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BLD2021-0742+Tree_Retention_or_Preservation_Plan+6.25.2021_6.46.55_PM+2270958RECEIVED BLD2021-0742 Sep 03 2021 CITY OF EDMONDS DEVELOPMENT SERVICES DEPARTMENT 702 Cedar Street Tree Retention Plan November 2020 Prepared Massimo Ramella-Pezza For: 702 Cedar Street Edmonds, Wa 98020 mmcedar(a-)icloud.com 206.618.5205 Prepared Davey Resource Group, Inc. By: 18809 10th Ave N E Shoreline, WA 98155 Contact: Travis West travis.west@davey.com Local Office: 206.714.3147 Corporate Office: 800.966.2021 tom. Resource Group Notice of Disclaimer Assessment data provided by Davey Resource Group is based on visual recording at the time of inspection. Visual records do not include testing or analysis and do not include aerial or subterranean inspection unless indicated. Davey Resource Group is not responsible for discovery or identification of hidden or otherwise non -observable risks. Records may not remain accurate after inspection due to variable deterioration of surveyed material. Risk ratings are based on observable defects and mitigation recommendations do not reduce potential liability to Owner. Davey Resource Group provides no warranty with respect to the fitness of the trees for any use or purpose whatsoever. Table Of Contents Introduction 3 Background 3 Assignment 3 Purpose and Use of the Report 4 Limits of the Assignment 4 Inventory Methods 5 Observations 7 Site Observations 7 Condition 7 Analysis 8 Tree Protection Zone & Timing 9 Conclusion 12 References 12 Appendix A. Maps 13 Appendix B: Additional Photos 14 Davey Resource Group, Inc 2 of 17 November 2020 Tree Health Report Ramella-Pezza Introduction Background In November 2020, Davey Resource Group, Inc. (DRG) was contracted to conduct an inventory and health assessment of the trees on and adjacent to the property at 702 Cedar Street, in Edmonds, WA (PIN 00484500300100). The results of the pre -construction tree health assessment are documented in this summary report. The goal of this tree health assessment was to provide information about the trees around the property and adjacent to the property with regards to tree health and management of tree risk. Considerations included; tree species, location, condition, size, structure, and health. A pre -construction tree health assessment is a useful tool for property developers. It should be accessed regularly to develop construction limits and plan strategies to mitigate potential hazards. These trees were inspected for condition and health. The data set was collected as a GIS-based tree inventory and will facilitate the property manager to better visualize, prioritize, and make decisions about the tree population. Assignment The arborist was assigned to conduct a visual assessment of the health and condition of trees on and adjacent to the property with a diameter of 2!6 inches at 4.5 feet above the soil and record species, size, condition, average canopy radius, and maintenance recommendations. The results were used to determine a benchmark of overall performance and identified individual tree health issues. Using a pen tablet computer, a DRG International Society of Arboriculture (ISA) Certified Arborist Using a pen tablet computer, the arborist visited each tree on the site which was visually assessed, and the required tree data was collected within a GIS database. Following data collection, specific tree preservation plan elements were calculated that identified each tree's drip line and Tree Protection Zone (TPZ) to better ensure survivability during the planned development. The following details are provided in alignment with the information required by the City of Edmonds Municipal Code (EMC 18.45.050 H): • A methodology section describing the arboricultural inventory process and rationale used to rate each tree. • A description of the tree protection zone (TPZ) and how it was calculated. • Tree Protection Zone (TPZ) standards and implementation for all trees recommended to remain. • Inventory data table(s) for each tree six (6") inches or greater in DBH and corresponding identification numbers that will identify each tree on the provided map. • Tree care recommendations for any and all work to take place in the TPZ of all retained trees. • Maps detailing all tree locations, dripline, and tag number. Davey Resource Group, Inc 3 of 17 November 2020 Tree Health Report Ramella-Pezza Purpose and Use of the Report This report documents the trees adjacent to the proposed construction at 702 Cedar Street. The data collected in this report will help to define the limits of construction while complying with the local ordinance to preserve trees on the property. This tree health assessment evaluated trees on and adjacent to the property to determine conflicts between construction desires and tree vitality. The recommendations provided with this report meet or exceed the performance standard for land development in the City of Edmonds for tree preservation. To care for this tree population, a current inventory and assessment of local tree health are helpful. Both