DNS RESUB 1-BLD2022-0926+Tree Protection_Report+3.7.2023_12.59.35_PM+3406571SHOFFNER CONSULTING
1015 10th St. Mukilteo, WA 98275 Mobile: (206)755- 9407 tony@tonyshoffner.com
February 22, 2023
Joseph Rowett
Landsverk Quality Homes
24113 56th Ave W.
Mountlake Terrace. WA
98043
RE: Tree Protection Report - Iron Vista, Edmonds, WA
Joseph:
This report is provided to provide protection measures for retained trees on the property
of the Iron Vista plat, as well as a 30" dbh black cottonwood (52) just off -site to the south
and a 7" dbh western red cedar (35) just off -site to the north. This report is provided to
address the requirements of EMC 23.10.
1.0 Professional Experience and Credentials
Following is a summarization of my experience and credentials as a consulting arborist:
• Master of Science in Urban Horticulture from Center for Urban Horticulture,
University of Washington, 1996. Focus of study and thesis was nursery
production of Pacific madrone (Arbutus menziesii) and establishment into a
natrual/urban ecosystem.
• ISA Certified Arborist since 1996.
• Tree Risk Assessment Qualified since 2012.
• Consulting arborist, 1996-present.
• Wetland Biologist, 1996-1998
• Other related experience: City of Everett Urban Forestry, summers 1989-1992;
Natural Resource Management staff and Bellevue Botanical Garden staff, City of
Bellevue, 1996-1997.
2.0 Tree Impact Assessmet - Methods and Results
To conduct this impact assessment, I reviewed a marked up site plan showing the
locations of proposed utilities and associated ground disturbances. The plan does not
show grading for the lots, such as cuts and fills.
3.0 Limits of Disturbance Discussion and Encroachment
The City of Edmonds requires Limits of Disturbance (LOD) be established as minimum
distance of protection for all retained trees on site and for those just off -site with
driplines that extend onto the property. Limits of development for each tree are provided
on the accompanying Tree Evaluation Data spreadsheet.
The LODs are set based upon the following criteria:
• For trees with higher crowns where development can occur below the crown, the
LODs are set a location to protect the structural root plate for below ground
features. Above ground features can be within the LOD as no root disturbance
will result.
• For small trees with low crowns, the LOD is set just beyond the edge of the drip
line in order to eliminate impacts to the crown. This distance is also adequate to
provide sufficient root protection and prevent significant disturbance.
4.0 Tree Retention, Impact Assessment and Protection.
The City of Edmonds tree retention, protect and replacement requirements are specified
in chapter 23.10 Tree Related Regulations.
Tree Retention - The City of Edmonds requires retention of 30% of the significant
trees. At 50 significant trees, 15 trees are required to be retained.
The project proposes to retain 27 significant trees and removes 23
trees for 54% retention.
Following are the impacts proposed near the retained trees and assessments of these
impacts by tree numbers:
On - Site Trees
1 - 11 A utility ditch is proposed within the right-of-way just to the east of trees #1-4,
within their drip lines and specified LODs of 16 feet. There are no impacts within
the LODs of trees 5-11. This ditch also passes through the drip lines of two
trees just off -site to the north.
Depending upon the distance from the trees to the edge of the utility trench, the
degree of root damage could be minor or significant. These are all large trees
so root damage, even on just one side, could be a significant impact. I
recommend either maintaining a distance of 10 feet minimum between the trees
and the western edge of the trench, or if the trench needs to be closer, then I
recommend that air excavation is done within the drip lines of these trees in
order to eliminate or minimize root damage and loss. If air excavation is the
option, it will be important to have a pre construction meeting with the project
consulting arborist and the air excavation operator to discuss the approach so
as to not cause unnecessary damage to roots.
36 - 51 A storm pipe is proposed just to the east of these trees. These trees are all
young and small, therefore, are less susceptible to being significantly impacted
by root damage and loss. I recommend a minimum distance of 6 feet between
the trees and the western edge of the utility trench.
Off - Site Trees
35 This tree is located just off -site to the north, approximately 3 feet off -site.
Currently there are no impacts proposed within its drip line. The only potential
impacts would be grading. This is a yound and small and less likely to be
impacted by any impacts, however, western red cedars are sensitive to root
damage and loss at any age.
52 This tree is located just off -site to the south. It is a 30" dbh black cottonwood. A
utility line is proposed to run along the southern property line within the setback,
within this tree's drip line and LOD. Depending upon the distance from the tree
to the edge of the utility trench, the degree of root damage could be minor or
significant. This tree is large so root damage, even on just one side, could be a
significant impact. I recommend either maintaining a distance of 10 feet
minimum between the treesand the southern edge of the trench, or if the trench
needs to be closer, then I recommend that air excavation is done within the drip
lines of these trees in order to eliminate or minimize root damage and loss. If air
excavation is the option, it will be important to have a pre construction meeting
with the project consulting arborist and the air excavation operator to discuss
the approach so as to not cause unnecessary damage to roots.
