2010-04-07 HEX# 10-002 Staff ReportDEPARTMENT OF COMMUNITY DEVELOPMENT SERVICES
STAFF REPORT TO THE
FEDERAL WAY HEARING EXAMINER
WSDOT Triangle Project
Process IV `Hearing Examiner's Decision'
Federal Way File No. 09-104380-00-UP
PUBLIC HEARING
Wednesday, April 7, 2010, 2:00 p.m.
City Council Chambers
Federal Way City Hall — 33325 8t' Avenue South
Report Prepared by:
Associate Planner Matthew Herrera
Report Date:
March 31, 2010
Table of Contents
I. PROJECT INFORMATION AND BACKGROUND.................................................................................. 1
II. PROCESS IV ADMINISTRATION....................................................................................................2
III. ENVIRONMENTAL REviEw...................................................................................................:......2
IV. COMMENTS RECEIVED ON MASTER LAND USE APPLICATION...................................................... 2
V. KEY ELEMENTS OF THE ENVIRONMENTAL IMPACTS/MITIGATION.......................................w .......2
VI. GENERAL CHARACTERISTICS OF SITE AND VICINITY .................................................... --- ......... 3
VII. DESCRIPTION OF IMPACTED CRITICAL AREAS ....................................
VIII. DESCRIPTION OF PROCESS IV REQUEST......................................................................................... 4
IX. FINDINGS & CONCLUSIONS OF PROPOSED STREAM RELOCATION................................................4
X. FINDINGS & CONCLUSIONS OF PROPOSED STREAM CULVERT ............................................ ....:.......7
XI. FINDINGS & CONCLUSIONS OF PROPOSED STREAM BUFFER INTRUSION ....................................... 8
XII. FINDINGS & CONCLUSIONS OF PROPOSED IMPROVEMENTS wrmiN REGULATED WETLANDS ....... 9
XIII. FINDINGS & CONCLUSIONS OF PROPOSED IMPROVEMENTS WITHIN WETLAND BUFFERS .......... 14
XIV. PROCESS IV HEARING EXAMINER DECISIONAL CRITERIA. ............... ......... 15
XV. RECOMMENDED CONDITIONS OF APPROVAL.........:.. ............16
LISTOF EXHIBTTS.................................................................. ........... ...................17
I. PROJECT INFORMATION AND BACKGROUND
Name of Project: Washington State Department of Transportation (WSDOT) Triangle Project
City File No: 09-104380-00-UP
Requested Decision: Applicant requests a Process IV `Hearing Examiner' decision pursuant to
Federal Way Revised Code (FWRC) Chapter 19.70. WSDOT issued an
Environmental Determination of Nonsignificance (DNS) pursuant to
State Environmental Policy Act (SEPA) procedures on May 11, 2007.
Staff
Recommendation: Approval with Conditions
Summary of
Proposal: Clearing and grading activities; wetland mitigation; permanent and
temporary wetland buffer intrusions; and stream culverting/relocating
associated with the replacement of Interstate-5 and SR 18 interchange
cloverleaf ramps and new direct connection from westbound SR 18 to
SR 161 in the vicinity of South 359t1i Street (Exhibit A).
Site Location: WSDOT right-of-way within the Federal Way city limits as shown on
the vicinity map (Exhibit 13). Portions of site work will take place on
several private parcels (Exhibit Q. Wetland compensatory mitigation
site is proposed at a WSDOT single-family zoned parcel located at 933
South 364`h Street (Exhibit D).
Applicant: Allison Hanson, Director of Environmental Services, ESO Mega Projects
WSDOT, 999 P Avenue, Suite 2424, Seattle, WA 98104
Owner: WSDOT
Comprehensive
Plan & Zoning
Designations: WSDOT right of way, WSDOT owned and privately held parcels zoned
Commercial Enterprise (CE). Compensatory mitigation site is located
within a single-family medium density residential RS35.0 zoning district.
Key Dates: Master Land Use application submitted December 1, 2009
Application determined complete December 17, 2009
Notice of application, December 19, 2009 (Exhibit E)
Notice of public hearing, March 20, 2010 (Exhibit F)
Staff
Representative: Associate Planner Matthew Herrera, 253-835-2638
WSDOT Triangle Project File tl09-104380-00-UP / Doc ID 52650
Hearing Examiner Staff Report Page 1 of 17
II. PROCESS IV ADMINISTRATION
The Master Land Use (MLU) application contains multiple components. The FWRC requires the
following review process for the applicant's requested activities:
1. Stream Relocation — Process IV Hearing Examiner Decision
2. Culverts — Process III Project Approval
3. Intrusion into Stream Setback (Essential Public Facility) — Director Approval
4. Improvements within Regulated Wetland — Process IV Hearing Examiner Decision
5. Improvements within Regulated Wetland Buffer (Essential Public Facility) — Director Approval
Pursuant to FWRC 19.70.010, if a Process IV request also includes activities which require
multiple review processes, the entire proposal will be decided upon using Process IV if it is
determined that it will result in more efficient decision making. As analysis for each component
can be combined into one document, staff finds separate permitting for each of the five above -
referenced activities would provide no benefit to the city or the applicant; therefore, the entire
proposal shall be decided upon using Process IV Hearing Examiner Decision.