the inventory and preservation plan provides strategies for ensuring the safety, vitality, and sustainability of the tree population. Limits of the Assignment Many factors can limit specific and accurate data when performing evaluations of trees, their conditions, and values. The determinations and recommendations presented here are based on current data and conditions that existed at the time of the evaluation and cannot be a predictor of the ultimate outcomes for the trees. Only a visual inspection was used to develop the findings, conclusions, and recommendations found in this report. Numerical values were assigned to grade the attributes of the trees, including structure and canopy health, and to obtain an overall condition rating. No physical inspection of the upper canopy, sounding, root crown excavation, and resistograph, or other technologies were used in the evaluation of the trees. Davey Resource Group, Inc 4 of 17 November 2020 Tree Health Report Ramella-Pezza Inventory Methods Inventory arborists are trained to collect accurate, standardized, and replicable data about trees. All personnel who collect field data follow consistent methods to ensure uniformity and avoid individual bias in evaluating the trees. The specific definitions below help maintain this standard, yielding highly reliable and accurate data about the inventoried trees and sites. An International Society of Arboriculture (ISA) Certified Arborist (PD-2444A) collected data about the trees on November 12th, 2020. The data was collected on a field computer, and site GPS coordinates were assigned based on aerial photographs. The following attributes were collected for each site: Location and Unique ID: An X and Y coordinate was generated for each tree site. DRG also assigned each tree a unique identification number and affixed an aluminum tag to the tree. Species: Trees were identified by genus, species, and common name. Diameter at Breast Height (DBH): Trunk diameter was recorded to the nearest inch at 4.5 feet (breast height) above grade except where noted. When limbs or deformities occurred at breast height, the measurement was taken below 4.5 ft. The DBH of multi -trunk trees was recorded. Height: The height of the tree was estimated to within 10 ft. Condition: The general condition of each tree was recorded in one of the following categories adapted from the rating system established by the International Society of Arboriculture: • Excellent • Good • Fair • Poor • Very Poor • Dead Maintenance Task: The suggested method of pruning and/or removal for sustained return on investment is identified. • Large Tree Routine Prune: Trees in this category have characteristics that could become hazardous if not corrected. Deadwood limbs are less than two inches in diameter. • Small Tree Routine Prune: This category includes small -growing trees that can generally be maintained from the ground, i.e., redbud, etc., and other trees 20 feet or less. • Training Pruning: This category includes trees under 20 feet tall with correctable structural problems or minor amounts of deadwood that pose a minimal threat of personal injury or property damage. Inexpensive pruning at this stage significantly affects the future of these trees. Young trees in this category that will be large at maturity generally require an annual pruning or inspection. • Priority 1 Pruning: Trees in this category need pruning to remove hazardous deadwood limbs greater than four inches in diameter and/or have broken, hanging, or diseased limbs. • Priority 2 Pruning: These trees need pruning to remove hazardous deadwood limbs greater than two but less than four inches in diameter. Davey Resource Group, Inc 5 of 17 November 2020 Tree Health Report Ramella-Pezza • Priority 1 Removal: These trees have defects that cannot be cost-effectively or practically treated, have a high amount of deadwood, or pose an immediate hazard to property or person. Davey recommends that these trees be removed immediately. • Priority 2 Removal: These trees are not as great of liability as Priority 1 Removals, being smaller and/or less hazardous, although they are also recommended for removal. Davey recommends that they be removed as soon as possible. • Priority 3 Removal: Trees designated for Priority 3 Removal do not pose a public hazard and are small, dead, or poorly formed. Smaller dead trees and failed transplants are in this category. Large trees in this category are generally poorly placed, of inferior quality, and pose little to no threat to the community. • Stump Removal: Stumps are identified separately since they may not be removed at the time of tree removal. • No Priority: No priority maintenance required. Maintenance Detail • Clean/Deadwood: Remove dead, dying, broken or diseased wood. • End Weight/Thin: Reduce the overall weight of tree canopy, most often removing water sprouts. • Remove: Remove the tree. • Raise: The tree requires pruning to remove low branches that may interfere or cause obstructions with sight or traffic. Typical standards for clearance are eight feet over sidewalks