20-104332-UP-Arborist Report-11-06-2020-V2
750 Sixth Street South | Kirkland, WA 98033
P 425.822.5242 | f 425.827.8136 | watershedco.com
October 29, 2020
Stan Afichuk
29328 1st Ave S
Federal Way, WA 98003
206-708-0065
Via email: stan@greenbuilddev.com
Re: Afichuk, Tree Inventory Report
The Watershed Company Reference Number: 191123
Dear Stan:
On July 1, 2020, ISA Certified Arborist® Roen Hohlfeld visited the undeveloped property (Parcel
#7202500080) located at 1xx S 293rd Street in Federal Way, Washington 98001 to inventory
existing trees on the property. This report summarizes the findings of the study and details
applicable regulations. The following documents are enclosed:
x Tree Inventory Table
x Off-Parcel Tree Inventory Table
x Tree Retention Plan
Findings Summary
A total of 37 significant trees were inventoried on the subject property, with an additional 23
non-significant trees tallied on-site, totaling 72.5 tree credits. Twenty-one off-parcel significant
trees were included in the inventory. Federal Way Revised Code (FWRC) requires 11 tree units
to meet density requirements on this 0.43-acre parcel.
Study Area
The subject property totals approximately 0.43 acres in size and is currently undeveloped. The
site is slopes steeply down to the north, with a ravine and small stream extending north from
the southeast area of the parcel. The site is generally forested with native deciduous trees; a
disturbed area is located in the southwest portion of the property.
Tree Inventory Report
Afichuk Project
October 2020
Page 2
Proposed Project
The subject property is proposed to be developed with a single-family residence, associated site
access and landscape improvements. To achieve this, trees located in proximity to the proposed
development may be impacted. Elements of proposed improvements that may impact trees
include clearing, grading, trenching for utilities, and altered environmental factors on-site
including wind direction, sun exposure, and decreased water infiltration from impervious
surfaces.
Methods
The study area for the tree inventory includes parcel #7202500080 and significant trees rooted
within approximately 50 feet of the parcel boundary. Per Federal Way Revised Code, a
significant tree is ‘any self-supporting perennial woody plant characterized by one main stem or
trunk of at least six inches in diameter measured four and one-half feet above ground, or a
multi-stemmed trunk system with a definite crown, maturing at a height of a least 20 feet above
ground level’ (FWRC 19.05.200). Inventory methods were developed to meet the City of Federal
Way tree retention requirements.
A round one-and-one-quarter inch-wide, numbered aluminum tag was affixed to the side of the
trunk of significant trees presumed to be located on-site (tree tag #1301-1340). Off-site trees were
not tagged nor measured; rather physical attributes were estimated from the subject property.
The attributes collected during the field survey are described in Table 1, below. The database
(Tree Inventory Table) contains the data collected for each tree inventoried. General attributes
documented for all inventoried trees include the unique identification number and name of
plant species. Physical attributes include number of stems, diameter at breast height (DBH),
height, canopy radius, condition, and assessment notes. Non-significant trees (one- to six-inches
DBH) located within the driplines of significant trees also were tallied during the assessment of
significant trees.
Tree Inventory Report
Afichuk Project
October 2020
Page 3
Table 1. Attributes recorded for all inventoried vegetation and that are presented in the spreadsheet
database.
Attribute Description of Attribute
ID NUMBER Unique number assigned to an assessed tree. This number corresponds to the tag
number in the field.
SCIENTIFIC NAME Formal scientific name conforming to the International Code of Nomenclature.
COMMON NAME Name that is based on normal or common language of the Pacific Northwest.
STEMS Number of trunks or shoots that contribute significantly to the canopy.
DBH Diameter at Breast Height; or 4.5 feet from the ground surface.
HEIGHT Approximate distance from the ground surface at the trunk to the highest point of
the subject tree as visually estimated.
CANOPY RADIUS Measurement from the stem to the limits of the drip line, or end of branches.
Critical root zone.
CONDITION
Health rating of an assessed tree using a 5-tier system as follows:
1 – Excellent: No apparent problems with the tree. Form is exemplary for the
species.
2 – Good: Few minor defects such as crossed branches, minor foliage die-back,
minor trunk damage, or unbalance canopy.
3 – Fair: Several minor problems exist.
