HomeMy WebLinkAboutRS_Arborist_Report_180928_v1.pdfPage 1 of 23
Maple Highlands
September 20, 2018
Chris Burrus
Jamie Waltier
Harbour Homes, LLC
400 N 34th St., Suite 300
Seattle, WA 98103
Site: Maple Highlands
16210 SE 134th St
Renton, WA 98056
TPN: 1457500025
181,209 sq. ft. = 4.2 acres
Dear Chris:
Thank you for requesting my services. On July 2, 2018, I performed a Visual Risk Assessment (VRA)
for all the significant* trees growing on the site above, as well as the offsite and ROW trees with
canopies that included coverage on the property.
The information gathered and included in this report is a necessary part of the of the redevelopment
process which requires that a Tree Retention Plan to be submitted as part of a proposed site
development (RMC 4.4.130).
In summary:
Tree Density Calculations
Total number of onsite trees 26
Total number of exempt trees 17
Total number of viable trees 9
Required number of retained trees (.3 X9) 3
Number of required replacement trees (3 X 12") 36"
Number of 2" caliper replacement trees (36"/2") 18
Minimum Tree density 2/5000 sq. ft. - existing trees 51
I have included a detailed report of my findings, if you have any questions please contact me. I can be
reached on my cell phone: 425.890.3808 or by email: sprince202@aol.com.
Warm regards,
Susan Prince
Creative Landscape Solutions
ISA Certified Arborist #1481
TRAQ Certified Arborist #481
Landscape Designer
425.890.3808
*A “significant” tree is a tree with a caliper of at least 6” or an alder or cottonwood trees with a caliper
of at least 8”. Trees planted within the most recent 10 years qualify as significant regardless of
caliper. A “landmark” tree is a tree with a caliper of at least 30”. (RMC 4.11.200)
Page 2 of 23
Maple Highlands
Personal qualifications, scope of work and methodology:
To evaluate the trees and prepare the report, I drew on my formal college education in botany and the
preparation and training used to obtain my ISA certification. In addition to my education and
certification, I relied heavily on my training to obtain my certification as a Tree Risk Assessor. I have
been worked in arboriculture since 1995 and been an ISA Certified Arborist since 1999. I have been
TRACE/TRAQ qualified since 2009.
I followed protocol delineated by the International Society of Arboriculture (ISA) for Visual Risk
Assessment (VRA). By doing so, I am examining each tree independently as well as collectively as
groups or stands of trees provide stability and can lower risk of independent tree failure. This scientific
process examines tree health (e.g. size, vigor, and insect and disease process) as well as site
conditions (soil moisture and composition, quantity of impervious surfaces surrounding the tree etc.)
Introduction:
Identifying and managing the risks associated with trees is still largely a subjective process. Since the
exact nature of tree failures remains largely unknown, our ability as scientists and arborists to predict
which trees will fail and in what fashion remains limited. As currently practiced, the science of hazard
tree evaluation involves examining a tree for structural defects, including genetic problems, those
caused by the local environmental that the tree grows in and those attributed to man (pruning etc.).
The assessment process involves evaluating three components: 1) a tree with the potential to fail, 2)
an environment that may contribute to that failure, and 3) a person or object that would be injured or
damaged (the target). A defective tree cannot be considered hazardous without the presence of a
target.
All trees have a finite life-span though it is not pre-programmed internally in the same manner as
annual plantings. As trees age, they are less able to compartmentalize structural damage following
injury from insects, disease or pruning. Trees in urban settings have a shorter life span than trees
grown in an undisturbed habitat.
Each species of trees grows differently. Evergreen trees have a “reputation” of growing slowly and
defensively. These trees allocate a high proportion of their resources to defending themselves from
pathogens, parasites and wounds. As a rule, trees with this type of growth tend to be long lived.
Though like all other living things, they have a predictable life span. Examples of this type of tree
include the northwest Pseudotsuga menziesii - Douglas fir, and Thuja plicata - Western red cedar.
Deciduous trees are trees that annually shed leaves or needles. These trees tend to grow quickly and
try to “outgrow” problems associated with insects, disease and wounds. They allocate a relatively
small portion of their internal resources to defense and rely instead upon an ability to grow more
quickly than the pathogens which infect them. However, as these trees age, their growth rate
declines and the normal problems associated with decay begins to catch up and compromise the tree’s
structural integrity. Examples of this type of tree include Salix, Populus and Alnus.
Knowledge of the growth and failure patterns of individual tree species is critical to effective hazard
analysis. Species vary widely in their rates of failure. The hazard tree evaluation rating system used
by most arborists was developed by the Colorado Urban Forest Council and recognizes this variation i n
species failure and includes a species component as part of the overall hazard evaluation.
Page 3 of 23
Maple Highlands
Method’s used to determine tree location and tree health:
Trees were identified previously by numbered aluminum tags attached to the western side of the tree.