III. ENVIRONMENTAL REVIEW
The proposed improvements and activities are not categorically exempt from the threshold
determination process pursuant to the State Environmental Policy Act (SEPA) Rules as identified
in Washington Administrative Code (WAC) Chapter 197-11. WSDOT, acting as Lead Agency,
issued a Determination of Nonsignificance (DNS) on May 11, 2007 (Exhibit G). No comments or
appeals on the DNS were submitted. Staff finds the analysis from the 2007 DNS valid for the
current proposal.
IV. COMMENTS RECEIVED ON MASTER LAND USE APPLICATION
No comments on the Process IV application have been received as of the date of this staff report.
Process IV administration rules allow any person to submit written comments anytime up to the
date of the public hearing and allow any person to provide verbal comments during the hearing.
V. KEY ELEMENTS OF THE ENVIRONMENTAL NTACTSIMITIGATION
As context for the Process IV request, the following is an outline of the key elements of the
environmental impacts and mitigation as a result of the roadway improvements
1. Abandonment and filling of 495 lineal feet of a designated minor stream and relocation of the
stream;
2. Three culvert extensions totaling 185 lineal feet and one new box culvert measuring 65 lineal
feet;
3. Temporary intrusions of 1.28 acres into stream setback areas for construction activities
associated with the roadway project;
4. Permanent intrusions of 4.64 acres into stream setback for new roadway and appurtenances;
5. Temporary intrusions of 0.6 acres into wetland buffer areas for construction activities
associated with the roadway project;
6. Permanent intrusions of 1.05 acres into wetland buffer areas for new roadway and
appurtenances;
7. Permanent intrusions of 0.23 acres into regulated wetlands; and
8. Off -site compensatory mitigation site of 3.37 acres that includes wetland creation/
enhancement, wetland buffer enhancement, and creation/enhancement of stream habitat.
WSDOT Triangle Project File #09-104380-00-UP / Doc ID 52650
Hearing Examiner Staff Report Page 2 of 17
VI. GENERAL CHARACTERISTICS OF SITE AND VICINITY
The subject area is within the WSDOT right-of-way Interstate-5 corridor between South 336"'
Street and State Route 161; WSDOT right-of-way within State Route 18 between Weyerhaeuser
Way and the Interstate 5 clover leaf; two parcels commercial zoned properties owned by
WSDOT; and three private parcels (Exhibit C) abutting the WSDOT right-of-way.
Areas abutting the WSDOT right-of-way where the proposed constriction activities will take
place contain Multi -Family, Commercial Enterprise, and Corporate Park comprehensive plan/
zoning designations. Current uses abutting the project area include retail, office, church, vacant
private parcels, and vacant parcels owned by WSDOT.
VU. DESCRIPTION OF IMPACTED CRITICAL AREAS
As shown in the applicant's wetland mitigation plan (Exhibit H, Page 18) and stream mitigation
plan (Exhibit I, Page 9), the following critical areas will be impacted due the Triangle Project
improvements.
1. East Branch Hylebos Creek (as identified by the city's critical areas inventory):
Tributary 0016 — Impacted areas are located east of the Interstate 5/State Route 18 clover
leaf. The city has identified the tributary a major stream; although, fish do not currently
inhabit the impacted reach due to man-made blockages downstream. The tributary remains a
major stream (fish bearing) as it does not contain natural fish barriers.
Tributary 0016A — Impacted areas are adjacent to Interstate-5 between South 336th Street and
South 3601h Street. The city's critical areas inventory has identified the tributary a major
stream The applicant has provided analysis (Exhibit K) that a permanent natural blockage
exists in the form of inadequate flows; therefore, the city has reclassified the watercourse
within the construction area as a minor stream (non -fish bearing).
2. Wetlands (as identified by the applicant's wetland report):
Wetland M— Located east of the Interstate-5 clover leaf and abutting the State Route 18
westbound lane. Wetland M is an approximately 1.16 acre scrub/shrub and forested wetland.
The city's wetland rating is Category II with a 100-foot buffer.
Wetland N— Located east of the Interstate-5 clover leaf and abutting the State Route 18
westbound lane. WetlandN is an approximately 0.20 acre scrub/shrub wetland. The city's
wetland rating is Category III with a 25-foot buffer.
Wetland AB — Located east of southbound Interstate-5 near South 360"' Street. Wetland AB is
an approximately 0.42 acre emergent and scrub/shrub wetland. The city's wetland rating is
Category II' with a 100-foot buffer.
Wetland K— Located north of the State Route 18 on -ramp near Weyerhaeuser Way South.
Wetland K is an approximately 0.13 acre scrub/shrub wetland. The city's wetland rating is
Category III with a 25-foot buffer.
1 Staff disagrees with the applicant's rating of Wetland AB as FWRC 19.175.020(1)(b) states wetlands containing two or more
wetland classes (scrub/shrub and emergent) and do not exhibit characteristics of a Category I wetland are classified as Category II.
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Hearing Examiner Staff Report Page 3 of' 17
Wetland P — Located west of southbound Interstate-5 near South 336`' Street. Wetland P is an
approximately 1.91 acre emergent and scrub/shrub wetland. The city's wetland rating is
Category II with a 100-foot buffer.
Wetland U— Located within the southwest clover leaf. Wetland U is an approximately 0.13
acre scrub/shrub wetland. The city's wetland rating is Category III with a 25-foot buffer.
VIII. DESCRIPTION OF PROCESS IV REQUEST
The Triangle Project will rebuild the Interstate-5 and State Route 18 interchange by replacing two
of the cloverleaf ramps with a westbound State Route 18 to southbound Interstate-5 flyover ramp
and eastbound State Route 18 to northbound Interstate 5 flyover ramp. The project will also build
a new direct connection from westbound State Route 18 to State Route 161 in the vicinity of
South 359'h Street.
