HomeMy WebLinkAboutRS_22129Lindahl7.29.22LakeStudyCOMPLETE_v2
LAKE STUDY
FOR
3719 LAKE WASHINGTON BLVD N - PILE REPAIR
CITY OF RENTON
Wetland Resources, Inc. Project #22129
Prepared By
Wetland Resources, Inc.
9505 19th Avenue SE, Suite 106
Everett, WA 98208
(425) 337-3174
Prepared For
Kevin Lindahl and Becky Byus
3719 Lake Washington Blvd N
Renton, WA 98056
First Submittal: July 29, 2022
ii
TABLE OF CONTENTS
1.0 PROPOSED PROJECT ...................................................................................................................1
1.1 PROJECT LOCATION .......................................................................................................................... 1
1.2 LANDSCAPE SETTING ......................................................................................................................... 1
1.3 SITE DESCRIPTION ............................................................................................................................. 3
1.4 PROJECT DESCRIPTION ...................................................................................................................... 3
2.0 LAKE STUDY ...............................................................................................................................3
2.1 ASSESSMENT METHODOLOGY .......................................................................................................... 3
Field Investigation ................................................................................................................................ 3
Limit of Study ....................................................................................................................................... 3
2.2 SITE CONDITIONS ANALYSIS ............................................................................................................. 4
Existing Conditions ............................................................................................................................... 4
Existing Ecological Functions ............................................................................................................... 4
2.3 TREE AND VEGETATION PROTECTION ............................................................................................. 6
3.0 PROJECT IMPACTS AND MITIGATION ........................................................................................6
3.1 PROJECT IMPACT ANALYSIS .............................................................................................................. 6
3.2 PROPOSED MITIGATION .................................................................................................................... 6
3.3 NO NET LOSS DISCUSSION ................................................................................................................ 7
4.0 USE OF THIS REPORT ................................................................................................................7
5.0 REFERENCES ..............................................................................................................................8
LIST OF FIGURES
- AERIAL OVERVIEW OF THE SUBJECT PROPERTY .........................................................1
- LANDSCAPE-SCALE VICINITY MAP (GOOGLE MAPS) ....................................................2
- REAR YARD (FACING NORTHWEST FROM THE DOCK) ................................................4
LIST OF APPENDICES
APPENDIX A: LAKE STUDY MAP
3719 Lk WA Blvd N Pile Repair 1 Lake Study
WRI #22129 July 29, 2022
1.0 PROPOSED PROJECT
1.1 PROJECT LOCATION
The project occurs on King County Tax Parcel 3342700190. This is a 0.19-acre parcel located at
3719 Lake Washington Blvd N in the city of Renton. Access to the property is from the east via
Lake Washington Blvd N. The Public Land Survey System Locator is Section 32, Township 24N,
Range 5E, WM.
- Aerial Overview of the Subject Property
1.2 LANDSCAPE SETTING
Basin: Puget Sound
Sub-Basin: East Lake Washington - Renton
Watershed: Water Resource Inventory Area (WRIA) 8 Lake Washington - Cedar - Sammamish
The study area is located on the east shore of Lake Washington. Lake Washington is the second-
largest natural lake in Washington State with a total surface area of over 22,000 acres. The lake is
approximately 20 miles in total length, with an average width of 1.5 miles (Kerwin, 2001). Lake
Washington is highly developed along much of the approximately 50 miles of lake shoreline.
The subject property is located approximately 1,000 feet to the south of the confluence of Lake
Washington and May Creek, and approximately 1.5 miles north of the confluence with the Cedar
River. May Creek originates between Squak and Cougar Mountains and flows west through May
Valley before entering Lake Washington. The Cedar River drains the entire upper basin of Water
Resource Inventory Area (WRIA) 8.
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WRI #22129 July 29, 2022
- Landscape-Scale Vicinity Map (Google Maps)
3719 Lk WA Blvd N Pile Repair 3 Lake Study
WRI #22129 July 29, 2022
1.3 SITE DESCRIPTION
The subject property is surrounded to the north and south by single-family residential
development, to the east by the Eastrail, and to the west by Lake Washington. An existing
residence, attached garage, driveway, and deck cover the entirety of the subject property.
The rear yard consists entirely of on-grade wood decking between the residence and an existing
rock bulkhead. No vegetation or bare ground is present. A dock extends west approximately 68
feet from the intersection of the bulkhead and decking.
Existing development in the lake is limited to the bulkhead, dock, and two moorage piles. The face
of the bulkhead clearly defines the ordinary high water mark (OHWM) of Lake Washington, which
was observed by WRI staff after the controlled rise to summer/recreational lake elevation. No
vegetation is present waterward of the OHWM and no aquatic vegetation or lake-fringe wetlands
were observed on or near the property. Lakebed substrate consists of sorted sand and large cobble
pieces on a moderate grade. On-site conditions are consistent with a high-energy shoreline. No
other habitat features were observed on or near the subject property.
