Hazard tree removal CRA2021-0052CITY OF EDMONDS
121 5th Avenue North, Edmonds WA 98020
Phone: 425.771.0220 • Fax: 425.771.0221 • Web: www.edmondswa.gov
DEVELOPMENT SERVICES DEPARTMENT • PLANNING DIVISION
"ne. 18y%J
May 3, 2021
Scott Newcom
19117 — Olympic View Dr.
Edmonds, WA 98020
Subject: Hazard Tree Removal
Dear Mr. Newcom,
The City of Edmonds has received a request to remove big leaf maple tree from your property located at
19117 — Olympic View Drive. The tree is located between the Newcom residence and the property to
the north. The tree stands on a slope that exceeds 25 percent grade, which is considered a critical area
pursuant to Chapter 23.80 of the Edmonds Community Development Code (ECDC). Generally, the
removal of trees, or any vegetation, within a critical area or critical area buffer is not an allowed activity,
unless, pursuant to ECDC 23.40.220.C.8, it involves the removal of invasive species or hazard trees.
Additionally, the tree is also greater than 24 inches at breast height and meets the definition of
"landmark tree." There is a current moratorium on removal of landmark trees unless the tree meets the
definition of hazard tree in ECDC 23.10.020.G or nuisance tree in 23.10.0201.
In order to fall under the hazard tree provisions of ECDC 23.10.040.F, a tree must be determined to be a
high risk by a certified arborist. The request to remove the tree included an ISA Tree Risk Assessment
form completed by certified arborist Katy Bigelow who found the tree to have an overall tree risk rating
of "High". Pursuant to ECDC 23.40.220.C.8.b.iv each hazard tree removed within a critical area or critical
area buffer must be replaced with new native trees at a ratio of two to one. It has been indicated that
you propose to replace the big leaf maple with two tree species from the list below (note: only
acceptable trees from the provided list are shown below):
• Vine maple, Acer circinatum
• Western red cedar, Thuja plicata
• Alaska cedar, Chamaecyparis nootkatensis
An exemption for the tree cutting is granted with the following conditions:
1. This approval only pertains to the big leaf maple tree identified in the attached materials.
Two tree must be planted to replace the subject big leaf maple. The replacement trees must be
native and indigenous in accordance with ECDC 23.40.220.C.8.b.iv.
The proposed replacement trees listed above are appropriate replacement tree species.
Alternative species must be approved by the City of Edmonds.
3. Replacement trees must be planted within one year of removal of the hazard trees. Please
notify the City once the replacement trees have been replanted for an inspection.
Feel free to contact me if you have any questions at Brad.Shiplev@edmondswa.gov, or 425-771-0220.
Sincerely,
b�,
Brad Shipley
Associate Planner
Encl: Cover Letter
ISA Tree Risk Assessment Form
Katy Bigelow
206.351.1375
arboristkaty@gmail.com
April 9, 2021
Scott Newcom
19117 Olympic View Dr.
Edmonds, WA 98020
Dear Mr. Newcom:
Thank you for asking me to provide a memo with observations and recommendations for trees
growing on a slope south of your home. To evaluate the trees addressed in this letter I combined
my field experience and education with current accepted practices as defined by the American
National Standards Institute (ANSI) and the International Society of Arboriculture (ISA).
The tools I use to make this assessment were limited to binoculars, compass, diameter tape, hand
trowel and laser pointer. A visual tree assessment and other methods are only conclusive for the
day of inspection and do not guarantee that conditions will remain the same in the future.
I was asked by Mr. Newcom to provide a memo detailing recommendations for work on one tree
growing on his property also suitable to use for applying for a tree removal permit from the City
of Edmonds. On April 7, 20211 completed a Level 2 tree assessment of this tree. All levels of
tree assessment are explained in an attachment to this report.
The tree I assessed is one bigleaf maple. It is located between Mr. Newcom's home and one
home north of his (Photo 1, Map 1). It stands on a gentle slope above a parking area for both
homes. Its diameter is greater than 24" categorizing it as a landmark tree by the City of
Edmonds.