and fourteen feet over roads. • Fertilize: Tree would benefit from fertilization • Install/Inspect Cables: Tree needs cabling to reduce risk of branch failure, or tree has cables that require routine inspection • Reduce: Tree requires selective pruning to decrease the height and/or the spread of the crown • Remove Stakes: Identifies where a new planting has stakes that should be removed • Stake: Identifies a new planting that needs stakes to stabilize the tree • Structural Prune: Identifies a young tree that would benefit from pruning to improve structure and health. • Treat Pest/Disease: Tree exhibiting pest or disease symptoms. • Water: Tree exhibiting symptoms of drought stress and will benefit from watering. • None: No (specific) maintenance required (Adding the word specific in there is very important, most trees we inventory don't need specific maintenance other than a routine trim schedule. Observations: The primary observation impacting the health and condition assessment of the tree. • Cavity Decay: The tree has a cavity and suspected structural decay. • Improperly Mulched: The tree has too much or too little coarse woody mulch. • Mechanical Damage: The tree has mechanical damage. • Nutrient Deficiency: The tree is exhibiting symptoms of nutrient deficiency. • Pest Problem: The tree has an insect or fungal problem. • Poor Location: The tree is in an unsuitable location for its size. • Poor Root System: The root system of the tree appears to be compromised. • Poor Structure: The overall tree structure is poorly developed. • Remove Hardware: The tree has hardware in it such as cabling or bracing. • Serious Decline: The tree is in serious decline. • Signs of Stress: The tree is exhibiting signs of stress. Davey Resource Group, Inc 6 of 17 November 2020 Tree Health Report Ramella-Pezza Additional Inspection Required: The tree warrants a secondary inspection beyond the scope of this inventory. The arborist will record any structural defect observed, as defined in ANSI A300, Part 9(a) 92.27, and will incorporate the observations into recommendations for future action. Notes: Additional information may be included in this field at the discretion of the arborist. Observations Site Observations The project site was listed as PIN 00484500300100, located at 702 Cedar Street in Edmonds, Washington. The project site was mostly flat with a steep drop from the plain of the parcel to the road grade in the north. Two trees were evaluated for this project: a Western Red Cedar (Thuja plicata) and a co -dominant stemmed White Birch (Betula pendula). The Western Red Cedar was located on the north edge of 702 Cedar Street. The tree was on a north -facing slope that led down sharply from the yard to street level, about seven (7) feet of elevation change. The White Birch tree was on the neighbor's property to the east. The birch tree was fourteen (14) inches below the grade of the subject property. The two properties were divided by a cement retaining wall. Condition Tree condition is important to evaluate because the preservation and maintenance of healthy trees should take priority over trees in poor condition. It may not be of value to try to preserve trees in poor condition when removal is a better option for the aesthetic value and health of the tree population as a whole. In Edmonds, excavation inside the Critical Root Zone (CRZ) is not allowed. The critical root zone is determined to be a circle around the tree whose diameter is equal to one foot per inch tree diameter. The Western Red Cedar (tree #1) was in good condition. It was growing on a steep slope between the road and the house footprint on the north side of the property. The visible roots sounded solid when mallet tested. The root crown and main stem as well gave solid feedback when tested with a mallet. The diameter of this tree, measured at four and a half (4.5) feet above the high side of the soil, was forty-one (41) inches in diameter. The height, measured with a laser range finder, was seventy-five feet high. There were no dead branches observed, but some co -dominant tops, less than three (3) inches in diameter making up the top ten (10) feet of tree height. The dripline for this tree averaged twenty-one (21) feet from the stem of the tree.. in this case, the CRZ equals 43' radius. The White Birch (tree #2) was in fair condition. It was a co -dominant stemmed tree, with both stems comparable in diameters. The stems of the birch tree were growing too closely together to get a diameter tape in between them at four and a half (4.5) feet above the soil. Measuring both stems where a diameter tape could fit, at seven (7) feet above the soil, gave stem diameters of twenty (20) inches and twenty-one (21) inches. The combined diameters at four and a half (4.5) feet above the soil was Davey Resource Group, Inc 7 of 17 November 2020 Tree Health Report Ramella-Pezza thirty-eight (38) inches. The mature birch tree had bark deformities that appeared to be the result of branch collars growing into the main stem of the tree. The birch tree was measured by a laser range finder to be seventy-five (75) feet in height. The canopy appeared to be healthy, with little to no dieback observed. The dripline for the tree averaged thirty (30) feet from the stem of the tree. The CRZ for the birch equals 38'. 