HomeMy WebLinkAboutTR_Arborist_Report_[Davey_Tree_Service]_221203_v1Arborist Report
May Creek Trail - Renton, WA
Prepared
For:
WSP USA
℅ Garth Nelson
Lead Engineer
33301 Ninth Ave S, Suite 300
Federal Way, WA 98003
garth.nelson@wsp.com,
206-819-3410
Prepared
By:
Davey Resource Group Inc.
18809 10th Ave NE
Shoreline, WA, 98155
Contact: Ian Scott
Local Office: 206.714.3147
Corporate Office:
800-828-8312
Ian.Scott@davey.com
Notice of Disclaimer
Assessment data provided by Davey Resource Group is based on visual recording at the time of inspection. Visual records do not include testing
or analysis and do not include aerial or subterranean inspection unless indicated. Davey Resource Group is not responsible for discovery or
identification of hidden or otherwise non-observable risks. Records may not remain accurate after inspection due to variable deterioration of
surveyed material. Risk ratings are based on observable defects and mitigation recommendations do not reduce potential liability to the owner.
Davey Resource Group provides no warranty with respect to the fitness of the trees for any use or purpose whatsoever.
Table of Contents
Introduction 3
Background 3
Limits of the Assignment 5
Methods 5
Observations 7
Analysis & Recommendations 7
Determining a Tree Protection Zone 9
Pre-Development Tree Care 10
Tree Care During Development 11
Concluding Remarks 12
Appendix A: Maps 13
Appendix B: Inventory Table 19
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Introduction
Background
The client contracted Davey Resource Group Inc.(DRG)to provide an arborist report on the health,size,
and location of the trees at the site of the proposed expansion of the May Creek Trail in May Creek Park
at 4260 Lake Washington Blvd N,Renton,WA 98056.In alignment with Renton Municipal Code (RMC)
4-4-130,tree retention and land clearing regulations were reviewed to further evaluate the significant
tree retention requirements by the City.Restrictions for Critical Areas:See subsection D3 of this Section,
Restrictions for Critical Areas – General, and RMC 4-3-050, Critical Areas Regulations.
RMC 4-4-130 TREE RETENTION AND LAND CLEARING REGULATIONS -
●RMC 4-4-130.D.3 -Restrictions for Critical Areas:General:Unless exempted by critical areas,
RMC 4-3-050.C,or Shoreline Master Program Regulations,RMC 4-3-090,no tree removal,or land
clearing, or ground cover management is permitted:
○On portions of property with:
■Critical areas, pursuant to RMC 4-3-050.B, Applicability;and
○On protected slopes except as allowed in this Section or in the Critical Areas Regulations,
RMC 4-3-050; or
○Areas classified as very high landslide hazards,except as allowed in this Section or in the
Critical Areas Regulations, RMC 4-3-050.
●RMC 4-4-130.D.4 Restrictions for Native Growth Protection Areas:Tree removal or land clearing
shall not be permitted within a native growth protection area except as provided in RMC
4-3-050.G.3, Native Growth Protection Areas. (Ord.5976, 8-3-2020; Ord. 5650, 12-12-2011
RMC 4-3-050 CRITICAL AREAS REGULATIONS:
●RMC 4-3-050C.3.Exemptions –Critical Areas and Buffers:Exempt activities are listed in the
following table.If an “X”appears in a box,the listed exemption applies in the specified critical
area and required buffer.If an “X”does not appear in a box,then the exemption does not apply
in the particular critical area or required buffer.Where utilized in the following table the term
“restoration”means returning the subject area back to its original state or better following the
performance of the exempt activity.Activities taking place in critical areas and their associated
buffers and listed in the following table are exempt from the applicable provisions of this
Section,provided a letter of exemption has been issued.Whether the exempted activities are
also exempt from permits will be determined based upon application of chapters 4-8 and 4-9
RMC,or other applicable sections of the Renton Municipal Code.All activities within shoreline
jurisdiction are subject to Shoreline Master Program Regulations in RMC 4-3-090 and 4-10-095.