This maple has been topped several times in its life. A very old topping wound has now left two
structural branches holding on to a significantly rotting area that is becoming worked on by
woodpeckers (Photos 2-3). One other structural trunk is completely dead and there are many
sizeable dead branches throughout the canopy.
Tree assessment — Newcom
19917 Olympic View Dr., Edmonds, WA
4/9/2021
Although the tree has good vigor and the lowest area of the main trunk is stable there is a high
probability that, especially when in leaf, one or both structural trunks pointed out in Photo 2 will
fail where they are attached. The target in the event of either failure is either the Newcom's
home, deck and parking area and/or the neighbor's home and parking area.
Tree risk assessment is a qualification that can be obtained through the ISA (International
Society of Arboriculture). The TRAQ (Tree Risk Assessment Qualification) methodology has
improved risk assessment by teaching assessors to follow a consistent format for examining a
tree.
Additionally, the TRAQ protocol includes defined terms for tree risk. The four terms under the
risk category Likelihood of Failure are Imminent, Probable, Possible and Improbable. Imminent
as defined in the TRAQ manual is an infrequent observance that would involve immediate risk
mitigation to prevent damage to a nearby target. The majority of trees I and other tree risk
assessors observe usually fall into the middle categories of Possible or Probable Likelihood of
Failure. Very rarely is a tree rated "Imminent" observed.
To assist in visualizing how a tree risk assessor determines risk, the following matrix used as part
of the protocols can be referred to below:
Matrix I. Likelihood matrix.
Likelihood
of Failure
Likelihood of Impact
Very low
Low
Medium
High
Imminent
Unlikely
Somewhat likely
Likely
Very likely
Probable
Unlikely
Unlikely
Somewhat likely
Likely
Possible
Unlikely
Unlikely
Unlikely
Somewhat likely
Improbable
Unlikely
Unlikely
Unlikely
Unlikely
Matrix 2. Risk rating matrix.
Likelihood of
Failure & Impact
Consequences of Failure
Negligible
Minor
Significant
Severe
Very likely
Low
Moderate
High
Extreme
Likely
Low
Moderate
High
High
Somewhat likely
Low
Low
Moderate
Moderate
Unlikely
Low
Low
Low
Low
Due to the rot extending under and into both structural branches pointed out in the photos, I
believe there is a probable potential for these to both fail with the consequences of failure being
significant or severe. If the tree is left as is, the consequences can increase over time.
11
Tree assessment — Newcom
19917 Olympic View Dr., Edmonds, WA
4/9/2021
I recommend this tree be cut down to leave a habitat trunk. The final shape of the tree can
include some shorter stubs of structural branches or be cut directly under where they are all
attached. This habitat tree trunk will likely keep growing with vigorous sprouts. Over time the
attachment of these sprouts to a rotting main trunk will need to be monitored to avoid the same
situation as is occurring now.
The tree can also be cut down to a shorter stump and also be expected to regrow. If this action is
chosen, its stump should be left intact and sprouts will be easier to monitor over time.
• No matter what option is chosen, all foliage and most of the logs shall be removed from
the site to allow areas for replanting to remain uncovered and to reduce tinder on site.
• Some logs can be left on the hillside but not all will be able to remain due to the amount
of tree and foliage needing to be removed.
• Wood chips generated from processing tree parts can be used to cover slope soils east of
the tree.
These trees stand in a Critical Area (slope, Map 2). Edmonds Municipal Code states (my
responses in red font), "The removal of trees from critical areas and buffers that are hazardous,
posing a threat to public safety, or posing an imminent risk of damage to private property;
provided, that:
i. The applicant submits a report from an ISA- or ASCA-certified arborist or registered landscape
architect that documents the hazard and provides a replanting schedule for the replacement trees
(this document completes this requirement);
ii. Tree cutting shall be limited to pruning and crown thinning, unless otherwise justified by a
qualified professional. Where pruning or crown thinning is not sufficient to address the hazard,
trees should be removed or converted to wildlife snags; (this document explains why this is not
the best option but is one option for this trees management)
iii. All vegetation cut (tree stems, branches, etc.) shall be left within the critical area or buffer
unless removal is warranted due to the potential for disease or pest transmittal to other healthy
vegetation or unless removal is warranted to improve slope stability; (this document explains
why removal debris should not be left in the area).
