HomeMy WebLinkAboutRS_Lake StudyEcological No Net Loss Assessment Report
Prepared for
Sunday Heilly
2727 Mountain View Ave N
Renton, WA 98056
Prepared by
Northwest Environmental Consulting, LLC
3639 Palatine Avenue North
Seattle, WA 98103
206-234-2520
December 2020
Heilly Ecological No Net Loss Report 1
Purpose
The purpose of this report is to fulfill the requirements of the City of Renton Municipal Code
(RMC) by assessing overall project impacts and proposed mitigation to determine if the project
meets the “No Net Loss” Regulation of the Shoreline Master Program.
No Net Loss is defined as “An ecological concept whereby conservation losses in one
geographic or otherwise defined area are equaled by conservation gains in function in another
area.”
Location
The project is located at 2727 Mountain View Ave N, Renton, WA 98056. (See Attachment A –
Sheet A1.0). The parcel is on the waterfront of Lake Washington, which contains several
endangered fish species listed under the Endangered Species Act and Washington State
designated priority fish species.
Project Description
The owner is proposing to repair the existing dock by repairing seven piles using steel sleeves
and re-decking the entire dock with ThruFlow decking. The three existing 10 to 12-inch timber
mooring piles will be replaced in kind with 10 to 12-inch steel piles
Project drawings are included in Appendix A – Drawings. Appendix B contains site photos.
Approach
Northwest Environmental Consulting LLC (NWEC) biologist Brad Thiele conducted a site visit in
November, 2020 to evaluate conditions on site and adjacent to the site. NWEC also consulted
the following sources for information on potential critical fish and wildlife habitat along this
shoreline:
• City of Renton COR Maps online database
(https://rp.rentonwa.gov/HTML5Public/Index.HTML?viewer=CORMaps)
• Washington Department of Fish and Wildlife (WDFW): Priority Habitats and Species
online database (http://apps.wdfw.wa.gov/phsontheweb/)
• WDFW Priority Habitats and Species online database
(http://apps.wdfw.wa.gov/phsontheweb/)
• WDFW SalmonScape online database of fish distribution and ESA listing units
(https://apps.wdfw.wa.gov/salmonscape/)
McShane Ecological No Net Loss Report 2
Site Description
The property and adjacent properties are single-family homes. Vegetation consists of lawns
and a mix of native and ornamental landscaping. The shoreline consists of a rock bulkhead.
Substrates along the shoreline include sand and gravel, with some cobble and debris mixed into
the sediments. No vegetation is present waterward of the bulkhead. Photos of the site are
shown in Appendix B – Photos.
The adjacent property to the north is similar with a rock bulkhead and dock, with ornamental
shoreline plantings. The Parcel to the South is Gene Coulon Memorial Beach Park and
contains a more open shoreline with grasses and a walking path. Multiple pilings are present
along the shoreline.
The project is on a waterfront lot on the shores of Lake Washington. No wetlands or streams
were present on the subject or adjacent properties. Lake Washington is a water of the U.S. and
is designated as a Shoreline of the State by the City of Renton.
Species Use
WDFW’s PHS mapping and SalmonScape mapping tools show the following salmonid species
using Lake Washington for migration and/or rearing: residential coastal cutthroat (Oncorhynchus
clarkii), winter steelhead (O. mykiss), Dolly Varden/bull trout (Salvelinus malma), sockeye
salmon (O. nerka), fall Chinook (O. tshawytscha), Coho salmon (O. kisutch), and kokanee (O.
nerka). The Salmonscape database maps the site as critical habitat to the Endangered Species
Units (ESU) of Threatened Chinook and steelhead. Sockeye are known to spawn along the
shoreline along the project area. The nearest spawning stream is May Creek, located
approximately 4,000 feet north of the project area, is modeled by Washington Department of
Fish and Wildlife (WDFW) for spawning of non-listed Coho and sockeye and listed Fall Chinook.
