series of levees,
revetments, and other infrastructure.
Shoreline
Residential
The purpose of the "shoreline residential"
environment is to accommodate residential
development and appurtenant structures that
are consistent with this chapter. An additional
purpose is to provide appropriate public access
and recreational uses.
This designation is most applicable for
those portions of Tukwila's shorelines
where the existing and planned
development pattern is for low density
(i.e., predominantly single-family)
residential uses or public recreation uses.
High -Intensity
The purpose of the "high-intensity"
environment is to provide for high-intensity
water -oriented commercial, transportation,
and industrial uses while protecting existing
ecological functions and restoring ecological
functions in areas that have been previously
degraded.
This designation is applicable along only
part of Tukwila's shorelines, in the
Manufacturing and Industrial Center
(MIC) north of the Tuming Basin. Water -
dependent uses are currently limited, as
only a small portion of the river in Tukwila
is navigable for commercial purposes, and
much of the river has levees, thus
restricting use immediately adjacent to the
river.
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7.4 Environment Designations
The Natural and Rural Conservancy Environments are not well suited to a highly
developed, urbanized river that is navigable for only a small portion of the system and is
significantly constrained by levees for flood management, such as the Green/Duwamish
River in Tukwila. The City's Shoreline Environments, which are identified on Map 3,
are:
• Shoreline Residential Environment
• Urban Conservancy Environment
• High -Intensity Environment
• Aquatic Environment
The City designated a buffer to replace the prior system of parallel shoreline management
zones. Instead of the prior River Environment, a minimum buffer was established for each
shoreline environment and allowed uses were designated for the buffer area along the river
and the remaining shoreline jurisdiction. This system is intended to facilitate the City's
long-range objectives for land and shoreline management, including:
• Ensuring no net loss of ecological shoreline functions;
• Providing for habitat protection, enhancement, and restoration to improve degraded
shoreline ecological functions over time and protection of already restored areas;
• Allowing continued and increased urban development in recognition of Tukwila's
role as a regionally significant industrial and commercial center; and
• Providing for improved flood control in coordination with King County and the
Army Corps of Engineers.
Table 3, on the following page, provides a summary of the characteristics of the river
shoreline in Tukwila to set the stage for the discussion in Section 7.5 on the determination
of shoreline buffers.
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Table 3. Summary of Buffer Widths for Land Use Zones and Shoreline Ecological
Conditions
Area
Characteristics
Environment
Buffer
Modification
MIC/H &
Fresh/Salt Water
High Intensity
100'
The Director may reduce the
MIC/L
zoned
Transition Zone,
Lower flooding
standard buffer on a case-by-case
basis by up to 50% upon
property
risk, Less than 20'
construction of the following cross
from North
difference from
section:
City Limits
OHWM to top of
- 1. Reslope bank from OHWM
to EMWS
bank, tidal
(not toe) to be no steeper than
Bridge, and
North
influence
3:1, using bioengineering
techniques
Potential
Annexation
- 2. Minimum 20' buffer landward
from top of bank
Area
- 3. Bank and remaining buffer to
be planted with native species
with high habitat value
Comment: Maximum slope is
reduced due to measurement from
OHWM and to recognize location in
the Transition Zone where
pronounced tidal influence makes
work below OHWM difficult.
Any buffer reduction proposal must
demonstrate to the satisfaction of the
Director that it will not result in
direct, indirect or long-term adverse
impacts to the river. In all cases a
buffer enhancement plan must also
be approved and implemented as a
condition of the reduction. The plan
must include using a variety of
native vegetation that improves the
functional attributes of the buffer
and provides additional protection
for the shoreline ecological
functions.
LDR zoned
Moderate flooding
Shoreline
Distance
Removal of invasive species and
property
risk, Less than 25'
Residential
required
replanting with native species of
w/o levees
difference from
to set
high habitat value voluntary unless
from
OHWM to top of
back
triggered by requirement for a
EMWS to
bank, tidal
slope
Shoreline Substantial Development
1-405
influence on
northern section
from toe
at 2.5:1
plus 20'
setback,
Min. 50'
width
permit.
SMP Public Review Draft - Strikeout 27
2/20/2020
Area
Characteristics
Environment
Buffer
Modification
LDR zoned
property with
levees from
EMWS to
I-405
Moderate flooding
risk, Less than 25'
difference from
OHWM to top of
bank, tidal
influence on
northern section
Shoreline
Residential
125'
Upon reconstruction of levee in
accordance with City levee
standards, the Director may reduce
the buffer to actual width required.
Comment: This applies to City -
owned property at Fort Dent.
Commercially
zoned
property from
42nd Ave S.
Bridge to
I-405
Moderate flooding
risk, Less than 25'
difference from
OHWM to top of
bank
Urban
Conservancy
100'
The Director may reduce the
standard buffer on a case-by-case
basis by up to 50% upon
construction of the following cross
section:
- 1. Reslope bank from toe to be
no steeper than 3:1, using
bioengineering techniques
- 2. Minimum 20' buffer
landward from top of bank
- 3. Bank and remaining buffer to
be planted with native species
with high habitat value
Any buffer reduction proposal
must demonstrate to the
satisfaction of the Director that it
will not result in direct, indirect or
long-term adverse impacts to
shoreline ecological functions. In
all cases a buffer enhancement
plan must also be approved and
implemented as a condition of the
reduction. The plan must include
using a variety of native vegetation
that improves the functional
attributes of the buffer and
provides additional protection for
the shoreline ecological functions.
West River
bank from
I-405 to
South City
Limit,
Tukwila 205
Levee and
South
Annexation
Area
High flooding risk,
Federally certified
and County levee,
large water level
fluctuations
Urban
Conservancy
125'
Upon construction or
reconstruction of levee in
accordance with City levee
standards the Director may reduce
the buffer to the actual width
required. In no case shall the
buffer be less than 50 feet.