All the trees on site were examined using the Matheny and Clark1 criteria for determining the potential
hazard of trees in an urban environment as well as the Tree Risk Assessment in Urban Areas and The
Urban/Rural Interface by Julian Dunster2. Tree diameters were measured using a logger’s tape, and
tree driplines were measured in four directions if necessary by a Nikon Forestry PRO Laser
RangefinderTM.
ABBREVIATED LEGEND- SEE REPORT FOR GREATER DETAIL
1. Numerical ordering
2. Tree tag #: numbered aluminum tags attached to the trees in the field
3. Tree species ID: common and botanical names
Apple: Malus sp.
American sycamore: Plantanus
occidentalis
Austrian pine: Pinus nigra
Bigleaf maple: Acer macrophyllum
Birch: Betula nigra
Bitter Cherry: Prunus emarginata
Blue atlas cedar: Cedrus atlantica
‘Glauca’
Cedar: Thuja plicata
Cherry: Prunus sp.
Dawn redwood: Chamaecyparis
nootkatensis
Deodora cedar: Cedrus deodara
Colorado blue spruce: Picea
pungens
Cottonwood: Populus trichocarpa
Dogwood: Cornus nuttallii
Douglas fir: Pseudotsuga menziesii
English laurel: Prunus laurocerasus
Filbert: Corylus avellana var.
Grand fir: Abies grandis
Hemlock: Tsuga hetrophylla
Holly: Ilex aquifolium
Japanese maple: Acer palmatum
Leylandii cypress: Cupressocyparis
leylandii
Lodgepole pine: Pinus contorta
Mountain ash: Sorbus americana
Mountain hemlock: Tsuga
mertensiana
Pear: Pyrus sp.
Plum: Prunus
Red Alder: Alnus rubra
Red maple: Acer rubrum
Walnut: Juglans sp.
Western red cedar: Thuja plicata
Weeping Alaska cedar:
Metasequoia glyptostrobides
White pine: Pinus strobus
4. DBH: diameter of the tree measured in inches at 4’ above grade
5. Adj. DBH: multiple trunk tree DBH in inches calculated per municipality directives
6. Dripline Radius: measurement in feet of the tree canopy from tree trunk to outermost branch
tip via laser rangefinder
7. Windfirm: whether the tree is not protected by other structures of trees remains windfirm
8. Health: a measurement of overall tree vigor and vitality rated as excellent, good, OK, fair or
poor based on an assessment of crown density, leaf color and size, active callusing, shoot
growth rate, extent of crown dieback, cambium layer health, and tree age
Excellent: Tree is an ideal specimen for the species with no obvious flaws
Good: Tree has minimal structural or situational defects
OK: Minimal structural issues with poor
Fair: Tree has structural or health issues that predispose it to failure if further stressed
but can be retained in a grove of 3 or more trees
Poor: Tree has significant structural and/or health issues. It is exempt from total tree
count.
9. Defects/Concerns: a measure of the tree’s structural stability and failure potential based on
assessment of specific structural features, e.g., decay, conks, co-dominant trunks, included
bark, abnormal lean, one-sided canopy, history of failure, prior construction impact, pruning
history, etc.
10. Proposed actions:
Retain
Remove due to viability
Page 4 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
Remove due to planned development (tree is otherwise healthy)
11. Limits of disturbance/Tree protection zone: the area surrounding the tree that defines the
area that surrounds the trunk that cannot be encroached upon during construction. This may
be a multiple of the trunk diameter (1 -1.5 times the trunk diameter converted to feet) or it
may be related to the width of the canopy. It is always determined by tree species and
environment and is up to the discretion of the ISA Certified Arborist to determine
12. Measure of tree “value” may be determined by municipality formula or a direct measure of the
trunk diameter, or a numerical count to determine significance; for the city of Renton
significant trees are counted numerically
Page 5 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
Specific Tree Observations:
1 2 3 4 5 6 7 8 9 10 11
#
Tree
Tag
#
Species ID DBH
(in)
Adj.
DBH
(in)
Drip-
line
radius
(ft)
Wind-
firm
OK in
grove Health Defects/Comments
Proposed
Action
CRZ/TPZ/LOD
Radius in feet
Ret Remove
N W E S Viable Non-viable Remove 1 1802 Apple 8, 7,
4, 9 14.5 14 Fair
Woodpecker activity,
carpenter ants, poor
pruning with decay,
moss and lichen, dead
wood, co-dominant
leaders with included
bark x4 @ 3'
1 14 14 14 14
2 1805 Apple 4, 5,
3, 5 8.5 10 Fair
Co-dominant leaders
with included bark x4 @
3', decay @ root crown
up to 1' towards south,
carpenter ants, moss
and lichen, poor
pruning with decay
1 10 10 10 10
3 1806 Apple 3, 4,
6, 7 10.5 12 OK
Moss and lichen, poor
pruning with decay, co-
dominant leaders with
included bark x4 @ 3',
typical of species
1 12 12 12 12
4 1807 Apple 8,
10 13 12 OK
Co-dominant leaders
with included bark x2 @
3', moss and lichen,
poor pruning with
decay, typical of species
1 12 12 12 12
Page 6 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
1 2 3 4 5 6 7 8 9 10 11
#
Tree
Tag
#
Species ID DBH
(in)
Adj.