Juveniles may rear in the waters near the project when traveling from spawning sites on other
lake tributaries to the lake’s outlet at the Locks. The project site is accessible to any fish
migrating or rearing in the lake, and Lake Washington is designated as critical habitat for
Endangered Fall Chinook salmon.
Other than Lake Washington, there are no priority habitats or species known to occur within a
half mile of the project.
Project Impacts and Conservation Measurements
Direct Impacts:
Sediments: During demolition, construction, and barge movement, silts and sediments may be
disturbed along the shoreline. Sediment suspension is expected to be short-term and localized.
Small salmonids could be temporarily displaced or stressed by increased turbidity, though the
project will meet state water quality criteria and any sediment suspension will be short in
duration.
Noise: Construction equipment, including the crane, excavator, and vibratory pile driver, will
create construction noise audible to neighbors and in-water in the action area. Noise
disturbance will be short-term, but could temporarily stress or displace any salmonids in the
vicinity. Noise from pile driving will not reach the injury threshold for juvenile or adult salmonids
McShane Ecological No Net Loss Report 3
(183 dB for juveniles, 187 dB for adults). Noise levels are available for steel piles 12 inches in
diameter; vibratory driving just barely reaches the behavioral disturbance threshold of 150 dB
SEL. Twelve-inch piles may reach 155 dB (WSDOT 2017). The area of potential fish behavioral
disturbance is very small, less than 200 feet, but is probably much less and will be done during
the inwater work window when juvenile salmonids are not likely present.
Lakebed coverage: The existing one 10” and two 12” mooring piles will be removed and
replaced with 10” epoxy coated steel piles. This will reduce the lakebed coverage at the site by
half a square foot.
Potential spills: Short-term risks include the potential for petroleum spills that can occur with
any equipment operation. The level of impact to the aquatic environment is expected to be
minor because of the small amount of petroleum products available for spillage during typical
construction activities, and because of spill containment measures that will be employed should
a spill occur.
Indirect Impacts:
Shading: The existing solid wood pier covers approximately 415 square feet of the lake. The
resurfaced deck will be 407 square feet over water.
Grated decking allows more light to penetrate the waters below a dock, which can increase
productivity in the waters, and reduce the full shade favored by salmonid predators. Salmonid
predators are known to use hard shadowing under solid-decked docks to ambush juvenile
salmonids. Reducing hard shadows limits the ability of predatory fishes to effectively hunt
salmonids.
ThruFlow grated decking has measured performance at 43 percent light penetration (ThruFlow
2020). Thus, the increase in lighting under the pier is effectively 57 percent of the area of a solid
decked structure. A summary of how this will affect this project’s shading is shown below:
Existing overwater coverage 415 sq. ft.
Proposed overwater coverage 407 sq. ft.
Effective overwater coverage with ThruFlow decking
(57% effective coverage)
232 sq. ft.
The proposed dock will decrease overwater coverage by 8 square feet. Installing ThruFlow
decking on the existing and new structure will result in a decrease of effective overwater
coverage by 183 square feet over existing conditions at the site.
Recreational Boating: The project supports continued recreational boating, which has been
identified as a limiting factor for salmonid populations in Lake Washington. The pier repair and
beach cove will not introduce additional boating to Lake Washington, as the owners could still
access the lake from a public boat launch or private moorage facility.
Other Conservation measures:
Work window: The work will be completed during the prescribed in-water work window for this
area of Lake Washington (July 16 to December 31). Operating within this time frame helps
protect Chinook salmon, steelhead, bull trout and other salmonid fish species.
Best Management Practices: Applicable BMPs will be used; such as:
• A floating boom around the in-water work area will contain any floating debris that may
McShane Ecological No Net Loss Report 4
escape during construction.
• The barge will have a perimeter containment sock to absorb oil and grease that may
wash from the barge during construction.
• Hazardous material containment materials such as spill absorbent pads and trained
personnel will be required onsite during any phase of construction where machinery is in
operation near surface waters.