1.4 PROJECT DESCRIPTION
The applicant proposes to install HDPE sleeves over two existing wood moorage piles located along
the north property line. Construction will occur during one or two days within the state/federal
work window to minimize impacts to aquatic resources, and access will be from a small barge.
Due to proposed shoreline modification, the applicant has contracted Wetland Resources, Inc. to
prepare a Lake Study that meets the requirements of Renton Municipal Code (RMC) 4-8-120D.19
- Stream or Lake Study, Standard. This report demonstrates compliance with the Stream or Lake Assessment
Narrative standards set forth in subsection c.
2.0 LAKE STUDY
2.1 ASSESSMENT METHODOLOGY
Field Investigation
Senior Ecologist, Niels Pedersen, PWS, and Associate Ecologist, Shaun Sweeney, conducted a site
investigation on May 24, 2022 to determine habitat conditions on and near the subject property.
Limit of Study
The proposed project occurs on tax parcel (tax ID number 3342700190). Lack of legal access to
adjacent parcels prevents Wetland Resources, Inc. (WRI) staff from performing detailed
investigation in surrounding areas 100 feet upstream and downstream from the property line, as
required by the RMC.
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WRI #22129 July 29, 2022
This report is based on physical inspection of the subject property, line-of-sight observations from
the edge of legal access, consideration of existing publicly available information, and using best
professional judgment.
2.2 SITE CONDITIONS ANALYSIS
Existing Conditions
Lake Washington, a Type S waterbody, is the only critical area located on or near the subject
property. The western portion of the property includes a concrete bulkhead with cinder blocks, a
wood deck covering the entire area of the rear yard, a dock, and two moorage piles. The dock
includes skirting along the north and south sides for approximately 50 feet from the approach. On-
site vegetation is limited to potted plants and sparse low groundcover along the top of the bulkhead.
The eastern portion of the property consist of impervious surfaces (residence and garage).
- Rear Yard (Facing Northwest from the Dock)
Existing Ecological Functions
Ecological functions on and near the site are impaired. The existing rock bulkhead deflects wave
energy, which can cause erosion that leads to deeper water along the shoreline. High-
energy/deepwater shorelines do not provide refuge opportunities for migrating fish. Bulkheads also
3719 Lk WA Blvd N Pile Repair 5 Lake Study
WRI #22129 July 29, 2022
prevent the establishment of riparian vegetation, which provides cover and forage opportunities
for juvenile salmon. The absence of overhanging vegetation further limits ecological support for
migrating fish. The existing impervious surface also limits the establishment of overhanging native
vegetation in upland areas, further reducing ecological value along the shoreline.
The existing dock is constructed with closed decking (no light penetration) and skirting around the
sides. See Figure 4 below. This type of overwater structure creates high underwater light contrast
by casting shade in ambient daylight conditions, which limits light availability for aquatic
vegetation to photosynthesize. Shading caused by overwater structures also increases predation
risk for juvenile salmon by altering migration patterns, distribution, and general behavior; fish that
rely on vision and light can become disoriented and subject to predation.
Due to altered sediment processes and in-water vegetation structure resulting from the hard-
armored bulkhead, lack of riparian vegetation due to built and impervious surfaces along the
shoreline, and increased predation risk for juvenile salmonids associated with the dock’s closed
decking and skirting, existing ecological functions are limited within the subject property.
Fish and Wildlife Presence
No fish or wildlife species were directly observed at the time of investigation although various
aquatic species are known to inhabit Lake Washington. The Washington Department of Fish and
Wildlife (WDFW), Pacific States Marine Fisheries Commission (PSMFC), and the Washington
Dept. of Natural Resources (WADNR) are the primary agencies that provide publicly available
information used for making species and habitat presence determinations. The following
information represents the findings from each source.
WDFW SalmonScape Map Tool
SalmonScape is an online GIS database that contains publicly available resource information for
fish population studies and general species distribution (both documented and modeled presence).
Within Lake Washington, the following species are depicted:
• Fall Chinook (documented presence),
• Coho (documented presence),
• Winter Steelhead (documented presence),
• Sockeye (documented presence),
• Bull Trout (documented rearing),
• Kokanee (documented presence)
PSMFC StreamNet Map Tool
StreamNet is a fish distribution database maintained by the PSMFC as a regional clearinghouse
for fish data. In the vicinity of the project area, fish presence is only depicted within Lake
Washington. StreamNet states the presence of the following species:
• Fall Chinook (migration only)
• Coho (migration only)
• Sockeye (migration only)
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• Winter Steelhead (migration only)
• Bull Trout (migration only)
WDNR Forest Practices Activity Mapping Tool (FPAMT)
FPAMT is an online GIS database that aids the process of submitting a Forest Practices permit
application. The tool is useful for the purposes of this study because WDNR models fish presence.
FPAMT depicts Lake Washington as a fish-bearing shoreline of the state. No other features are
noted in the vicinity of the project.
WDFW Priority Habitat and Species (PHS) Maps
No terrestrial priority habitats are listed on or near the site. Aquatic priority habitats for the above-
listed species are noted on the PHS maps.