Several wetlands and two tributaries to the East Branch Hylebos Creek will be affected due to
roadway expansions and widening associated with the Triangle Project. Stream relocation,
culverting, and wetland encroachment will be a necessary component of the project. To mitigate
the environmental impacts of the project, the applicant has purchased a parcel within the same
drainage basin to perform wetland and stream habitat mitigation.
Note — Staff has partitioned each of the applicant's requests and provided separate analysis
(findings) and decisional criteria (conclusions) for each item. Conclusions are based on individual
decisional criteria provided in the city's Critical Areas Ordinance (CAO) and codified in FWRC
Title 19. The overall Process IV decisional criteria (conclusions) are located in Section XVI of
this report.
IX. ANALYSIS OF STREAM RELOCATION REQUEST AND DECISIONAL CRITERIA PURSUANT TO
FWRC 19.165.020
Improvements for the proposed State Route 18 to State Route 161 direct connection will require
the abandonment and filling of 495 lineal feet of Tributary 0016A. The applicant is proposing to
relocate the stream section west of the existing channel.
Findings & Conclusions
The following analysis and decisional criteria is provided in accordance to the relocation section
of the city's CAO as codified in FWRC 19.165.020.
FWRC 19.165.020(3)(a) — The creation of a natural meander pattern.
As shown in Exhibit J, the proposed relocation of Tributary 0016A will result in an
approximately 580-lineal foot channel meandering in a southwesterly direction prior to
entering a culvert beneath the newly created roadway section.
FWRC 19.165.020(3)(b) — The formation of gentle side slopes, at least two feet horizontally to
one foot vertically, and the installation of erosion control features for stream side slopes.
2H:1 V side slopes are provided as shown on the right and left meander cross -sections
(Exhibit J). It will be necessary to clear existing vegetation on both sides of the newly
created channel to accommodate the 2:1 side slopes.
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Hearing Examiner Staff Report Page 4 of 17
Erosion controls for the stream side slopes include amended soil and coir matting.
Construction of the new channel and installation of the erosion control materials will
occur prior to any water being diverted.
FWRC 19.165.020(3)(c) — The creation of a narrow subchannel, where feasible, against the south
or west bank.
As the existing stream does not contain a subchannel and is bound by native vegetation
as well as a future roadway, the creation of a narrow subchannel is not feasible with the
current proposal.
FWRC 19.165.020(3)(d) — The utilization of natural materials, wherever possible.
Large woody debris (LWD), coir matting, and new landscaping is proposed within the
relocated corridor. As shown on the relocation plan (Exhibit J) and detailed in the
stream mitigation plan (Exhibit I, Page 36), LWD with and without root boles will be
placed along glide and meander locations along the channel to increase habitat
diversity. Coir matting derived from coconut husks will provide erosion control for the
stream banks. Native trees and shrubs will be planted in the relocated stream buffer
area providing support to existing wildlife in the project area.
FWRC 19.165.020(3)(e) — The use of vegetation normally associated with streams, including
primarily native riparian vegetation.
The proposed vegetation enhancement of the riparian area will use native trees and
shrubs including, but not limited to: bulrushes; sedges and rushes; red alder, black
cottonwood; and big leaf maple, Douglas fir, and western hemlock. The planting of the
above -referenced vegetation will occur in the following four zones, respectively:
emergent bottom zone; riparian emergent zone; riparian forest/scrub-shrub zone; and
upland riparian forest zone.
FWRC 19.165.020(3)(1)— The creation of spawning and nesting areas, wherever appropriate.
The applicant proposes the construction of habitat improvement structures including
brush piles, snags, and bat boxes. The structures will provide cover from predators,
assist thermal regulation, and provide nesting areas. Such enhancements are intended to
increase stream riparian and wildlife functions.
FWRC 19.165.020(3)(g) — The re-establishment of the fish population, wherever feasible.
Areas within the projected scope of work do not support fish populations. The existing
fish blockage is downstream and outside the scope of this project.
FWRC 19.165.020(3)(h) — The restoration of water flow characteristics compatible with fish
habitat areas, wherever feasible.
The restoration of water flow characteristics compatible with fish habitat areas is not
feasible due to the following: lack of perennial headwater source; high proportions of
impervious surfaces in the immediate area that result in flashy flow conditions during
rainfall; and zero flow periods during the summer months.
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Hearing Examiner Staff Report Page 5 of 17
FWRC 19.165.020(3)(i) — The filling and re -vegetation of the prior channel.
A majority of the filled channel will used for the new roadway section. The northern
portion of the prior channel will be filled and planted with upland riparian forest
vegetation as shown on the relocation site plan (Exhibit J).
FWRC 19.165.020(3)6) — A proposed phasing plan specifying time of year for all project phases.
As a contractor for the stream relocation work has not yet been determined, a phasing
plan was not provided. As a condition of approval, staff recommends the applicant
submit a phasing plan upon selection of a contractor.
Stream Relocation Decisional Criteria
FWRC 19.165.020(4) — The city will allow a stream to be relocated only if water quality, habitat,
and stormwater retention capability of the streams will be significantly improved by the
relocation. Convenience to the applicant in order to facilitate general site design may not be
considered.
The stream relocation will improve water quality, habitat, and stormwater retention
capabilities via the following improvements:
+ Water Quality — Below the Ordinary High Water Mark (OHWM), bulrush and
bur -reed plugs will be planted. Above the OHWM in seasonally and occasionally
inundated areas, slough sedge and various rush species will be planted. New
plantings, the imported stream substrate, and coir matting erosion control features
will improve the water quality of the tributary.