SMP Public Review Draft Clean 28 2/20/2020
Area
Characteristics
Environment
Buffer
Modification
East River
bank
without
levee from
I-405 south
to City
Limits
Moderate flooding
risk, 20 to 25'
difference from
OHWM to top of
bank, Moderate
slumping risk,
large water level
fluctuations
Urban
Conservancy
100'
The Director may reduce the
standard buffer on a case-by-case
basis by up to 50% upon
construction of the following cross
section:
- 1. Reslope bank from toe to be no
steeper than 3:1, using
bioengineering techniques
- 2. Minimum 20' buffer landward
from top of bank
- 3. Bank and remaining buffer to
be planted with native species
with high habitat value
Any buffer reduction proposal must
demonstrate to the satisfaction of the
Director that it will not result in
direct, indirect or long-term adverse
impacts to shoreline ecological
functions. In all cases a buffer
enhancement plan must also be
approved and implemented as a
condition of the reduction. The plan
must include using a variety of
native vegetation that improves the
functional attributes of the buffer
and provides additional protection
for the shoreline ecological
functions.
East River
bank with
levee from
I-405 to
South City
Limit
Moderate flooding
risk, 20 to 25'
difference from
OHWM to top of
bank, Moderate
slumping risk,
large water level
fluctuations
Urban
Conservancy
125'
Upon reconstruction of levee in
accordance with City levee
standards the Director may reduce
the buffer to the actual width
required for the levee. In no case
shall the buffer be less than 50 feet.
Any
shoreline
environment
where street
or road runs
parallel to
the river
through the
buffer
End buffer on river side of existing
improved street or roadway.
SMP Public Review Draft Clean 29 2/20/2020
r s MILE
Map 3
/
Turning Basin
Reach G2
Legend
Tukwila City Limits
PM Potential Annexation Areas
-"••••• Urban Conservancy Shoreline Environment
w�. High Intensity Shoreline Environment
r.�
—w.• Shoreline Residential Environment Me
SMP Public Review Draft Clean
30
2/20/2020
7.5 Determination of Shoreline Buffers
The determination of the buffer distances for each shoreline environment was based on
several factors including the analysis of buffer functions needed for protecting and
restoring shoreline ecological function (as presented in the Shoreline Inventory and
Characterization Report) and the need to allow space for bank stability and for protecting
human life and structures from damage from high flows, erosion and bank failures. Safety
of residents and people who work in buildings along the shoreline has become even more
important in recent years due to the increase in stormwater entering the river from
increasing impervious surfaces throughout the watershed and increasing frequency and
intensity of flows during high rain events. These higher and more frequent flows will put
more stress on over -steepened banks all along the river, increasing the possibility of bank
erosion, levee failures, and bank failures. Thus, ensuring that new structures are not built
too close to the river's edge is crucial to avoid loss of human life.
Staff also reviewed the rationale for the buffer widths established for watercourses under
TMC Chapter 18.45, the Critical Areas Ordinance, as well as buffer widths recommended
by resource agencies, such as the State Department of Fish and Wildlife, Department of
Natural Resources and the recent Biological Opinion issued by National Marine Fisheries
Service in relation to FEMA's National Flood Insurance Program.
The final buffer widths proposed by staff for each shoreline environment attempted to
balance shoreline ecological function needs, human life and property protection needs
(including future levee repair/reconstruction), existing land use patterns, and state and
federal agency policies.
The following information summarizes the analysis carried out and the rationale used for
determining buffer widths.
A. Buffer Functions Supporting Shoreline Ecological Resources, Especially
Salmonids
Buffers play an important role in the health of any watercourse and an even more important
role when considering the health of salmonids in the Green/Duwamish River system. The
key buffer functions for the river are summarized below.
The Shoreline Management Act and the Department of Ecology regulations require
evaluation of ecological functions and that local SMPs ensure that the policies and
regulations do not cause any net loss of shoreline ecological function. In addition, the SMP
must identify mechanisms for restoration of lost ecological functions.
The crucial issue for the Green/Duwamish River is the presence of salmonids that are on
the Endangered Species list. To protect and restore ecological functions related to these
species it is important to provide for the installation of native vegetation along the
shoreline. Such vegetation provides shade for improving temperature conditions in the
river and habitat for insects on which fish prey. Trees along the shoreline also provide a
SMP Public Review Draft Clean 31 2/20/2020
source of large woody debris (tree trunks, root wads, limbs, etc. that fall into the water),
which in turn provides pooling and areas of shelter for fish and other animals. In order to
allow for planting of native vegetation, banks need to be set back to allow for less steep
and more stable (requiring less armoring) slopes, so that they can be planted, which is
crucial for improving shoreline ecological functions that are needed in the river.
The buffer widths needed to achieve a particular buffer function vary widely by function
type from as little as 16 feet for large woody debris recruitment (assuming the buffer has
large trees) to over 400 feet for sediment removal. The Washington State Department of
Fish and Wildlife (WDFW) recommends a riparian buffer width of 250 feet for shorelines
of statewide significance (this applies to the Green/Duwamish River). The Washington
Department of Natural Resources (WDNR) recommends a riparian buffer of 200 feet for
Class 1 Waters (the Green/Duwamish River is a Class 1 Water under the WDNR
classification scheme). The National Marine Fisheries Service (responsible at the federal
level for overseeing protection of endangered salmonids under the Endangered Species
Act) has recommended a buffer of 250 feet in mapped floodplain areas to allow for
protection of shoreline functions that support salmonids.' Tukwila's Critical Areas
Ordinance (TMC Chapter 18.45) has established a 100 -foot buffer for Type 2 watercourses
in the city (those that bear salmonid species).
The key buffer functions for the river are summarized below.
1. Maintenance of Water Quality
Salmonid fish require water that is both colder and has lower nutrient levels than
many other types of fish. Vegetated shoreline buffers contribute to improving
water quality as described below.
a. Water Temperature: The general range of temperatures required to support
healthy salmonid populations is generally between 39 degrees and 63 degrees.
Riparian vegetation, particularly forested areas, can affect water temperature
by providing shade to reduce exposure to the sun and regulate high ambient
air temperatures.
b. Dissolved Oxygen: Dissolved oxygen is one of the most influential water
quality parameters for aquatic life, including salmonid fish. The most
significant factor affecting dissolved oxygen levels is water temperature—
cooler streams maintain higher levels of oxygen than warmer waters.
c. Metals and Pollutants: Common pollutants found in streams, particularly in
urban areas, are excessive nutrients (such as phosphorous and nitrogen),
pesticides, bacteria and miscellaneous contaminants such as PCBs and heavy
metals. Impervious surfaces collect and concentrate pollutants from different
sources and deliver these materials to streams during storm events. The
1 Endangered Species Act — Section 7 Consultation, Final Biological Opinion and Magnuson—Stevens Fishery
Conservation and Management Act Essential Fish Habitat Consultation, Implementation of the Flood
Insurance Program in the State of Washington, Phase One Document, Puget Sound Region, September, 2008.
