HomeMy WebLinkAboutEx05_Arborist_Report LAYTON TREE CONSULTING, LLC
It’s all about trees……
PO BOX 572, SNOHOMISH, WA 98291-0572 * 425-220-5711 * bob@laytontreeconsulting.com
ARBORIST REPORT/TREE PLAN
130XX 156th Avenue SE – Short Plat
King County Parcel 366450-0185
Renton, WA
Report Prepared by:
Bob Layton
Registered Consulting Arborist #670
Certified Arborist #PN-2714A
April 11, 2025
Exhibit 5
RECEIVED
09/25/2025 IHarris
PLANNING DIVISION
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Arborist Report – 130XX 156th Ave SE Short Plat - Renton
Page 2 Layton Tree Consulting LLC April 11, 2025
Table of Contents
Assignment.................................................................................................................................................... 3
Description .................................................................................................................................................... 3
Methodology ................................................................................................................................................. 3
Judging Condition...................................................................................................................................... 4
Judging Retention Suitability .................................................................................................................... 4
Observations ................................................................................................................................................. 4
Discussion/Recommendations ...................................................................................................................... 5
Tree Protection Guidelines ............................................................................................................................ 6
Tree Density-Tree Replacement ................................................................................................................... 6
Arborist Disclosure Statement ...................................................................................................................... 7
Attachments
Photos, pages 8 - 11
Tree Summary Table
Tree Plan Map
City of Renton - Tree Retention and Credit Worksheet
City of Renton Tree List
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Arborist Report – 130XX 156th Ave SE Short Plat - Renton
Page 3 Layton Tree Consulting LLC April 11, 2025
Assignment
Layton Tree Consulting, LLC was asked to compile an Arborist Report for a parcel in Renton. The subject
property is located at 130XX 156th Avenue SE, King County Parcel 366450-0185. Lot 3 of the proposed 3-lot
short plat has been recently developed. The purpose of the report is to satisfy City requirements associated
with tree retention regulations for the proposed 3-Lot short plat.
My assignment is to prepare a written report on present tree conditions, which is to be submitted to the
City with the development application materials.
This report covers all of the criteria set forth under the City of Renton’s tree regulations, Municipal Code
Section 4-4-130 - Tree Retention and Land Clearing Regulations.
Date of Field Examination: April 9, 2025
Description
13 trees of ‘significant’ size were identified and assessed on the subject parcel. A ‘significant’ tree as defined
by the City is ‘A tree with a caliper of at least six inches (6"), or an alder or cottonwood tree with a caliper of
at least eight inches (8"). Trees qualified as dangerous shall not be considered significant. Trees planted
within the most recent ten (10) years shall qualify as significant trees, regardless of the actual caliper’.
The majority of the property is scarcely treed. Trees are primarily located on the south perimeter. These
are native species of Douglas fir, Scouler’s willow and Western red cedar.
Trees were identified in the field with a numbered aluminum tag, attached to the lower trunk. These tag
numbers correspond with the numbers on the attached Tree Summary Table and attached Tree Plan Map.
There are three significant neighboring trees whose crowns or canopies extend onto the subject property.
These trees were assessed and are included in this report.
The two fir trees in the 156th ROW and several of the neighboring trees that appear on the survey no longer
exist at the site. These have been cut and removed. See the attached map.
Methodology
Each tree in this report was visited. Tree diameters were measured by tape. The tree heights were
measured using a Spiegel Relaskop. Each tree was visually examined for defects and vigor. The tree
assessment procedure involves the examination of many factors:
• The crown or canopy of the tree is examined for current vigor/health by examining the foliage for
appropriate color and density, the vegetative buds for color and size, and the branches for structural
form and annual shoot growth; and the overall presence of limb dieback and/or any disease issues.
• The trunk or main stem of the tree is inspected for decay, which includes cavities, wounds, fruiting
bodies of decay (conks or mushrooms), seams, insect pests, bleeding or exudation of sap, callus
development, broken or dead tops, structural defects and unnatural leans. Structural defects can
include but are not limited to excessive or unnatural leans, crooks, forks with V-shaped crotches,
multiple attachments.
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Arborist Report – 130XX 156th Ave SE Short Plat - Renton
Page 4 Layton Tree Consulting LLC April 11, 2025
• The root collar and exposed surface roots are inspected for the presence of decay, insect damage, as
well as if they have been injured or wounded, undermined or exposed, or the original grade has
been altered.
