Tree Conservation Plan-04-03-2020-V2FORESTRY AND VEGETATION MANAGEMENT SPECIALISTS
WFCI
3601943-1 723
FAX 3601943-4 1 28
1919 Yelm Hwy SE, Suite C
Olympia, WA 98501
URBANIRURAL FORESTRY TREE APPRAISAL HAZARD TREE ANALYSIS
RIGHT-OF-WAYS VEGETATION MANAGEMENT ENVIRONMENTAL STUDIES CONTRACT FORESTERS
Member of International Society of Arboriculture and Society of American Foresters
- Tree Conservation Plan -
THE WOODLANDS AT REDONDO CREEK
Pacific Hwy. & S. 304th St.
Federal Way, WA
Prepared for: American Classic Homes
Prepared by: Washington Forestry Consultants, Inc.
Date of Report: March 20, 2020
Introduction
The project proponent is planning to construct 67 new homes on 21.85 acres in Federal Way,
Washington. The proponent has retained WFCI to:
• Complete and inventory and assessment of the trees on the site, excluding the critical
areas and their buffers.
• Make recommendations for retention, removal, protection, and/or cultural care.
• Complete tree retention and replacement calculations according to Federal Way
municipal code 19.120.130.
• Prepare a tree protection plan.
Observations
Methodology
WFCI has evaluated significant trees 6 inches diameter at breast height (DBH) and larger in the
proposed project area, and assessed their potential to be incorporated into the new project. Areas
of potential save trees were identified as well. Twelve variable area plots were installed on a
systematic grid across the interior of the site. The plot locations are marked in the field with
pink and black stripped flagging. Data from the counts of significant trees were entered into
SuperAce®, a forest inventory software program that projected the total number of significant
trees in the interior, buildable area of the project. This plot data will be used to determine tree
unit density of 25 tree units per acre of net developable acreage for single family residential zone
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development. Sampling was designed to, and achieved a 95% confidence level for the projection
of the population of significant trees.
Site Description
The project area includes 2 parcels totaling 21.85 acres. There is no history of development on
this parcel. Topography is gently sloping west to a wetland area. There is extensive garbage
covering the site with many active homeless camps. The project area is bordered by single
family homes to the north and east, S. 304th Street to the south and Pacific Hwy. to the west.
Soils Depth and Productivity
According to the Natural Resource Conservation Service Soil Survey, the soil type on the site is
an Alderwood gravelly sandy loam, a moderately deep, moderately well drained soil found on
glacial till plains. It is formed in ablation till overlying basal till. A weakly cemented hardpan is
at a depth of 20 to 40 inches. Permeability is moderately rapid above the hardpan and very slow
in the pan. Available water capacity is low. Effective rooting depth is 20-40 inches. A perched
seasonal high water table is at a depth of 18-36 inches from November to March. The potential
for windthrow of trees is moderate under normal conditions. New trees require irrigation for
establishment.
In areas where grading brings the hardpan nearer to the surface, the hardpan must be
fractured under new trees to provide soil volume for root development and to improve
drainage around the tree.
Tree Conditions
There are two forest cover types on the site for the purposes of description. A stand table
summary of species by diameter range for each type is located in Attachment 3.
Type I. – This is a red alder (Alnus rubra) dominant stand with Douglas-fir (Pseudotsuga
menziesii) and western hemlock (Tsuga heterophylla). There are 1,746 trees in this type, with
288 trees being in ‘Fair’ or better condition. The diameter range for trees in the type is from 8 to
26 inches DBH. Tree conditions range from ‘Dead’ to ‘Good’ with most trees described as
being in ‘Poor’ condition or worse.
Table 1. Summary of Trees in Cover Type I.
Species DBH Range
(in.) Condition Range
# of Healthy
Significant
Trees
# of
Unhealthy
Significant
Trees
Red Alder 8-20 ‘Dead’ – ‘Fair’ 172 1,323
Western
Hemlock 9-18 ‘Poor’ – ‘Fair’ 79 109
Douglas-fir 20-26 ‘Poor’ - ‘Good’ 37 26
Total 8-26 ‘Dead’ – ‘Good’ 288 1,458
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The understory vegetation consists of dense shrubs including salal (Gaultheria shallon),
salmonberry (Rubus spectabilis), sword fern (Polystichum munitum), Indian plum (Oemleria
cerasiformis) and Himalayan blackberry (Rubus armeniacus).
Type II. – This is a Douglas-fir dominant stand with red alder, western hemlock and bigleaf
maple (Acer macrophyllum). There are 853 trees in this type, with 253 trees being in ‘Fair’ or
better condition. The diameter range for trees in the type is from 8 to 42 inches DBH. Tree
conditions range from ‘Dead’ to ‘Good’ with most trees described as being in ‘Poor’ condition or
worse.
Table 2. Summary of Trees in Cover Type II.