SMP Public Review Draft Clean 32 2/20/2020
concentration of pollutants increases in direct proportion to the total amount
of impervious area. Undisturbed or well vegetated riparian buffer areas can
retain sediment, nutrients, pesticides, pathogens and other pollutants,
protecting water quality in streams. Elevated nitrogen and phosphorus levels
in runoff are a typical problem in urban watersheds and can lead to increased
in -stream plant growth, which results in excess decaying plant material that
consumes oxygen in streams and reduces aquatic habitat quality.
2. Contributing to in -stream structural diversity
a. Large woody debris (LWD) refers to limbs and tree trunks that naturally fall
into the stream bed from a vegetated buffer. LWD serves many functions in
watercourses. LWD adds roughness to stream channels, which in turn slows
water velocities and traps sediments. Sources of LWD in urban settings are
limited where stream corridors have been cleared of vegetation and developed
and channel movement limited due to revetments and levees. Under natural
conditions, the normal movement of the stream channel, undercutting of
banks, wind throw, and flood events are all methods of LWD recruitment to
a stream channel.
b. LWD also contributes to the formation of pools in river channels that provide
important habitat for salmonids. Adult salmonids require pools with
sufficient depth and cover to protect them from predators during spawning
migration. Adult salmon often hold to pools during daylight, moving
upstream from pool to pool at night.
3. Providing Biotic Input of Insects and Organic Matter
a. Vegetated buffers provide foods for salmonids and other fish, because insects
fall into the water from overhanging vegetation.
b. Leaves and other organic matter falling into streams provide food and
nutrients for many species of aquatic insects, which in turn provide forage for
fish.
B. Bank Stability and Protection of Human Lives and Structures
The main period of runoff and major flood events on the Green River is from November
through February. The lower Green and Duwamish levees and revetments form a nearly
continuous bank protection and flood containment system. Farmers originally constructed
many of these levees and revetments as the protection to the agricultural lands of the area
and this original material is still in place as the structural core. In particular, these
protection facilities typically have over -steepened banks and areas with inadequate rock
buttressing at the toe, and lack habitat -enhancing features such as overhanging vegetation
or in -water large woody debris. Because of these design and construction shortcomings,
the protection to riverbanks has not always performed as intended. Instead, there have
been bank failures that have threatened structures and infrastructure; erosion of banks—
making them even steeper; and damage to levees that has required a series of repair
proj ects.
SMP Public Review Draft Clean 33 2/20/2020
The damage to the levee system in storm events led to discussions among the City, U.S.
Army Corps of Engineers and the King County Flood Control District to determine the
best levee design to prevent the recurring problem of continued levee repairs. The criteria
used to design a levee profile are:
• Public safety;
• Maintaining levee certification;
• Solutions that eliminate or correct factors that have caused or contributed to the
need for the levee repair;
• Levee maintenance needs; and
• Environmental considerations.
To overcome the existing problems and to reduce future maintenance and repair costs, the
Corps chose to lessen the overall slope to a stable grade. This selected method is consistent
with recommendations set forth in the Corps of Engineers' Manual for Design and
Construction of Levees (EM 1110-2-1913) for slope stability. It also is consistent with the
levee rehabilitation project constructed on the nearby Briscoe School levee that has proven
to be a very effective solution to scour problems—the design slows the river down,
provides additional flood storage and allows a vegetated mid -slope bench for habitat
improvements. This profile was used to repair two areas of the federally -certified levee in
Tukwila—the Lily Point project and the Segale project, which were about 2,000 linear feet
of repairs. Costs of these repairs were around $7 million dollars, not including any costs
of land acquisition for laying back the levees. It is expected that the use of this levee design
or an environmentally superior solution will reduce the need to continually repair the levee
in those areas, thus avoiding such high expenditures in the future and saving money in the
long run.
The profile discussed above is illustrated in Figure 2 below:
SMP Public Review Draft Clean 34 2/20/2020
(— 10'
18'
Typical Shoreline Buffer in Leveed Areas -Width Will Vary
2 r� 1-11
2'
17
iitir' n'�` " n:1- 47 `\Ii1
Reconfigured Levee
Vegetated Bench
Willows
1.5 Existing Levee
Maintenance Easement
' Reconfigured Slope averages 2.5:1 with bench
c']
Ordinary High
Water Mark
OHWM
Minimum Levee Profile
Not To Scale
Figure 2. Briscoe Levee Profile
Because of the similarities in the soil conditions and taking into consideration the tidal
influence, the Green/Duwamish River can be divided into three areas—South of I-405;
North of I-405; and areas around residential neighborhoods. Looking at the slope geometry
and the difference in height between the ordinary high water mark and the 100 -year flood
elevation for these three areas, it was found that 125 feet of setback distance (buffer) is
needed to accommodate the "lay back" of the levee in the area south of I-405 and around
Fort Dent Park.2 During high flow events, the water surface can be as much as 16 feet
above the OHWM in these areas. At locations further downriver, the water surface
elevation difference is much less pronounced due to the wider channel and proximity to
Puget Sound. For areas without levees, north of I-405 and those areas south of I-405 on
the east side of the river (right bank), a 100 -foot setback distance is required to
accommodate the slopes needed for bank stability. Within residential neighborhoods, a
minimum 50 -foot setback is justified because of the less intense land use associated with
single-family home construction and the estimated amount of space needed to achieve the
natural angle of repose for a more stable slope.
Even though the above explanation for determining appropriate buffer distance used levee
design as the example, the same problems exist where there are no levees. The river makes
no distinction between an over -steepened slope associated with a levee or a riverbank.
Scouring within the river will cause sloughing and slope stability will be weakened,
potentially resulting in the loss of structures. In fact, the non -leveed riverbank can be more
2 The 125 foot distance includes a slope no steeper than 2.5:1 with a mid -slope bench incorporated, 18 feet
at the top of the levee and 10 feet on the back side of the levee for access and inspection.
SMP Public Review Draft Clean 35 2/20/2020
prone to these problems since they tend to be steeper and consist mainly of sand and silt.