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EXEMPT ACTIVITIES – PERMITTED WITHIN CRITICAL AREAS AND ASSOCIATED BUFFERS
EXEMPT ACTIVITY
Flood
Hazard
Areas
Geologic
Hazard
Area
Habitat
Conservation
Area
Streams and
Lakes: Type
F, Np, & Ns
Wellhead
Protection
Areas
Wetlands
Conservation, Enhancement, Education and Related Activities:
i. Natural Resource/Habitat Conservation
or Preservation X X X X X X
ii. Enhancement activities as defined in
Chapter 4-11 RMC X X X X X
iii. Approved Restoration/Mitigation X X X X X X
On November 8,2022,an International Society of Arboriculture (ISA)Certified Arborist (WE-12666A)
completed an inventory of all significant,heritage,and landmark trees near the proposed trail extension
on the south side of May Creek.The trees were assessed by their location,size,current condition,overall
health,and species.This data was used to determine the Tree Protection Zones (TPZ)around each tree,
which will help guide construction options and mitigate potential impacts.Ultimately the data can be
used to determine which trees would be good candidates for retention and those that could be removed
regardless of trail construction plans.
Using a GIS application,a DRG International Society of Arboriculture (ISA)Certified Arborist surveyed all
the trees (≥6”DBH)within the limits of proposed trail construction and trees adjacent to the area that
have driplines or root zones that could be impacted..Each tree was visually assessed and the required
tree data was collected within a GIS database.
The data collection and arborist report include:
●A numbering system of all subject trees on the property.
●Tree type or species and DBH (Diameter at 4.5’ above soil level).
●A complete description of each tree’s health, condition and viability.
●A description of the method(s)used to determine the limits of disturbance (i.e.,critical root
zone, root plate diameter, or a case-by-case basis description for individual trees).
●Map illustrations and locations of the TPZs.
●A discussion of timing for installation of tree protection measures.
●Any special instructions for tree care when work may be required within the TPZ.
●Any trees requiring pruning or maintenance to increase tree tolerance to construction, clearance
or safety on the site prior to construction.
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Limits of the Assignment
There are many factors that can limit specific and accurate data when performing evaluations of trees,
their conditions,and values.The determinations and recommendations presented here are based on
current data and conditions that existed at the time of the evaluation and cannot be a predictor of the
ultimate outcomes for the trees.A visual inspection was used to develop the findings,conclusions,and
recommendations found in this report.Values were assigned to grade the attributes of the trees,
including structure and canopy health,and to obtain an overall condition rating.No physical inspection
of the upper canopy,sounding,root crown excavation,and resistograph or other technologies were used
in the evaluation of the trees.
Methods
Data was collected in November,2022 by an ISA Certified Arborist (WE-666A)and Qualified Tree Risk
Assessor.A visual inspection was used to develop the findings,conclusions,and recommendations found
in this report.No physical inspection of the upper canopy,sounding,root crown excavation,and
resistograph or other technologies were used in the evaluation of the trees.The results will be used to
determine the tree protection zone (TPZ) and tree preservation measures required during construction.
The following attributes were collected for each site:
Tree Number:Tree ID number was assigned and a numbered tag was affixed ott he tree.
Species: Trees were identified by genus and species,cultivar if evident, and by common name.
Diameter at Breast Height (DBH):Trunk diameter was recorded to the nearest inch at 4.5 feet (standard
height)above grade except where noted.When limbs or deformities occurred at standard height,
measurement was taken below 4.5 ft.The DBH of multi-trunk trees was determined by taking the square
root of the sum of the DBH for each individual stem squared.
Height:Tree Height estimated to the nearest <5ft.
Avg. Crown Radius:Average dripline distance was measured.
Condition:Condition ratings were based on but not limited to:(1)the condition and environment of the
tree’s root crown;(2)the condition of the trunk,including decay,injury,callusing or presence of fungus
sporophore;(3)the condition of the limbs,including strength of crotches,amount of dead wood,hollow
areas,and whether there was excessive weight borne by them;(4)the condition and growth rate history
of the twigs,including pest damage and diseases;(5)the leaf appearance,including abnormal size and
density as well as pest and disease damage.
Using an average of the above factors together with the arborist’s best judgment,the general condition
of each tree was recorded in one of the following categories adapted from the rating system established
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by the International Society of Arboriculture and 10th Edition of the Council of Tree &Landscape Appraisers
(CTLA)Guide for Plant Appraisal :1
●Excellent (81%-100%):High vigor and near perfect health with little or no twig dieback,discoloration,
or defoliation.Nearly ideal and free of structural defects.Nearly ideal form for the species and
generally symmetrical.
●Good (61%-80%):Vigor is normal for the species and no significant damage due disease or pests.
Twig dieback,discoloration,or defoliation is minor.Well developed structure with minor defects that
can be corrected easily.Minor asymmetries/deviations from species norm.Function and aesthetics
are not compromised.