Species DBH Range
(in.) Condition Range
# of Healthy
Significant
Trees
# of
Unhealthy
Significant
Trees
Douglas-fir 8-42 ‘Poor’ – ‘Good’ 196 188
Red Alder 9-16 ‘Dead’ – ‘Fair’ 57 380
Western
Hemlock 16-28 ‘Poor’ 0 24
Bigleaf Maple 24 ‘Very Poor’ 0 8
Total 8-42 ‘Dead’ – ‘Good’ 253 600
The understory vegetation consists of dense shrubs including salal, salmonberry, and Himalayan
blackberry.
Overall Summary of Trees
There are a total of 2,058 trees of which 541 are in ‘Fair’ or better condition. Trees in Poor,
Very Poor, or that are ‘Dead’ are unhealthy and not considered to be long-term trees. These
unhealthy trees have no potential to be saved in a development project.
Off-Site Impacts
Tree removal for this project may impact off-site trees on the northern and eastern sides of the
project area. A tree risk assessment should be conducted on these trees after site clearing if trees
are to be removed from these margins of the property.
Planned Tree Retention
Tree retention will occur in three designated tracts on the site. The required grading limits the
potential for tree retention in other areas of the project. Tracts A & D occur in the western
portion of the site along Redondo Creek. Tract F is located in the northern area of the site.
Planned Tree Retention by Tract:
Tract A: 123 Healthy Significant Trees- 246.0 Tree Units
Tract D: 18 Healthy Significant Trees- 36.5 Tree Units
Tract F: 6 Healthy Significant Trees- 12.0 Tree Units
Totals: 147 Healthy Significant Trees- 294.5 Tree Units
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Tree Retention Calculations
Federal Way municipal code 19.120.130 requires a minimum tree unit density of 25 tree units
per acre for single family residential zone development. The developable area is 17.82 acres, so
446 total tree units will need to be retained on site.
The following is a summary of the planned tree retention and removal:
Total Project Acreage: 21.85 acres
Net Development Area: 17.82 acres
Minimum Density Requirement: 445.5 tree units
(25 tree units/acre x 17.82 acres)
Planned Tree Retention: 294.5 tree units
Shortfall of Tree Unit Requirement: 151.0 tree units
By retaining 294.5 tree units in 147 of the healthy significant trees on the site, this plan falls short
of the minimum tree density requirement by 151.0 tree units. A total of 151 medium canopy tree
species or 100 large canopy tree species will be required to meet the minimum tree density
requirement.
Tree Protection Measures
Trees to be saved must be protected during construction by a six foot high chain link fencing
(Attachment 4), located 5 feet outside of the drip line of the trees. An existing fence surrounds
much of the property – this should be adequate to protect these edges. Placards shall be placed
on the fencing every 50 feet indicating the words, "NO TRESPASSING - Protected Trees". The
individual RPZ are a radius of one foot for each one inch of DBH (6 feet minimum), unless
otherwise delineated by WFCI.
There should be no equipment activity (including rototilling) within the critical root zone. No
irrigation lines, trenches, or other utilities should be installed within the CRZ. Cuts or fills
should impact no more than 25% of a tree’s root system. If topsoil is added to the root zone of a
protected tree, the depth should not exceed 2 inches of a sandy loam or loamy fine sand topsoil
and should not cover more than 25% of the root system.
If roots are encountered outside the RPZ during construction, they should be cut cleanly with a
saw and covered immediately with moist soil. Noxious vegetation within the critical root zone
should be removed by hand. If a proposed save-tree must be impacting by grading or fills, then
the tree should be re-evaluated by WFCI to determine if the tree can be saved with mitigating
measures, or if the tree should be removed.
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Pruning and Thinning
All individual trees to be saved near or within developed areas should have their crowns raised to
provide a minimum of 8 feet of ground clearance over sidewalks and landscape areas, 15 feet
over parking lots or streets, and at least 10 feet of building clearance.
All pruning should be done according to the ANSI A300 standards for proper pruning, and be
completed by an International Society of Arboriculture Certified Arborist®, or be supervised by a
Certified Arborist®.
Conclusions and Timeline for Activity
1. The final, approved tree conservation plan map should be included in the construction
drawings for bid and construction of the project and should be labeled as such.
2. Stake and heavily flag the clearing limits.
3. Contact WFCI to attend pre-job conference and discuss tree protection issues with
contractors. WFCI can verify all trees to be saved and/or removed are adequately marked for
retention. WFCI can inspect and mark any additional hazard trees or trees that will be
impacted by grading, trenching or development for removal.
4. Complete logging. Complete necessary hazard tree removals and invasive plant removals
from the tree protection areas. No equipment should enter the tree protection areas during
logging. WFCI should inspect the save trees after logging, to identify any trees that may
have been damaged, or any other hazard trees. The logger can then remove these trees before
they depart the site.
5. Install tree protection fences along the 'limits of construction'. The fences should be located
at the limits of construction or 5 feet outside of the drip line of the save tree or as otherwise
specified by WFCI.
