Report mcg vG1 c 11 111-40-‘ St-
RECEIVED
Morgan �olen
971.409.9354 P2
JUL 2 5 2019 3 Monroe Parkway,Suite P 220
Lake Oswego,Oregon 97035
--8--A! OCIATJL _ Consulting Arborists and Uri561-A6r( fiMiIi {Rat morgan.holen@comcast.net
iUll_UINU UlV1 !Ul'!
DATE: June 30, 2019
TO: Samantha Zimmer, Development Manager, Pacific Lifestyle Homes
FROM: Morgan Holen,Consulting Arborist
RE: Willow Brook-Tree Protection for Lot 4
MHA18080
Morgan Holen & Associates, LLC, was contracted by Kurt Dalbey of Mission Homes on behalf of Pacific
Lifestyle Homes to review the previously approved Urban Forestry Plan and provide tree protection
recommendations for individual plot plans for the Willow Brook subdivision project in Tigard, Oregon.
Pacific Lifestyle Homes provided me a copy of the previously approved Urban Forestry Plan prepared by
Multnomah Tree Experts and a plot plan for lot 4. I visited the site on Thursday, November 29, 2018 to
assess a group of existing with a root protection zones overlapping the lot in terms of recommendations
for tree protection for proposed homebuilding. This memo replaces the December 16, 2018 memo
regarding tree protection for lot 4 because a different house plan with a reduced tree protection zone
encroachment area has been selected.
The attach plot plan depicts the root protection zones of each individual tree per the previously
approved Urban Forestry Plan which I concur with. At the time of my site visit, tree protection fencing
was satisfactorily in place at the prescribed root protection zone however a minor adjustment will be
needed adjacent to trees#64 and#65 prior to homebuilding.These trees are both Douglas-firs with 18-
and 16-foot root protection zones, respectively. The southeast corner of the proposed house is
approximately 12-feet from tree #65 and the southeast corner of a proposed deck or patio is
approximately 14-feet from tree #64. The plot plan depicts the recommended location for tree
protection fencing to be adjusted for homebuilding; the encroachment area is limited to one quadrant
of the root protection zone and affects a relatively small percentage of the total root protection zone
radius and both trees are not expected to be detrimentally harmed by the proposed work provided that
the tree protection recommendations herein are followed. The closest encroachment is approximately
11-feet from tree#65 directly adjacent to the corner of the house; over-dig should be minimized to the
greatest possible extent in an effort to limit excavation to no closer than 1/2 the root protection zone
radius of 8-feet. Some root pruning may be required but critical roots are unlikely to be encountered.
Healthy Douglas-firs are generally tolerant of root pruning as a species'. Nevertheless, this work should
be supervised by the project arborist to monitor and document exposed roots and direct root pruning.
Minor crown pruning for building clearance may be required in accordance with tree protection
specification 4 in the previously approved Urban Forestry Plan.
Recommendations:
1. Protection Fencing. Adjust the location of protection fencing in the western quadrant of the
root protection zones to the limits of allowed encroachment as depicted on the plot plan.
2. Foundation Excavation.The contractor shall coordinate with the project arborist to monitor and
document excavation within the allowed encroachment area and direct root pruning if
necessary. Over-dig for foundation excavation should minimized to the greatest possible extent
within the encroachment area to minimize tree root impacts.
'N. Matheny&J.R.Clark. Trees and Development. A Technical Guide to Preservation of Trees During Land
Development.Champaign,IL: International Society of Arboriculture, 1998.
Willow Brook—Tree Protection for Lot 4
June 30,2019
Page 2 of 2
3. Pruning. The project arborist can help identify if and where root or crown pruning is necessary
while work is being monitored during construction. Crown pruning shall be performed by a
Qualified Tree Service.
Prior to homebuilding, the project arborist should inspect adjustments made to tree protection fencing
and provide written verification to the City that tree protection measures are satisfactorily in place and
in good repair. During periods of active construction,the project arborist should visit the site once every
other week to inspect tree protection measures and submit written monitoring reports to the Owner,
Contractor and City. The project arborist should also be available on-call as needed to assist the
contractor with on-the-ground recommendations and documentation if ever tree protection fencing
needs to be opened, adjusted or removed and in case tree roots are encountered or crown pruning may
be needed.
The client may choose to accept or disregard the recommendations contained herein or seek additional
advice. Neither this author nor Morgan Holen &Associates have assumed any responsibility for liability
associated with the trees on or adjacent to this site. Thank you for the opportunity to provide
construction phase consulting arborist services for the Willow Brook project. Please contact us if you
have questions or need any additional information or further assistance.
Thank you,
Morgan Holen&Associates, LLC
Morgan E. Holen, Member
ISA Board Certified Master Arborist, PN-6145B
ISA Tree Risk Assessment Qualified
Forest Biologist
Enclosures: Plot Plan Mark-up for Lot 4
t ' DRAWN BY: S.C. • 11815 NE NTH 5T,SHITE 1200
DATED: 06/19/2019 Pacific Lifestyle q GARRETTE VANCOUVER.WA X682
11815NENT 81 ,SUI E120601
SCALE: 1"=20' HOMES CUSTOM HOMES www.PaafioufeslyleHem••.cam
www.Gam•tt•CuslomHomeawm
PRELIMINARY PLOT PLANWILLOW BROOK, LOT 4
PARCEL#2S115AB05900
GENERAL NOTES
1. TOPO LINES AND ELEVATIONS ARE
APPROXIMATE.
— — _ GRAPHIC KEY
® WATER OR WELL CONNECTION
O SEWER OR SEPTIC CONNECTION
— , il , O ELECTRICAL CONNECTION
(SW)STORMWATER CONNECTION
AREAS
LOT AREA 6629 S.F.
S GABRIEL STREET
BUILDING COVERAGE *S.F.
1�° —�_ _ % COVERAGE *%%
2O 172 �'_ IMPERVIOUS AREA 8 S.F.
FIXED
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6463 62
11117 ,
_O N89°4821°W• ._� R=275.0'
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—' ROOT PROTECTION ZONE PER \ 0 .. 8 R�
I I PREVIOUSLY APPROVED URBAN �Sg
♦..1 FORESTRY PLAN `i N 35°26'42 E
^� 6.00' .,�
tir,
RECOMMENDED LOCATION FOR • p
i
. . TREE PROTECTION FENCING PRIOR
TO HOMEBUILDING
' AREA OF ALLOWED ENCROACHMENT
STREET TREE PER APPROVED PRELIMINARY PLAN
TREE MITIGATION PLAN THIS IS A PRELIMINARY SITE PLAN, MEANT TO BE
(FLOWERING DOGWOOD, USED AS A GRAPHIC ILLUSTRATION OF THE
MINIMUM 11/2"CALIPER) PROPOSED HOME CONSTRUCTION. TOPOGRAPHY,
IF SHOWN,IS APPROXIMATE AND TO BE CONFIRMED N
ON-LOT TREE PER APPROVED WHEN THE BUILDING PERMIT IS PREPARED AND
TREE MITIGATION PLAN SUBMITTED.FINAL HOME PLACEMENT AND GARAGE
(RAYWOOD ASH, ORIENTATION IS SUBJECT TO CHANGE, PENDING4—
MINIMUM 1i"CALIPER) FINAL BUILDING DEPARTMENT APPROVAL.
EXISTING TREE TO REMAIN
SCALE:1"=20'