23-105817-Arborist-Report_Ohashi-SP-12-06-23CASCARA TREE CONSULTING
ARBORIST REPORT
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TO:
Shellie Emiko Ohashi
REFERENCE:
Tree Inventory & Arborist Report
SITE ADDRESS:
1225 SW 296th St, Federal Way, WA (Parcel #: 5153200015)
DATE:
6/14/2023
PREPARED BY: Katie Hogan, ISA Certified Arborist PN-8078A
ISA Tree Risk Assessment Qualified
Summary
This report documents the June 3, 2023 tree inventory and assessment at the above-addressed site. This
assessment was requested in preparation for the submittal of building permits to the City of Federal Way and to
meet the requirements of Federal Way Revised Code (FWRC) 19.120.130.
There are 11 trees that measured 6-inches Diameter at Breast Height (DBH) or larger or which will reach 20-feet
tall or greater at maturity on the subject property. There are 15 additional trees located adjacent to the site with
overhanging canopy.
The City requires that 25 tree credit units are retained per acre of site. For this 0.69-acre property, 18 tree units
must be retained or replanted.
The proposed short subdivision and new single-family home supports the retention of 9 of the 11 trees. One
additional tree is recommended for removal due to declining condition resulting in total retention of 13 tree unit
credits. Five additional tree unit credits are required for replanting to meet the tree retention standards in FWRC
19.120.130(2).
Arborist Report: Ohashi Short Plat – Federal Way
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Observations & Discussion
Site Conditions
The subject site is a 0.69-acre property located in the City of Federal Way. The site currently has a single-family
residence and is planned for a short subdivision with a new home proposed in the southern lot.
The vegetation is mostly maintained ornamental trees and shrubs, with a few larger conifer trees in the
southern portion of the lot.
Trees
Eleven trees exist on the subject property, most of which are in fair condition. There are five native trees located
in the proposed southern lot; two of which are proposed for removal. One additional tree (#50503) is
recommended for removal due to being previously topped with a weak attachment at the old topping point.
This tree is not a good long-term tree and may pose future risk to the new residence.
Tree #s 50504 and 50506 are proposed for removal to accommodate the new residence and driveway.
Tree #s 50514 and 50532 are in the southeast corner of the lot and are proposed for retention. Both trees will
be approximately 7-feet away from the new home and driveway, however, they are located upslope on a
rockery and impacts should be minimal. See the recommendations section below for specifications for working
around these trees. Tree #50532 is enveloping the existing wire fencing and may be more suitable for removal is
desired.
There are 13 trees located off-site along the existing utility easement. The plans propose to utilize this easement
as the main access for the new residence which includes slightly widening the access easement and adding 400
additional square feet of pavement. No neighboring trees will be impacted by this proposed work.
Tree Retention
The proposed project is required to replant 5 additional tree unit credits to meet the requirements of FWRC
19.120.130(2). The City requires that replacement tree species be a mix of evergreen and deciduous trees and
be a minimum size of 6-feet in height for evergreen trees and two-inches caliper for deciduous trees.
Table 1. Tree Units
Summary Tree Unit Credit Table
Total Tree Units Required 18
Total Existing Tree Units 18.5
Total Tree Units Retained 13
Additional Tree Units Required 5
Arborist Report: Ohashi Short Plat – Federal Way
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Tree Planting Recommendations
Five tree unit credits are required to replant on the subject property. See table below with recommendations
for tree species, quantity, and spacing of replacement trees.
Table 2. Recommended species
Species Size Spacing Mature
Canopy Size
Quantity Tree Unit
Credits
Chamaecyparis nootkatensis
‘Pendula’
(Weeping nootka cypress)
6 feet tall 12’ on
center
Small 2 0.5
Acer palmatum
(Japanese Maple)
2 inches
caliper
10’ on
center
Small 2 0.5
Cercis canadensis
(Eastern redbud)
2 inches
caliper
15’ on
center
Medium 1 1.0
Styrax japonicus
(Japanese Snowbell)
2 inches
caliper
15’ on
center
Medium 2 1.0
Total Tree Units 5.0
Arborist Report: Ohashi Short Plat – Federal Way
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Recommendations/Specifications
Tree #s 50514, 50532 – Impacts from foundation and driveway construction.
• Use flat front buckets to avoid ripping/tearing of roots which can be worsened with toothed buckets.
• Roots 2-inches diameter or greater shall be cleanly cut using a sharp saw or other implement to avoid
fracturing or breaking roots.
• Tree protection fencing shall not be moved unless adequate soil protection is placed over top of
exposed soil. Acceptable soil protection methods include laying ¾ inch plywood over 6 inches of
woodchip mulch or utilizing alternative materials such as geotextile mats.
General Tree Protection Standards
• Landscaping. When installing final landscaping, minimize disturbances within the dripline of all existing
trees. Choose small container sizes where possible in areas beneath trees to reduce the size of the hole
that is required to install the plant(s). Avoid tilling or stripping the soil within the driplines of trees.
• Roots. If any roots 2-inches or greater in diameter are encountered, cleanly cut the root using a sharp
saw or other implement. Avoid ripping or tearing roots.