4 – Poor: Major defects visible such as significant trunk decay, codominant
leaders with included bark, significant canopy die-back, major cracks in a
stem or major limbs, and/or other structural problems. Topped trees are
generally considered poor.
5 – Dying: Tree is in a state of significant decline.
6 – Dead: Tree is dead.
In general, tree diameter was measured at four feet above the ground surface (diameter at
breast height, or “DBH”) using a graduated metal logger’s DBH tape. Trees with multiple
trunks arising from the ground were measured using methodology from Guide for Plant
Appraisal (Gooding, et al. 2000). The cross-sectional areas of stems contributing to the canopy
were summed and used to generate a singular combined DBH for the tree. The singular DBH
number allows for comparison to other single-stemmed trees and for more accurate permitting
and tree retention calculations.
Methods for measuring diameter of trees with major leans, on steep slopes, and with multiple
trunks or stems generally followed those outlined in the Guide for Plant Appraisal (Gooding, et
Tree Inventory Report
Afichuk Project
October 2020
Page 4
al. 2000). Visual estimates of trunk diameter were used where direct access to the tree was not
allowed or not feasible.
Tree data and geospatial locations were collected in the field using an iPad with ArcGIS
Collector application. Data collected in the field are summarized in the Tree Inventory Sketch
and Tree Inventory Table, attached.
Findings
Tree Inventory Results
A total of 37 significant trees are located on the subject parcel. 23 non-significant trees (one to six
inches in diameter) were tallied on-site. A total of 21 off-site trees were assessed from the parcel
boundary.
Significant tree species on the subject parcel were limited to Acer macrophyllum (bigleaf maple),
Alnus rubra (red alder), and Tsuga heterophylla (western hemlock), all native to the Pacific
northwest. The most common tree species on the subject parcel is red alder, followed by bigleaf
maple with 23 and 11 individuals, respectively.
Overall, the average DBH of significant trees located on the parcel is 16.7-inches, with 13 trees
measuring greater than 18-inches DBH. The largest tree is a bigleaf maple (#1328) with a DBH of
55.1 inches. Fourteen trees, or 38-percent of the total, were given a health rating of 4 (poor) or
worse; many of these trees have been previously topped. A summary of attributes for
significant tree species identified on-site is provided in Table 2 below.
Table 2. Summary of tree species and DBH size.
The twenty-one off-parcel significant trees included in the inventory consist of the same species
as those rooted within the subject parcel. The average DBH of these trees is approximately 19-
inches. 10 trees were estimated to have a DBH greater than 18-inches. The three largest trees, all
Tree Name Total
Inventoried
Average DBH
(In.)
Largest DBH
(In.)
Acer macrophyllum (Bigleaf maple) 11 20.7 55.1
Alnus rubra (red alder) 23 14.1 23.6
Tsuga heterophylla (Western hemlock) 3 21.7 24.6
TOTAL 37 16.7 55.1
Tree Inventory Report
Afichuk Project
October 2020
Page 5
bigleaf maples, were each estimated to have a DBH of 36 inches. Five trees were given a health
rating of 4 (poor) or worse.
Tree Retention and Removal
With the proposed site plan (provided by Urban Design Group, May 22, 2020) trees located in
proximity to the development area will be impacted to varying degrees. Table 3 summarizes
trees that are anticipated to be impacted by the proposed development as a result of disturbance
with the critical root zone (CRZ), defined as 12 inches radius for every one inch of tree diameter
measured at four and one-half feet above ground.
Table 3. Tree Impact and Removal Summary.
The proposed development area has been cited in a previously disturbed area in order to
minimize impacts to significant trees. However, implementation of the site plan will require the
removal of two trees, #1308 and #1309. Tree #1308 and #1308 are both red alders in poor (4)
condition with DBHs of 10.7-inches and 8.9-inches, respectively. These trees will be directly
impacted by construction of the single-family residence and related grading.
