APPROVED TRE BLD2022-0462 REVISION 1 TREE RETENTION PLANArborist Report
Tree Protection Plan
23625 84th Ave. W, Edmonds, WA
Ki nq County Eagle
REVISION
Aug 08 2022
CITY OF EDMONDS
DEVELOPMENT SERVICES
DEPARTMENT
BLD2022-0462
Approved 8/23/22 DP
see Appendix A markups
Prepared Liu Brothers, LLC
For:
% David Cohanim
Project Manager
9858 NE 22nd St.
Bellevue, WA 98004
david Dsynergyconstruction.com
Prepared Davey Resource Group Inc.
By:
18809 10th Ave N E
Shoreline, WA, 98155
Contact: Todd Beals
todd.beals(a)davey.com
Local Office: 253.656.1650
Corporate Office: 800.828.8312
Notice of Disclaimer
Resource Group
0
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
Summary
Introduction
Background
Limits of the Assignment
Methods
Quality Control Procedures
Observations
Analysis & Recommendations
Tree Preservation Priority
Soil Remediation
Replacement Required
Tree Protection Zone & Timing
Concluding Remarks
Appendix A: Maps
3
4
4
4
5
6
7
8
9
9
11
12
15
16
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Summary
In April 2022, an International Society of Arboriculture (ISA) Certified Arborist (NE-6913A) completed an
inventory of the trees on and adjacent to the property at 23625 84th Avenue West in Edmonds, WA. The
following data was collected:
• A total of 19 trees were cataloged
o Thirteen (13) trees were on the neighboring properties with canopies that extended onto
the subject parcel. These trees were in good condition.
o Six (6) trees were on the subject parcel.
■ Five (5) trees were in good condition.
■ One (1) tree was in very poor condition.
• Preservation Priority was determined as:
o Priority 2: Eighteen (18) trees.
o Priority 4: One (1) tree (Tree ID# 8594)
The following recommendations were made based on the collected data:
• Remove Tree ID# 8594 due to poor condition.
• Remove Tree ID# 8582 for development purposes.
o The rounded functional replacement cost was $11,600 for Tree ID# 8582.
o Install tree protection fencing 5 ft. outside the dripline or the limits of disturbance,
whichever is greater, of all the trees on the neighboring parcel and those trees
determined to remain on the subject parcel.
• Apply a 3-inch layer of mulch starting at the trunk and extending out past the dripline of the
retained trees.
• Retain a Certified Arborist to periodically monitor tree health and maintenance needs every 3-5
years or as need dictates.
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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 significant trees on the property at 23625 84th Ave. W, Edmonds, WA. as well as
identify tree protection and retention measures. Using a pen tablet computer, a DRG International Society
of Arboriculture (ISA) Certified Arborist inspected the trees on April 27, 2022. Each tree was visually
assessed and the required tree data was collected within a GIS database.
Following data collection, specific tree preservation plan elements were calculated that identified each
tree's dripline and Tree Protection Zone (TPZ) to better ensure survivability during the project. The data
collection and arborist report includes:
• A numbering system of all existing trees 3 inches or greater in diameter at 4.5 feet in the project
area and those trees on neighboring parcels which had driplines extending onto the subject
parcel.
• Tree type or species and DBH (Diameter at 4.5' above soil level).
• A complete description of each tree's health, condition and viability.
• Determination of the Tree Protection Zone (TPZ) of all trees to be preserved and a description of
the methods used to establish a Tree Protection Zone.
• A discussion of timing for installation of tree protection measures.
• Any special instructions for tree care when work may be required within the TPZ.
• Map illustrations of tree locations, identification number, and dripline dimensions.
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.
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Methods
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 any other tree protection measures required during construction.
The following attributes were collected for each site:
Tree Number: Tree ID number was assigned and a numbered aluminum tag affixed to the tree. The
condition and DBH of the trees on neighboring parcels were estimated and assigned an identification
number.
Location and Unique ID: An X and Y coordinate was generated for each tree site.