• Habitat — Large woody debris, native plantings, brush piles, snags, and bat boxes
placed within the relocation corridor will provide improved habitat for existing
and new wildlife in the project area.
■ Storinwater Retention — Newly planted vegetation within the riparian corridor
will provide improved opportunities for stormwater containment by capturing
and storing rainfall in the canopy and releasing water into the atmosphere
through evaporation. In addition, tree roots and leaf litter create soil conditions
that promote the infiltration of rainwater into the soil.
• Convenience to Site Design — Several alternatives were developed and analyzed
during the design process. The proposed plan was selected for its top scores in
minimizing environmental impacts.
FWRC 19.165.020(6) — The amount of flow and velocity of the stream may not be increased or
decreased as the stream enters or leaves the subject property.
There are no sources of runoff entering or leaving Tributary 0016A within the
realigned stream segment resulting in zero increase or decrease in flows or velocities as
the stream enters or leaves the subject property.
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Hearing Examiner Staff Report Page 6 of 17
X. ANALYSIS OF CULVERT REQUEST AND DECISIONAL CRITERIA PURSUANT TO
FWRC 19.165.040
The proposed road improvements will require the applicant to extend three culverts for a total of
185-lineal feet and install one new culvert measuring 65-lineal feet. As shown on page 9 of the
stream mitigation plan (Exhibit 1) the culverting request includes:
1) One 50-foot extension will be placed beneath the new southbound off ramp from
Interstate-5 to South 348"' Street;
2) One 50-foot extension will be placed beneath the new southbound onramp to
Interstate-5 from South 348`F' Street;
3) One 85-foot extension' will be placed beneath Interstate-5 south of the proposed
South 356`}' Street off ramp; and
4) One new 65-foot culvert will be placed beneath the proposed South 3561h Street off
ramp.
Findings & Conclusions
The following analysis and decisional criteria is provided in accordance to the culvert sections of
the city's CAO as codified in FWRC 19.165.040.
FWRC 19.165.040(4) — The culvert must be designed and installed to allow passage of fish
inhabiting or using the stream The culvert must be large enough to accommodate a 100-year storm.
Although the city's critical areas inventory currently classifies the watercourse a Major
Stream (fish -bearing) analysis provided by the applicant concludes the stretch within
the construction zone would constitute a Minor Stream (non -fish bearing) due to
natural permanent blockage.
FWRC 19.05.130 defines a major stream as: any stream, and the tributaries to any
stream, which contains or supports, or under normal circumstances contains or
supports, resident or migratory fish. If there exists a natural permanent blockage on the
stream course which precludes the upstream movement of anadromous salmonid fish,
then that portion of the stream which is downstream of the natural permanent blockage
shall be regulated as a major stream
Within the construction area, Tributary 0016A does contain a natural permanent
blockage in the form of intermittent and flashy flows which do not support or under
normal circumstances support resident or migratory fish. As detailed in the applicant's
analysis (Exhibit K), fish are not capable of inhabiting the portion of the stream within
the construction boundaries due to inadequate flows.
Staff finds the stretch of watercourse within the construction zone would constitute a
minor stream' as defined by FWRC 19.05.130 due to natural permanent blockage,. -
therefore, fish passable culverts are not required.
One -Hundred Year Storm — The estimated 100-year floor for the new culvert beneath
South 356t1i Street and Interstate 5 is 32 cfs. Based on the channel and culvert grade, the
culvert extensions have the capacity to pass a maximum flow of 120 cfs and 130 cfs,
respectively.
The 35-foot callout on page 23 Figure 6 is incorrect. The extension as concluded in the analysis on page 9 of the report states
the extension is 85-feet.
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Hearing Examiner Staff Report Page 7 of 17
FWRC 19.165.040(5) — The applicant shall, at all times, keep all culverts on the subject property
free of debris and sediment so as to allow free passage of water and, if applicable, fish. The city
shall require a bond under Chapter 19.25 FWRC to ensure maintenance of the culvert approved
under this section.
The WSDOT Maintenance and Operation Division `Maintenance Manual' requires
inspection and cleaning a minimum of two times per year. Additional inspections may
occur due to heavy precipitation and flooding.
Pursuant to the Revised Code of Washington (RCW) 35.21.470, bonding of government
agencies is not permitted. Staff finds the department's maintenance procedures adequate
to provide continuous flow through the proposed culverts.
Culvert Approval Criteria
FWRC 19.165.040(3)(a) — The city will allow a stream to be put in a culvert only if no significant
habitat area will be destroyed.
No significant habitat areas will be destroyed as the culverts are within areas that are
currently inhospitable to typical wildlife habitat as it is adjacent to major interstate and
commercially zoned properties. The applicant proposes to provide native plantings in
areas that will be impacted and provide off -site mitigation to a separate tributary to the
Hylebos Creek.
FWRC 19.165.040(3)(b) — The city will allow a stream to be put in a culvert only if it is necessary
for some reasonable use of the subject property. Convenience to the applicant in order to facilitate
general site design will not be considered. The applicant must demonstrate, by submitting
alternative site plans showing the stream in an open condition, that no other reasonable site design
exists.
Several alternatives were developed and analyzed during the design process. The
proposed plan was selected for its top scores in minimizing environmental impacts. The
new roadway sections require extensions to existing culverts and one new culvert. Staff
did not find it necessary for the applicant to submit alternative plans as the existing
roadway sections and the proposed expansions did not make it possible for the stream
to flow in an open condition.