Tag # Tree Name Combined
DBH (In)
Height
(Ft)
Radius
(Ft) Condition Tree
Units
Proposed
for Removal
1301 Alnus rubra
(Red Alder)
11.5 60 15 2 1.5 NO
1302 Alnus rubra
(Red Alder)
10.8 60 12 2 1.5 NO
1303 Alnus rubra
(Red Alder)
13.6 60 15 2 2.0 NO
1305 Alnus rubra
(Red Alder)
9.8 60 10 4 n/a NO
1306 Alnus rubra
(Red Alder)
11.6 60 15 3 1.5 NO
1307 Alnus rubra
(Red Alder)
11.8 65 15 2 1.5 NO
1308 Alnus rubra
(Red Alder)
10.7 25 5 4 n/a YES
1309 Alnus rubra
(Red Alder)
8.9 50 12 4 n/a YES
Tree Inventory Report
Afichuk Project
October 2020
Page 6
Additionally, six trees (#1301, 1302, 1303, 1305, 1306, and 1307) are expected to receive impacts
to their critical root zones. These trees are all red alders with DBHs ranging from 9.8-inches to
13.6-inches. The trees are generally in fair to good condition, with the exception of #1305 which
has a poor (4) condition rating. It is not expected that the extent of impacts proposed within the
critical root zones of these six trees will cause their conditions to decline to a point that would
require their removal when tree protection measures are followed. No off-parcel tree impacts or
removals are anticipated.
Local Regulations
The City of Federal Way’s tree and vegetation retention standards are outlined in the Federal
Way Revised Code (FWRC), Chapter 19.120 – Clearing, Grading, and Tree and Vegetation
Retention.
The subject parcel is zoned RS9.6 – Residential and therefore requires a tree unit density of 25
tree units per acre (FWRC 19.120.130-2). To calculate the total number of tree units required, the
gross site acreage is multiplied by 25 (the required tree unit density based on land use
designation). As such, the 0.43-acre parcel requires a total of 11 tree units to meet density
requirements. Tree units must be maintained during and after development. Site development
shall consider the location of existing healthy tree stands both on-site and on adjacent
properties. Trees that are damaged, diseased, are a hazard, nuisance or invasive species shall
not count towards tree retention requirements. Tree density requirements should be met
primarily with the conservation of existing trees, however in situations where a development
design would preclude the retention requirement, replacement trees may be authorized (FWRC
19.120.130-1).
Table 4 summarizes tree unit credits for retention and replacement trees as required by Federal
Way Revised Code. Due to the high overall tree count on the forested parcel, the existing tree
unit credits currently far exceed minimum standards with 72.5 credits available (Table 5). Both
trees proposed for removal are in poor (4) condition, and therefore do not contribute tree unit
credits. As a result, the subject parcel is anticipated to maintain 72.2 tree credits during and after
construction.
Tree Inventory Report
Afichuk Project
October 2020
Page 7
Table 4. Tree unit credits (FWRC Table 19.120.130-2).
Table 5. Tree unit credit calculations.
* Trees that are damaged, diseased, are a hazard, nuisance or invasive species shall not count towards tree
retention requirements. Trees that were given a health rating of 4 (poor) or 5 (dying) are not included in the tree
unit credit calculations table.
All trees and vegetation proposed for retention shall be protected during construction according
to the standards as outlined below in FWRC 19.120.160 Tree and vegetation protection during
construction:
Existing Tree Category Tree Unit Credit
Existing Tree 1" to 6" d.b.h. 1.0 tree units per tree retained
Existing Tree > 6" to 12" d.b.h. 1.5 tree units per tree retained
Existing Tree > 12" to 18" d.b.h. 2.0 tree units per tree retained
Existing Tree > 18" to 24" d.b.h. 2.5 tree units per tree retained
Existing Tree > 24" d.b.h. 3.0 tree units per tree retained
Replacement Tree Category
Replacement Tree, Small Canopy Species (Mature
canopy area < 450 SF)
.50 tree units per tree planted
Replacement Tree, Medium Canopy Species
(Mature canopy area 450 to 1,250 SF)
1.0 tree units per tree planted
Replacement Tree, Large Canopy Species (Mature
canopy area > 1,250 SF)
1.5 tree units per tree planted
Existing Tree Category Tree Count* Tree Unit Credit
Available
Existing Tree 1" to 6" d.b.h. 23 23
Existing Tree > 6" to 12" d.b.h. 5 7.5
Existing Tree > 12" to 18" d.b.h. 9 18
Existing Tree > 18" to 24" d.b.h. 6 15
Existing Tree > 24" d.b.h. 3 9
TOTAL 46 72.5
Tree Inventory Report
Afichuk Project
October 2020
Page 8
(1) No clearing shall be allowed on a proposed development site until the tree retention and
landscape plans have been approved by the city of Federal Way.