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
cumulative total of each stem 6" or greater.
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 the strength of crotches, amount of deadwood, 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 by
the International Society of Arboriculture and 10th Edition of the Council of Tree & Landscape Appraisers
(CTLA) Guide for Plant Appraisal' :
• 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 has no significant damage due to 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.
'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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• 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 capture the priority for preservation of an individual tree 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 concern. 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.).
Additional Inspection Required - Any trees that warrant a secondary inspection beyond the scope of
this inventory.
Notes - Additional comments that warrant recording will also be collected for each inventoried tree.
Quality Control Procedures
Data was collected and verified with the following quality control measures:
• Personnel Training — Quality control procedures ensure quality data. The first step in DRG's
quality control is to provide proper training to qualified individuals. The field personnel on this
project was an ISA Certified Arborist with up-to-date credentials.
• Data Collections Specification — A clear understanding of the data and the methods for
collection and categorization ensure high -quality, standardized collection.
• Quality Control Methods — Quality control of data was completed electronically. Errors were
corrected as they were found.
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Observations
A total of 19 trees were cataloged. Thirteen (13) trees were on the neighboring property to the east and
west with canopies that extended onto the subject parcel. Six (6) trees were on the subject parcel.
Condition ratings were based on the system established by the International Society of Arboriculture and
10th Edition of the Council of Tree & Landscape Appraisers (CTLA) Guide for Plant Appraisal and the
arborist's best judgment from a visual inspection. Tree condition is important to evaluate because healthy
trees can better withstand environmental stressors. In addition, it is not recommended to try to preserve
trees in poor condition when removal and replacement is a better option for the aesthetic value and health
of the tree population as a whole. Trees in poor condition do not always necessitate removal and for that
reason, some poor condition trees can be considered priority 3 and be acceptable for retention.
Eighteen (18) trees were in good condition,and one (1) tree was in very poor condition.
Table 1. Tree Inventory Table
Maple, Bigleaf (Acer
Client
8582
25 55
macrophyllum)
Cypress, Lawson (Chamaecyparis
Client
8588
19 65
lawsoniana)
Cypress, Lawson (Chamaecyparis
Client
8590
28 65
lawsoniana)
Cypress, Lawson (Chamaecyparis
Client
8592
25 65
lawsoniana)
Cypress, Lawson (Chamaecyparis
Client
8593
28 65
lawsoniana)
Locust, Black (Robinia
Client
8594
26 65
pseudoacacia)
Neigh
Cypress, Lawson (Chamaecyparis
8586
22 65
bor
lawsoniana)
Neigh
Cypress, Lawson (Chamaecyparis
8581
31 65
bor
lawsoniana)
Neigh
Cypress, Lawson (Chamaecyparis
8583
27 65
bor
lawsoniana)
Neigh
Cypress, Lawson (Chamaecyparis
8584
27 65
bor
lawsoniana)
Neigh
Cypress, Lawson (Chamaecyparis
8585
21 65
bor
lawsoniana)
Neigh
Cypress, Lawson (Chamaecyparis
8587
22 65
bor
lawsoniana)
Avg
Canopy Preservation
Condition Status Observations
Radius Priority
(ft)
15
... 2 REMOVEOnesided
25 ..• 2 RETAIN Lean q�
25 Good 2 RETAIN Onesided
20 Good 2 RETAIN Full Crown
20 Good 2 RETAIN ' Full Crown
15 Very Poor 4 REMOVE Vines
25 Good 2 RETAIN Onesided
25 Good 2 RETAIN Onesided
25 Good 2 RETAIN I Onesided
25 Good 2 RETAIN Onesided
25 Good 2 RETAIN Onesided
25 Good 2 RETAIN Onesided
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Neigh
Cypress, Lawson (Chamaecyparis
bor
8589
lawsoniana)
23
65
Neigh
Cypress, Lawson (Chamaecyparis
bor
8591
lawsoniana)
28
65
Neigh
N1
Cedar, Western -red (Thuja plicata)
17
70
bor
Neigh
Cypress, Lawson (Chamaecyparis
bor
N2
lawsoniana)
17
65
Neigh
N3
Cedar, Deodar (Cedrus deodara)
29
85
bor
Neigh
N4
Pine, Austrian (Pinus nigra)
14
45
bor
Neigh
N5
Pine, Austrian (Pinus nigra)
18
45
bor
25
Good
2
RETAIN
Onesided
20
Good
2
RETAIN
Full Crown
10
Good
2
RETAIN
Full Crown
20
Good
2
RETAIN
Onesided
15
Good
2
RETAIN
Full Crown
10
Good
2
RETAIN
Full Crown
10
Good
2
RETAIN
Full Crown
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. The resulting findings guide the
beginning stages of the preservation process.