Judging Condition
The three condition categories are described as follows:
Good – free of significant structural defects, no disease concerns, minor pest issues, no significant root
issues, good structure/form with uniform crown or canopy, foliage of normal color and density, average or
normal vigor, will be wind firm if isolated or left as part of a grouping or grove of trees, suitable for its
location
Fair – minor to moderate structural defects not expected to contribute to a failure in near future, no disease
concerns, moderate pest issues, no significant root issues, asymmetric or unbalanced crown or canopy,
average or normal vigor, foliage of normal color, moderate foliage density, will be wind firm if left as part of
a grouping or grove of trees, cannot be isolated, suitable for its location
Poor – major structural defects expected to cause fail in near future, disease or significant pest concerns,
obvious irreversible decline due to old age, disease or pests, not suitable for its location
The attached tree plan maps indicate the ‘condition rating’ of the subject trees found at the site. The
attached Tree Summary Table provides specific information on tree sizes and condition; and drip-line
measurements for trees with a potential for retention.
Judging Retention Suitability
Not all trees necessarily warrant retention. The three retention suitability categories as described in
ANSI A300 Part 5 (Standard Practices for the Management of Trees During Site Planning, Site
Development and Construction) are as follows:
Good – trees are in good health condition and structural stability and have the potential for longevity at
the site
Fair – trees are in fair health condition and/or have structural defects that can be mitigated with
treatment. These trees may require more intense management and monitoring, and may have shorter
life-spans than those in the “good” category.
Poor – trees are in poor health condition and have significant defects in structure that cannot be
mitigated with treatment. These trees can be expected to decline regardless of management. The
species or individual tree may possess characteristics that are incompatible or undesirable in landscape
settings or be unsuited for the intended use of the site.
Observations
The subject property is scarcely or lightly treed and contains primarily native species. Trees are only
found on the south perimeter of the site. These include a planted row of 10 Douglas fir and two
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Arborist Report – 130XX 156th Ave SE Short Plat - Renton
Page 5 Layton Tree Consulting LLC April 11, 2025
Western red cedar. These are young to semi-mature specimens. All are of good vigor with foliage of
normal color and density. The majority have natural leans to the north from a large maple tree that
used to exist south of them. Now that the maple is no longer there, trees can be expected to grow
vertical.
Tree #13 is a mature native Scouler’s willow cluster on the south perimeter in the middle of the
property. It is in obvious decline due to old age with dead tops and the development of significant trunk
decay; which is common for the species. It is in ‘poor’ condition and has poor retention suitability.
Neighboring/Off-site Trees
Tree #101 is a semi-mature to mature Scots pine located close to the south property line between
proposed Lots 1 and 2. Vigor is good. The trunk forks at roughly 8-feet above ground into codominant
(equal diameter) tops. There is a significant build-up of included or embedded bark between the forked
stems. Condition is ‘fair’.
Tree #102 is a young Western red cedar located close to the south property line at the southeast corner
of Lot 2. It is in ‘good’ condition with no concerning issues.
Tree #103 is a semi-mature to mature Western red cedar. It is in ‘good’ condition with no concerning
issues.
Discussion/Recommendations
Only one of the subject significant trees is rated as ‘poor’ condition, Tree #13. It can be expected to
continue to naturally decline and fail in the near future, due to dead tops and advanced decay within the
lower trunk. Retention is not appropriate.
The proposal is to retain Trees #1 > #5 at the back of proposed Lot 1. These are well-positioned for
successful retention. The other significant trees are located too far of off the property line to be feasibly
retained. These will be significantly impacted by lot development. Removal and replacement are
proposed.
The attached Tree Plan Map indicates the driplines of retained and protected off-site trees, and the
location of a tree protection barrier. Position the tree protection barrier a few feet beyond the driplines
for optimal protection as shown on the attached map.
Neighboring or off-site trees are not expected to be impacted by the proposal. No work is proposed
within a proximity of them.
There are a few smaller, non-significant sized Douglas fir trees mixed in between the trees to be
retained. These should be cut out and removed to afford the significant trees more room to develop
better structure; and to reduce the competition for sunlight and moisture.