iv. The land owner shall replace any trees that are removed with new trees at a ratio of two
replacement trees for each tree removed (2:1) within one year in accordance with an approved
restoration plan. Replacement trees may be planted at a different, nearby location if it can be
determined that planting in the same location would create a new hazard or potentially damage
the critical area. Replacement trees shall be species that are native and indigenous to the site and
3
Tree assessment — Newcom
19917 Olympic View Dr., Edmonds, WA
4/9/2021
a minimum of one to two inches in diameter at breast height (dbh) for deciduous trees and a
minimum of six feet in height for evergreen trees as measured from the top of the root ball..."
(recommendations for replanting two new trees are included below)
There are no tree species indigenous to the PNW that grow in small stature appropriate to plant
on the sloped site. There are however cultivars of native trees bred to stay small and a plethora
of ornamental trees and shrubs that do stay short. A mix of native and non-native species of
small trees and shrubs would work well to fill in spaces behind (east of) where the maple is
growing. Appropriate native species include but are not limited to:
Shrubs
• Low Oregon Grape, Mahonia nervosa
• Creeping Oregon Grape, Mahonia repens
• Pacific Wax Myrtle, Morella californica
• Salal, Gaultheria shallon
• Evergreen Huckleberry, Vaccinium ovatum
• Rhododendron
Trees
• Vine maple, Acer circinatum
• Strawberry tree (small cultivars)
• Western red cedar (small cultivars)
• Weeping Alaska cedar (Chamaecyparis nootkatensis 'Pendula')
The best time to plant new trees is fall so they can establish with the assistance of cooler weather
and added rain water. Surround new plantings with coarse woody mulch (not bark only mulch)
up to three inches deep. Mulch can assist in keeping the root zone cool, moist and weed free.
Add supplemental water by deep soaking after planting for up to one year, especially in warmer
summer months.
Thank you very much for calling me for your arboricultural concerns.
Katy Bigelow
Board Master Certified Arborist
PNW ISA member # PN-6039B
Tree Risk Assessment Qualified
Registered Consulting Arborist® #490
rd
Tree assessment — Newcom
19917 Olympic View Dr., Edmonds, WA
4/9/2021
Levels of Tree Assessment
LEVEL 1: The Level 1 assessment is a visual assessment from a specified perspective of an individual
tree or a population of trees near specified targets to identify obvious defects or specified conditions. A
limited visual assessment typically focuses on identifying trees with an imminent and/or probable
likelihood of failure.
Limited visual assessments are the fastest but least thorough means of assessment and are intended
primarily for large populations of trees.
LEVEL 2: This is a basic assessment completing a detailed visual inspection of a tree and surrounding site,
and a synthesis of the information collected. This assessment requires that a tree risk assessor walk
completely around the tree —looking at the site, buttress roots, trunk, and branches.
A basic assessment may include the use of simple tools to gain additional information about the tree or
defects. Basic is the standard assessment that is performed by arborists in response to a client's request for
tree risk assessment. Simple tools may be used for measuring the tree and acquiring more information
about the tree or defects. However, the use of these tools is not mandatory unless specified in the Scope of
Work.
LEVEL 3: Advanced assessments are performed to provide detailed information about specific tree parts,
defects, targets, or site conditions. They are usually conducted in conjunction with or after a basic
assessment if the tree risk assessor needs additional information and the client approves the additional
service. Specialized equipment, data collection and analysis, and/or expertise are usually required for
advanced assessments. These assessments are therefore generally more time intensive and more
expensive.
5
Tree assessment — Newcom
19917 Olympic View Dr., Edmonds, WA
4/9/2021
Maps
41 1
19117 "01 mpic,V ew D
Edmonds WA 980� 0
i '1 1
O
•� 'ice..
Map 1 — Location of the tree shown by blue circle.
Tree assessment — Newcom
19917 Olympic View Dr., Edmonds, WA
4/9/2021
Map 2: Critical Areas shown by yellow, red and orange overlays. Tree shown by blue circle.
7
13
d061w.
Tree assessment — Newcom
19917 Olympic View Dr., Edmonds, WA
4/9/2021
Photo 2: Portion of the maple canopy poised to fail.