This makes them susceptible to erosion. Because the non -leveed riverbanks are for the
most part privately owned, they are not actively monitored for damage by the City or
County.
C. Conclusions
The determination of buffer widths was based on two important criteria:
(1) the need to achieve bank stability and protect structures along the shoreline from
damage due to erosion and bank failures; and
(2) to protect and enhance shoreline ecological function.
Applying the 200 to 250 foot buffer widths recommended by WDFW and WDNR would
not be practical given the developed nature of the shoreline. It was also felt that a buffer
less than that already established for Type 2 Watercourses under the City's Critical Areas
Ordinance would not be sufficiently protective of shoreline functions, unless those
functions were enhanced through various restoration options. Therefore, 100 feet was
established as the starting point for considering buffer widths from the standpoint of
shoreline ecological function in each of the Shoreline Environments. Between 100 and
125 feet was the starting point for buffer widths from the standpoint of bank stability and
property protection.
Thus buffers were established taking into account (as explained in the following sections)
the characteristics of each Shoreline Environment, needs for protection/restoration of
shoreline ecological functions, and needs for stable banks and protection of human life and
property.
7.6 Shoreline Residential Environment
A. Designation Criteria
All properties zoned for single-family use from the ordinary high water mark landward 200
feet. In addition, those areas zoned for single family use but developed for public
recreation or open space within 200 feet of the shoreline shall also be designated Shoreline
Residential, except Fort Dent Park.
B. Purpose of Environment and Establishment of River Buffer
The purpose of the Shoreline Residential Environment is to accommodate urban density
residential development, appurtenant structures, public access and recreational activities.
However, within the 200 foot shoreline jurisdiction in the Shoreline Residential
Environment there will be a protective buffer along the river, where development will be
limited to protect shoreline function.
SMP Public Review Draft Clean 36 2/20/2020
The purpose of the river buffer in the shoreline residential environment is to:
• Ensure no net loss to shoreline ecological functions;
• Help protect water quality and habitat function by limiting allowed uses;
• Protect existing and new development from high river flows by ensuring
sufficient setback of structures;
• Promote restoration of the natural character of the shoreline environment; and
• Allow room for reconstructing over -steepened riverbanks to achieve a more
stable slope and more natural shoreline bank conditions and avoid the need for
shoreline armoring.
C. Analysis of Development Character of Residential Shoreline
An analysis was prepared that looked at the residential properties along the shoreline and
identified the number of parcels with structures within 50 feet and 100 feet of the OHWM.
This analysis showed the following:
ZONE
Number of
parcels
within 50
feet of
OHWM
Number of
vacant
parcels
within
50 feet
Number of
parcels with
structures
within
50 feet / %
Number of
parcels
within
100 feet of
OHWM
Number of
vacant
parcels
within
100 feet
Number of
parcels with
structures
within
100 feet / %
LDR
135
12
67 / 49%
201
25
165 / 82%
As can be seen from the chart above, almost half of the parcels in the residential
neighborhoods have a structure within 50 feet of the OHWM—a direct result of the current
King County regulations. To apply a buffer width that is consistent with the City's Critical
Areas Ordinance of 100 feet would create a situation where 82% of the properties along
the river would have nonconforming structures as they relate to the proposed shoreline
buffer.
Expansion of single family nonconforming structures in the proposed SMP buffer would
be governed by Tukwila Municipal Code Section 18.44.110, which permits an expansion
of only 50% of the square footage of the current area that intrudes into the buffer and only
along the ground floor of the structure. For example, if 250 square feet of a building
extended into the proposed buffer, the ground floor could be expanded a maximum of 125
feet in total area along the existing building line.
A buffer of 100 feet was considered for the shoreline residential properties, with the
potential of a property owner applying for a buffer reduction of 50%; however, under the
Shoreline Management Act, this would have required an application for a shoreline
variance for each requested buffer reduction, a process that requires review and approval
both at the local and state level (Ecology must review and approve the variance in addition
to the City of Tukwila). This did not seem a reasonable process to require of so many
property owners.
SMP Public Review Draft Clean 37 2/20/2020
The riverbank in the Shoreline Residential Environment is typically in a modified and
degraded state but generally not stabilized with revetments, dikes or levees. Based on an
analysis of the river elevations and existing banks, a 50 -foot minimum buffer in the
Shoreline Residential Environment would allow room to achieve a 2.5:1 bank slope with
an additional 20 -foot setback from the top of the slope—a distance that will allow for bank
stability and, in -turn, protection of new structures from high flows, and bank failures. A
schematic of the shoreline jurisdiction showing the buffer is provided in Figure 3.
200'
Shoreline Residential
Environment 50'
min
Buffer
-- 20' --i
20 feet from top of ----
reconfigured
reconfigured river bank
Ordinary High Water Mark
\ iver
Figure 3. Schematic of Shoreline Residential Environment and Buffer
The proposed buffer area for the Shoreline Residential Environment will allow for removal
of invasive plants, planting of native vegetation in the riparian zone and inclusion of other
features to improve shoreline habitat. It also will prevent the placement of any structures
in an area that could potentially prove unstable. In the event of bank erosion or slope
failures, the buffer will provide sufficient space for re -sloping the bank to a more stable
2.5:1 slope, either through bank stabilization projects or through natural bank failures that
result in the natural angle of repose (2.5:1 or greater).
7.7 Urban Conservancy Environment
A. Designation Criteria
This environment will be designated in the area between the Ordinary High Water Mark
and 200 feet landward as regulated under the Shoreline Management Act and applied to all
shorelines of the river except the Shoreline Residential Environment and the High Intensity
Environment. The Urban Conservancy Environment areas are currently developed with
dense urban multifamily, commercial, industrial and/or transportation uses or are
designated for such uses in the proposed south annexation area. This environment begins
at the southern end of the Turning Basin and includes portions of the river where levees
and revetments generally have been constructed and where the river is not navigable to
large watercraft. Uses will be restricted immediately adjacent to the river by establishment
of a minimum protective buffer.
SMP Public Review Draft Clean 38 2/20/2020
B. Purpose of Environment
The purpose of the Urban Conservancy Environment is to protect ecological functions
where they exist in urban and developed settings, and restore ecological functions where
they have been previously degraded, while allowing a variety of compatible uses.