Mitigation Strategy
Avoidance and Minimization
The proposed project cannot be avoided if the existing structure is to be maintained and
updated to meet current Lake Washington Design standards. The project has been designed to
reduce impacts by using grated decking and maintain the existing pilings as applicable. No
treated timber will be used below the water line to repair existing piles or other structures.
Mitigation Approach
The project does not require mitigation because of the design standards being applied to the
project.
Shoreline Function and Values Improvements
As discussed above, using grated decking allows light penetration into the littoral zone of the
lake and reduces the use of the overwater structure by predatory fish. In addition, grating the
decking within the first 30 feet of the shoreline, may help reduce the outmigration times of
salmon that sometimes pause before passing under overwater structures. These changes will
improve the shoreline ecological functions and values.
Conclusion
Salmon species are present within Lake Washington, including species listed under the federal
Endangered Species Act (ESA). Listed species include Puget Sound Chinook (threatened),
Puget Sound steelhead (threatened), and bull trout (threatened). Other species of important
local significance include kokanee, cutthroat trout, Coho salmon, and sockeye. There are no
fish-bearing stream outlets near the site.
The project will overall have a net benefit to the nearshore environment. There will be temporary
impacts from noise and disturbed sediments during demolition and reconstruction of the pier,
and during work on the bulkhead and cove. However, these impacts are offset by a permanent
functional reduction of about 178 square feet of the pier’s shading by installing ThruFlow grated
decking throughout. This grating will reduce the hard shadows favored by salmonid predators
and increase productivity in waters under the pier. In addition, a native planting plan will
enhance shoreline conditions by providing some native vegetation that will eventually create
overhanging vegetation of the lake.
The project will follow the prescribed fish windows and use applicable BMPs to prevent
construction spills and turbidity from occurring.
McShane Ecological No Net Loss Report 5
This project has been designed to meet current residential dock standards and will use Best
Management Practices to reduce project impacts. The conservation measures are designed to
improve ecological functions or prevent further degradation of habitat and will result in No Net
Loss of ecological functions at the site. The planting plan once established will improve
ecological conditions at the site long term over the existing condition.
McShane Ecological No Net Loss Report 6
REFERENCES
King County iMap. 2019. Interactive property and critical areas mapping tool.
http://www.kingcounty.gov/operations/GIS/Maps/iMAP.aspx. Queried December 2016.
Washington Department of Fish and Wildlife. 2019. SalmonScape interactive mapping tool.
http://fortress.wa.gov/dfw/gispublic/apps/salmonscape/default.htm. Queried February
2018.
Washington Department of Transportation (WSDOT), 2019.
https://www.wsdot.wa.gov/Environment/Biology/BA/BAguidance.htm
Aqua Dock Ecological No Net Loss Report 6
Appendix A:
Figures and Project Drawings
VICINITY MAP (ZOOMED)
SITE PLAN
SUBJECT
PROPERTY
SHEETA1.0 NWS-2020-XXX
10PAGE 1 OF
Pin: 334210-4050