5.0 Tree Protection Measures
The following tree protection measures are required by 23.10.070 of the ECDC:
Prior to development activity or initiating tree removal on the site, vegetated areas,
individual trees and soil to be preserved shall be protected from potentially damaging
activities pursuant to the following standards:
A. Preconstruction Meeting Required. Prior to the commencement of any permitted
clearing and grading activity, a preconstruction meeting shall be held on site with the
permittee and appropriate city staff. The project site shall be marked in the field as
follows:
1. The extent of clearing and grading to occur;
2. Delineation and protection of any critical areas and critical area buffers with clearing
limit fencing;
3. Flagging of trees to be removed and tags on trees to be retained; and
4. Property lines.
B. Placing Materials Near Trees. No person may conduct any activity within the
protected area of any tree designated to remain, including, but not limited to, operating
or parking equipment, placing solvents, storing building material or stockpiling any
materials, or dumping concrete washout or other chemicals. During construction, no
person shall attach any object to any tree designated for protection.
C. Protective Barrier. Before development, land clearing, grading, filling or any land
alteration, the applicant shall:
1. Erect and maintain readily visible temporary protective tree fencing along the limits of
disturbance which completely surrounds the protected area of all retained trees, groups
of trees, vegetation and native soil. Tree protective fencing shall be a minimum height of
three feet, visible and of durable construction; orange polyethylene laminar fencing is
acceptable.
2. Install highly visible signs spaced no further than 15 feet apart along the entirety of
the protective tree fencing. Said sign must be approved by the director and shall state,
at a minimum, "Tree and Soil Protection Area, Entrance Prohibited," and provide the city
phone number for code enforcement to report violations.
3. Prohibit excavation or compaction of soil or other potentially damaging activities
within the barriers; provided, that the director may allow such activities approved by a
qualified professional and under the supervision of a qualified professional retained and
paid for by the applicant.
4. Maintain the protective barriers in place for the duration of the project until the
director authorizes their removal.
5. Ensure that any approved landscaping done in the protected zone subsequent to the
removal of the barriers shall be accomplished with machinery from outside the protected
zone or by hand.
6. In addition to the above, the director may require the following:
a. If equipment is authorized to operate within the protected zone, the soil and critical
root zone of a tree must be covered with mulch to a depth of at least six inches or with
plywood, steel plates or similar material in order to protect roots and soil from damage
caused by heavy equipment.
b. Minimize root damage by hand -excavating a two -foot -deep trench, at edge of critical
root zone, to cleanly sever the roots of trees to be retained. Never rip or shred roots with
heavy equipment.
c. Corrective pruning performed on protected trees in order to avoid damage from
machinery or building activity.
d. Maintenance of trees throughout construction period by watering and fertilizing.
D. Grade.
1. The grade shall not be elevated or reduced within the critical root zone of trees to be
preserved without the director's authorization based on recommendations from a
qualified professional. The director may allow coverage of up to one-half of the area of
the tree's critical root zone with light soils (no clay) to the minimum depth necessary to
carry out grading or landscaping plans, if it will not imperil the survival of the tree.
Aeration devices may be required to ensure the tree's survival.
2. If the grade adjacent to a preserved tree is raised such that it could slough or erode
into the tree's critical root zone, it shall be permanently stabilized to prevent soil erosion
and suffocation of the roots.
3. The applicant shall not install an impervious surface within the critical root zone of
any tree to be retained without the authorization of the director. The director may require
specific construction methods and/or use of aeration devices to ensure the tree's
survival and to minimize the potential for root -induced damage to the impervious
surface.
4. To the greatest extent practical, utility trenches shall be located outside of the critical
root zone of trees to be retained. The director may require that utilities be tunneled
under the roots of trees to be retained if the director determines that trenching would
significantly reduce the chances of the tree's survival.
5. Trees and other vegetation to be retained shall be protected from erosion and
sedimentation. Clearing operations shall be conducted so as to expose the smallest
practical area of soil to erosion for the least possible time. To control erosion, it is
encouraged that shrubs, ground cover and stumps be maintained on the individual lots,
where feasible.
6. The director may approve the use of alternative tree protection techniques if those
techniques provide an equal or greater degree of protection than the techniques listed in
this subsection.
E. Directional Felling. Directional felling of trees shall be used to avoid damage to trees
designated for retention.
F. Additional Requirements. The director may require additional tree protection
measures that are consistent with accepted urban forestry industry practices. [Ord.
4218 § 1 (Att. A), 2021 ].
6.0 Use of This Report
This report is provided as a means of addressing the impacts to and protection
measures for retained trees on site and just off -site of the Iron Vista project in the City of
Edmonds, WA. This report addresses only trees on this property. There is no gurarantee
that retained trees will survive through construction, and as trees are dynamic and their
conditions can change rapidly due to environmental changes, Shoffner Consulting
cannot be held liable for the failure of any retained trees.
Cordially,
Tony Shoffner
ISA Certified Arborist #PN-0909A
TRAQ