DBH
(in)
Drip-
line
radius
(ft)
Wind-
firm
OK in
grove Health Defects/Comments
Proposed
Action
CRZ/TPZ/LOD
Radius in feet
Ret Remove
N W E S Viable Non-viable Remove 5 1808 Apple 10,
12 15.5 20 OK
Carpenter ants,
woodpecker activity,
co-dominant leaders
with included bark x2 @
3', moss and lichen,
poor pruning with
decay, typical of species
1 20 20 20 20
6 1813 Bigleaf
maple 13 13 18 OK
Slight lean towards
north, asymmetric
canopy towards west,
suppressed canopy,
typical of species, moss
and lichen
1 18 18 18 18
7 1818 Dogwood 7, 7,
8 12.5 12 Fair
Co-dominant leaders
with included bark x3 @
root crown, vertical
crack @ root crown up
to 6' towards south,
poor pruning with
decay, dead scaffolds,
buried in black berries
1 12 12 12 12
8 1819 River birch
16,
15,
14
26 21 Poor
Co-dominant leaders
with included bark x3 @
root crown, typical of
species, dead scaffolds,
previous top loss,
woodpecker activity
1 21 21 21 21
Page 7 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
1 2 3 4 5 6 7 8 9 10 11
#
Tree
Tag
#
Species ID DBH
(in)
Adj.
DBH
(in)
Drip-
line
radius
(ft)
Wind-
firm
OK in
grove Health Defects/Comments
Proposed
Action
CRZ/TPZ/LOD
Radius in feet
Ret Remove
N W E S Viable Non-viable Remove 9 1820 Japanese
maple
14,
8,
14,
10,
8,
10,
6,
12,
5
30.5 20 Fair
Co-dominant leaders
with included bark x9 @
root crown, moss and
lichen, several vertical
cracks towards north,
typical of species, moss
and lichen, thin canopy
1 20 20 20 20
10 1821 Japanese
maple
5, 6,
4, 2,
4, 3,
3, 2
11 16 Fair
Co-dominant leaders
with included bark x8 @
root crown, vertical
cracks @ 2' up to 4'
towards south, poor
pruning with decay
1 16 16 16 16
11 1822 Dogwood 5, 5,
5, 4 9.5 16 Fair
Co-dominant leaders
with included bark x4@
2', moss and lichen,
poor pruning with
decay, anthracnose
1 16 16 16 16
12 1824 Apple 8 8 15 Fair
Poor pruning with
decay, moss and lichen,
lean towards east
1 15 15 15 15
13 1825 Apple
4, 8,
7, 8,
10
17 14 Poor
Large cavity @ root
crown up to 3' towards
east, moss and lichen,
poor pruning with
decay, co-dominant
leaders with included
bark x5 @ 4'
1 14 14 14 14
Page 8 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
1 2 3 4 5 6 7 8 9 10 11
#
Tree
Tag
#
Species ID DBH
(in)
Adj.
DBH
(in)
Drip-
line
radius
(ft)
Wind-
firm
OK in
grove Health Defects/Comments
Proposed
Action
CRZ/TPZ/LOD
Radius in feet
Ret Remove
N W E S Viable Non-viable Remove 14 1826 Apple 7,
10 12 16 Poor
Co-dominant leaders
with included bark x2 @
3', dead scaffolds, dead
wood, moss and lichen,
carpenter ants,
woodpecker activity
1 16 16 16 16
15 1827 Douglas fir 40 40 20 OK
Free flowing sap,
epicormic branch
formation, asymmetric
canopy towards
southwest, hanger,
dead wood, dominant
canopy, typical of
species
1 20 20 20 20
16 1828 Cottonwood 30 30 24 Fair
Low live crown ratio <
30%, sway towards
west, co-dominant
canopy, typical of
species
1 24 24 24 24
17 1829 Cottonwood 40 40 18 Fair
Moss and lichen,
dominant canopy, dead
wood, broken branches,
typical of species
1 18 18 18 18
18 1832 Douglas fir 36 36 16 Fair
Free flowing sap,
hanger, co-dominant
canopy, previous top
loss, elongated
branches
1 16 16 16 16
Page 9 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
1 2 3 4 5 6 7 8 9 10 11
#
Tree
Tag
#
Species ID DBH
(in)
Adj.