• Filter Fabric/Silt Fencing. If filter fencing is required within the dripline of protected trees, utilize
alternative methods for installation that does not require trenching such as weighing the fence down by
gravel or sand bags.
FWRC 19.120.160 Tree Protection Requirements
• 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.
• 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.
• 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.”
• 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.
• 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.
• 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).
• No trenching is allowed in any critical tree root zone areas.
• 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
Arborist Report: Ohashi Short Plat – Federal Way
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concrete or asphalt) may be used. Boardwalks or bridging may span root zones without harming the tree
roots.
• 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.
• Alternative protection methods may be used if accepted by the director to provide equal or greater tree
protection.
• Encroachment into the no disturbance area may be allowed where the director determines
encroachment would not be detrimental to the health of the tree.
Attachments
1) Photographs
2) Glossary
3) References
4) Inspection Methods
5) Appendix A – Assumptions & Limiting Conditions
6) Appendix B – Certification of Performance
7) Site Map/Plans
8) Tree Table
Arborist Report: Ohashi Short Plat – Federal Way
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PHOTOGRAPHS
Photo 1. Looking north toward proposed new lot.
Arborist Report: Ohashi Short Plat – Federal Way
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Photo 2. Tree #s 50503 (left) and 50504 (right). Tree 50503 is recommended for removal.
Arborist Report: Ohashi Short Plat – Federal Way
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Photo 3. Looking west toward location of proposed driveway with tree #s 50514 and 50532 to left.
Arborist Report: Ohashi Short Plat – Federal Way
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Photo 4. Looking west down existing utility easement.
Arborist Report: Ohashi Short Plat – Federal Way
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GLOSSARY
ANSI A300: American National Standards Institute (ANSI) standards for tree care
Chlorotic: discoloration caused by lack of chlorophyll in the foliage
Codominant Stems: two or more stems (or leaders) of relatively similar size that emerge from the same location
on the main trunk (Gilman, 2002)
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 a given 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 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 authority 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
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
Arborist Report: Ohashi Short Plat – Federal Way
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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)
Arborist Report: Ohashi Short Plat – Federal Way
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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.
Arborist Report: Ohashi Short Plat – Federal Way
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INSPECTION METHODS
I performed a Level 2 Visual Tree Assessment (VTA) for each tree. I visually inspected the tree from the ground,
walking around the tree to inspect for any basal defects. I then further from the tree, looking up into the crown
and branches for any notable defects and symptoms of canopy decline.
I measured the diameter of each tree using a Spencer Logging Tape. If a tree had multiple times, I measured
each stem individually and used the method outlined in the Guide for Plant Appraisal, 10th Edition Second
Printing, to obtain a single-stem equivalent diameter. The single-stem equivalent is calculated in post-processing
and due to this, some trees inventoried on the site may be smaller than the significant/regulated tree size for
the subject jurisdiction. These trees are included in the deliverables for informational purposes but are not
considered or discussed in the report. When ivy or other obstructions are present, I adjusted the diameter by
taking the ivy or obstruction into account. I measured the dripline of the first 5 trees using a measuring tape and
then estimated the average dripline of the remaining trees.
Using the VTA method, I rated the health and structural condition of each tree. This inspection method is an
international industry standard for assessing trees from the ground level and identifies external signs of decay,
physical damage, growth related defects, and abnormal or declining foliage. Tree health and structure are each
assigned their own condition rating. The following ratings are used:
Poor: Lacking a full crown, with more than 50% decline and dieback that especially affects larger branches.
Low life expectancy for the species.
Fair: Crown decline and dieback up to 30% of the canopy. Below-average life expectancy for the species.
Good: Imperfect canopy density in 10% or less of the tree. Typical life expectancy for the species.
Excellent: Perfect specimen with excellent form and vigor, along with a well-balanced crown. Exceptional
life expectancy for the species.
Arborist Report: Ohashi Short Plat – Federal Way
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APPENDIX A - ASSUMPTIONS & 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 though 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) The assessment in this report is based on information and data from sources believed to be reliable,
correct, and accurately reported. No responsibility is assumed for false or misleading 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.
Arborist Report: Ohashi Short Plat – Federal Way
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APPENDIX B - CERTIFICATION OF PERFORMANCE
I, Katie Hogan, certify that:
• I have personally inspected the trees on the property referenced in this report and the statements of
fact contained in this report are true and correct.
• I have no present or prospective interest in the property that is the subject of this report, and I have no
personal interest with respect to the parties involved.
• The reported analysis, opinions, and conclusions are my personal, unbiased professional analysis,
opinions, and conclusions.
• My analysis, opinions, and conclusions were developed, and this report has been prepared according to
commonly accepted arboricultural best practices.
• No individuals or organizations have provided significant assistance with the preparation of this report,
except those named in the report.
• My compensation for completing this assignment is not contingent upon the development or reporting
of a predetermined outcome or direction that favors the cause of the client, the results of the
assessment, or the occurrence of any subsequent events.