Roughly one half of a tree's biomass is underground in the form of structural and absorptive roots. These
roots take up water and nutrients that trees need to survive, so minimizing impact to these roots is crucial
to reducing tree stress. Roots can be damaged by even light -weight equipment operating in the root zone,
an impact that may not be visible until the tree begins to show signs of stress months or years later. The
ability of a tree to survive root removal 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.
Another root impact occurs when materials are improperly stored or disposed of in the root zone. This can
injure tree roots and contaminate the soil. Finally, an obvious impact can occur when equipment damages
trunks and branches. To avoid these impacts, it is a best management practice to establish fenced tree
protection zones to exclude any grading, trenching, soil compaction, material storage, or mechanical
damage. These tree protection zones are based on calculated critical root zones (CRZs). Any tree that
will have major encroachments into the CRZ should be considered for removal, rather than tree
protection.
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Tree Preservation Priority
In order to evaluate the priority for the preservation of an individual tree 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 concern. 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.).
Table 2. Tree Preservation Priority
Priority 2 18
Priority 4 1
Based on the findings, the following recommendations are provided:
• Remove Tree ID# 8594 due to poor condition.
• Remove Tree ID# 8582 for development purposes.
o The rounded functional replacement cost was $11,600 for Tree ID# 8582.
o Install tree protection fencing 5 ft. outside the dripline or the limits of disturbance,
whichever is greater, of all the trees on the neighboring parcel and those trees
determined to remain on the subject parcel.
• Install tree protection fencing 5 ft. outside the dripline or the limits of disturbance, whichever is
greater, of all the trees on the neighboring parcel and those trees determined to remain on the
subject parcel.
• Apply a 3-inch layer of mulch starting at the trunk and extending out past the dripline of the
retained trees.
• Retain a Certified Arborist to periodically monitor tree health and maintenance needs every 3-5
years or as need dictates.
Soil Remediation
Excavation will take place in the tree protection zone of Tree ID#'s 8591, 8592, & 8593. The soil in this
area is contaminated and will be removed and replaced with healthy soil. It is unlikely that the excavation
will compromise the structural stability or long term health of these trees. If it is determined by the site
arborist that root pruning to allow for the excavation will be detrimental to the trees, then the trees will be
removed and replaced according to ECDC 23.10.060(A). The recommendations for tree preservation are
as follows:
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• Delineate the Limits of Disturbance (LOD) in the field
• Using a pneumatic air -knife, remove the soil -6 inches outside the LOD to a depth of 12 inches
and 6 inches wide. This trench will allow the site arborist to view the roots that are within the
excavation area. A determination of tree retention or removal can then be made by the site
arborist.
• If tree retention is not viable, the trees will be removed and replaced according to ECDC
23.10.060(A
• If tree retention is recommended, the site arborist will prune any tree roots that are in danger of
being torn by excavation equipment during the soil remediation process.
• The pruned roots should then be covered by soil so that they do not dry out during the excavation
process.
• Add a 12-inch layer of wood chips over any parts of a root zone not protected by the TPZ fencing
where heavy machinery will operate. Adding plywood on top of the mulch is also recommended.
This aids in reducing the impact of soil compaction from heavy equipment during the upcoming
construction activities. Reduce the mulch to 3-inches once protection is no longer needed.