(2) A no disturbance area shall be established for each tree to be protected. The no disturbance zone
shall be equal to the critical root zone which is defined as 12 inches radius for every one inch
of tree diameter measured at four and one-half feet above ground. Any other no disturbance
area proposed by the applicant shall be determined by a qualified arborist and subject to review
and approval by the director.
(3) The no disturbance zone shall be identified during the construction stage with:
(a) A temporary five-foot chain-link fence; and
(b) Tree protection signage attached to the fence which reads “TREE PROTECTION FENCE – No
soil disturbance, parking, storage, dumping, or burning of materials is allowed within
the Tree Protection Fence.”
(4) No soil disturbance, parking, storage, dumping, burning of materials, impervious surfaces, fill,
excavation, or storage of construction materials shall be permitted within the no disturbance
area.
(5) If the grade level around the tree is to be raised by more than one foot, a rock well shall be
constructed. The inside diameter of the rock well shall be equal to the diameter of the tree trunk
plus 10 feet. Proper drainage, and irrigation if necessary, shall be provided in all rock wells.
(6) The grade level shall not be lowered within the larger of the drip line of the tree(s) or the critical
root zone of the tree(s).
(7) No trenching is allowed in any critical tree root zone areas.
(8) No installation of any impervious surfaces is allowed in critical root zones. Where road or
sidewalk surfaces are needed within critical root zones, unmortared porous pavers or flagstone
(rather than concrete or asphalt) may be used. Boardwalks or bridging may span root zones
without harming the tree roots.
(9) Tree protection areas (i.e., critical root zone) must be prepared to better withstand the stresses
of the construction phase by, if necessary, fertilizing, pruning, and mulching around them well in
advance of beginning any construction activities.
(10) Alternative protection methods may be used if accepted by the director to provide equal or
greater tree protection.
(11) Encroachment into the no disturbance area may be allowed where the director determines
encroachment would not be detrimental to the health of the tree.
Disclaimer
The information contained in this letter is based on the application of technical guidelines
currently accepted as the best available science and in conjunction with the manuals and criteria
referenced above. All discussions, conclusions and recommendations reflect the best
professional judgment of the author(s) and are based upon information available at the time the
study was conducted. All work was completed within the constraints of budget, scope, and
timing. The findings of this report are subject to verification and agreement by the appropriate
local, state and federal regulatory authorities. No other warranty, expressed or implied, is
made.
Tree Inventory Report
Afichuk Project
October 2020
Page 9
Please call if you have any questions or if we can provide you with any additional information.
Sincerely,
Roen Hohlfeld
Ecologist / ISA Certified Arborist® PN-8562A
Enclosures
Tree Inventory Report
Afichuk Project
October 2020
Page 10
References
Council of Tree & Landscape Appraisers. 2000. Guide for Plant Appraisal, 9th Edition. Chicago:
International Society of Arboriculture.
Tree Inventory Table - Stan Afichuck
1XX S 293rd Street - Federal Way, WA
parcel # 7202500080
Table Issued: 10/29/2020
Site Visit: 7/1/2020
TAG #TREE NAME # STEMSCOMBINED DBH (IN)HEIGHT (FT)RADIUS (FT)CONDITIONNOTES
1301 Alnus rubra (Red alder)1 11.5 60 15 2
1302 Alnus rubra (Red alder)1 10.8 60 12 2
1303 Alnus rubra (Red alder)1 13.6 60 15 2
1304 Alnus rubra (Red alder)1 14.5 60 15 2
1305 Alnus rubra (Red alder)1 9.8 60 10 4
1306 Alnus rubra (Red alder)1 11.6 60 15 3
1307 Alnus rubra (Red alder)1 11.8 65 15 2
1308*Alnus rubra (Red alder)1 10.7 25 5 5 Topped at 6 feet, regrowth.
1309 Alnus rubra (Red alder)1 8.9 50 12 4
1310 Alnus rubra (Red alder)1 9.1 55 15 4
1312 Alnus rubra (Red alder)1 9.0 50 10 2
1313 Alnus rubra (Red alder)1 16.0 55 20 2
1314 Alnus rubra (Red alder)1 14.3 65 15 2
1315 Alnus rubra (Red alder)2 16.4 65 25 3
1316*Acer macrophyllum (Bigleaf maple)1 7.7 12 5 5 Topped at 6 feet, regrowth.