DBH
(in)
Drip-
line
radius
(ft)
Wind-
firm
OK in
grove Health Defects/Comments
Proposed
Action
CRZ/TPZ/LOD
Radius in feet
Ret Remove
N W E S Viable Non-viable Remove 19 1833 Douglas fir 14 14 14 Poor
Previous top loss, dead
top @ 60', suppressed
canopy, free flowing
sap, calloused wound @
root crown up to 3'
towards north, dead
wood, broken branches,
dead twigs
1 14 14 14 14
20 1834 Douglas fir 36 36 16 OK
Sway towards west, co-
dominant canopy, low
live crown ratio < 30%,
hanger, dead wood,
broken branches,
typical of species
1 16 16 16 16
21 1835 Douglas fir 18 18 14 OK
Lean towards south,
asymmetric canopy
towards south,
suppressed canopy,
typical of species,
broken branches, dead
wood
1 14 14 14 14
Page 10 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
1 2 3 4 5 6 7 8 9 10 11
#
Tree
Tag
#
Species ID DBH
(in)
Adj.
DBH
(in)
Drip-
line
radius
(ft)
Wind-
firm
OK in
grove Health Defects/Comments
Proposed
Action
CRZ/TPZ/LOD
Radius in feet
Ret Remove
N W E S Viable Non-viable Remove 22 1836 Bigleaf
maple 60 60 30 Poor
Co-dominant leaders
with included bark x4 @
6', large cavity @ root
crown up to 3' towards
south, carpenter ants,
woodpecker activity,
calloused wound @ 3'
towards south, dead
wood, typical of
species, hypoxylon
canker, vertical crack @
6' up to 12' towards
west, cavity @ root
crown up to 3' towards
west
1 30 30 30 30
23 1837 Cottonwood 38 38 26 Fair
Co-dominant canopy,
ivy @ root crown up to
70', low live crown ratio
< 10%, lean towards
west
1 26 26 26 26
24 1838 Cottonwood 44 44 22 Fair
Exposed roots, column
of decay @ root crown
up to 2' towards west,
carpenter ants,
woodpecker activity,
typical of species
1 22 22 22 22
25 1864 Hemlock 8 8 10 Y Fair
Nurse tree, tag on
branch, co-dominant
leaders with included
bark x2 @ 8', typical of
species
1 10 10 10 10
Page 11 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
1 2 3 4 5 6 7 8 9 10 11
#
Tree
Tag
#
Species ID DBH
(in)
Adj.
DBH
(in)
Drip-
line
radius
(ft)
Wind-
firm
OK in
grove Health Defects/Comments
Proposed
Action
CRZ/TPZ/LOD
Radius in feet
Ret Remove
N W E S Viable Non-viable Remove 26 1866 Douglas fir 37 37
16
over
fence
OK Typical of species 1 16 16 16 16
4 17 5
Offsite potentially impacted trees:
1 2 3 4 5 6 7 8 9 10 11
#
Tree
Tag
#
Species ID DBH
(in)
Adj.
DBH
(in)
Drip-
line
radius
(ft)
Wind-
firm
OK in
grove Health Defects/Comments
Proposed
Action
CRZ/TPZ/LOD
Radius in feet
Ret Remove
N W E S Viable Non-viable Remove 1 1801 Ornamental
pear
15,
7, 6 17.5 12 Poor
Conk, co-dominant
leaders with included
bark x3 @ root crown,
decay @ root crown,
carpenter ants,
woodpecker activity,
poor pruning with
decay, dead scaffolds
1 12 12 12 12
2 1803 Austrian
pine
11,
6 12.5 10 Fair
Co-dominant leaders
with included bark x2 @
3', poor pruning with
decay, fused trunk, free
flowing sap, decay @
root crown
1 10 10 10 10
Page 12 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
1 2 3 4 5 6 7 8 9 10 11
#
Tree
Tag
#
Species ID DBH
(in)
Adj.
DBH
(in)
Drip-
line
radius
(ft)
Wind-
firm
OK in
grove Health Defects/Comments
Proposed
Action
CRZ/TPZ/LOD
Radius in feet
Ret Remove
N W E S Viable Non-viable Remove 3 1804 Douglas fir 26 26 18 Y Fair
Exposed roots, poor
pruning with decay,
broken branches, dead
wood, co-dominant
leaders with included
bark x2 @ 20', twisted
trunks
1 18 18 18 18
4 1809 Red alder 7, 7,
9 13.5 12 OK
Co-dominant leaders
with included bark x3 @
root crown, nurse tree,
typical of species
1 12 12 12 12
5 1817 Apple 8, 4 7 10 Fair
Carpenter ants,
woodpecker activity,
broken branches, dead
wood, poor pruning
with decay, cavity @
root crown up to 1'
towards south, co-
dominant leaders with
included bark x2 @ 4'
1 10 10 10 10
6 1823 Cherry 6 6 16 Fair
Serpentine trunk, moss
and lichen, poor
pruning with decay
1 16 16 16 16
7 1830 Douglas fir 28 28 18 OK
Free flowing sap from
small crack @ 3'
towards south, co-
dominant canopy, dead
wood, broken branches,
typical of species
1 18 18 18 18
Page 13 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
1 2 3 4 5 6 7 8 9 10 11
#
Tree
Tag
#
Species ID DBH
(in)
Adj.