Legal Description:HILLMANS LK WN GARDEN OF EDEN #1 LOT 88 TGW SELY 1/2 LOT 87 MEAS MIDWAY
BTWN NWLY & SELY LNS SD LOT 87 & SH LDS ADJ
Plat Block: A
Plat Lot: 87 & 88
LAT: 47.51639 LONG: -122.20925
Prepared By:
Seaborn Pile Driving
1080 W Ewing St
Seattle, WA 98119
Office: 206-236-1700
permits@seabornpiledriving.com
www.seabornpiledriving.com
Scope of Work: We propose to repair (7) supporting piles using steel sleeves, replace (3) existing mooring piles with steel mooring piles and re-deck
the existing dock with thruflow decking.Created: 7/29/2020Purpose: The proposed dock is to provide for safe boat moorage and safe water recreational activities for a single family residence.Adjacent Owners:WINTER MARLENE R2731 MOUNTAIN VIEW AVE N 98056RENTON CITY OF2550 LAKE WASHINGTON BLVD 98056Datum: CORPS OF ENGINEERS 1919NE Quarter Of Section 6, Township 23, Range 05Applicant: Sunday Heilly2727 Mountain View Ave N.Renton, WA 98056County: King CountyLocation: Lake WashingtonLast Updated: 7/29/2020 12:05 PM KelseConctractor: Seaborn Pile Driving Company1080 W Ewing StSeattle, WA 98119S E A B O R N
PILE DRIVING COMPANY
N
3'-7"
51'-10"
8'
58'-8"
6'-10"
EXISTING CONDITIONS
SHEETA2.0 NWS-2020-XXX
10PAGE 2 OF
N
Prepared By:
Seaborn Pile Driving
1080 W Ewing St
Seattle, WA 98119
Office: 206-236-1700
permits@seabornpiledriving.com
www.seabornpiledriving.com
Scope of Work: We propose to repair (7) supporting piles using steel sleeves, replace (3) existing mooring piles with steel mooring piles and re-deck
the existing dock with thruflow decking.Created: 7/29/2020Purpose: The proposed dock is to provide for safe boat moorage and safe water recreational activities for a single family residence.Adjacent Owners:WINTER MARLENE R2731 MOUNTAIN VIEW AVE N 98056RENTON CITY OF2550 LAKE WASHINGTON BLVD 98056Datum: CORPS OF ENGINEERS 1919NE Quarter Of Section 6, Township 23, Range 05Applicant: Sunday Heilly2727 Mountain View Ave N.Renton, WA 98056County: King CountyLocation: Lake WashingtonLast Updated: 7/29/2020 12:05 PM KelseConctractor: Seaborn Pile Driving Company1080 W Ewing StSeattle, WA 98119S E A B O R N
PILE DRIVING COMPANY
HEILY JOHN PATRICK+SUNDAY G
2727 MOUNTAIN VIEW AVE N 98056
Parcel #: 334210-4050
WINTER MARLENE R
2731 MOUNTAIN VIEW AVE N 98056
RENTON CITY OF
2550 LAKE WASHINGTON
BLVD 98056
LAKE WASHINGTONLATER
AL LI
N
E
LATER
AL LI
N
E
EXISTI
N
G
PI
E
R:
N
O
W
O
R
K P
R
O
P
O
S
E
D
10' SETB
A
C
K
10' SETB
A
C
K
**CLEAN UP LAKE AROUND PROJECT**
OHWM -21.8'
15' DEPTH
OHWM 30' OFFSET
EXISTING PIER TO BE REPAIRED
5'10'0'20'
SCALE: 1" = 20'-0"
EXISTING BOAT LIFT
TO REMAIN
3'-7"
8'
6'-10"
51'-10"
58'-8"SHEETA3.0 NWS-2020-XXX
10PAGE 3 OF
PROPOSED CONDITIONS
N 5'10'0'20'
SCALE: 1" = 20'-0"
Prepared By:
Seaborn Pile Driving
1080 W Ewing St
Seattle, WA 98119
Office: 206-236-1700
permits@seabornpiledriving.com
www.seabornpiledriving.com
Scope of Work: We propose to repair (7) supporting piles using steel sleeves, replace (3) existing mooring piles with steel mooring piles and re-deck
the existing dock with thruflow decking.Created: 7/29/2020Purpose: The proposed dock is to provide for safe boat moorage and safe water recreational activities for a single family residence.Adjacent Owners:WINTER MARLENE R2731 MOUNTAIN VIEW AVE N 98056RENTON CITY OF2550 LAKE WASHINGTON BLVD 98056Datum: CORPS OF ENGINEERS 1919NE Quarter Of Section 6, Township 23, Range 05Applicant: Sunday Heilly2727 Mountain View Ave N.Renton, WA 98056County: King CountyLocation: Lake WashingtonLast Updated: 7/29/2020 12:05 PM KelseConctractor: Seaborn Pile Driving Company1080 W Ewing StSeattle, WA 98119S E A B O R N