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Arborist Report – 130XX 156th Ave SE Short Plat - Renton
Page 6 Layton Tree Consulting LLC April 11, 2025
Tree Protection Guidelines
Tree protection fencing shall be positioned around any retained trees or off-site protected trees prior to
site demolition or bringing any heavy equipment onto the site. This will help to define clearing limits
and protect soils and surface roots. Existing grades within the fenced areas shall not be altered.
Position fencing as shown on the attached tree plan map.
Any excavation within the driplines of retained trees and/or the neighboring trees shall be monitored by
the project arborist so necessary precautions can be taken to minimize overall impacts.
Any roots that are damaged outside of the fenced protection area shall be pruned clean at sound tissue
prior to backfilling or finishing areas. Sound tissue is where the root is undamaged and the bark is
completely intact with the root. This will help roots to seal off potential decay and allow them to sprout
new growth. Any disturbed areas at the outer edge of the protection area shall be watered weekly
during the dry season of June through September. This will help to create a favorable environment for
new root growth and reduce the overall stress associated with root loss and disturbance.
Simply finish the landscape within the driplines of save trees by cutting/hand-pulling any unwanted
vegetation and applying a 2 to 4-inch covering of organic mulch/beauty bark. Retain any existing native
shrubs. Avoid large plantings, irrigation trenches and the construction of hardscapes within the driplines
of retained trees.
Tree Density-Tree Replacement
RMC 4-4-130 H. 1. Protected Trees – Retention Required: a. Minimum Tree Retention Requirements:
Properties subject to an active land development permit shall retain a minimum of thirty percent (30%) of
all significant trees on site.
b. Tree Credit Requirements: With the exception of interior remodels not involving any building addition,
removal of trees, or alteration of impervious areas, properties subject to an active land development
permit shall comply with all of the following minimum tree credit requirements, and apply the tree credit
value table in subsection H1bv of this Section:
i. Tree credit requirements shall apply at a minimum rate of thirty (30) credits per net acre.
ii. Either tree retention or a combination of tree retention and supplemental tree planting (with new small,
medium, or large tree species) shall be provided to meet or exceed the minimum tree credits required for
the site.
The subject site requires the retention of 30% of significant trees. Of the 12 trees viable significant trees
on the property, five will be retained for a retention percentage of 42%.
The required minimum number of tree credits for the +/- 45,871 sq.ft. parcel is 32 tree credits. The five
trees to be retained equate to 22 tree credits. See the attached Tree Retention and Credit Worksheet.
10 supplemental tree credits are required to achieve the required minimum density for the parcel.
In addition, each lot is required to meet the minimum rate of thirty (30) credits per net acre.
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Arborist Report – 130XX 156th Ave SE Short Plat - Renton
Page 7 Layton Tree Consulting LLC April 11, 2025
Lot Size (sq.ft.) Minimum Tree
Density (Credits)
Retained Tree
Credits
Supplemental
Tree Credits
1 12,262 8 22 0
2 11,569 8 0 8
3 17,842 12 0 12
To achieve the required minimum tree density, Lots 2 and 3 will require the planting of supplemental
trees. This can be achieved by the planting of 8 and 12 medium sized trees, or a combination of small,
medium and large trees to attain the required credits. See the bottom of page 3 of the attached
worksheet. Species can be selected from the City’s tree list, also attached.
There is adequate available open-space at the back and front of the lots to sustain the required tree
replacement.
Arborist Disclosure Statement
Arborists are tree specialists who use their education, knowledge, training and experience to examine
and assess trees, recommend measures to enhance the beauty and health of trees, and attempt to
reduce the risks associated with living near trees. Clients may choose to accept or disregard the
recommendations of the arborist, or to seek additional advice.
Arborists cannot detect every condition that could possibly lead to the structural failure of a tree. Trees
are living organisms that grow, respond to their environment, mature, decline and sometimes fail in
ways we do not fully understand. Conditions are often hidden within trees and below ground.
Arborists cannot guarantee that a tree will be healthy and/or safe under all circumstances, or for a
specified period of time. Likewise, remedial treatments, like any medicine, cannot be guaranteed.
Treatment, pruning and removal of trees may involve considerations beyond the scope of the arborist’s
services such as property boundaries, property ownership, site lines, disputes between neighbors, and
other issues. Arborists cannot take such considerations into account unless complete and accurate
information is disclosed to the arborist. An arborist should then be expected to reasonably rely upon
the completeness and accuracy of the information provided.