DBH
(in)
Drip-
line
radius
(ft)
Wind-
firm
OK in
grove Health Defects/Comments
Proposed
Action
CRZ/TPZ/LOD
Radius in feet
Ret Remove
N W E S Viable Non-viable Remove 8 1831 Douglas fir 36 36 18 Fair
Nailed on post, hanger,
carpenter ants, free
flowing sap, abnormal
bark, shedding bark,
popping bark, coning,
dead twigs
1 18 18 18 18
9 1839 Red alder 14 14 17 Poor
Lean towards west,
decay @ 8' up to 12
towards west
1 17 17 17 17
10 1840 Douglas fir 44 44 18 OK Typical of species, thin
canopy 1 18 18 18 18
11 1841 Red alder 17 17 18 Poor
Sway towards east,
moss and lichen,
previous top loss
1 18 18 18 18
12 1842 Red alder 16 16 12 Poor
Previous top loss @ 20',
weak laterals, moss and
lichen, decay @ root
crown up to 4'
1 12 12 12 12
13 1843 Scouler
willow 16 16 16 Poor
Mostly dead, decay @
root crown up to 6'
towards south, co-
dominant leaders with
included bark x2 @ 6',
dead trunks, carpenter
ants, woodpecker
activity
1 16 16 16 16
14 1844 Cottonwood 38 38 18 OK
Moss and lichen, co-
dominant canopy,
asymmetric canopy
towards east, typical of
species
1 18 18 18 18
Page 14 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
1 2 3 4 5 6 7 8 9 10 11
#
Tree
Tag
#
Species ID DBH
(in)
Adj.
DBH
(in)
Drip-
line
radius
(ft)
Wind-
firm
OK in
grove Health Defects/Comments
Proposed
Action
CRZ/TPZ/LOD
Radius in feet
Ret Remove
N W E S Viable Non-viable Remove 15 1845 Cottonwood 41 41 18 Fair
Exposed roots, co-
dominant canopy,
vertical crack @ root
crown up to 3' towards
south, moss and lichen,
typical of species
1 18 18 18 18
16 1846 Cottonwood 14 14 17 Fair
Previous top loss, dead
wood, lean towards
east, typical of species
1 17 17 17 17
17 1847 Cottonwood 42 42 17 OK
Co-dominant canopy,
asymmetric canopy
towards west, moss and
lichen, typical of species
1 17 17 17 17
18 1848 Cottonwood 12 12 14 Fair
Moss and lichen lean
towards east, exposed
roots, no taper
1 14 14 14 14
19 1849 Cottonwood 36 36 18 Fair
Moss and lichen, decay
@ root crown, lean
towards north
1 18 18 18 18
20 1850 Scouler
willow 8 8 12 Poor
Failing to north, mostly
dead, carpenter ants,
woodpecker activity
1 12 12 12 12
21 1851 Scouler
willow 10 10 9 Poor Low live crown ratio <
15%, mostly dead 1 9 9 9 9
22 1852 Red alder 12,
4 12.5 10 Poor
Previous top loss, co-
dominant leaders with
included bark x2 @ root
crown, co-dominant
leaders with included
bark x4 @ 20', twisted
trunk
1 10 10 10 10
Page 15 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
1 2 3 4 5 6 7 8 9 10 11
#
Tree
Tag
#
Species ID DBH
(in)
Adj.
DBH
(in)
Drip-
line
radius
(ft)
Wind-
firm
OK in
grove Health Defects/Comments
Proposed
Action
CRZ/TPZ/LOD
Radius in feet
Ret Remove
N W E S Viable Non-viable Remove 23 1853 Red alder 8,
10 13 10 Poor
Co-dominant leaders
with included bark x2 @
root crown, dead top,
previous top loss @ 30'
1 10 10 10 10
24 1854 Red alder
18,
16,
6
25 16 Poor
Co-dominant leaders
with included bark x3 @
root crown, co-
dominant leaders with
included bark x6 @ 8',
moss and lichen, dead
wood, mostly dead,
dead scaffolds
1 16 16 16 16
25 1855 Red alder 8 8 14 Fair
Moss and lichen,
asymmetric canopy
towards east, lean
towards east, typical of
species
1 14 14 14 14
26 1856 Red alder 16 16 16 Fair
Moss and lichen,
dominant canopy,
twisted trunks, dead
top
1 16 16 16 16
27 1857 Scouler
willow
14,
22 26 19 Poor
Co-dominant leaders
with included bark x2 @
root crown, moss and
lichen, dead wood,
broken branches,
mostly dead
1 19 19 19 19
28 1858 Red alder 14 14 12 Poor Vertical crack @ 3' up
to 16', mostly dead 1 12 12 12 12
Page 16 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
1 2 3 4 5 6 7 8 9 10 11
#
Tree
Tag
#
Species ID DBH
(in)
Adj.