PILE DRIVING COMPANY
GRATED THRUFLOW DECKING TO REPLACE
SOLID SURFACE DECKING THROUGHOUT
HEILY JOHN PATRICK+SUNDAY G
2727 MOUNTAIN VIEW AVE N 98056
Parcel #: 334210-4050
WINTER MARLENE R
2731 MOUNTAIN VIEW AVE N 98056
RENTON CITY OF
2550 LAKE WASHINGTON
BLVD 98056
LAKE WASHINGTONLATER
AL LI
N
E
LATER
AL LI
N
E
EXISTI
N
G
PI
E
R:
N
O
W
O
R
K P
R
O
P
O
S
E
D
10' SETB
A
C
K
10' SETB
A
C
K
**CLEAN UP LAKE AROUND PROJECT**
OHWM -21.8'
15' DEPTH
OHWM 30' OFFSET
EXISTING PIER TO BE REPAIRED
EXISTING BOAT LIFT
TO REMAIN
LEGEND
(7) EXISTING PILES - TO BE REPAIRED
(3) EXISTING PILES - TO BE REPLACED
(6) EXISTING PILES - NO WORK TO BE DONE
Area: 439 sqft (total)
Area: 415 sqft (over water)
Area: 439 sqft (new thruflow grated decking)
A'A'
10"
10"
12"
12"
12"
10"
12"
10"
12"
12"
12"
10"8"
10"12"12"
58'-8"
8'
3'-7"
6'-10"SHEETA4.0 NWS-2020-XXX
10PAGE 4 OF
PIER DETAILS
PLAN VIEW
Prepared By:
Seaborn Pile Driving
1080 W Ewing St
Seattle, WA 98119
Office: 206-236-1700
permits@seabornpiledriving.com
www.seabornpiledriving.com
Scope of Work: We propose to repair (7) supporting piles using steel sleeves, replace (3) existing mooring piles with steel mooring piles and re-deck
the existing dock with thruflow decking.Created: 7/29/2020Purpose: The proposed dock is to provide for safe boat moorage and safe water recreational activities for a single family residence.Adjacent Owners:WINTER MARLENE R2731 MOUNTAIN VIEW AVE N 98056RENTON CITY OF2550 LAKE WASHINGTON BLVD 98056Datum: CORPS OF ENGINEERS 1919NE Quarter Of Section 6, Township 23, Range 05Applicant: Sunday Heilly2727 Mountain View Ave N.Renton, WA 98056County: King CountyLocation: Lake WashingtonLast Updated: 7/29/2020 12:05 PM KelseConctractor: Seaborn Pile Driving Company1080 W Ewing StSeattle, WA 98119S E A B O R N
PILE DRIVING COMPANY
EXISTING BOAT LIFT
TO REMAIN
EXISTING MOORING PILES
TO BE REPLACED
EXISTING MUD SUBSTRATE
LAKE
WASHINGTON
58'-8"
6"
25'
5'-6"
OHWL
SHEETA5.0 NWS-2020-XXX
10PAGE 5 OF
PIER DETAILS
SECTION VIEW
Prepared By:
Seaborn Pile Driving
1080 W Ewing St
Seattle, WA 98119
Office: 206-236-1700
permits@seabornpiledriving.com
www.seabornpiledriving.com
Scope of Work: We propose to repair (7) supporting piles using steel sleeves, replace (3) existing mooring piles with steel mooring piles and re-deck
the existing dock with thruflow decking.Created: 7/29/2020Purpose: The proposed dock is to provide for safe boat moorage and safe water recreational activities for a single family residence.Adjacent Owners:WINTER MARLENE R2731 MOUNTAIN VIEW AVE N 98056RENTON CITY OF2550 LAKE WASHINGTON BLVD 98056Datum: CORPS OF ENGINEERS 1919NE Quarter Of Section 6, Township 23, Range 05Applicant: Sunday Heilly2727 Mountain View Ave N.Renton, WA 98056County: King CountyLocation: Lake WashingtonLast Updated: 7/29/2020 12:05 PM KelseConctractor: Seaborn Pile Driving Company1080 W Ewing StSeattle, WA 98119S E A B O R N
PILE DRIVING COMPANY
OHWL
Floatation
Sediment
Containment
Curtain
Weighted Chain
EXISTING
LAKEBED/SOIL
DETAIL 1.1 DETAIL 1.2
SHEETA7.0 NWS-2020-XXX
10PAGE 7 OF
BMP INFORMATION
A.Constant vigilance shall be kept for the presence of protected fish species during all aspects of the
proposed action, particularly during in-water activities such as vessel movement, deployment of anchors &
spuds, pile driving, dredging, and placement of gravels and other fill.