Trees can be managed, but they cannot be controlled. To live near trees is to accept some degree of
risk. The only way to eliminate all risk associated with trees is to eliminate all trees.
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Arborist Report – 130XX 156th Ave SE Short Plat - Renton
Page 8 Layton Tree Consulting LLC April 11, 2025
Photo Documentation
Looking east down south perimeter of property, Trees #1 and #2 in foreground
Close-up of trees pictured above
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Arborist Report – 130XX 156th Ave SE Short Plat - Renton
Page 9 Layton Tree Consulting LLC April 11, 2025
Looking east across the back of proposed Lot 1, Trees #1 > #6 on right
Trees at back of proposed Lot 1
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Arborist Report – 130XX 156th Ave SE Short Plat - Renton
Page 10 Layton Tree Consulting LLC April 11, 2025
Trees at back of proposed Lot 1
Looking west across o the back of proposed Lot 2
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Arborist Report – 130XX 156th Ave SE Short Plat - Renton
Page 11 Layton Tree Consulting LLC April 11, 2025
Neighboring Tree #101 right of fence
Looking towards southeast corner of Lot 2, neighboring Tree #102 at corner
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Layton Tree Consulting LLC
For:Kushal Varma
Site:130XX 156th AVE SE - Renton
Tree Summary Table
Date:
Tree/DBH Height Retention
Tag #Species (inches)(feet)Condition Suitability Comments Proposal
N S E W
1 Douglas fir 11 30 8 6 4 8 Fair Good slight lean north Retain
2 Douglas fir 9 34 8 6 6 4 Fair Good slight lean north Retain
3 Douglas fir 7 28 6 4 4 6 Fair Good slight lean north Retain
4 Douglas fir 6 20 6 4 6 4 Fair Good slight lean north Retain
5 Western red cedar 10 30 6 4 4 4 Good Good slight lean north Retain
6 Douglas fir 9 42 6 4 4 4 Fair CBC slight lean north Remove
7 Douglas fir 26 80 12 8 6 8 Good CBC no concerns Remove
8 Douglas fir 14 68 10 6 4 4 Fair CBC no concerns Remove
9 Douglas fir 14 75 10 6 4 4 Fair CBC no concerns Remove
10 Douglas fir 14 74 10 6 6 4 Fair CBC no concerns Remove
11 Western red cedar 13 42 10 6 4 6 Good CBC no concerns Remove
12 Douglas fir 10 47 8 6 8 4 Fair CBC suppressed, lean Remove
13 Scoulers willow 16,10,9 (21)58 x x x x Poor Poor over mature, extensive trunk decay Remove
101 Scots pine 26 87 12 NA NA NA Fair Fair trunk forks at 8 feet, significant included bark Protect
102 Western red cedar 12 35 12 NA NA NA Good Good no concerns Protect
103 Western red cedar 31 78 16 NA NA NA Good Good no concerns Protect
Drip-Line measurements from face of trunk
Measurements for neighboring trees from property line
CBC - Compromised by new Construction
Drip-Line
(feet)
Calculated DBH: the DBH is parenthesis is the square root of the sum of the dbh for each individual stem squared
(example with 3 stems: dbh = square root [(stem1)2 +(stem2)2 +(stem3)2 ]).
4/9/2025
Neighboring/Off-site Trees
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
rentonwa.gov/permitcenter | planningcustomerservice@rentonwa.gov | 425-430-7294 10/6/2022 Page 1 of 3
CITY OF RENTON Ι PERMIT CENTER
TREE RETENTION AND CREDIT WORKSHEET
TREE RETENTION REQUIREMENTS
A minimum retention of thirty percent (30%) of all significant trees (as defined in RMC 4-11-200) is required on site.
Please complete the form below to verify compliance with minimum tree retention requirements.
• Identify total number of trees 6-inch caliper or greater (or alder or
cottonwood trees 8-inch caliper or greater) on site: Trees
Trees
Trees
Trees
Trees
Trees Required
Trees Proposed
•Deductions – Certain trees are excluded from the retention calculation:
o Trees that are high-risk, as defined in RMC 4-11-200:
o Trees within existing and proposed public right-of-way:
o Trees within wetlands, streams, very high landslide hazards,
protected slopes, and associated buffers:
•Total remaining trees after deductions:
•Required tree retention (30%):
•Identify number of trees proposed for retention:
•Identify number of trees requested for replacement in lieu of retention
(skip page 3 if no tree replacement is requested):Trees
TREE CREDIT REQUIREMENTS
Tree credit requirements apply at a minimum rate of thirty (30) credits per net acre. Complete the form below to
determine minimum tree credit requirements.