●Fair (41%-60%):Reduced vigor.Damage due to insects or diseases may be significant and associated
with defoliation but is not likely to be fatal.Twig dieback,defoliation,discoloration,and/or dead
branches may comprise up to 50%of the canopy.A single structural defect of a significant nature or
multiple moderate defects.Structural defects are not practical to correct or would require multiple
treatments over several years.Major asymmetries/deviations from species norm.Function and
aesthetics are compromised.
●Poor (21%-40%):Unhealthy and declining in appearance.Poor vigor and low foliage density and poor
foliage color are present.Potentially fatal pest infestation.Extensive twig or branch dieback.A single
serious structural defect or multiple significant defects.Observed structural problems cannot be
corrected.Failure may occur at any time.Largely asymmetrical or abnormal form.Form detracts from
aesthetics or intended use to a significant degree.
●Very Poor (6%-20%):Poor vigor and appears to be dying.Little live foliage.Single or multiple severe
structural defects. Visually unappealing and provides little or no function in the landscape.
●Dead (0%-5%)
Tree Preservation Priority:In order to establish a priority for tree preservation as it relates to planning for
development projects,DRG utilized a rating scale of one to four,with one being the highest priority for
protection and four being of least value for protection.The condition rating of an individual tree is an
important component of the priority rating,but several other variables are factored in:species desirability,
species longevity,species sensitivity to root loss and construction impacts,uniqueness,and aesthetics both of
the tree itself and its relation to the site.It is important to note that these are qualitative ratings based solely
on the site,individual tree,and existing conditions at the time of the inventory.Proposed development and
construction plans are not considered when assigning ratings.The following criteria constituted the basis of
tree placement in a particular category of priority:
●Priority 1:Highest priority for protection (i.e.particularly good condition,unique tree,and/or should
be protected at all reasonable cost).
●Priority 2:Good or fair condition tree well worth protecting though not uniquely valuable.
●Priority 3:Poor condition average tree that will not be missed if it were gone,not worth any special
protection measures.
●Priority 4:Trees that should be removed under most or any circumstances (i.e.,invasive or
undesirable species, poor condition or critical trees, particularly high-risk situations, etc.).
1 Council of Tree and Landscape Appraisers. (2019).Guide for Plant Appraisal, 10th Edition, Second Printing.Atlanta, GA: International Society of
Arboriculture.
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Observations
A total of 151 trees were inventoried at the site near the proposed trail expansion.There were
eighty-one (81)red alder,thirty-six black cottonwood,twenty-six (26)bigleaf maple,three (3)Douglas-fir,
two (2) willow, two (2) Western-red cedar, and one (1) oak.
Tree condition is important to evaluate because healthy trees can better withstand construction impacts
and partial root loss.Of the 152 site trees,one (1)was in excellent condition,twenty-six (26)were in
good condition,seventy-four (74)were in fair condition,twenty-six (26)were in poor condition,three (3)
were in poor condition, twenty-one (21) trees were dead or dying.
Table 1. Tree species and condition
Species Excellent Good Fair Poor Very Poor Dying Dead TOTAL
Alder, Red (Alnus rubra)1 10 37 20 1 2 10 81
Cottonwood, Black (Populus trichocarpa)7 21 3 1 4 36
Maple, Bigleaf (Acer macrophyllum)8 13 1 4 26
Douglas-fir (Pseudotsuga menziesii)3 3
Willow (Salix spp.)1 1 2
Cedar, Western-red (Thuja plicata)1 1 2
Oak (Quercus spp.)1 1
TOTAL 1 26 74 26 3 2 19 151
Analysis & Recommendations
Successful tree preservation efforts begin in the planning and design phase.In order to select the
appropriate trees for preservation and then incorporate those trees into future development plans,site
managers and designers need detailed information on the health and status of the existing trees.This
report satisfies the conditions of the critical first step in the preservation process:a tree inventory,
assessment, and analysis conducted by a qualified professional.
As with most tree preservation planning,a critical element is in minimizing root disturbance.When
evaluating tree root disturbance during construction there are two considerations;the removal of
absorption roots and removal of anchoring roots.Removal (or compaction in the area)of the absorption
roots can cause immediate water stress and a significant decline in tree health.The ability of a tree to
survive loss of absorption roots is dependent on its tolerance of drought,tree health,and the ability to
form new roots quickly.Removal of the larger anchoring roots can lead to structural instability.Trees that
suffer substantial root loss or damage are seldom good candidates for preservation.
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A preservation priority was determined for each tree based on condition and the arborist’s best
judgment.No consideration for development impacts was used in this determination.There were five (5)
trees considered Priority 1,eighty-two (82)trees were Priority 2,twenty-six (26)trees were considered
Priority 3,and thirty-eight (38)trees were considered Priority 4.Trees that were determined to be
Priority 4 were not considered significant or landmark trees and are recommended for removal if the
proposed trail will be within striking distance or any disturbance within the proposed tree protection
zone is anticipated.