DBH
(in)
Drip-
line
radius
(ft)
Wind-
firm
OK in
grove Health Defects/Comments
Proposed
Action
CRZ/TPZ/LOD
Radius in feet
Ret Remove
N W E S Viable Non-viable Remove 29 1859 Red alder 6, 8 10 14 Poor
Co-dominant leaders
with included bark x2 @
3', previous top loss,
suppressed canopy,
dead wood, dead top,
decay throughout
1 14 14 14 14
30 1860 Red alder 12 12 20 Poor Failing towards north 1 20 20 20 20
31 1861 Scouler
willow
36,
12 38 24 Poor
Co-dominant leaders
with included bark x2 @
root crown, large cavity
of decay throughout
tree, dead wood, moss
and lichen
1 24 24 24 24
32 1862 Poplar 18,
13 22 10 Fair Typical of species 1 10 10 10 10
33 1863 Douglas fir 16 16 17 OK
Dead wood, broken
branches, typical of
species
1 17 17 17 17
34 1865 Douglas fir 36 36
10
over
fence
OK Typical of species 1 10 10 10 10
35 1867 Douglas fir 28 28
12
over
fence
OK
Typical of species, dead
wood, broken branches,
asymmetric canopy
towards west, typical of
species
1 12 12 12 12
36 1868 Red alder 10 8 8 Y Fair Typical of species 1 8 8 8 8
4 28 4
Page 17 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
Site:
Proposed site improvements:
Page 18 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
Discussion and Conclusion:
Tree Density Calculations
Total number of onsite trees 26
Total number of exempt trees 17
Total number of viable trees 9
Required number of retained trees (.3 X9) 3
Number of required replacement trees (3 X 12") 36"
Number of 2" caliper replacement trees (36"/2") 18
Minimum Tree density 2/5000 sq. ft. - existing trees 51
Lot Area Table
Lot Lot area (sq.
ft)
# of
Trees of
trees
required/
5,000
sq. ft
Minus
the # of
existing
trees
Total #
of
replace-
ment
trees
1 12,425 5 5
2 10,510 4 4
3 10,208 4 4
4 9,906 4 1 3
5 9,604 4 4
6 9,302 4 4
7 9,000 4 4
8 9,868 4 4
9 10,035 4 4
10 9,742 4 4
11 9,449 4 4
12 9,122 4 4
13 15,198 6 6
Tract
A 6,149 3
Tract
B
Total 55 4 51
The site is currently referred to as “Maple Highlands”. There is a total of 26 trees onsite; nine (9) are
viable; five (5) are proposed to be removed and four (4) are proposed to be retained.
The City of Renton requires a 30% tree retention for zoning R-4, or 9 *.3 = 3 trees. The proposed
improvements meet the city standards.
Mitigation:
The required mitigation for the removal of viable onsite trees is 36”. The minimum caliper tree
acceptable per the RMC is a 2” caliper, eight (8) 2” caliper trees meets the requirement, or 18 trees.
In addition, the City requires a minimum tree density of 2 trees/ 5000 sq. ft. The table above shows
the lot requirements to meet this density. The mitigation is 51 trees.
DEPARTMENT OF COMMUNITY
AND ECONOMIC DEVELOPMENT
TREE RETENTION WORKSHEET
Planning Division
1055 South Grady Way-Renton, WA 98057
Phone: 425-430-7200 | www.rentonwa.gov
1.Total number of trees over 6” diameter 1, or alder or cottonwood
trees at least 8” in diameter on project site trees
2.Deductions: Certain trees are excluded from the retention calculation:
Trees that are dangerous 2 trees
Trees in proposed public streets trees
Trees in proposed private access easements/tracts trees
Trees in critical areas3 and buffers trees
Total number of excluded trees: trees
3.Subtract line 2 from line 1:trees
4.Next, to determine the number of trees that must be retained 4, multiply line 3 by:
0.3 in zones RC, R-1, R-4, R-6 or R-8
0.2 in all other residential zones
0.1 in all commercial and industrial zones trees
5.List the number of 6” in diameter, or alder or cottonwood trees
over 8” in diameter that you are proposing5 to retain4:trees
6.Subtract line 5 from line 4 for trees to be replaced:
(if line 6 is zero or less, stop here. No replacement trees are required) trees
7.Multiply line 6 by 12” for number of required replacement inches:inches
8.Proposed size of trees to meet additional planting requirement:
(Minimum 2” caliper trees required for replacement, otherwise enter 0)inches per tree
9.Divide line 7 by line 8 for number of replacement trees 6:
(If remainder is .5 or greater, round up to the next whole number) trees
1 Measured at 4.5’ above grade.
2 A tree certified, in a written report, as dead, terminally diseased, damaged, or otherwise dangerous to persons or property by a licensed
landscape architect, or certified arborist, and approved by the City.