C. Establishment of River Buffers
The Urban Conservancy environment will have two different buffers, depending on the
location along the river and whether or not the shoreline has a flood control levee. The
purpose of Urban Conservancy River Buffers is to:
• Protect existing and restore degraded ecological functions of the open space,
floodplain and other critical areas in the developed urban settings;
• Ensure no net loss of shoreline function when new development or re-
development is proposed;
• Provide opportunities for restoration and public access;
• Allow for adequate flood and channel management to ensure protection of
property, while accommodating shoreline habitat enhancement and promoting
restoration of the natural character of the shoreline environment, wherever
possible;
• Avoid the need for new shoreline armoring; and
• Protect existing and new development from high river flows.
Buffer in Non -Levee Areas:
A buffer width of 100 feet is established for the Urban Conservancy Environment for all
non-residential areas without levees. This buffer width is consistent with that established
by the City's Critical Areas Ordinance for Type 2 streams that support salmonid use, which
is based on Best Available Science. In addition, as noted above, looking at the slope
geometry and the difference in height between the ordinary high water mark and the 100 -
year flood elevation for these areas, it was found that a 100 -foot setback distance is required
to accommodate the slopes needed for bank stability.
The buffer width of 100 feet allows enough room to reconfigure the riverbank to achieve a
slope of 3:1, the "angle of repose" or the maximum angle of a stable slope and allow for
some restoration and improvement of shoreline function through the installation of native
plants and other habitat features. The actual amount of area needed to achieve a 3:1 slope
may be less than 100 feet, depending on the character of the riverbank and can only be
determined on a site -by -site basis.
As an alternative to the 100 -foot buffer, a property owner may re -slope the riverbank to be
no steeper than 3:1, provide a 20 -foot setback from the top of the new slope and vegetate
both the riverbank and the 20 -foot setback area in accordance with the standards in the
Vegetation Protection and Landscaping Section. Any buffer reduction proposal must
demonstrate to the satisfaction of the Director that it will not result in direct, indirect or
SMP Public Review Draft Clean 39 2/20/2020
long-term adverse impacts to shoreline ecosystem functions. In all cases a buffer
enhancement plan must also be approved and implemented as a condition of the reduction.
The plan must include removal of invasive plants, and plantings using a variety of native
vegetation that improves the functional attributes of the buffer and provides additional
protection for the watercourse functions. In no case shall the buffer be less than 50 feet.
In areas of the river where this condition currently exists or where the property owner has
constructed these improvements, the buffer width will be the actual distance as measured
from the ordinary high water mark to the top of the bank plus 20 feet.
The shoreline jurisdiction and buffers for the Urban Conservancy Environment are
depicted in the schematic in Figures 4 and 5 below.
Allow room to
reconfigure
river bank to
3:1 slope
200'
Urban Conservancy Environment
100'
Buffer
Ordinary High Water Markt
Figure 4. Schematic of Shoreline Jurisdiction and Buffers for the Urban
Conservancy Environment in Areas without Levees
Buffer in Levee Areas:
For properties located behind the Army Corps of Engineers (ACOE) Certified 205 levee
and County constructed levees, the buffer will extend 125 feet landward from the ordinary
high water mark, determined at the time of development or redevelopment of the site or
when levee replacement or repair is programmed. This buffer width is the maximum
needed to reconfigure the riverbank to the minimum levee profile and to achieve an overall
slope of 3:1, the "angle of repose" or the maximum angle of a stable slope. The
establishment of the 3:1 slope along the Corps certified 205 levee in the Tukwila Urban
Center will allow for incorporating a mid -slope bench that can be planted with vegetation
to improve river habitat. The mid -slope bench also will allow access for maintenance
equipment, when needed. An easement to allow access for levee inspection is required on
the landward side of the levee at the toe.
SMP Public Review Draft Clean 40 2/20/2020
200'
Urban Conservancy Environment
125'
Allow room -4
for Levee
repair or
replacement
Buffer
Ordinary High Water Mark
Figure 5. Schematic of Shoreline Jurisdiction and Buffers for the
Urban Conservancy Environment in Areas with Levees
As an alternative to the 125 foot buffer for leveed areas, a property owner may construct
levee or riverbank improvements that meet the Army Corps of Engineers, King County
Flood Control District, and City of Tukwila minimum levee standards. These standards at
a minimum shall include an overall slope no steeper than 3:1 from the toe of the levee to
the riverward edge of the crown, 16 -foot access across the top of the levee, a 2:1 back
slope, and an additional no -build area measured from the landward toe for inspection and
repairs. In instances where an existing building that has not lost its nonconforming status
prevents achieving an overall slope of 3:1, the slope should be as close to 3:1 as possible.
A floodwall is not the preferred back slope profile for a levee but may be substituted for
all or a portion of the back slope where necessary to avoid encroachment or damage to a
structure legally constructed prior to the date of adoption of this Master Program which has
not lost its nonconforming status and to preserve access needed for building functionality.
The floodwall shall be designed to provide 15 -foot clearance between the levee and the
building or to preserve access needed for building functionality while meeting all
engineering safety standards. A floodwall may also be used where necessary to avoid
encroachment on a railroad easement or to provide area for waterward habitat restoration.
In areas of the river where the property owner or a government agency has constructed a
levee with an overall waterward slope of 3:1 or flatter, the buffer will be reduced to the
actual distance as measured from the ordinary high water mark to the landward toe of the
levee or face of a floodwall, plus 15 feet. In the event that the owner provides the City
and/or applicable agency with a levee maintenance easement measured landward from the
landward toe of the levee or levee wall (which easement prohibits the construction of any
structures and allows the City and/or applicable agency to access the area to inspect the
levee), then the buffer shall be reduced to the landward toe of the levee, or landward edge
of the levee floodwall, as the case may be.
SMP Public Review Draft Clean 41 2/20/2020
In cases where fill is placed along the back slope of the levee, the shoreline buffer may be
further reduced to the point where the ground plane intersects the back slope. The area
between the landward edge of the buffer and a point 15 feet landward of the underground
levee toe shall be covered by an easement prohibiting the construction of any structures
and allowing the City and/or applicable agency to access the area to inspect the levee and/or
floodwall and make any necessary repairs. See Figure 6 below.