Signed:
Cascara Tree Consulting, LLC
Client: OhashiSite Address: 1225 SW 296th St, Federal Way6/14/2023 Page 1 of 2Tree Inventory TablePrepared by: Cascara Tree ConsultingPN-8078A, TRAQTree No. Location Scientific Name Common Name Adjusted DBH (inches)Health Structural Arb Tag # Dripline Radius (feet)Tree Unit CreditsProposed ActionNotes/Defects50322 LOT 1Juniperus scopulorumRocky Mountain juniper7.2 Fair Fair 152 10.0 1.5 Retain Slightly suppressed, multi-trunk form, roots slightly uplifting59321 LOT 1Cornus floridaEastern Dogwood 7.9 Fair Fair 152 10.0 1.5 Retain Slightly suppressed with minor canopy decline50324 LOT 1Juniperus scopulorumRocky Mountain juniper13.3 Fair Poor 154 15.0 2.0 Retain One trunk failed, heavy sapsucker damage, canopy decline50356 LOT 1Sorbus aucupariaMountain-Ash 6.0 Fair Fair 155 5.0 1.0 Retain Previously topped, visible decay50355 LOT 1Sorbus aucupariaMountain-Ash 9.0 Poor Poor 156 8.0 1.5 Retain Previously topped, hollow50539 LOT 2Laurus nobilisBay laurel 5.7 Good Good 157 5.0 1.0 Retain Tag hanging on east side of canopy50503 LOT 2Pseudotsuga menziesiiDouglas-fir 11.0 Fair Fair 158 12.0 1.5RemovePreviously topped, very narrow union at 6 feet with weak attachment, branch die back, not good long-term tree & potential future hazard 50504 LOT 2Pseudotsuga menziesiiDouglas-fir 16.4 Fair Poor 159 15.0 2.0RemovePreviously topped at 15 feet, U-shaped union, likely some central decay, not good long-term tree & potential future hazard50506 LOT 2Thuja plicataWestern Redcedar 15.0 Good Good 160 12.0 2.0RemoveImpacted from proposed driveway50514 LOT 2Thuja plicataWestern Redcedar 20.0 Good Good 161 20.0 2.5 Retain Healthy cedar tree50532 LOT 2Alnus rubraRed alder 12.7 Good Fair 161 18.0 2.0 Retain Young alder tree, enveloping fence, narrow union at baseTotal Tree Units Required18.0Total Existing Tree Units18.5Total Tree Units Retained13.0Additional Tree Units Required5Summary Replanting TableOn-Site TreesCascara Tree Consulting
Client: OhashiSite Address: 1225 SW 296th St, Federal Way6/14/2023 Page 2 of 2Tree Inventory TablePrepared by: Cascara Tree ConsultingPN-8078A, TRAQTree No. Location Scientific Name Common Name Adjusted DBH (inches)Health Structural Arb Tag # Dripline Radius (feet)Tree Unit CreditsProposed ActionNotes/Defects50319 ROWJuniperus scopulorumRocky Mountain juniper10.2 Good Good 150 7.0 - Retain Maintained as shrub, view pruned50320 ROWAcer palmatumJapanese Maple 6.0 Good Good 151 4.0 - Retain Maintained as shrub, purple lace leaf maple50550 ESMTCalocedrus decurrensIncense Cedar 22.0 Good Good A 14.0 - Retain Growing atop rockery along access easement 50549 ADJ PROPThuja plicataWestern Redcedar 16.0 Good Good B 15.0 - Retain Growing atop rockery along access easement 50568 ADJ PROPAcer circinatumVine Maple 8.7 Good Good C 10.0 - Retain Growing atop rockery along access easement 50567 ADJ PROPArbutus unedoStrawberry tree 9.0 Good Good D 8.0 - Retain Growing atop rockery along access easement 50565 ADJ PROPPrunus domesticaCommon plum 5.0 Good Good E 6.0 - Retain Growing atop rockery along access easement, plum tree 50564 ADJ PROPAcer palmatumJapanese Maple 8.2 Good Good F 10.0 - Retain Growing atop rockery along access easement 50590 ROWCalocedrus decurrensIncense Cedar 8.0 Good Good G 4.0 - Retain At entryway to driveway about 3 feet from edge of driveway 50591 ROWFraxinus pennsylvanicaGreen Ash 8.0 Good Good H 15.0 - Retain At entryway to driveway about 8 feet from edge of driveway 50589 ROWPseudotsuga menziesiiDouglas-fir 10.0 Good Fair I 12.0 - Retain At entryway to driveway about 4 feet from edge of driveway 50585 ADJ PROPAcer palmatumJapanese Maple 6.0 Good Good J 10.0 - Retain Located on north side of driveway about 3 feet from edge of driveway50586 ADJ PROPAcer macrophyllumBigleaf Maple 3.0 Good Good K 4.0 - Retain Located on north side of driveway about 3 feet from edge of driveway50587 ADJ PROPMalus sp.Apple 4.0 Poor Poor L 6.0 - Retain Located on north side of driveway about 3 feet from edge of driveway50588 ADJ PROPCrataegus monogynaCommon hawthorn 4.0 Good Good M 6.0 - Retain Located on north side of driveway about 3 feet from edge of drivewayOff-Site TreesCascara Tree Consulting