6. Complete clearing of the project. Maintain fences throughout construction.
7. Do not excavate stumps within 10’ of trees to be saved. These should be individually
evaluated by WFCI to determine the method of removal.
8. Complete all necessary pruning on save trees or stand edges to provide at least 8’ of ground
clearance near sidewalks and trails, and 15’ above all driveways or access roads.
9. Complete grading and construction of the project.
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Summary
Federal Way municipal code 19.120.130 requires a minimum tree unit density of 25 tree units
per acre for net developable acreage. The developable area is 17.82 acres, so 446.0 total tree
units will need to be retained on site. There are very few trees on the site that have the potential
to be retained because of poor health or grading issues. One hundred and forty-seven (147)
healthy trees are planned to be retained in three tracts on the site for a total 294.5 tree units. This
falls short of the required tree unit retention by 151.0 tree units requiring replacement trees to be
planted.
Please give us a call if you have any further questions.
Respectfully submitted,
Washington Forestry Consultants, Inc.
Galen M. Wright, ACF, ASCA
ISA Bd. Certified Master Arborist PN-129BU
Certified Forester No. 44
ISA Tree Risk Assessor Qualified
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Attachment 1. Aerial Photo of The Woodlands at Redondo Creek Site
(King County iMap).
Property Boundary
Forest Cover Type Boundaries
N
Cover Type I
Cover Type I
Cover Type II
Cover Type II
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Attachment 2. The Woodlands at Redondo Creek Preliminary Site Plan
Tree Protection
Fence Locations
Tract F
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Attachment 3. Stand Table Reports for The Woodlands at Redondo Creek
tree inventory.
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Attachment 4. Tree Protection Fence Detail
Temporary Chain Link on Driven Posts
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Attachment 5. Individual Tree Rating Key for Tree Condition
RATING SYMBOL DEFINITION
Very Good VG • Balanced crown that is characteristic of the species
• Normal lateral and terminal branch growth rates for the species and
soil type
• Stem sound, normal bark vigor
• No root problems
• No insect or disease problems
• Long-term, attractive tree
Good G • Crown lacking symmetry but nearly balanced
• Normal lateral and terminal branch growth rates for the species and
soil type
• Minor twig dieback O.K.
• Stem sound, normal bark vigor
• No root problems
• No or minor insect or disease problems – insignificant
• Long-term tree
Fair F • Crown lacking symmetry due to branch loss
• Slow lateral and terminal branch growth rates for the species and
soil type
• Minor and major twig dieback – starting to decline
• Stem partly unsound, slow diameter growth and low bark vigor
• Minor root problems
• Minor insect or disease problems
• Short-term tree 10-30 years
Poor P • Major branch loss – unsymmetrical crown
• Greatly reduced growth
• Several structurally import dead or branch scaffold branches
• Stem has bark loss and significant decay with poor bark vigor
• Root damage
• Insect or disease problems – remedy required
• Short-term tree 1-10 years
Very Poor VP • Lacking adequate live crown for survival and growth
• Severe decline
• Minor and major twig dieback
• Stem unsound, bark sloughing, previous stem or large branch
failures, very poor bark vigor
• Severe root problems or disease
• No or minor insect or disease problems
• Mortality expected within the next few years
Dead DEAD • Dead
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Attachment 6. Assumptions and Limiting Conditions
1) Any legal description provided to the Washington Forestry Consultants, Inc. is assumed to be
correct. Any titles and ownership's 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, unless otherwise stated.
3) Care has been taken to obtain all information from reliable sources. All data has been verified
insofar as possible; however, Washington Forestry Consultants, Inc. can neither guarantee nor be
responsible for the accuracy of information.
4) Washington Forestry Consultants, Inc. shall not be required to give testimony or to attend court by
reason of this 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 invalidated 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 Washington Forestry Consultants, Inc.
7) Neither all or any part of the contents of this 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 Washington Forestry Consultants, Inc. --
particularly as to value conclusions, identity of Washington Forestry Consultants, Inc., or any
reference to any professional society or to any initialed designation conferred upon Washington
Forestry Consultants, Inc. as stated in its qualifications.
8) This report and any values expressed herein represent the opinion of Washington Forestry
Consultants, Inc., and the fee is in no way contingent upon the reporting of a specified value, a
stipulated result, the occurrence neither of a subsequent event, nor upon any finding in to reported.
9) Sketches, diagrams, graphs, and photographs in this report, being intended as visual aids, are not
necessarily to scale and should not be construed as engineering or architectural reports or surveys.
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 no warranty or guarantee, expressed or implied, that problems or
deficiencies of the tree or other plant or property in question may not arise in the future.
Note: Even healthy trees can fail under normal or storm conditions. The only way to eliminate all risk is
to remove all trees within reach of all targets. Annual monitoring by an ISA Certified Arborist or
Certified Forester will reduce the potential of tree failures. It is impossible to predict with certainty that a
tree will stand or fail, or the timing of the failure. It is considered an ‘Act of God’ when a tree fails,
unless it is directly felled or pushed over by man’s actions.