XI. ANALYSIS OF STREAM BUFFER INTRUSION PURSUANT TO FWRC 19.165.070
Essential Public Facilities, Public Utilities and Other Public bnprovements — The director of
community development may permit the placement of an essential public facility, public utility,
or other public improvements in a setback from a stream if he or she determines that the line or
improvement must traverse the setback area because no feasible alternative location exists based
on an analysis of technology and system efficiency. The specific location and extent of the
intrusion into the setback area must constitute the minimum necessary encroachment to meet the
requirements of the public facility or utility.
Findings & Conclusions
The following analysis and decisional criteria is provided in accordance to the intrusion into
setbacks with regard to essential public facilities section of the city's CAO as codified in FWRC
19.165.070.
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Hearing Examiner Staff Report Page 8 of 17
Due to roadway sections expansions and construction of new stormwater retention/water quality
facilities, approximately 4.64 acres of streambuffer area will be pennanently impacted.
Construction activities associated with the proposed improvements will temporarily impact
approximately 1.28 acres of buffer area.
As mentioned previously, several alternatives were developed and analyzed during the design
process. The proposed plan was selected for its top scores in minimizing environmental impacts.
Staff finds the proposed roadway improvements minimize buffer impacts to the extent possible.
While not required by FWRC, the applicant has proposed offsite mitigation on the Corrington site
that would provide buffer habitat to the North Fork of West Branch of Hylebos Creek.
XII. ANALYSIS OF STRUCTURES, IMPROVEMENTS, AND LAND SURFACE MODIFICATIONS
WITHIN REGULATED WETLANDS PURSUANT TO FWRC 19.175.030
A proposed retaining wall and grading activities to support roadway expansion along State Route
18 will result in the loss of Wetland M and Wetland N (Exhibit H, Pages 19 & 20). Total
improvements and surface modifications to the wetlands total 0.23 acres, which the applicant
proposes to mitigate at a WSDOT owned 3.37 acre parcel (Corrington site) containing existing
in -kind wetlands and the North Fork of Hylebos Creek. The applicant has chosen off -site
mitigation opposed to onsite mitigation as it will provide a greater increase of wetland and
wildlife habitat values for the overall Hylebos Creek watershed. Onsite mitigation is not a
practical approach due to the adjacent high use of automobile traffic and resulting in limited
potential for wildlife habitat.
Findings & Conclusions
The following analysis and decisional criteria is provided in accordance to the structures,
improvements, and land surface modifications within regulated wetlands section of the city's
CAO as codified in FWRC 19.175.030.
FWRC 19.175.030(5)(a), Mitigation Plan Elements
i) Environmental Goals and Objectives
The goal of the proposed mitigation is to ensure that no net loss of wetland
functions and values occurs as a result of the proposed wetland and buffer impacts.
The plan proposes to reach the goal by achieving these objectives:
• Creation of 0.32 acres of new wetland.
• Enhancement of 1.37 acres of existing emergent wetland.
• Enhancement of 1.09 acres of wetland and riparian buffer.
■ Improve water quality, hydrologic, and habitat functions of wetlands by
increasing flood storage capacity and adding additional vegetation classes.
ii) Performance Standards
Performance standards provide benchmarks for measuring achievement of the
goals and objectives of the Corrington site within a specified period.
Hydrologic —
Years 1, 2, and 3 — The soils will be saturated to within six inches of the surface,
or standing water will present within 12-inches of the surface for at least four
consecutive weeks of the growing season in years when rainfall meets or exceeds
the 30-year average.
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Year 10 — The Corrington wetland area will be delineated using current methods
to assure that the mitigation site contains a minimum of 0.32 acres of created
wetland.
Wetland and Buffer Vegetation —
Years 1 and 3 — Native wetland woody species will achieve an average density of
at least four plants per 100 square feet in scrub -shrub and forested connnunities.
Year 3 — Aerial cover of native herbaceous species will be at least 30 percent in
emergent areas.
Year 5 — Aerial cover of native scrub -shrub and forested communities will be at
least 35 percent.
Year 7 — Aerial cover of scrub -shrub and forested communities will be at least 50
percent.
Years 1, 3, 5, and 7 — Class -A noxious weeds and invasive species will not
exceed 25 percent of aerial cover.
Year 10 — Aerial cover of native scrub -shrub and forested communities will be at
least 60 percent.
Wildlife Structures —
Year 1 — Ensure the following structures have been planted within the wetland and
buffer areas and meet the specific size requirements within the mitigation plan.
• Ten large woody debris items
Four snags
Five habitat brush piles
iii) Detailed Construction Plans
The following plans (Exhibit M) prepared by Berger/Abam provide a
comprehensive overview of construction activity:
• General notes & legend
• Site prep, Temporary Erosions and Sedimentation Control (TESC),
and staging
• Grading
• Cross sections
■ Planting, details, and data sheet
iv) Timing
Following installation of erosion control items, grading of the offsite mitigation site
will begin during the spring/summer and will last approximately three weeks. The
site will be prepared and soil remediated in the northern portion of the property
after grading has been completed. The installation of the proposed wildlife habitat
enhancement features will follow grading.
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All bare ground will be covered with a four -inch layer of mulch and hydroseed.