1 Western Thuja 43 red cedar plicato 75 21 43 Good Prune for 1 Clearance European Betula 2 38 75 30 38 Fair 1 white birch pendula Table 1: Observed tree conditions and CRZ calculation. Analysis This tree inventory and health assessment represent the first step in managing tree health for withstanding the impacts of construction. A tree health assessment can help the property manager better understand the maintenance needs of the trees on the property and plan for their care. Following recommended tree preservation steps will help the trees on the site to thrive during and after construction. The observations of both the birch tree and the cedar tree do not raise concerns for the health of either tree. The birch tree, while having a co -dominant stem, appears healthy. The foliage is full and vigorous, there are no major dead limbs. The stems have included bark where they touch, but there is no sap ooze, cracks, or other indication of disease. Mallett sounding on the trunk was solid. The accessible roots, when struck with a mallet, sounded solid. The mature birch tree had some swelling around old branch collars, but that is a normal growth pattern for this species of birch trees. The cedar tree was growing on a steep grade, and the tree exhibited signs of wind resistance from the reaction wood that has developed. The tree maintained its robust diameter for half of its height, where it then started to taper towards the top. This is a growth pattern consistent with open -grown trees that endure strong winds without other trees for protection. The location of the tree is important for slope stability. The root system of the cedar tree helps to hold the slope in place and resist erosion. Some tree work, pruning to raise the canopy, had recently been performed. The pruning cuts followed ANSI A300 part 1 pruning standards. Davey Resource Group, Inc 8 of 17 November 2020 Tree Health Report Ramella-Pezza The location of the house in relation to the two trees indicates there would be few absorption roots or structural roots from the cedar tree under the existing house. The grade change from the neighbors' birch tree to the construction zone restricts root intrusion across property lines. Roots need to exchange gasses to live, and birch trees have shallow root systems to allow for better water absorption. With a fourteen (14) inch grade change, there might not be significant birch roots growing where there is proposed construction. Recommendations There are two considerations when evaluating tree root disturbance during construction; the removal of absorption roots and anchoring roots. Removal (or compaction in the area) of the feeder roots can cause immediate water stress and a significant decline in tree health. The ability of a tree to survive root removal is dependent on its tolerance of drought, tree health, and the ability to form new roots quickly. Removal of the larger anchoring roots can lead to structural instability. Remove too many roots and the tree may fail when stressed. Before construction, find the extent of root intrusion into the proposed construction limits using air -spade techniques. Complete tree pruning to accommodate the limits of the proposed construction. Install tree protection fencing around tree drip lines, or where modifications have been made. Cover the tree protection areas with four (4) inches of mulch over the root zone to help maintain soil moisture and reduce soil compaction. During construction, maintain tree protection fencing. Keep exposed roots covered and moist to avoid unnecessary root dieback. Restrict access to the tree protection zone and do not store materials in the tree protection zone. Monitor tree health during construction for changes in tree health. Contact an arborist for tree health assessments if major changes in tree health are observed. Continue monitoring tree health after construction. Retain an arborist to perform periodic health assessments on the two trees once a year for three years after construction. Edmonds requires a simple rope fence to mark off the Tree Protection Zone (EMC 18.45.050). In the following section, more robust tree protection measures are recommended. Tree Protection Zone & Timing To ensure the long-term viability of trees identified for protection, construction activities shall comply with minimum required tree protection through an established Tree Protection Zone for those trees determined to remain on the site. The Tree Protection Zone for each tree is the tree drip line. The CRZ is considered the ideal preservation area of the root zone of a tree. It is equal to one (1) foot for every inch of trunk diameter measured at 4.5 feet from grade. For example; a tree with a DBH of 27 inches has a calculated CRZ diameter of 27 feet (radius of 13.5 feet) from the trunk. Davey Resource Group, Inc 9 of 17 