Table 2. Preservation Priority by species
Species 1 2 3 4 TOTAL
Alder, Red (Alnus rubra)1 38 19 23 81
Cottonwood, Black (Populus trichocarpa)24 4 8 36
Maple, Bigleaf (Acer macrophyllum)1 19 2 4 26
Douglas-fir (Pseudotsuga menziesii)2 1 3
Willow (Salix spp.)2 2
Cedar, Western-red (Thuja plicata)1 1 2
Oak (Quercus spp.)1 1
TOTAL 5 82 26 38 151
Landmark status,according to RMC 4-4-130-9(A),was calculated for each tree.Significant trees
measured between 6 and 29 inches in DBH.Landmark trees were those that measured 30 inches or
greater in DBH.Trees that were determined to be Preservation Priority 4 were inventoried but appear in
the tables as n/a and are recommended for removal.After condition analysis,there were eighty-one (81)
significant and thirty-two (32) landmark trees in the proposed trail expansion area.
Table 3. Renton status by species
Species Significant (6-29”)Landmark (30+”)n/a (Priority 4)TOTAL
Alder, Red (Alnus rubra)49 9 23 81
Cottonwood, Black (Populus trichocarpa)11 17 8 36
Maple, Bigleaf (Acer macrophyllum)20 2 4 26
Douglas-fir (Pseudotsuga menziesii)1 2 3
Willow (Salix spp.)2 2
Cedar, Western-red (Thuja plicata)2 2
Oak (Quercus spp.)1 1
TOTAL 81 32 38 151
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In addition to site specific recommendations above,the following sections identify general best
practice recommendations for tree preservation.
Determining a Tree Protection Zone
Tree Protection Zone (TPZ)fencing should be installed at dripline or designated Limit of Disturbance
(LOD)of the trees to be retained and remain in place for the entirety of the project.Access into the TPZ
should not be allowed unless determined to be necessary and only under the supervision of a certified
arborist.The tree protection area may be reduced according to a plan prepared by a certified arborist
and approved by the city.
●It is recommended that the TPZ fencing be installed at the dripline.Where approved excavation
and root pruning take place,the TPZ fencing may be installed closer to the trunk and will need to
be determined by the site arborist at the time of installation.
●TPZ fencing shall be a minimum of 6 feet high,constructed of chain link or polyethylene laminar
safety fencing or similar material subject to approval by an ISA Certified Arborist,completely
encircle the tree or groups of trees using pier blocks.Avoid posts or stakes which may damage
the root zone.
●“Tree Protection Area -Keep Out”or similar signs shall accompany the TPZ fencing every 15 feet
and include contact information to report violations.
●TPZs shall be constructed in such a fashion as to not be easily moved or dismantled.
●TPZs shall remain in place for the entirety of the project and only removed,temporarily or
otherwise, by an ISA Certified Arborist after submission and approval of intent.
●No stockpiling of materials,vehicular traffic,or storage of equipment or machinery shall be
allowed inside the TPZ.
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An example illustration of a Tree Protection Zone. Contact information of the site manager or consulting arborist should also
be included on the sign.
Pre-Development Tree Care
Successful tree preservation efforts begin in the planning and design phase.In order to select the
appropriate trees for preservation and then incorporate those trees into future development plans,site
managers and designers need detailed information on the health and status of the existing trees.This
report satisfies the conditions of the critical first step in the preservation process:a tree inventory,
assessment,and analysis conducted by a qualified professional.The resulting findings guide the
beginning stages of the preservation process.
Condition rating and preservation priority rating help nominate potential candidates for preservation.
Development plans should ensure that no impact or root damage occurs within the inner root zone and
plans should take into consideration the significant reduction in likelihood of tree survival when the root
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zone is impacted.After individual trees are selected for preservation,the following action-steps are
recommended prior to development activities:
●Prune trees,as necessary,to remove existing deadwood and stubs.This strategy controls
potential future vectors of decay.Clean cuts made at branch collars allow the tree to undergo its
natural process of compartmentalizing wounds,preventing the spread of decay.During the
pruning process,remove as minimal amount of live foliage as possible and no more than 25%
removal in any one season while allowing for the safe and unimpeded operation of construction
activities.
●Install Tree Protection Zone (TPZ)fencing out to the furthest possible radius distance from the
tree.