1317*Acer macrophyllum (Bigleaf maple)1 6.7 12 5 5 Topped at 6 feet, regrowth.
1318*Acer macrophyllum (Bigleaf maple)1 7.9 20 10 5 Topped at 6 feet, regrowth.
1321 Acer macrophyllum (Bigleaf maple)3 30.3 25 12 5 Topped at 20 feet, regrowth.
1322 Acer macrophyllum (Bigleaf maple)1 31.2 70 30 2
1323 Alnus rubra (Red alder)1 6.2 50 15 4
1324 Alnus rubra (Red alder)1 16.4 70 15 2
1325*Alnus rubra (Red alder)1 15.5 70 15 2
1326 Acer macrophyllum (Bigleaf maple)3 21.4 70 15 4
1327 Acer macrophyllum (Bigleaf maple)3 22.1 60 15 4
1328 Acer macrophyllum (Bigleaf maple)1 55.1 75 30 3
1329 Alnus rubra (Red alder)1 23.0 75 20 2
1330 Alnus rubra (Red alder)1 19.5 70 20 3
1331*Tsuga heterophylla (Western hemlock)1 19.8 75 15 3
1332 Alnus rubra (Red alder)1 18.0 80 20 3
1333 Acer macrophyllum (Bigleaf maple)1 20.0 70 15 4
1334*Tsuga heterophylla (Western hemlock)1 20.6 80 15 3 Limbed up 30 feet; climbing spike wounds.
1335*Tsuga heterophylla (Western hemlock)1 24.6 80 15 3 Limbed up 30 feet; climbing spike wounds.
1336 Acer macrophyllum (Bigleaf maple)2 15.5 65 20 4 Climbing spike wounds.
1337 Alnus rubra (Red alder)1 20.9 75 15 3 Climbing spike wounds.
1338 Alnus rubra (Red alder)1 23.6 70 20 3 Climbing spike wounds, partialy girdled.
1339 Alnus rubra (Red alder)1 13.7 75 15 2
1340 Acer macrophyllum (Bigleaf maple)1 9.3 8 8 5 Topped at 4 feet, regrowth.
* Tree has not been surveyed; location is aƉproximate.
750 6th Street South
(425) 822-5242 PAGE 1 OF 1
Tree Inventory Table (Off Parcel) - Stan Afichuck
1XX S 293rd Street - Federal Way, WA
parcel # 7202500080
Table Issued: 10/29/2020
Site Visit: 7/1/2020
TAG #TREE NAME # STEMSCOMBINED DBH (IN)CONDITION1 Alnus rubra (Red alder)1 20.0 3
2 Alnus rubra (Red alder)1 18.0 4
3 Alnus rubra (Red alder)1 20.0 2
4 Tsuga heterophylla (Western hemlock)1 16.0 3
5 Acer macrophyllum (Bigleaf maple)1 12.0 3
6 Acer macrophyllum (Bigleaf maple)1 10.0 4
7 Acer macrophyllum (Bigleaf maple)1 24.0 2
8 Acer macrophyllum (Bigleaf maple)1 24.0 3
9 Acer macrophyllum (Bigleaf maple)1 8.0 3
10 Acer macrophyllum (Bigleaf maple)1 36.0 3
11 Alnus rubra (Red alder)1 10.0 3
12 Alnus rubra (Red alder)1 10.0 3
13 Alnus rubra (Red alder)1 10.0 3
14 Tsuga heterophylla (Western hemlock)1 12.0 5
15 Acer macrophyllum (Bigleaf maple)1 36.0 3
16 Acer macrophyllum (Bigleaf maple)1 36.0 2
17 Tsuga heterophylla (Western hemlock)1 12.0 2
18 Acer macrophyllum (Bigleaf maple)1 16.0 3
19 Alnus rubra (Red alder)1 14.0 2
1319 Acer macrophyllum (Bigleaf maple)1 22.0 5
1320 Acer macrophyllum (Bigleaf maple)1 22.0 5
750 6th Street South
(425) 822-5242 PAGE 1 OF 1