•Gross area of property in square feet: Square Feet
•Deductions: Certain areas are excluded from tree credit calculation:
o Existing and proposed public right-of-way: Square Feet
o Wetlands, streams, very high landslide hazards, protected slopes,
and associated buffers: Square Feet
•Total excluded area:Square Feet
•Net land area (after deductions) in square feet:Square Feet
•Net land area (after deductions) in acres:Acres
•Required tree credits:Tree Credits Required
13
1
12
3.5999999999999996
5
0
45871
0
0
45871
1.05
32
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
rentonwa.gov/permitcenter | planningcustomerservice@rentonwa.gov | 425-430-7294 10/6/2022 Page 2 of 3
TREE RETENTION AND CREDIT WORKSHEET
PROPOSED TREE CREDITS
Please complete the table below to calculate the total tree credits proposed for your project. Identify the quantity of trees
for each tree category, after deducting trees within excluded areas, as shown in the previous section.
TREE SIZE TREE CREDITS TREE QUANTITY TOTAL TREE CREDITS
RETAINED TREES
Preserved tree 6 – 9” caliper 4
Preserved tree 10 – 12” caliper 5
Preserved tree 12 – 15” caliper 6
Preserved tree 16 – 18” caliper 7
Preserved tree 19 – 21” caliper 8
Preserved tree 22 – 24” caliper 9
Preserved tree 25 – 28” caliper 10
Preserved tree 29 – 32” caliper 11
Preserved tree 33 – 36” caliper 12
Preserved tree 37” caliper and greater 13
NEW TREES
New small species tree (30' or less at maturity) 0.25
New medium species tree (30' to 50' at maturity)
1
New large species tree (50' or more at maturity) 2
TREE CREDITS PROPOSED:
3
2
10
32
12
10
0
0
0
0
0
0
0
0
0
10
0
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
rentonwa.gov/permitcenter | planningcustomerservice@rentonwa.gov | 425-430-7294 10/6/2022 Page 3 of 3
TREE RETENTION AND CREDIT WORKSHEET
TREE REPLACEMENT JUSTIFICATION
Replacement may be authorized as an alternative to 30% retention provided the removal is the minimum necessary to
accomplish the desired purpose and provided the proposal meets one of the following options:
a. There are special circumstances related to the size, shape, topography, location, or surroundings of the subject
property; or
b. The strict application of the code would prevent reasonable use of property; or
c. The strict application of the code would prevent compliance with minimum density requirements of the zone; or
d. The project is a short plat with four (4) or fewer lots.
Please attach a written justification demonstrating compliance with the requirements and criteria as descripted above.
TREE REPLACEMENT QUANTITY
Tree replacement quantity is determined based on the credit value of the trees proposed for removal. Larger, higher
priority trees shall be used for calculation of tree replacement. Identify the quantity of each tree requested to be removed
in lieu of 30% retention, based on tree size. List the identification number of each tree, as indicated in the arborist report.
TREE SIZE TREE CREDITS TREE QUANTITY TREE INDENTIFICATION # TOTAL TREE CREDITS
Tree 37” caliper + 13
Tree 33 – 36” caliper 12
Tree 29 – 32” caliper 11
Tree 25 – 28” caliper 10
Tree 22 – 24” caliper 9
Tree 19 – 21” caliper 8
Tree 16 – 18” caliper 7
Tree 12 – 15” caliper 6
Tree 10 – 12” caliper 5
Tree 6 – 9” caliper 4
REPLACEMENT CREDITS REQUIRED:
TREE REPLACEMENT PLANTING
Identify the quantity of proposed new replacement trees (minimum size of 2-inch caliper). The total replacement credits
proposed should be equal to or greater than the replacement credits required, as shown in the previous section.
TREE SIZE TREE CREDITS TREE QUANTITY TOTAL TREE CREDITS
New small species tree (30' or less at maturity) 0.25
New medium species tree (30' to 50' at maturity)
1
New large species tree (50' or more at maturity) 2
REPLACEMENT CREDITS PROPOSED:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5
Docusign Envelope ID: 85515A60-0856-8EA6-8102-3141314330A5