●If the soil within the TPZ is compacted,then aerate the soil using an air spade to alleviate
compaction and promote the flow of oxygen and water to the roots.
●Add a 3-inch layer of mulch to the portion of the root zone protected by the TPZ.Be sure not to
cover/bury the tree root collar.Mulch aids the soil in water retention and also helps insulate the
soil from hot and cold weather extremes.
●Where possible,add a 12-inch layer of wood chips over any parts of a root zone not protected
by the TPZ.This aids in reducing the impact of soil compaction from heavy equipment during the
upcoming construction activities.
Tree Care During Development
Once development begins,several measures are necessary to help ensure optimal outcomes for all trees
selected for preservation:
●Retain a Certified Arborist on site to monitor activities and assess impacts to trees.The arborist
can make as-needed recommendations to improve tree preservation activities throughout the
development process.This is particularly important in order to make a timely response when a
preserved tree is accidentally damaged or otherwise impacted during development.
●Signage instructing site workers not to enter Tree Protection Zones should be posted throughout
the job site.Signage should be posted in both English and Spanish as well as any other language
as deemed necessary by site managers.
●Discuss tree protection regularly at required staff meetings.Reiterate the importance of
respecting the Tree Protection Zone as critical to the safety of staff working on site and the
success of tree preservation efforts.
●Strictly enforce the Tree Protection Zones as “No-Go”zones.No activity,human or machinery,
should breach the established TPZ.
●Root prune where any grading or trenching occurs within the critical root zone.
●Ensure the area within the TPZ receives the weekly watering equivalent to the amount of
average natural rainfall for the specific development site.When the amount of natural rainfall
received is less than the historical average,manual watering methods should be employed.The
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on-site Certified Arborist can make the determination when additional manual watering is
necessary.
●Do not raise or lower the soil grade near the TPZ.A tree relies upon small,non-woody roots
called feeder roots for the absorption of water and nutrients.These roots predominantly reside
in the upper several inches of soil,just below grade.Lowering the soil grade,even just a few
inches,will sever these feeder roots and compromise tree health.Raising the soil above existing
grade,such as through the addition of fill soil,buries feeder roots too deep and restricts feeder
root access to water and oxygen.
Concluding Remarks
This report,along with the tree inventory,is the first step in preserving the health,function,and value of
the trees on the site during and after development.Trees and green spaces provide benefits and add
value to residential properties.Tree preservation starts with a basic understanding of the health and
structure of the trees on the site.With proper care and protection,these trees can continue to thrive.
Tree protection guidelines and strategies should be shared with contractors and employers prior to any
disturbance at the site.
The suitability of a tree for preservation is a qualitative process based on the interaction of a variety of
influencing factors.A tree inventory and arborist report provides a snapshot in time of each individual
tree assessed across many of the most important observable factors relative to preservation.Healthy,
vigorous trees better tolerate impacts from construction and more readily adapt to the new site
conditions that exist after completion of development.Additionally,tolerance to impact from
construction activities varies across species and sites.The percentage impact to the root zone also
greatly influences the suitability of a particular tree for preservation.
A successful tree preservation plan requires a team effort to find the right balance and select the
appropriate trees.Using the findings of this report as a guiding foundation,planners are equipped to
design, prepare, and implement a tree preservation plan tailored to achieving the optimal outcome.