Woody vegetation and aquatic plugs will be planted between December I" and
March 31".
v) Monitoring Program for a Minimum of Five Years
WSDOT has proposed a monitoring program of the Corrington site for 10-years
following installation of the mitigation items. If performance standards are
achieved in less than 10 years, WSDOT will terminate the monitoring. The city's
Critical Areas Ordinance does require a minimum of five years of monitoring with
no option of early termination.
Monitoring will be designed to determine if the performance measure/standards
have been met. Quantitative and qualitative monitoring will be completed and
documented in the 1", 2°d, 3"d, 5`h, 7`h and 10`h years following mitigation
construction. Monitoring reports will be submitted to the city for review and
comment.
vi) Contingency Plan
Hydrology — Contingency measures will be implemented based on observed
conditions or monitoring data. Steps to address insufficient or excessive
hydrology are:
• Clearly identify the source of the problem.
• Consult with the mitigation design team to determine an appropriate
course of action.
• Adjust elevation or install water management structures to achieve
appropriate hydrologic conditions.
Vegetation — Contingencies for plant mortality and poor plant cover include:
• Plant replacement
• Weed control
• Herbivore control
• Fence installation and sensitive area signage
Wildlife Structures — Replace or repair missing or damaged structures.
FWRC 19.175.030(5)(b), Mitigation
Applicants are permitted to choose creation, restoration, or enhancement as a means to adequately
mitigate permanent impacts to regulated wetlands. To mitigate the permanent impacts to the 0.03
acre Category II Wetland M and 0.20 Category III Wetland N, the applicant proposes offsite
compensatory mitigation that includes creation and enhancement. Project site mitigation was not
chosen as the Corrington site would provide a higher functioning wetland and habitat value to the
drainage basin than providing mitigation adjacent to roadways.
The Corrington mitigation site contains a Category I wetland and is within the same drainage
basin (Hylebos Creek) as the two wetlands that will be permanently impacted. The site was
chosen for its high potential for success and relatively low development that surround the area. As
shown in the tables below, and presented in the mitigation plan (Exhibit H), the proposed
mitigation will result in no net loss of wetland area and exceeds in -kind requirements. Minimum
acreage mitigation ratios pursuant to FWRC 19.175.030(5)(c) are satisfied.
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FWRC 19.175.030(5)O, Minimum Acreage Mitigation Ratio
Minimum Mitigation — The following mitigation ratios apply to each of the following permanently
affected wetlands.
Wetland
Creation/
Enhancement
Required Acreage of
Rating/Size
Restoration
In -Kind Mitigation
Wetland M
0.06 creation/restoration; or 0.12
Category II
2:1
4:1
enhancement
0.03 acres
Wetland N
0.30 creation/restoration; or 0.60
Category III
1.5:1
3:1
enhancement
0.20 acres
Total
0.36 creation/restoration; or 0.72
0.23 acres
enhancement
Proposed Mitigation — The applicant proposes to mitigate each affected wetland on the
Corrington site using a combination of creation and enhancement. While the creation ration is
short 0.04 acres of the minimum, the enhancement component exceeds the 0.72 minimum Staff
finds the ratios provide adequate mitigation as it provides a near 7:1 acre ratio of mitigation and
no net loss of wetlands within the Hylebos Creek basin.
Wetland
Creation
Enhancement
Total Acreage of
Rating
In -kind Mitigation
Corrington Site
Category I
0.32 acres
1.37 acres
1.69 acres
FWRC 19.175.030(5)(d), Timing
The applicant proposes off -site mitigation work to begin concurrently with construction of the
Triangle Project. State law prohibits the city to require WSDOT to provide a performance and
maintenance bond for the mitigation construction.
FWRC 19.175.030(5)(e), Inspections
As a code based condition, the applicant will be required to submit monitoring reports, conducted
by a professional approved by the city, for a minimum of five years following completion of the
mitigation project.
Wetland Mitigation Approval Criteria
a) It will not adversely affect water quality.
The off -site mitigation site will not adversely affect water quality as it will create an
additional Category I wetland and enhance the existing wetland buffer. Such
improvements provide a natural detention and filtration process that prevent
pollutants from traveling downstream Therefore, the proposed wetland mitigation
will not adversely affect water quality.
b) It will not adversely affect the existing quality of the wetland's or buffer's wildlife habitat.
The mitigation plan will have habitat features that include large woody debris, snags,
and wildlife habitat brush piles. Habitat features and native wetland vegetation
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plating will provide a significant improvement to the existing site conditions as it has
lost plant diversity due to invasive species becoming established on most of the
property. Therefore, the proposed wetland mitigation will not adversely affect the
existing quality of wetland or buffer wildlife habitat.
c) It will not adversely affect drainage or stormwater retention capabilities.
The net increase in wetlands, coupled with the enhancement of existing wetlands,
will provide a larger more improved functioning area to store and treat stormwater
before it is naturally released downstream. Therefore, the proposed wetland
mitigation will not adversely affect drainage or stormwater retention capabilities.
d) It will not lead to unstable earth conditions nor create erosion hazards.
Typical erosion and sedimentation practices such as silt fencing, covering exposed
soils, and berms will provide adequate erosion control. Grading activities will take
place during the summer construction window. Proposed contours and native
vegetative planting will provide erosion control and stabilization following
construction. Therefore, the proposed wetland mitigation will not lead to unstable
earth conditions or create erosion hazards.
e) It will not be materially detrimental to any other property in the area of the subject property,
nor to the city as a whole, including the loss of open space.