3 Critical areas, such as wetlands, streams, floodplains and protected slopes, are defined in RMC 4-3-050.
4 Count only those trees to be retained outside of critical areas and buffers.
5 The City may require modification of the tree retention plan to ensure retention of the maximum number of trees per RMC 4-4-130H7a.
6 When the required number of protected trees cannot be retained, replacement trees, with at least a two-inch (2") caliper or an evergreen at least
six feet (6') tall, shall be planted. See RMC 4-4-130.H.1.e.(ii) for prohibited types of replacement trees.
1
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Page 20 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
Glossary:
ANSI A300: American National Standards Institute (ANSI) standards for tree care
Chlorotic: discoloration caused by lack of chlorophyll in the foliage
Conifer: A tree that bears cones and has evergreen needles or scales
Crown: the above ground portion of the tree comprised of branches and their foliage
Crown raise pruning: a pruning technique where the lower branches are removed, thus raising the
overall height of the crown from the ground
DBH or DSH: diameter at breast or standard height; the diameter of the trunk measured 54 inches
(4.5 feet) above grade
Deciduous: tree or other plant that loses its leaves annually and remains leafless generally during the
cold season
Epicormic: arising from latent or adventitious buds
Evergreen: tree or plant that keeps its needles or leaves year-round; this means for more than one
growing season
Increment: the amount of new wood fiber added to a tree in each period, normally one year.
ISA: International Society of Arboriculture
Landscape function: the environmental, aesthetic, or architectural functions that a plant can have
Lateral: secondary or subordinate branch
Limits of disturbance: The boundary of minimum protection around a tree, the area that cannot be
encroached upon without possible permanent damage to the tree. It is a distance determined
by a qualified professional and is based on the age of the tree, its health, the tree species
tolerance to disruption and the type of disturbance. It also considers soil and environmental
condition and previous impacts. It is unique to each tree in its location.
Limited visual assessment: a visual assessment from a specified perspective such as foot, vehicle, or
aerial (airborne) patrol of an individual tree or a population of trees near specified targets to
identify specified conditions or obvious defects (ISA 2013)
Live crown ratio: the percentage of living tissue in the canopy versus the tree’s height. It is a good
indicator of overall tree health and the trees growing conditions. Trees with less than a 30%
Crown ratio often lack the necessary quantity of photosynthetic material necessary to sustain
the roots; consequently, the tree may exhibit low vigor and poor health.
Monitoring: keeping a close watch; performing regular checks or inspections
Owner/manager: the person or entity responsible for tree management or the controlling authorit y
that regulates tree management
Pathogen: causal agent of disease
Phototropic growth: growth toward light source or stimulant
ROW: Right-of-way; generally referring to a tree that is located offsite on a city easement
Page 21 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
Reaction wood: Specialized secondary xylem which develops in response to a lean or similar
mechanical stress, it serves to help restore the stem to a vertical position
Self-corrected lean: a tree whose trunk is at an angle to the grade but whose trunk and canopy
changes to become upright/vertical
Significant tree: a tree measuring a specific diameter determined by the municipality the tree grows
in. Some municipalities deem that only healthy trees can be significant, other municipalities
consider both healthy and unhealthy trees of a determined diameter to be significant
Snag: a tree left partially standing for the primary purpose of providing habitat for wildlife
Soil structure: the size of particles and their arrangement; considers the soil, water, and air space
Sounding: process of striking a tree with a mallet or other appropriate tool and listening for tones that
indicate dead bark, a thin layer of wood outside a cavity, or cracks in wood
Structural defects: flaws, decay, or other faults in the trunk, branches, or root collar of a tree, which
may lead to failure; may be genetic, or environmental
Tree credit: A number assigned to a tree by a municipality that may be equal to the diameter of the
tree or a numerical count of the tree, or related to diameter by a factor conveyed in a table of
the municipal code
Trunk area: the cross-sectional area of the trunk based upon measurement at 54 inches (4.5 ft.)
above grade
Visual Tree Assessment (VTA): method of evaluating structural defects and stability in trees by noting
the pattern of growth. Developed by Claus Mattheck (Harris, et al 1999) detailed visual
inspection of a tree and surrounding site that may include the use of simple tools. It requires
that a tree risk assessor walk completely around the tree trunk looking at the site,
aboveground roots, trunk, and branches (ISA 2013)
Page 22 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
References
Dirr, Michael A. Manual of Woody Landscape Plants, Their Identification, Ornamental Characteristics,
Culture, Propagation, and Uses. Champaign: Stipes Publishing Company, 1990.