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Appendix A: Maps
Map A1. Overview of the site and tree inventory
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Map A2
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Map A3
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Map A4
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Map A5
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Map A6
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Appendix B: Inventory Table
Tree
ID Species DBH
(in)
Height
(ft)
Avg Dripline
(ft)Condition Preservation
Priority Status
73 Alder, Red (Alnus rubra)73 40 10 Fair 2 Landmark
166 Alder, Red (Alnus rubra)12 45 10 Fair 2 Significant
167 Maple, Bigleaf (Acer macrophyllum)14 50 20 Good 2 Significant
168 Alder, Red (Alnus rubra)15 60 10 Poor 4 n/a
169 Cottonwood, Black (Populus trichocarpa)22 60 5 Dead 4 n/a
170 Maple, Bigleaf (Acer macrophyllum)13 50 15 Fair 2 Significant
171 Maple, Bigleaf (Acer macrophyllum)17 60 20 Good 2 Significant
172 Cottonwood, Black (Populus trichocarpa)41 105 15 Fair 2 Landmark
173 Cottonwood, Black (Populus trichocarpa)11 45 5 Fair 3 Significant
174 Cottonwood, Black (Populus trichocarpa)28 95 10 Fair 2 Significant
175 Cottonwood, Black (Populus trichocarpa)42 115 15 Fair 2 Landmark
176 Cottonwood, Black (Populus trichocarpa)46 70 15 Poor 3 Landmark
177 Cottonwood, Black (Populus trichocarpa)29 25 5 Very Poor 4 n/a
178 Cottonwood, Black (Populus trichocarpa)62 115 20 Fair 3 Landmark
179 Cottonwood, Black (Populus trichocarpa)25 75 15 Fair 3 Significant
180 Cottonwood, Black (Populus trichocarpa)8 25 5 Dead 4 n/a
181 Cottonwood, Black (Populus trichocarpa)30 80 15 Fair 2 Landmark
182 Cottonwood, Black (Populus trichocarpa)29 90 10 Fair 2 Significant
183 Maple, Bigleaf (Acer macrophyllum)12 50 5 Dead 4 n/a
921 Maple, Bigleaf (Acer macrophyllum)10 50 25 Good 2 Significant
1000 Douglas-fir (Pseudotsuga menziesii)41 135 35 Fair 1 Landmark
8971 Alder, Red (Alnus rubra)15 35 5 Poor 4 n/a
9501 Alder, Red (Alnus rubra)32 145 25 Fair 2 Landmark
9502 Alder, Red (Alnus rubra)27 140 15 Fair 2 Significant
9503 Maple, Bigleaf (Acer macrophyllum)29 90 10 Fair 2 Significant
9504 Cottonwood, Black (Populus trichocarpa)29 95 10 Fair 2 Significant
9505 Alder, Red (Alnus rubra)11 45 10 Poor 2 Significant
9506 Maple, Bigleaf (Acer macrophyllum)10 45 10 Fair 2 Significant
9507 Maple, Bigleaf (Acer macrophyllum)10 70 15 Fair 2 Significant
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Tree
ID Species DBH
(in)
Height
(ft)
Avg Dripline
(ft)Condition Preservation
Priority Status
9508 Maple, Bigleaf (Acer macrophyllum)13 70 15 Fair 1 Significant
9509 Cottonwood, Black (Populus trichocarpa)43 90 20 Fair 2 Landmark
9510 Alder, Red (Alnus rubra)11 35 10 Fair 3 Significant
9801 Maple, Bigleaf (Acer macrophyllum)6 40 5 Dead 4 n/a
9802 Maple, Bigleaf (Acer macrophyllum)6 45 15 Good 2 Significant
9803 Cottonwood, Black (Populus trichocarpa)18 65 5 Poor 4 n/a
9804 Cottonwood, Black (Populus trichocarpa)19 60 5 Dead 4 n/a
9805 Alder, Red (Alnus rubra)23 70 20 Fair 2 Significant
9806 Alder, Red (Alnus rubra)18 50 10 Fair 2 Significant
9807 Alder, Red (Alnus rubra)20 50 25 Fair 2 Significant
9808 Alder, Red (Alnus rubra)21 20 5 Dead 4 n/a
9809 Alder, Red (Alnus rubra)12 40 5 Fair 3 Significant
9810 Alder, Red (Alnus rubra)11 35 10 Fair 2 Significant
9811 Alder, Red (Alnus rubra)13 35 5 Dead 4 n/a
9812 Willow (Salix spp.)19 50 5 Poor 4 n/a