Much of the surrounding area is designated open space and lower density residential
owned by the city or state. Wetland and riparian enhancement activities on the
Corrington site will improve the Hylebos Creek watershed by increasing habitat and
hydrological functions. Therefore, the proposed wetland mitigation will not be
materially detrimental to any other property in the area, the city as a whole, or result
in the loss of open space.
f) It will result in no net loss of wetland area, fienction, or value.
Off site wetland mitigation will provide approximately 7:1 ratio of in -kind mitigation
via creation and enhancement. Although 0.23 acres of wetlands will be permanently
impacted, 0.32 acres of wetland will be created and 1.37 acres will be enhanced.
Functions and values of the mitigated area include flood flow attenuation; sediment
removal; toxicant and nutrient uptake; habitat for amphibians and aquatic invertebrates;
and general fish habitat. Therefore, the improvements will result in no net loss of
wetland area, function or value.
g) The project is in the best interest of the public health, safety, or welfare.
The Triangle Project will improve safety, relieve congestion, and improve mobility for
the citizens of Federal Way. The proposed mitigation will result increased habitat and
hydrological functions that will ultimately improve the Hylebos Creek watershed.
Therefore, the proposal is in the best interest of the public health, safety, or welfare.
h) The applicant has demonstrated sufficient scientific expertise and supervisory capability to
carry out the project.
The applicant has provided a wetland mitigation plan prepared by wetland scientists
contracted by Berger/ABAM with consultation provided by the Army Corp of
Engineers. The site will be monitored for a minimum of five years with status
updates provided to the city, Washington State Department of Ecology, and Army
Corp of Engineers. Therefore, the applicant has demonstrated sufficient scientific
expertise and supervisory capability to carry out the project.
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i) The applicant is committed to monitoring the project and to making corrections if the Project
fails to meet the projected goals.
The city's Critical Areas Ordinance requires a five year monitoring plan, which the
applicant has extended to ten -years. Contingency plans have been provided for
failures associated with hydrology, vegetation, and wildlife structures. Therefore, the
city finds the applicant is committed to monitoring the project and to making
corrections if the project fails to meet projected goals.
XIII. ANALYSIS OF STRUCTURES, IMPROVEMENTS, AND LAND SURFACE MODIFICATIONS
WITHIN WETLAND BUFFERS PURSUANT TO FWRC 19.175.040
Essential Public Facilities, Public Utilities, and Other Public Improvements — The director of
community development may permit the placement of an essential public facility, public utility,
or other public improvements in a regulated wetland buffer if he or she determines that the line or
improvement must traverse the buffer because no feasible or alternative location exists, based on
an analysis of technology and system efficiency. The specific location and extent of the intrusion
into the buffer must constitute the minimum necessary encroachment to meet the requirements of
the public facility or utility.
Findings & Conclusions
The following analysis and decisional criteria is provided in accordance to the structures,
improvements and land surface modifications within regulated wetland buffers with regard to
essential public facilities section of the city's CAO as codified in FWRC 19.175.0400.
Temporary Encroachments — Construction activities associated with the proposed road
improvements will require temporary wetland buffer intrusions totaling 0.60 acres. As shown in
the wetland mitigation plan (Exhibit H, Pages 22-25), the temporarily affected wetland buffers
are M, K, P, U, and AB. The applicant proposes to mitigate the temporary construction impacts
by re -vegetation via hydro -seeding or native shrub/tree plantings where appropriate.
Permanent Encroachments — Wetland buffer intrusions to accommodate new structures and
improvements total 1.05 acres. As shown in the wetland mitigation plan sheets (Exhibit H, Pages
22-25), the permanently affected wetland buffers are M, P, U, and AB.
1. Wetland M —Permanent impacts to wetland buffer M, totaling 0.56 acres, are
required due to grade/fill, expansion of the roadway. and the installation of a
retaining wall.
2. Wetland P —Permanent impacts to wetland buffer P, totaling 0.12 acres, are
required due to grade/fill and expansion of the roadway.
3. Wetland U — Permanent impacts to wetland buffer U, totaling 0.14 acres, are
required due to grade/fill activities associated with roadway replacement.
4. Wetland AB — Permanent impacts to buffer AB, totaling 0.23 acres, are required
due to grade/fill activities, stormwater facility improvements, retaining wall, and
expansion of the roadway.
The applicant proposes approximately 1.03 acres of wetland buffer enhancement at the Corrington
compensatory site to offset permanent buffer impacts within the project area. Enhancements
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include native plantings, large woody debris, and habitat brush piles. Such mitigation is not a
requirement for wetland buffer encroachments associated with essential public facilities.
In order to avoid and minimize buffer impacts, the applicant chose the current design from 11
total alternatives. The current option was chosen, in part, due to its minimized impact to the
environment. Total avoidance of the wetland buffer was not possible due to existing roadway
segments and constraints associated with safety and design guidelines. Staff finds the proposal
constitutes the minimum necessary encroachment.
XIV. PROCESS IV HEARING EXAMINER DECISIONAL CRITERIA AS LISTED WITHIN
FWRC 19.70.150(3)
a) It is consistent with the comprehensive plan.
The proposed environmental mitigation is consistent with the following goals and policies of
the Federal Way Comprehensive Plan (FWCP).
NEP4 — The City should work in concert with internal departments, state, and
regional agencies, as well as with neighboring jurisdictions and tribes, to protect
sensitive areas and the ity's natural environment.
NEGS — Protect, restore, and enhance the City's lakes and streams.
NEP37 — Erosion control measures shall be used for any work in or adjacent to
stream or lake buffers.