Tree assessment — Newcom
19917 Olympic View Dr., Edmonds, WA
4/9/2021
Assumptions, Limiting Conditions and General Waiver
I, Katy Bigelow, certify that:
I have personally inspected the tree(s) and or the property referred to in this report;
I have no current or prospective financial or other interest in the vegetation or the property which
is the subject of this report and have no personal interest or bias in favor of or against any of the
involved parties or their respective position(s), if any;
The analysis, opinions and conclusions stated herein are the product of my independent
professional judgment and based on current scientific procedures and facts, and the foregoing
report was prepared according to commercially reasonable and generally accepted arboricultural
standards and practices for the Pacific Northwest and Puget Sound areas;
The information included in this report covers only those trees that were examined and reflects
the condition of the trees as of the time and date of inspection;
This report and the opinions expressed herein are not intended, nor should they be construed, as
any type of warranty or guarantee regarding the condition of the subject trees in the future;
Covenants, Conditions, and Restrictions ("CC&Rs") may restrict the number, type and height of
vegetation on the subject property, and I have made no investigation regarding whether the
property is subject to such CC&Rs; and
To the best of my knowledge and belief, all statements and information in this report are true and
correct and information provided by others is assumed to be true and correct.
I am not an attorney or engineer. This report does not cover these areas of expertise and
represents advice only of arboricultural nature. Without limiting the generality of the preceding
sentence, it is specifically understood that nothing contained in this report is intended as legal
advice, or advice or opinions regarding soil stability or zoning laws, and this report should not be
relied upon to take the place of such advice.
Katy Bigelow
Board Master Certified Arborist
PNW ISA member # PN-6039B
Tree Risk Assessment Qualified
Registered Consulting Arborist® #490
11
ISA. Basic Tree Risk Assessment Form
Client Newcom
Address/Tree location 19117 Olympic View Dr.
Tree species bigleaf maple (Acer macrophyllum)
Assessor(s) Katy Bigelow
Date 4-7-2021
Tree no
dbh Height
Time frame Tools
Target Assessment
Time
Sheet
Crown spread dia. _
of 1
Target zone
Occupancy
M1•
r
a
3
=
v
t
2
rate
1—rare
m
c
F
Target description
d a
E
3 x
u1
z—occasional
F W
` F
F 1Z
ai
—frequent3
u>
u
4—costant
6` E
z `L
1
Newcom home
✓
✓
✓
3
no
no
2
Newcom parking area
✓
✓
✓
3
no
no
3
Neighbors parking area
✓
✓
✓
3
no
no
4
Site Factors
History of failures - Topography Flat❑ SlopeO % Aspect
Site changes None 0 Grade change ❑ Site clearing❑ Changed soil hydrology Root cuts Describe
Soil conditions Limited volume 0 Saturated ❑ Shallow Compacted ❑ Pavement over roots ❑ % Describe
Prevailing wind direction SW Common weather Strong winds ❑ Ice ❑ Snow ❑ Heavy rain ❑ Describe
Tree Health and Species Profile
Vigor Low ❑ Normal 0 High ❑ Foliage None (seasonal) ❑ None (dead) ❑ Normal % Chlorotic % Necrotic %
Pests Abiotic
Species failure profile Branches❑ Trunk❑ Roots❑ Describe
Load Factors
Wind exposure Protected ❑ Partial0 Full ❑ Wind funneling❑
Relative crown size Small ❑ Medium ❑ Large 0
Crowndensity Sparse❑ Normal❑ Dense❑ Interior branches Few[] Normal❑ Dense❑ Vines/Mistletoe/Moss❑
Recent or planned change in load factors
Tree Defects and Conditions Affecting the Likelihood of Failure
— Crown and Branches —
Unbalanced crown ❑ LCR %
Cracks ❑ Lightning damage ❑
Dead twigs/branches ❑ %overall Max. dia.
Codominant ❑ Included bark ❑
Broken/Hangers Number Max. dia.
Weak attachments ❑ Cavity/Nest hole % circ.