Image 1. The yellow outlined area is the location of the soil remediation and excavation at the southern
portion of the site.
remedial
xcavatior
VON
0M
AoSk
_
r ti
• y
- 190•
4MW—
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Replacement Required
Tree replacement is required for tree removal associated with the development types identified in ECDC
23.10.060(A). Each significant tree to be removed shall be replaced as follows:
• For each significant tree between six inches and 10 inches DBH removed, one replacement
tree is required.
• For each significant tree between 10.1 inches and 14 inches in DBH removed, two replacement
trees are required.
• For each significant tree greater than 14 inches and less than 24 inches in DBH removed,
three replacement trees are required.
• For each significant tree greater than 24 inches in DBH removed, a fee based on an appraisal of
the tree value by the city tree protection professional using trunk formula method in the current
edition of the Guide for Plant Appraisal shall be required. The appraisal was completed using the
10th Edition of the Council of Tree & Landscape Appraisers (CTLA) Guide for Plant Appraisal
Trunk Formula Technique.
o The rounded functional replacement cost of the one (1) tree >_ 24" in diameter that
will be removed was $11,600 total. This valuation includes the cost of purchasing new
trees and installation. The results do not take into account all of the future maintenance
needs of the tree including regular watering, fertilization, and pruning.
The Functional Replacement method was used to value the trees in this report. This approach
extrapolates the cost to purchase the largest commonly available nursery tree to the size of the tree being
appraised (the basic tree cost). From this basic tree cost, the value is depreciated based on the existing
condition of the tree (it's health, structure, and form), any functional limitations (the space it grows), and
any external limitations (outside factors influencing tree growth). These values are adjusted according to
the species of the tree and its physical condition and landscape placement. This approach does not take
into account the maintenance costs of a newly planted tree which can be considerable over the life of the
tree. The majority of costs for the care of a new tree likely occur within the first 5-10 years after planting.
The Trunk Formula Technique is calculated as Value = Basic Tree Cost x Condition Rating % x
Functional Limitations % x External Limitations %.
• Basic Tree Cost = (Trunk Area Increase of appraised tree)x(Unit Tree Cost + Installed Tree Cost)
• Condition Rating = a percentage scale based on the tree's health, structure, and form.
• Functional Limitations = a percentage scale associated with the interaction of the tree and its
planting site.
• External Limitations = a percentage scale associated with factors outside the property or control
of the property owner.
According to an estimate provided by Northwest Nurseries in Redmond, WA, the largest available
replacement would be a 2.5-inch caliper specimen (Table 3). The trees were determined to be in good
condition.
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Table 3. Basic Tree Cost Variables
LCANT Size (in. diam @ 12" above grade) 2.5 in.
LCANT Cross -Sectional Area (sq in) 4.91 sq in.
LCANT Cost ($) $160.00
LCANT Source Northwest Nurseries
Unit Tree Cost ($/Sq In) $40.74
Replacement Tree Installation Cost ($) $400.00
Replacement Tree Aftercare Cost ($) $500.00
Other Costs (Cleanup, site preparation, fertilizer, etc.) $200.00
Table 4. Appraisal Calculations
8582 Maple, Bigleaf (Acer 25 490.88 $ 19,998 $ 10,529 $ 1,100 $ 11,600
macrophyllum)
Tree Protection Zone & Timing
To ensure the long-term viability of trees and stands identified for protection, construction activities shall
comply with the minimum required tree protection through an established Tree Protection Zone (TPZ) for
those trees determined to remain on the site.
• Preventative measures are recommended in addition to the installation of tree protection barriers
including mulching over drip line, fertilization for stressed trees, supplemental irrigation as
necessary, soil amendments and soil aeration, and pruning to remove deadwood or create
clearance on trees to be protected.
• At a minimum the TPZ barrier shall be installed 5 feet out from the dripline or follow the back of
existing hardscape when the hardscape falls within 5-0" offset of dripline.