NEP39 — Essential public facilities and utilities may cross lakes or streams where
no other feasible alternative exists. The amount of intrusion shall be the minimum
necessary to complete the project.
NEG7 — Protect and enhance the functions and values of the City's wetlands.
NEP43 — The City will protect its wetlands with an objective of no overall net -loss
of functions or values.
NEP44 — The City shall, as a minimum standard, use the methodology in the
March 1997 Washington State Wetlands Identification and Delineation Manual
(Department of Ecology Publication #96-94) as set forth in WAC 173-22-080, as it
exists as of November 1, 1999, or as subsequently amended for identification and
delineations of wetlands within the City.
NEP49 — Mitigation sites should replace or augment the wetland values to be lost
as a result of a development proposal. Sites should be chosen that would contribute
to an existing wetland system or, if feasible, restore an area that was historically a
wetland.
In addition to the goals and policies mentioned above, the Triangle Project is
specifically included as the city's highest priority project on Interstate-5 on FWCP
page III-38. The proposal is consistent with the following goals and policies from the
transportation element of the comprehensive plan:
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TG2 — Provide a safe, efficient, convenient and financially sustainable
transportation system with sufficient capacity to move people, goods and services
at an acceptable level of service.
TG9 — Improve movement of freight and goods throughout the region and within
the city, while maintaining quality of life, realizing the vision of our
comprehensive plan, and ininimizing undue impacts to city infrastructure.
TP11 — Coordinate street and roadway improvement programs with appropriate
state, regional and local agencies.
b) It is consistent with all applicable provisions of this title and all other applicable laws.
The application has been reviewed under the FWCP and FWRC Title 19 `Zoning and
Development Code' with special attention to Division V `Critical Areas.' The
applicant acted as lead agency and issued a DNS on May 11, 2007, pursuant to
SEPA. The applicant has also submitted a Joint Aquatic Resources Permit
Application (JARPA) form (Exhibit N).
c) It is consistent with the public health, safety, and welfare.
The Triangle Project will improve safety, relieve congestion, and improve mobility
for the citizens of Federal Way. Offsite mitigation will provide additional wetlands
and improved function and value to the Hylebos Creek drainage basin.
d) The streets and utilities in the area of the subject property are adequate to serve the
anticipated demand from the proposal.
The Triangle Project will alleviate congestion and safety problems within the State
Route 161, State Route 18, and Interstate 5 corridors.
e) The proposed access to the subject property is at the optimal location and configuration.
Not applicable. The Triangle Project is an improvement to existing state and
interstate roadways.
0 Traffic safety impacts for all modes of transportation, both on and off site, are adequately
mitigated.
As mentioned previously, the Triangle Project will reduce traffic congestion, increase
vehicle and freight mobility, and address safety issues as a result of additional
automobile use in the corridor.
XV. RECOMMENDED CONDITIONS OF APPROVAL
1. As required by FWRC 19.165.020(5), prior to diverting water into the new channel, a
qualified professional approved by the city shall inspect the new channel following its
completion and issue a written report to the director of community development stating that
the channel complies with the requirements of this section.
2. As required by FWRC 19.165.020(3)0), the applicant shall submit a phasing plan upon
selection of a chosen contractor for stream relocation activities.
3. As required by FWRC 19.175.030(5)(v), the applicant shall monitor the Corrington wetland
compensatory mitigation site for a minimum of five years.
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4. As required by FWRC 19.175.030(e), the applicant shall submit monitoring reports, per
scheduling provided in the wetland mitigation plan, for a nunimum of five years following
completion of the mitigation project. Any third party review fees incurred by the city shall be
reimbursed by the applicant.
5. The applicant shall obtain an engineering permit for grading activities on the Corrington,
stream relocation and stream culverting areas.
LIST OF EXHIBITS
Note: Copies of the exhibits listed below are not attached to all copies of this report. All exhibits have been
provided to the Hearing Examiner. Copies of exhibits may be obtained upon request at the City of Federal Way's
Department of Community Development Services.
Exhibit A — I-5 - SR161/SR 18 Triangle Improvements Project Description Prepared by WSDOT
Exhibit B — Project Area Vicinity Map Prepared by WSDOT
Exhibit C — Temporary Construction Easements and Vicinity Map
Exhibit D — Compensatory Mitigation Site Vicinity Map
Exhibit E — Notice of Application
Exhibit F — Notice of Public Hearing
Exhibit G — Determination of Nonsignificance (DNS) Issued by WSDOT, May 11, 2007
Exhibit H — Draft Wetland Mitigation Plan Prepared by Berger/ABAM, February 2009
Exhibit I — Draft Stream Mitigation Plan Prepared by Berger/ABAM, February 2009
Exhibit J — Stream Relocation Plan
Exhibit K — Hylebos Creek Tributary 16A Habitat Assessment
Exhibit L — Withdrawn
Exhibit M — Corrington Site Construction Plans
Exhibit N — Joint Aquatic Resources Permit Completed by WSDOT, October 22, 2008
TRANSMITTED TO THE PARTIES LISTED HEREAFTER:
Hearing Examiner — Phil Olbrechts, Ogden Murphy Wallace, 1601 5th Avenue, Suite 2100, Seattle, WA 98101
Project Applicant — Allison Hanson, Director of Environmental Services, ESO Mega Projects, WSDOT, 999 31d Avenue, Suite
2424, Seattle, WA 98104
Federal Way Staff— Associate Planner Matthew Herrera and Senior Engineering Plan Reviewer Ann Dower
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