1.The project manager shall designate an appropriate number of competent observers to survey the project
site and adjacent areas for protected species, including the presence of fish as conditions allow.
2.Visual surveys shall be made prior to the start of work each day, and prior to resumption of work following
any break of more than an hour. Periodic additional visual surveys throughout the work day are strongly
recommended.
3.All in-water work shall be done during the in-water work window for the waterbody. Where there is a
difference between the USCOE and WDFW work windows, the overlap of the two shall apply.
4.All pile driving and extraction shall be postponed or halted when obvious aggregations or schooling of fish
are observed within 50 yards of that work, and shall only begin/resume after the animals have voluntarily
departed the area.
5.When piloting vessels, vessel operators shall operate at speeds and power settings to avoid grounding
vessels, and minimize substrate scour and mobilization of bottom sediments.
B.No contamination of the marine environment shall result from project-related activities.
1.Appropriate materials to contain and clean potential spills shall be stored and readily available at the work
site and/or aboard project-related vessels.
2.The project manager and heavy equipment operators shall perform daily pre-work equipment inspections
for cleanliness and leaks. All heavy equipment operations shall be postponed or halted should a leak be
detected, and shall not proceed until the leak is repaired and the equipment is cleaned.
3.To the greatest extent practicable, utilize biodegradable oils for equipment that would be operated in or
near water.
4.Fueling of land-based vehicles and equipment shall take place at least 50 feet away from the water,
preferably over an impervious surface. Fueling of vessels shall be done at approved fueling facilities.
5.Turbidity and siltation from project-related work shall be minimized and contained through the appropriate
use of erosion control practices, effective silt containment devices, and the curtailment of work during
adverse weather and tidal/flow conditions.
6.All wastes shall be collected and contained for proper disposal at approved upland disposal sites
appropriate for the material(s).
7.When removing piles and other similarly treated wood, containment booms must fully enclose the work
area. Wood debris, oils, and any other materials released into lake waters must be collected, removed,
and properly disposed of at approved disposal sites.
8.All in- and over-water wood cutting would be limited to the minimum required to remove the subject wood
component, and all cutting work should be enclosed within floating containment booms.
9.When removing piles, no actions shall be taken that would cause adhering sediments to return to lake
waters.
10.Above-water containment shall be installed around removed piles to prevent sediment laden waters from
returning to lake waters.
11.Construction staging (including stocking of materials, etc.) will occur on the supply barge.