Buffer that could -
Be Replaced
by Easements
New Ground
Plane
> Buffer Reduction
10'
Access/
Inspection
i �liCl I�T�I
Fill
il—liiir—III—n-1=iT i
—11(-1 1 1E11_01=11 El I ElEi i f l I;=
i — u -iii ,—4u—.—�7a11i 1F1 C
lE1I 111 —;i,,
II-III=i I E11E1I
a 1-11l=l11=1
2*
Proposed Levee
18' Top Width
1
Landward
Levee Toe
Buffer Reduction with Backfill Option
Not To Scale
Figure 6. Schematic of Buffer Reduction Through
Placement of Fill on Levee Back Slope
7.8 High Intensity Environment
A. Designation Criteria
The High Intensity Shoreline Environment area is currently developed with high intensity
urban commercial, industrial and/or transportation uses or is designated for such uses in
the proposed north annexation area. This environment begins at the Ordinary High Water
Mark and extends landward 200 feet and is located from the southern edge of the Turning
Basin north to the City limits and includes the North PAA. This Environment is generally
located along portions of the Duwamish River that are navigable to large watercraft. Uses
will be restricted immediately adjacent to the river by establishment of a minimum
protective buffer.
The Transition Zone is located partly in the High Intensity Environment. The Transition
Zone is the location where freshwater from a river and saltwater from the marine salt wedge
mix creating brackish conditions. Often it is also where the river widens, stream velocities
decrease and estuarine mudflats begin to appear. Habitat associated with the Transition
Zone is critically important for juvenile Chinook and chum smolts making the transition to
salt water. The Transition Zone moves upstream and downstream in response to the
combination of stream flow and tidal elevations and as a result varies over a 24-hour period
and seasonally. The Transition Zone is a crucial habitat for salmonids.
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B. Purpose of Environment and Establishment of River Buffer
The purpose of the Urban High Intensity Environment is to provide for high intensity,
commercial, transportation and industrial uses and to promote water dependent and water
oriented uses while protecting existing shoreline ecological functions and restoring
ecological functions in areas that have been previously degraded.
The purposes of the High Intensity River Buffer are to:
• Protect existing and restore degraded ecological functions of the open space,
floodplain and other critical areas in the developed urban settings;
• Ensure no net loss of shoreline function when new development or re-
development occurs;
• Provide opportunities for shoreline restoration and public access;
• Allow for adequate flood and channel management to ensure protection of
property, while accommodating shoreline habitat enhancement and promoting
restoration of the natural character of the shoreline environment, wherever
possible;
• Avoid the need for new shoreline armoring; and
• Protect existing and new development from high river flows.
A buffer of 100 feet is established, which allows enough room to reconfigure the riverbank
to achieve a slope of 3:1 (starting at the OHWM rather than the toe), the "angle of repose"
or the maximum angle of a stable slope and allow for some restoration and improvement
of shoreline function through the installation of native plants and other habitat features.
The actual amount of area needed to achieve a 3:1 slope may be less than 100 feet,
depending on the character of the riverbank, and can only be determined on a site -by -site
basis.
Allow room to
reconfigure
river bank to
3:1 slope
r
200' >
High Intensity Environment
K--- 100' 4
Buffer
Ordinary High Water Mark
Figure 7. Schematic Showing the Proposed Shoreline Jurisdiction
and Buffer for the High Intensity Environment
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As an alternative to the 100 -foot buffer, a property owner may re -slope the riverbank to a
maximum 3:1, provide a 20 -foot setback from the top of the new slope and vegetate both
the riverbank and the 20 -foot setback area in accordance with the standards in the
Vegetation Protection and Landscaping Section. The property owner must also
demonstrate that this approach will not result in a loss of ecological functions of the
shoreline. In areas of the river where this condition currently exists or where the property
owner has constructed these improvements, the buffer width will be the actual distance as
measured from the Ordinary High Water Mark to the top of the bank plus 20 feet. In no
case shall the buffer be less than 50 feet.
In any shoreline environment where an existing improved street or road runs parallel to the
river through the buffer, the buffer would end on the river side of the street or road.
7.9 Aquatic Environment
A. Designation Criteria
All water bodies within the City limits and its potential annexation area under the
jurisdiction of the Shoreline Management Act waterward of the ordinary high water mark.
The aquatic environment includes the water surface together with the underlying lands and
the water column.
B. Purpose
The purpose of this designation is to protect the unique characteristics and resources of the
aquatic environment by managing use activities to prioritize preservation and restoration
of natural resources, navigation, recreation and commerce, and by assuring compatibility
between shoreland and aquatic uses.
8. SHORELINE USE REGULATIONS AND DEVELOPMENT
STANDARDS
Uses that are permitted outright, permitted as a Conditional Use, or prohibited altogether
for each Shoreline Environment are provided in TMC Section 18.44.030 along with special
conditions and general requirements controlling specific uses. These regulations are
intended to implement the purpose of each Shoreline Environment designation adopted
with this SMP. Development standards such as setbacks, height limitations, water quality
regulations, flood hazard reduction, shoreline stabilization, protection of archaeological
resources, environmental impact mitigation, parking and over water structures
requirements are codified in TMC Chapter 18.44.
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The Administrative procedures codified in TMC Chapter 18.44 are designed to:
• Assign responsibilities for implementation of the Master Program and Shoreline
Permits.
• Establish an orderly process by which to review proposals and permit
applications.
• Ensure that all persons affected by this Master Program are treated in a fair and
equitable manner.
These procedures include permit application requirements, conditional use approval
criteria, variance approval criteria, and regulations for non -conforming development.
9. ENVIRONMENTALLY CRITICAL AREAS WITHIN THE
SHORELINE JURISDICTION
9.1 Applicable Critical Areas Regulations
A. The following critical areas shall be regulated in accordance with the provisions of the
Critical Areas Ordinance (TMC Chapter 18.45), Ordinance No. 2625, March 2, 2020,
which is herein incorporated by reference into this SMP, except for the provisions excluded
in subsection B of this section:
1. Wetlands
2. Watercourses (Type F, Type Np, Type Ns)
3. Areas of potential geologic instability
4. Fish and wildlife habitat conservation areas
Such critical area provisions shall apply to any use, alteration, or development within
shoreline jurisdiction whether or not a shoreline permit or written statement of exemption
is required. Unless otherwise stated, no development shall be constructed, located,
extended, modified, converted, or altered, or land divided without full compliance with the
provision adopted by reference and the Shoreline Master Program. Within shoreline
jurisdiction, the regulations of TMC Chapter 18.45 shall be liberally construed together
with the Shoreline Master Program to give full effect to the objectives and purposes of the
provisions of the Shoreline Master Program and the Shoreline Management Act. If there
is a conflict or inconsistency between any of the adopted provisions below and the
Shoreline Master Program, the most restrictive provisions shall prevail.