Dunster & Associates Environmental Consultants Ltd. Assessing Trees in Urban Areas and the Urban-
Rural Interface. US Release 1.0. Silverton: Pacific Northwest Chapter ISA, 2006.
Dunster, J. A. 2003. Preliminary Species Profiles for Tree Failure Assessment. Bowen Island: Dunster
& Associates Environmental Consultants Ltd.
Dunster, Julian A., E. Thomas Smiley, Nelda Matheny and Sharon Lilly. Tree Risk Assessment Manual.
Champaign, Illinois: International Society of Arboriculture, 2013.
Harris, Richard W, James Clark, and Nelda Matheny. Arboriculture, Integrated Management of
Landscape Trees, Shrubs, and Vines. 4th ed. Upper Saddle River: Prentice Hall, 2004.
Lilly, Sharon. Arborists’ Certification Study Guide. Champaign, IL: The International Society of
Arboriculture, 2001.
Matheny, Nelda and Clark, James R. A Photographic Guide to the Evaluation of Hazard Trees in
Urban Areas. Second Edition. Champaign, IL: The International Society of Arboriculture,
1994.
Matheny, Nelda and Clark, James R. Trees and Development: A Technical Guide to
Preservation of Trees During Land Development. Champaign, IL: The International Society
of Arboriculture, 1998.
Mattheck, Claus and Breloer, Helge. The Body Language of Trees: A Handbook for Failure Analysis.
London: HMSO, 1994
Schwarze, Francis W.M.R. Diagnosis and Prognosis of the Development of Wood Decay in Urban Trees.
Australia: ENSPEC Pty Ltd. 2008
Sinclair, Wayne A., Lyon, Howard H., and Johnson, Warren T. Diseases of Trees and Shrubs. Ithaca,
New York: Cornell University Press, 1987.
Smiley, E. Thomas, Nelda Matheny, and Sharon Lilly, Tree Risk Assessment Best Management
Practices, ANSI A300 Part 9: Tree, Shrub, and Other Woody Plant Management—Standard
Practices (Tree Risk Assessment: Tree Structure Assessment). The International Society of
Arboriculture Press. Champaign. IL. 2011.
Thies, Walter G. and Sturrock, Rona N. Laminated root rot in Western North American. United States
Department of Agriculture. Pacific Northwest. Resource Bulletin PNW-GTR-349. April 1995.
Page 23 of 23
Maple Highlands
Susan Prince Creative Landscape Solutions 425.890.3808
ISA Certified Arborist #PNW 1481 – A sprince202@aol.com
TRAQ/TRACE Certified #481
Assumptions and Limiting Conditions
1. Any legal description provided to the consultant/appraiser is assumed to be correct. Any titles
and ownerships to any property are assumed to be good and marketable. No responsibility is
assumed for matters legal in character. Any and all property is appraised or evaluated as thou
free and clear, under responsible ownership and competent management.
2. It is assumed that any property is not in violation of any applicable codes, ordinances, statutes
or other governmental regulations.
3. Care has been taken to obtain all information from reliable sources. All data has been verified
insofar as possible; however, the consultant/appraiser can neither guarantee nor be
responsible for the accuracy of information provided by others.
4. The consultant/appraiser shall not be required to give testimony or to attend court by reason
of the report unless subsequent contractual arrangements are made including payment of an
additional fee for such services as described in the fee schedule and contract of engagement.
5. Loss or alteration of any part of this report invalidates the entire report.
6. Possession of this report or a copy thereof does not imply right of publication or use for any
purpose by any other than the person to whom it is addressed, without the prior expressed
written or verbal consent of the consultant/appraiser.
7. Neither all nor any part of the contents of the report, nor copy thereof, shall be conveyed by
anyone, including the client to the public through advertising, public relations, news, sales or
other media, without the prior expressed written or verbal consent of the consultant/appraiser
– particularly as to value conclusions, identity of the consultant/appraiser, or any reference to
any professional society or instate or to any initialed designation conferred upon the
consultant/appraiser as stated in her qualification.
8. The report and any values expressed herein represent the opinion of the consultant/appraiser,
and the consultant’s/appraiser’s fee is in no way contingent upon the reporting of a specified
value, a stipulated result, the occurrence of subsequent event, nor upon any finding to be
reported.
9. Sketches, diagrams, graphs and photographs in this report, being intended as visual aid, are
not necessarily to scale and should not be construed as engineering or architectural reports or
survey.
10. Unless expressed otherwise: 1) information contained in this report covers only those items
that were examined and reflects the condition of those items at the time of inspection; and 2:
the inspection is limited to visual examination of accessible items without dissection,
excavation, probing or coring. There is not warranty or guarantee, expressed or implied, that
problems or deficiencies of the plants or property in question may not arise in the future.