9813 Willow (Salix spp.)12 35 10 Very Poor 4 n/a
9814 Cottonwood, Black (Populus trichocarpa)11 25 5 Dead 4 n/a
9815 Maple, Bigleaf (Acer macrophyllum)11 50 15 Fair 3 Significant
9816 Cottonwood, Black (Populus trichocarpa)34 110 20 Good 2 Landmark
9817 Cottonwood, Black (Populus trichocarpa)38 115 30 Fair 2 Landmark
9818 Maple, Bigleaf (Acer macrophyllum)7 50 15 Good 2 Significant
9820 Cottonwood, Black (Populus trichocarpa)8 45 5 Fair 2 Significant
9822 Cottonwood, Black (Populus trichocarpa)34 100 15 Fair 2 Landmark
9823 Cottonwood, Black (Populus trichocarpa)29 95 15 Poor 4 n/a
9826 Maple, Bigleaf (Acer macrophyllum)14 60 20 Good 2 Significant
9827 Cottonwood, Black (Populus trichocarpa)41 105 15 Fair 2 Landmark
9828 Cottonwood, Black (Populus trichocarpa)40 100 10 Fair 2 Landmark
9829 Alder, Red (Alnus rubra)8 40 15 Excellent 2 Significant
9830 Cottonwood, Black (Populus trichocarpa)44 100 20 Good 2 Landmark
9831 Cottonwood, Black (Populus trichocarpa)34 100 10 Fair 2 Landmark
9833 Cottonwood, Black (Populus trichocarpa)22 90 5 Fair 2 Significant
9834 Cottonwood, Black (Populus trichocarpa)42 95 15 Good 2 Landmark
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Tree
ID Species DBH
(in)
Height
(ft)
Avg Dripline
(ft)Condition Preservation
Priority Status
9835 Alder, Red (Alnus rubra)10 35 5 Poor 4 n/a
9836 Alder, Red (Alnus rubra)13 35 10 Poor 3 Significant
9837 Alder, Red (Alnus rubra)13 40 5 Dead 4 n/a
9839 Alder, Red (Alnus rubra)10 40 5 Poor 4 n/a
9840 Alder, Red (Alnus rubra)9 30 10 Fair 3 Significant
9841 Cottonwood, Black (Populus trichocarpa)25 80 15 Good 2 Significant
9842 Cottonwood, Black (Populus trichocarpa)36 90 15 Good 2 Landmark
9843 Cottonwood, Black (Populus trichocarpa)23 85 5 Fair 2 Significant
9844 Cottonwood, Black (Populus trichocarpa)25 60 10 Fair 2 Significant
9845 Cottonwood, Black (Populus trichocarpa)39 90 10 Fair 2 Landmark
9846 Alder, Red (Alnus rubra)16 15 5 Dying 4 n/a
9847 Cottonwood, Black (Populus trichocarpa)43 90 15 Fair 4 n/a
9848 Cottonwood, Black (Populus trichocarpa)23 85 10 Good 2 Significant
9849 Maple, Bigleaf (Acer macrophyllum)18 50 15 Fair 2 Significant
9850 Alder, Red (Alnus rubra)13 60 10 Fair 3 Significant
9851 Alder, Red (Alnus rubra)23 80 15 Fair 2 Significant
9852 Alder, Red (Alnus rubra)16 50 10 Poor 3 Significant
9853 Alder, Red (Alnus rubra)28 85 15 Fair 2 Significant
9854 Maple, Bigleaf (Acer macrophyllum)29 45 15 Good 2 Significant
9855 Alder, Red (Alnus rubra)30 85 15 Good 2 Landmark
9857 Oak (Quercus spp.)41 75 35 Dead 4 n/a
9858 Cottonwood, Black (Populus trichocarpa)34 95 25 Good 2 Landmark
9859 Alder, Red (Alnus rubra)8 30 5 Fair 3 Significant
9860 Alder, Red (Alnus rubra)64 30 5 Very Poor 4 n/a
9861 Alder, Red (Alnus rubra)18 65 10 Fair 3 Significant
9862 Alder, Red (Alnus rubra)14 40 5 Poor 4 n/a
9863 Maple, Bigleaf (Acer macrophyllum)11 50 15 Fair 2 Significant
9864 Alder, Red (Alnus rubra)45 95 15 Fair 2 Landmark
9865 Alder, Red (Alnus rubra)25 80 10 Fair 2 Significant
9866 Alder, Red (Alnus rubra)21 70 10 Fair 2 Significant
9868 Alder, Red (Alnus rubra)25 80 15 Fair 2 Significant
9869 Alder, Red (Alnus rubra)20 70 5 Poor 3 Significant
Prepared by: DRG Inc.Page21 of 23
Prepared for: WSP USA INC. December 3, 2022
Tree
ID Species DBH
(in)
Height
(ft)
Avg Dripline
(ft)Condition Preservation
Priority Status
9870 Alder, Red (Alnus rubra)51 80 20 Good 1 Landmark
9872 Alder, Red (Alnus rubra)11 25 5 Dead 4 n/a