B. The following provisions of TMC Chapter 18.45 do not apply within the Shoreline
jurisdiction:
1. Critical Area Master Plan Overlay (TMC Section 18.45.160)
2. Reasonable Use Exceptions (TMC Section 18.45.180)
3. Time Limitation, Appeals and Vesting (TMC Section 18.45.190)
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4. Wetlands Uses, Alterations and Mitigation (TMC Section 18.45.090). Activities
and alterations to wetlands and their buffers located within shoreline jurisdiction
shall be subject to the provisions and permitting mechanisms of this Master
Program.
C. Critical areas comprised of frequently flooded areas and areas of seismic instability are
regulated by the Flood Zone Management Code (TMC Chapter 16.52) and the Washington
State Building Code, rather than by TMC Chapter 18.44.
9.2 Purpose
A. The Growth Management Act (RCW 36.70A) and Shoreline Management Act (RCW
90.58) require protection of critical areas, defined as wetlands, watercourses, frequently
flooded areas, geologically hazardous areas, critical aquifer recharge areas, and fish and
wildlife conservation areas.
B. The purpose of protecting environmentally critical areas within the shoreline
jurisdiction is to:
1. Minimize developmental impacts on the natural functions and values 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.
10. Incorporate the use of the most current, accurate, and complete scientific and
technical information available in the regulation and protection of critical areas
as required by the state Shoreline Management Act, according to WAC 173-26-
201 and WAC 173-26-221.
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C. The goal of these critical area regulations is to provide a level of protection to critical
areas located within shorelines of the state that assures no net loss of shoreline ecological
functions necessary to sustain shoreline natural resources. Critical areas currently
identified in the shoreline jurisdiction are discussed in the Shoreline Inventory and
Characterization Report, which forms part of this Shoreline Master Program. The locations
are mapped on the Critical Areas in the Shoreline Map (Map 4). This map is based on
assessment of current conditions and review of the best available information. However,
additional critical areas may exist within the shoreline jurisdiction and the boundaries of
the critical areas shown are not exact. It is the responsibility of the property owner to
determine the presence of critical areas on the property and to verify the boundaries in the
field.
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RIa1. 1. 1.
•
•
t,
Map 4
1<
wore
4
1.
Turning Basin
Critical Areas
in the
Shoreline
The mapping of
areas of potential
geologic instability
is approximate. On
site verification of
topography and
geology is
necessary.
Wetland and
locations are
approximate only
and watercourses
shown on this map
have not been
surveyed.
Legend
0010, Tukwila City Limits
Type F Shoreline Wetland
Type F Shoreline Wetland Buffer (80')
Fish & Wildlife Habitat Conservation Area
Fish & Wildlife Habitat Buffer (100')
o 0 f Type F Stream
Type F Stream in Pipe
Type Np Stream
Type Np Stream in Pipe
Type Ns Stream
Type Ns Stream in Pipe
Type F Watercourse Buffer (100')
Type Np Watercourse Buffer (80')
Type Ns Watercourse Buffer (50')
200ft River Buffer
E1
Slope Classifications
Landslide potential is moderate; slope is between 15% and 40%
2 and underlain by relatively permeable soils.
Landslide potential is high; slope is between 15% and 40% and
3 underlain by relatively impermeable soils or by bedrock: also
includes all areas sloping more than 40%.
4 Landslide potential is very high; includes sloping
areas with mappable zones of groundwater 2/20 Source:
seepage and existing mappable landslide City of Tukwila GIS
deposits regardless of slope. King County GIS
*Fish and Wildlife Habitat Conservation Areas shown are salmon
habitat enhancement projects completed or underway. The river
itself is also a Fish and Wildlife Habitat Conservation Area.
ul
/4*1
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10. PUBLIC ACCESS TO THE SHORELINE
Public access to the shorelines of the state is one of the key goals of the Shoreline
Management Act. Of the seven uses identified in RCW 90.58.020 as having preference in
the shoreline, two relate to public access and recreational opportunities along the shoreline.
The City of Tukwila is fortunate to have a number of public access sites already along the
Green/Duwamish River in addition to the Green River Trail, which runs along almost the
entire length of the river through the City. Other public access points are available at the
North Winds Wier, the Tukwila Community Center, Codiga Park, Bicentennial Park at
Strander Boulevard and parking available on Christianson Road, and at S. 180th Street. A
habitat restoration project is underway at Duwamish Riverbend Hill on South 115th Street,
which also includes public access to the river. The Shoreline Public Access Map (Map 5)
identifies several street ends that could be improved or to which amenities could be added
that would offer opportunities for neighborhood access to the river and/or the Green River
Trail.
The Shoreline Public Access map identifies several potential trail sites on the river to
supplement the existing Green River trail system. The largest stretch of potential trail runs
from S. 180th on the left bank to the end of the south annexation area. A pedestrian bridge
to link the area south of S. 180th Street to the existing trail on the right bank is being
discussed as well. A second area where improvement is needed in public access relates to
boat launches for small hand -launched boats. Several potential sites have been identified
in the Tukwila Parks Department Capital Improvement Program to address this need at
City -owned sites. A comprehensive regional inventory of public access points to the River
should be completed to identify gaps and opportunities.
Requirements for public access to shorelines have been codified in TMC Chapter 18.44.
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Tuming Basin
Potential
Trai
1
1
1.