BMP NOTES:
DETAIL 1.1 & 1.2
Prepared By:
Seaborn Pile Driving
1080 W Ewing St
Seattle, WA 98119
Office: 206-236-1700
permits@seabornpiledriving.com
www.seabornpiledriving.com
Scope of Work: We propose to repair (7) supporting piles using steel sleeves, replace (3) existing mooring piles with steel mooring piles and re-deck
the existing dock with thruflow decking.Created: 7/29/2020Purpose: The proposed dock is to provide for safe boat moorage and safe water recreational activities for a single family residence.Adjacent Owners:WINTER MARLENE R2731 MOUNTAIN VIEW AVE N 98056RENTON CITY OF2550 LAKE WASHINGTON BLVD 98056Datum: CORPS OF ENGINEERS 1919NE Quarter Of Section 6, Township 23, Range 05Applicant: Sunday Heilly2727 Mountain View Ave N.Renton, WA 98056County: King CountyLocation: Lake WashingtonLast Updated: 7/29/2020 12:05 PM KelseConctractor: Seaborn Pile Driving Company1080 W Ewing StSeattle, WA 98119S E A B O R N
PILE DRIVING COMPANY
LAKE WASHINGTONLATER
AL LI
N
E
HEILY JOHN PATRICK+SUNDAY G
2727 MOUNTAIN VIEW AVE N 98056
Parcel #: 334210-4050
WINTER MARLENE R
2731 MOUNTAIN VIEW AVE N
98056
RENTON CITY OF
2550 LAKE WASHINGTON
BLVD 98056
LATER
AL LI
N
E TEMP. SEDI
MENT CURTAIN1.1SHEETA6.01.2SHE
ET
A6.0
OHWM -21.8'
EXISTI
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PI
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R:
N
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W
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R
K
P
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P
O
S
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D
CONSTRUCT MOUND OF EXCAVATED SOIL
TO SET ROOTBALL AT PROPER ELEVATION
FINISHED GRADE
SETTLE BACKFILL WITH
WATER IMMEDIATELY
AFTER PLANTING. ADD
BACKFILL AS NECESSARY
TO ACHIEVE LEVEL
SURFACE
DEPTH AS NECESSARY
TO ACHIEVE PROPER
HEIGHT OF TRUNK
FLARE
5' DIAMETER PLANTING PIT
REMOVE ALL WIRE, TWINE, AND BURLAP
FROM ROOTBALL. SCARIFY AND CUT
GIRDLING ROOTS.
SET CROWN OF ROOTBALL AT TOP OF
BACKFILL/FINISH GRADE. REMOVE EXCESS SOIL
FROM TOP OF ROOTBALL TO EXPOSE CROWN.
2" DIAMETER X 6' TALL WITH TAPERED
BOTTOM, PRESSURE TREATED
LODGEPOLE TREE STAKE
CENTER TREE IN PIT AND SET PLUMB AND
STRAIGHT, ADJUST TREE BY MOVING
ROOTBALL WHILE PROTECTING THE CROWN
FROM BREAKING. DO NOT ADJUST TREE BY
MOVING ONLY THE TRUNK
1/3 THE TREE HEIGHT
30"
NOTES:
1.LOWEST BRANCH HEIGHT SHALL BE 6 FEET ABOVE
ROOT CROWN.
2.AVOID DAMAGE TO ROOTBALL - STAKES SHALL NOT
PENETRATE ROOTBALL.
3.GUY WIRES WILL NOT BE ACCEPTED
4.PROVIDE STAKING FOR WINDY LOCATION. FORWARD
STAKE SHALL BE WINDWARD OF TREE.
5.TREES SHALL BE PLANTED A MINIMUM OF 10 FEET ON
CENTER
1 INCH WIDTH BLACK WEBBING FOR
TENSIONING TREE. SECURE TO POST USING 1
INCH, 8 GAUGE, GALVANIZED DOUBLE WIRE
STAPLES, TWO PER WEB STRAP
SHREDDED WOOD MULCH, 3" MIN. COMPACTED
DEPTH. PULL MULCH 3" AWAY FROM TRUNK
3" HIGH X 10' WIDE MULCH BERM, COMPACTED
FIRMLY
PLANTING PIT BACKFILL WITH A MIX OF 3:1
TOPSOIL TO COMPOSTPREVAILINGWINDROOTBALL
3" BERM
CENTER OF TREE STEM OR
CLUSTER OF TREE STEMS
2" DIAMETER POLE
3"
MULCH LAYER, PULL MULCH
AWAY FROM STEMS
PLANTING PIT BACKFILL WITH A MIX OF 3:1
TOPSOIL TO COMPOST
TREE PLANTING DETAILS (NTS)
SHRUB AND GROUNDCOVER
PLANTING DETAILS (NTS)
3"
SEE PLANTING PLAN
FOR SPACINGNOTES:
1.INSTALLATION SHALL INCLUDE LOOSENING SIDES AND
BOTTOM OF PLANTING PIT AND REMOVE DEBRIS
3.THE PIT SHALL BE SOAKED WITH WATER PRIOR TO,
AND SUBSEQUENT TO, INSTALLATION
4.PRIOR TO INSTALLATION, LOOSENING OF PLAT
ROOTBALLS SHALL OCCUR
5.SHRUBS SHALL BE PLANTED A MINIMUM OF 5 FEET ON
CENTER.SHEETA7.0 NWS-2020-XXX
10PAGE 7 OF
MITIGATION PLAN
Notes:
1.Shrubs are show, and shall be planted, at least five feet on center. Trees are show, and shall be planted, at least ten feet to
center.