• TPZs will follow the edge of building/road/paved path where necessary and are not required to
extend to the dripline where impervious surfaces are determined to be the limiting factor for root
development.
• All construction activities are prohibited within TPZ. This includes but is not limited to the storage
of materials, parking, contaminating soil by washing out equipment, (concrete, paint, etc.),
changing soil grade, or damaging overhead branches.
• Any entry or work within the TPZ of retained or impacted trees will need to occur under the direct
supervision of a certified arborist.
• TPZ fencing shall be a minimum of 4 feet high, constructed of chain link or polyethylene laminar
safety fencing or similar material.
• "Tree Protection Area - Keep Out' or similar signs is required to accompany the TPZ fencing at
regular intervals and include the contact information of the consulting arborist or entity
responsible for enforcing tree protection standards
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August 8, 2022
• 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, with authorization by an ISA certified arborist.
An example illustration of a Tree Protection Zone barrier. Contact information of the site manager or
consulting arborist should also be included on the sign.
O -
Pre -Development Tree Care - 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.
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• 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.
• 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. Reduce the mulch to 3-inches once protection is no longer
needed.
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 and 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. The 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.
Post -Development - A successful tree preservation effort continues well past the conclusion of
development activities:
• The preserved trees should be re -inspected for signs of impact that may have gone undetected
during construction and mitigation measures assigned accordingly.
• The preserved trees should be placed on a seasonal care plan for two years that includes both
monitoring and routine soil inoculation treatments designed to stimulate new root growth.
• Retain a Certified Arborist to periodically monitor tree health and maintenance needs every 3-5
years or as need dictates.Annual monitoring should continue for several years after development.
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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. 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. The importance of protecting
trees that have been selected for preservation should be clearly communicated to contractors, equipment
operators, and workers before any land disturbance. This message can be reinforced by establishing
penalties that must be paid if trees are injured or killed during construction.
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 Critical Root Zone also greatly influences
the suitability of a particular tree for preservation. Exploratory soil excavation and root pruning is
recommended to determine the size and quantity of the roots that require pruning.
Preconstruction tree maintenance is recommended, including mulch, fertilization, supplemental irrigation
as necessary, and pruning to remove dead, structurally weak, and low -hanging branches. This will
increase the overall condition of the population and will enable the trees to better withstand many
development impacts throughout the project. It is also recommended to conduct a tree inspection during
and immediately following completion of the construction project to identify any changes in tree health or
risk that may occur. Multiple tree inspections may be required during the construction phase of the project
depending on the length it will take to complete. Any inspections or tree maintenance should be
completed by or under the supervision of an ISA Certified Arborist.
Successful tree preservation 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.
Prepared by: DRG Page 15 of 16
Prepared for: Terrace Place August 8, 2022
Appendix A: Maps
Map Al. Site map showing tree ID number and TPZ.
1. On -site Tree #8594 is approved for removal. Tree 8582 is to remain.
2. Off -site Trees #N1-5 and on -site Trees #8581, 8583-8590: mulch (see below) and
install tree protection fence at Canopy Radius Distances (in feet) noted in Table 1 per
ECDC 23.10.070.0 fence standards.
3. Mulch within fence boundaries shall be 6" depth wood chips, pulled away 3" from trunk.
4. Trees #8581-8593: soil removal within the Canopy Radius Distance (average 25' from
trunk) shall be conducted by or under the supervision of a Certified Arborist using an air
spade and vactor truck as described on p. 10, OR...
5. Seek permission from adjacent property owner for the removal of shared boundary
Trees #8591-8593. DP 8/23/22
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Tree Inventory Feet
• RETAIN A 0 25 50 too
►& REMOVE Terrace Place
_ Avg. Dripline 23625 84th Ave W DAVEY�
Q Parcel Boundaries Edmonds, WA
June 7, 2022
Resource Group
' Aerial imagery is from 2019; Tree locations and property boundaries are approximateto
Prepared by: DRG Page 16 of 16
Prepared for: Terrace Place August 8, 2022