Map 5
Shoreline
Public Access
Green River
Trail
Legend
L..., Tukwila City Limits
t • ! Potential Annexation Areas
® City of Tukwila Property
Q4-^• Interurban Trail
�++ Green River Trail
-"J.Potential New Trail
Street Ends Potential,,
Public Access
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50 2/20/2020
11. SHORELINE DESIGN GUIDELINES
The Green/Duwamish River is an amenity that should be valued and celebrated when
designing projects that will be located along its length. The river and its tributaries support
salmon runs and resident trout, including the ESA -listed Chinook salmon, Bull Trout and
Steelhead. If any portion of a project falls within the shoreline jurisdiction, then the entire
project will be reviewed under the shoreline specific guidelines codified in TMC Chapter
18.44, as well as the relevant sections of the Design Review Chapter of the Zoning Code
(TMC Chapter 18.60). The standards of TMC Chapter 18.60 shall guide the type of review,
whether administrative or by the Board of Architectural Review.
The standards apply to development, uses and activities in the Urban Conservancy and
High Intensity Environments and non-residential development in the Shoreline Residential
Environment.
12. SHORELINE RESTORATION
The Shoreline Restoration Plan, found in Appendix B, identifies the sites that have been
identified to -date as possible locations for habitat restoration along the Green/Duwamish
River. The City will continue to add sites to the Restoration Plan as they are identified and
will include them in the City's Capital Improvement Program for acquisition and
improvement. Project sites in the Transition Zone have the highest priority for acquisition.
Amendments or revisions to the Shoreline Restoration Plan do not require an amendment
to the Shoreline Master Program.
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13. ADMINISTRATION
The Administrative procedures below are designed to:
• Assign responsibilities for implementation of the Master Program and Shoreline
Permit
• Establish an orderly process by which to review proposals and permit applications
• Ensure that all persons affected by this Master Program are treated in a fair and
equitable manner.
13.1 Applicability of Shoreline Master Program and Substantial Development Permit
A. Development in the Shoreline Jurisdiction
Based on guidelines in the Shoreline Management Act for a minimum shoreline
jurisdiction, Tukwila's Shoreline Jurisdiction is defined as follows:
The Tukwila Shoreline Jurisdiction includes the channel of the
Green/Duwamish River, its banks, the upland area which extends from
the ordinary high water mark landward for 200 feet on each side of the
river, floodways and all associated wetlands within its floodplain. The
floodway shall not include those lands that have historically been
protected by flood control devices and therefore have not been subject to
flooding with reasonable regularity.
B. Applicability
The Tukwila Shoreline Master Program applies to uses, change of uses, activities or
development that occurs within the above -defined shoreline jurisdiction. All proposed uses
and development occurring within the shoreline jurisdiction must conform to Chapter 90.58
RCW, the Shoreline Management Act, and this Master Program whether or not a permit is
required. Except that requirements to obtain a substantial development permit, conditional
use permit, variance, letter of exemption, or other review to implement the Shoreline
Management Act do not apply to the following described in WAC 173-27-044 and WAC
173-27-045:
1. Remedial actions. Pursuant to RCW 90.58.355, any person conducting a
remedial action at a facility pursuant to a consent decree, order, or agreed order
issued pursuant to Chapter 70.105D RCW, or to the Department of Ecology when
it conducts a remedial action under Chapter 70.105D RCW.
2. Boatyard improvements to meet NPDES permit requirements. Pursuant to
RCW 90.58.355, any person installing site improvements for storm water
treatment in an existing boatyard facility to meet requirements of a national
pollutant discharge elimination system storm water general permit.
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3. WSDOT facility maintenance and safety improvements. Washington State
Department of Transportation projects and activities meeting the conditions of
RCW 90.58.356 are not required to obtain a substantial development permit,
conditional use permit, variance, letter of exemption, or other local review.
4. Projects consistent with an environmental excellence program agreement
pursuant to RCW 90.58.045.
5. Projects authorized through the Energy Facility Site Evaluation Council process,
pursuant to Chapter 80.50 RCW.
13.2 Relationship to Other Codes and Regulations
1. Compliance with this Master Program does not constitute compliance with other
federal, state, and local regulations and permit requirements that may apply. The
applicant is responsible for complying with all other applicable requirements.
2. Where this Master Program makes reference to any RCW, WAC, or other state
or federal law or regulation, the most recent amendment or current edition shall
apply.
3. When any provision of this Master Program or any other federal, state, or local
provision conflicts with this Master Program, the provision that is most protective
of shoreline resources shall prevail, except when constrained by federal or state
law, or where specifically provided otherwise in this Master Program.
4. Relationship to Critical Areas Regulations.
(a) For protection of critical areas where they occur in shoreline jurisdiction, this
Master Program adopts by reference the City's Critical Areas Ordinance,
which is incorporated into this Master Program with specific exclusions and
modifications in Section 9 of this SMP.
(b) All references to the Critical Areas Ordinance are for the version adopted
March 2, 2020. Pursuant to WAC 173-26-191(2)(b), amending the
referenced regulations in the Master Program for those critical areas under
shoreline jurisdiction will require an amendment to the Master Program and
approval by the Department of Ecology.
(c) Within shoreline jurisdiction, the Critical Areas Ordinance shall be liberally
construed together with this Master Program to give full effect to the
objectives and purposes of the provisions of this Master Program and
Chapter 90.58 RCW.
14. APPEALS
Any appeal of a decision by the City on a Shoreline Substantial Development Permit,
Shoreline Conditional Use, Unclassified Use or Shoreline Variance must be appealed to
the Shoreline Hearing Board.
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15. MASTER PROGRAM REVIEW AND AMENDMENTS
15.1. This Master Program shall be periodically reviewed and adjustments shall be made as
are necessary to reflect changing local circumstances, new information or improved data, and
changes in State statutes and regulations. This review process shall be consistent with WAC
173-26 and shall include a local citizen involvement effort and public hearing to obtain the
views and comments of the public.
15.2 Any provision of this Master Program may be amended as provided for in RCW
90.58.080 and WAC 173-26-090 and 173-26-100. Amendments or revisions to the Master
Program, as provided by law, do not become effective until 14 days following written
approval by the Washington State Department of Ecology.
15.3 Proposals for shoreline environment re -designations (i.e. amendments to the shoreline
maps and descriptions) must demonstrate consistency with the criteria set forth in WAC 173-
26 and this program.
16. LIABILITY
16.1. Liability for any adverse impacts or damages resulting from work performed in
accordance with a permit issued on behalf of the City within the City limits, shall be the sole
responsibility of the owner of the site for which the permit was issued.
16.2 No provision of or term used in the Master Program is intended to impose any duty
upon the City or any of its officers or employees that would subject them to damages in a civil
action.
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