2.3 TREE AND VEGETATION PROTECTION
Proposed pile sleeving will occur from a small barge and will not result in vegetation/tree removal.
3.0 PROJECT IMPACTS AND MITIGATION
3.1 PROJECT IMPACT ANALYSIS
The proposed pile sleeving does not create new long-term impacts within the terrestrial
environment; vegetation removal is not necessary for access or materials transport, new
structures/impervious surfaces are not proposed, and construction will occur from a barge.
Some short-term effects related to construction can be expected in the aquatic environment,
including sediment disturbance, aquatic vegetation disturbance, and elevated in-water noise levels
caused by the barge and pile sleeving. In-water noise levels are not expected to create any
measurable impacts because fish are adapted to relatively high ambient noise levels that regularly
occur in streams and freshwaters. Although sediment and aquatic vegetation disturbance from
propeller wash could temporarily alter salmonid behavior in the vicinity of the project, these
actions are not expected to create any measurable impacts to shoreline function (i.e. fish injury,
mortality, or habitat loss). No long term or permanent impacts are anticipated as a result of the
proposed project.
3.2 PROPOSED MITIGATION
As previously stated, temporary noise and sedimentation resulting from pile sleeving are expected
to be small, transitory impacts. Appropriate mitigation was determined by WRI staff based on-site
limitations (hard surfaces throughout entire rear yard) and the magnitude of project impacts.
Proposed mitigation includes the placement of one cubic yard of two-inch rounded gravel within
the nearshore zone of the lake adjacent to the bulkhead. The gravel is a suitable spawning substrate
and will be dispersed within the nearshore zone at a depth of approximately three inches, in an
area totaling approximately 100 square feet. Habitat value within Lake Washington is in part
limited by the effect of altered sediment processes; bulkheads prevent natural recruitment and
movement of rock substrate in the lake. Placement of clean, rounded rock is expected to provide
nourishment along a disturbed reach of the lake.
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The rock will temporarily benefit areas near the subject property, until wave energy re-distributes
the gravel. The proposed mitigation plan is expected to modestly improve habitat quality within
the lake and was designed to provide an ecological uplift relative to proposed impacts.
3.3 NO NET LOSS DISCUSSION
RMC 4-3-090D.2.a.i requires applicants to ensure that development will not result in a net loss of
shoreline ecological functions or processes. Due to the anticipated temporary construction impact,
some compensatory mitigation is warranted. In consideration of the minor transitory impact,
proposed mitigation includes the placement of two-inch round rock within the nearshore zone of
the lake. Placement of the gravel within the nearshore zone will aid in lake bed stabilization,
substrate nourishment, and will result in a modest long-term habitat quality improvement for
aquatic vegetation and fish.
WRI staff concluded that providing a modest long-term benefit to ecological functions exceeds the
temporary impact associated with construction. Therefore, proposed mitigation will result in no
net loss of functions.
4.0 USE OF THIS REPORT
This Lake Study is supplied to Kevin Lindahl and Becky Byus as a means of determining the
presence of critical habitat, as required by the City of Renton during the permitting process. This
report is based largely on readily observable conditions and, to a lesser extent, on readily
ascertainable conditions. No attempt has been made to determine hidden or concealed conditions.
The laws applicable to salmonid habitat are subject to varying interpretations and may be changed
at any time by the courts or legislative bodies. This report is intended to provide information
deemed relevant in the applicant's attempt to comply with the laws now in effect.
The work for this report has conformed to the standard of care employed by ecologists. No other
representation or warranty is made concerning the work or this report and any implied
representation or warranty is disclaimed.
Wetland Resources, Inc.
Shaun Sweeney
Associate Ecologist
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5.0 REFERENCES
Anderson et al. 2016. Determining the Ordinary High Water Mark for Shoreline Management Act Compliance
in Washington State. WA Department of Ecology. Publication #16-06-029.
Kerwin, J. 2001. Salmon and Steelhead Habitat Limiting Factors Report for the Cedar – Renton Basin (Water
Resource Inventory Area 8). Washington Conservation Commission. Olympia, WA.
http://www.pugetsoundnearshore.org/supporting_documents/WRIA_8_LFR_FINAL.p
df. Accessed June 2022.
NOAA. 2022. National Weather Service Forecast Office, Seattle, Washington.
http://www.weather.gov/climate/index.php?wfo=sew. Accessed June 2022.
StreamNet. 2022. StreamNet Mapper. http://www.streamnet.org/mapping_apps.cfm. Accessed
June 2022.
U.S. Fish & Wildlife Service (USFWS). 2022. National Wetlands Inventory (NWI) Online Mapper.
http://www.fws.gov/wetlands/Data/Mapper.html. Accessed June 2022.
Washington State Department of Fish and Wildlife (WDFW).2022a. Priority Habitats and Species:
PHS on the Web. http://wdfw.wa.gov/mapping/phs/. Accessed June 2022.
WDFW. 2022b. SalmonScape Online Mapping Application.
http://apps.wdfw.wa.gov/salmonscape/map.html. Accessed June 2022.