9873 Alder, Red (Alnus rubra)14 45 5 Fair 3 Significant
9874 Alder, Red (Alnus rubra)11 40 5 Poor 4 n/a
9875 Alder, Red (Alnus rubra)11 40 5 Fair 3 Significant
9876 Alder, Red (Alnus rubra)28 80 15 Fair 2 Significant
9877 Alder, Red (Alnus rubra)26 80 10 Fair 2 Significant
9878 Alder, Red (Alnus rubra)25 75 10 Good 2 Significant
9879 Alder, Red (Alnus rubra)24 80 25 Fair 2 Significant
9880 Alder, Red (Alnus rubra)27 85 25 Fair 2 Significant
9881 Alder, Red (Alnus rubra)17 35 5 Poor 4 n/a
9882 Alder, Red (Alnus rubra)12 60 5 Poor 3 Significant
9883 Alder, Red (Alnus rubra)38 85 15 Good 2 Landmark
9884 Alder, Red (Alnus rubra)26 65 10 Poor 3 Significant
9885 Alder, Red (Alnus rubra)15 60 5 Dead 4 n/a
9887 Alder, Red (Alnus rubra)18 70 10 Fair 2 Significant
9888 Alder, Red (Alnus rubra)12 60 5 Dead 4 n/a
9889 Alder, Red (Alnus rubra)12 40 10 Good 2 Significant
9890 Alder, Red (Alnus rubra)15 70 5 Good 2 Significant
9891 Alder, Red (Alnus rubra)8 35 5 Fair 3 Significant
9892 Alder, Red (Alnus rubra)10 35 5 Poor 4 n/a
9893 Alder, Red (Alnus rubra)24 85 10 Fair 2 Significant
9894 Alder, Red (Alnus rubra)18 45 5 Dead 4 n/a
9895 Alder, Red (Alnus rubra)12 25 5 Dead 4 n/a
9897 Alder, Red (Alnus rubra)14 40 5 Dead 4 n/a
9898 Maple, Bigleaf (Acer macrophyllum)18 45 5 Poor 3 Significant
9899 Maple, Bigleaf (Acer macrophyllum)13 50 10 Fair 2 Significant
9900 Alder, Red (Alnus rubra)48 100 20 Fair 2 Landmark
9901 Douglas-fir (Pseudotsuga menziesii)37 130 25 Fair 1 Landmark
9902 Cedar, Western-red (Thuja plicata)50 90 20 Good 1 Landmark
9903 Alder, Red (Alnus rubra)50 60 15 Poor 3 Landmark
9904 Maple, Bigleaf (Acer macrophyllum)11 50 10 Fair 2 Significant
9905 Douglas-fir (Pseudotsuga menziesii)11 95 20 Fair 2 Significant
Prepared by: DRG Inc.Page22 of 23
Prepared for: WSP USA INC. December 3, 2022
Tree
ID Species DBH
(in)
Height
(ft)
Avg Dripline
(ft)Condition Preservation
Priority Status
9906 Cedar, Western-red (Thuja plicata)50 90 10 Poor 3 Landmark
9909 Alder, Red (Alnus rubra)9 40 5 Fair 3 Significant
9910 Alder, Red (Alnus rubra)20 45 15 Fair 2 Significant
9911 Alder, Red (Alnus rubra)19 60 20 Fair 2 Significant
9912 Maple, Bigleaf (Acer macrophyllum)37 70 20 Good 2 Landmark
9913 Alder, Red (Alnus rubra)8 25 5 Dying 4 n/a
9914 Alder, Red (Alnus rubra)22 60 10 Poor 4 n/a
9915 Alder, Red (Alnus rubra)25 70 10 Poor 3 Significant
9916 Maple, Bigleaf (Acer macrophyllum)12 60 10 Fair 2 Significant
9917 Maple, Bigleaf (Acer macrophyllum)16 50 15 Fair 2 Significant
9918 Alder, Red (Alnus rubra)24 70 10 Fair 2 Significant
9920 Alder, Red (Alnus rubra)14 60 5 Good 2 Significant
9921 Alder, Red (Alnus rubra)25 70 25 Good 2 Significant
9922 Alder, Red (Alnus rubra)24 65 15 Fair 2 Significant
9992 Alder, Red (Alnus rubra)19 50 15 Poor 3 Significant
9993 Alder, Red (Alnus rubra)14 40 10 Poor 3 Significant
9994 Alder, Red (Alnus rubra)14 25 5 Dead 4 n/a
9995 Alder, Red (Alnus rubra)16 50 10 Poor 4 n/a
9996 Alder, Red (Alnus rubra)22 60 25 Good 2 Significant
9997 Alder, Red (Alnus rubra)26 50 25 Good 2 Significant
9999 Alder, Red (Alnus rubra)18 60 15 Fair 2 Significant
9826a Maple, Bigleaf (Acer macrophyllum)11 35 5 Dead 4 n/a
9847a Alder, Red (Alnus rubra)43 95 25 Fair 2 Landmark
9916a Maple, Bigleaf (Acer macrophyllum)25 60 5 Dead 4 n/a
9918a Maple, Bigleaf (Acer macrophyllum)48 80 30 Fair 2 Landmark
Prepared by: DRG Inc.Page23 of 23
Prepared for: WSP USA INC. December 3, 2022