Over -extended branches ❑
Previous branch failures ❑ Similar branches present ❑
Pruning history
Crown cleaned ❑ Thinned ❑ Raised ❑
Dead/Missing bark ❑ Cankers/Galls/Burls ❑ Sapwood damage/decay ❑
Reduced ❑ Topped ❑ Lion -tailed ❑
Conks ❑ Heartwood decay ❑
Flush cuts ❑ Other
Response growth
Main concern(s) See report
Load on defect N/A ❑ Minor ❑ Moderate
❑ Significant ❑
Likelihood of failure Improbable ❑ Possible ❑ Probable
❑ Imminent ❑
—Trunk —
— Roots and Root Collar —
Dead/Missing bark ❑ Abnormal bark texture/color ❑
Collar buried/Not visible ❑ Depth Stem girdling ❑
Codominant stems ❑ Included bark ❑ Cracks ❑
Dead ❑ Decay ❑ Conks/Mushrooms ❑
Sapwood damage/decay ❑ Cankers/Galls/Burls ❑ Sap ooze ❑
Ooze ❑ Cavity ❑ % circ.
Lightning damage ❑ Heartwood decay Conks/Mushrooms ❑
Cracks ❑ Cut/Damaged roots ❑ Distance from trunk
Cavity/Nest hole % circ. Depth Poor taper ❑
Root plate lifting ❑ Soil weakness ❑
Lean ° Corrected?
Response growth
Response growth
Main concern(s) See report
Main concern(s) Limited soil area
Load on defect N/A ❑ Minor ❑ Moderate ❑ Significant ❑ Load on defect N/A ❑ Minor ❑ Moderate ❑ Significant ❑
Likelihood of failure
Likelihood of failure
Improbable ❑ Possible ❑ Probable ❑ Imminent ❑'KImprobable
❑ Possible ❑ Probable ❑ Imminent ❑
Page I of 2
Risk Categorization
Likelihood
-0
E
u
a)
-0
Consequences
Failure
Impact
Failure & Impact
(from Matrix 1)
c
N
+°
Risk
rating
s
„
a
c
Conditions
L
°
°'
uLa
Tar et
g
o
a
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of part
(from
c°�
Tree part
of concern
a
LL
protection
£
a
a
>
°
_
°
>
z
0
0
Matrix 2)
Structural
rot under their
00O00
0
0000000
high
1
branches
attachments, see
report
0I0I00
00�0
00I00
0000
00000000
00
000
0000
O
00
00
000
0000
0000
O
000
2
00000
0
000
0000
0000
000
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3
0000
0000
000000,00
0000010000000
0000
010100
001010
00
0
0000
000001000
000
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4
010100
O
00
0100
000
Matrix I. Likelihood matrix.
Likelihood
of Failure
Likelihood of Impacting Target
Very low
Low
Medium
High
Imminent
Unlikely
Somewhat likely
Likely
Very likely
Probable
Unlikely
Unlikely
Somewhat likely
Likely
Possible
Unlikely
Unlikely
Unlikely
Somewhat likely
Improbable
Unlikely
Unlikely
Unlikely
Unlikely
Matrix2. Risk rating matrix.
Likelihood of
Failure & Impact
Consequences of Failure
Negligible
Minor
Significant
Severe
Very likely
Low
Moderate
High
Extreme
Likely
Low
Moderate
High
High
Somewhat likely
Low
Low
Moderate
Moderate
Unlikely
Low
Low
Low
Low
Notes, explanations, descriptions
See report
Mitigation options Create a short habitat trunk or cut to a stump. See report for details.
Overall tree risk rating
Overall residual risk
Low ❑ Moderate ❑ High 0 Extreme ❑
Low 0 Moderate ❑ High ❑ Extreme ❑
North
Residual risk low
Residual risk
Residual risk
Residual risk
Work priority 1 0 20 30 40
Recommended inspection interval none
Data M Final ❑ Preliminary Advanced assessment needed ❑No ❑Yes-Type/Reason
Inspection limitations ONone ❑Visibility ❑Access ❑Vines ❑Root collar buried Describe
This datasheet was produced by the International Society of Arboriculture (ISA) and is intended for use by Tree Risk Assessment Qualified (TRAQ) arborists — 2013
Page 2 of 2