2.The property owner will implement and abide by the shoreline planting plan. The plants shall be installed before or
concurrent with the work authorized by this permit. A report, as-built drawing and photographs demonstrating the plants
have been installed or a report on the status of project construction will be submitted to the U.S. Army Corps of Engineers,
Seattle District, Regulatory Branch, within 12 months from the date of permit issuance. This reporting requirement may be
met by completing and submitting a U.S. Army Corps of Engineers approved Report for Mitigation Work Completion form.
3.The property owner will maintain and monitor the survival of installed shoreline plantings for five years after the U.S. Army
Corps of Engineers accepts the as-built report. Installed plants shall achieve 100% survival during monitoring Years 1 and 2.
Installed plants shall achieve at least 80% survival during monitoring Years 3, 4 and 5. Percent survival is based on the total
number of plants installed in accordance with the approved riparian planting plan. Individual plants that die will be replaced
with native riparian species in order to meet the survival performance standards.
4.The property owner will provide annual monitoring reports for five years (Monitoring Years 1-5). Each annual monitoring
report will include written and photographic documentation on plant mortality and replanting efforts and will document
whether the performance standards are being met. Photos will be taken from established points and used repeatedly for each
monitoring year. In addition to photos at designated points, photo documentation will include a panoramic view of the entire
planting area. Submitted photos will be formatted on standard 8 1/2 x 11" paper, dated with the date the photo was taken,
and clearly labeled with the direction from which the photo was taken. The photo location points will be identified on an
appropriate drawing. Annual shoreline planting monitoring reports will be submitted to the U.S. Army Corps of Engineers,
Seattle District, Regulatory Branch, by November 31 of each monitoring year. This reporting requirement may be met by
completing and submitting a U.S. Army Corps of Engineers approved Mitigation Planting Monitoring Report form.
Prepared By:
Seaborn Pile Driving
1080 W Ewing St
Seattle, WA 98119
Office: 206-236-1700
permits@seabornpiledriving.com
www.seabornpiledriving.com
Scope of Work: We propose to repair (7) supporting piles using steel sleeves, replace (3) existing mooring piles with steel mooring piles and re-deck
the existing dock with thruflow decking.Created: 7/29/2020Purpose: The proposed dock is to provide for safe boat moorage and safe water recreational activities for a single family residence.Adjacent Owners:WINTER MARLENE R2731 MOUNTAIN VIEW AVE N 98056RENTON CITY OF2550 LAKE WASHINGTON BLVD 98056Datum: CORPS OF ENGINEERS 1919NE Quarter Of Section 6, Township 23, Range 05Applicant: Sunday Heilly2727 Mountain View Ave N.Renton, WA 98056County: King CountyLocation: Lake WashingtonLast Updated: 7/29/2020 12:05 PM KelseConctractor: Seaborn Pile Driving Company1080 W Ewing StSeattle, WA 98119S E A B O R N
PILE DRIVING COMPANY
PLANTS: Shrubs to be installed 5ft on center and trees to be installed 10ft on center.
PROPOSED PLANTING SPECIES/QUANTITIES
SYMBOL LATIN NAME COMMON NAME QTY SIZE
Thuja picatta Western Redcedar 2 3 ft
Rosa nutkana Nootka Rose 1 1 Gallon
Philadelphus lewisii Mock Orange 2 1 Gallon
10' MITIGATION OFFSET
OHWM -21.8'
Aqua Dock Ecological No Net Loss Report 7
Appendix B:
Site Photographs