November 2020 Tree Health Report Ramella-Pezza • Preventative measures are recommended in addition to the installation of tree protection barriers including mulching over drip line, fertilization for stressed trees, supplemental irrigation as necessary, soil amendments, soil aeration, and pruning to remove deadwood or create clearance on trees to be protected. • Prune Tree ID# 2 to ensure clearance for proposed construction. • Air -Spade the limits of construction where excavation is planned to take place. • Prune roots encroaching into the excavation area. • Mulch the root zones of all significant trees to be retained during construction with 4" of organic mulch or arborist wood chips to help maintain moisture, avoid soil compaction, and avoid runoff. • Install TPZ barriers at the dripline and follow the back of the existing curb or paved surface (fence following existing curb does not trigger 'impact' status). TPZs will follow the edge of building/road/paved paths where necessary and are not required to extend to the dripline where impervious surfaces are determined to be the limiting factor for root development. • TPZ fencing in Edmonds only requires rope fencing, but the following additional measures are recommended: Fencing should be a minimum of 4 feet high, constructed of chain link or polyethylene laminar safety fencing. • Signage reading "Tree Protection Area - Keep Out" or similar signs are required to accompany the TPZ fencing at regular intervals and include the contact information of the consulting arborist or entity responsible for enforcing tree protection standards. • Constructed TPZs shall be made in such a fashion as to not be easily moved or dismantled. • The duration of TPZs shall extend for the entirety of the project and only be removed, temporarily or otherwise, with authorization by an ISA certified arborist. • Limit construction activities to the outside of the TPZ where tree protection barriers shall be installed before any land disturbance. This includes but is not limited to the storage of materials, parking, contaminating soil by washing out equipment, (concrete, paint, etc.), changing soil grade, or damaging overhead branches. • Arborist supervision of any entry or work within the TPZ of retained or impacted trees is needed. • Retained trees shall not have the soil grade altered within its drip line or within the CRZ, whichever is greater. • Post -construction, a health assessment should be conducted once a year for the next three years to document the health of the impacted trees. Davey Resource Group, Inc 10 of 17 November 2020 Tree Health Report Ramella-Pezza Figure 1: An example of a Tree Protection Zone barrier. Contact information of the site manager or consulting arborist should also be included on the sign. TPZ shall be installed at the dripline of the tree or greater where applicable. Davey Resource Group, Inc 11 of 17 November 2020 Tree Health Report Ramella-Pezza Conclusion A tree health assessment and arborist report provides a snapshot in time of each tree assessed across many of the most important observable factors relative to tree health. This report is the first step in preserving the health, function, and value of the trees on the site. Trees and green spaces provide benefits and add value to residential properties. Tree care starts with a basic understanding of the health and structure of the trees on the site. With proper care and protection, these trees can continue to thrive for many years. Using the findings of this report as a guiding foundation, managers are equipped to design, prepare, and implement a tree preservation plan tailored to achieving the optimal outcome. The City of Edmonds generally prohibits construction within the drip lines of trees in or near construction areas. Grade changes (excavation) are not allowed within certain ranges of trees. Either the tree drip line or a circle with a diameter twelve (12) times the tree diameter, whichever is greater (EMC 18.45.050). However, showing that the requirements of tree retention can be met using alternate methods to meet the intent of the regulation is possible. A technique of using compressed air to blow dirt away from the roots of trees without damaging the roots (air -spading) could be used to explore the proposed construction area to determine the presence of structural roots. Air -spading around the drip line and pruning roots appropriately is one way to meet the goals of tree preservation and development needs. References Methany, Nelda, and James Clark. Trees and Development: A Technical Guide to Preservation of Trees During Land Development. Champaign: International Society of Arboriculture, 1998. Davey Resource Group, Inc 12 of 17 November 2020 Tree Health Report Ramella-Pezza Appendix A. Maps 1 -low 30 60ft Map Al: Overview of the inventory area. Tree #1 and tree #2 are identified in orange Davey Resource Group, Inc 13 of 17 November 2020 Tree Health Report Ramella-Pezza ,r I.A. AA 2 _ �1 Photo 2: Cedar tree roots growing on a steep slope, helping to hold the soil in place. Davey Resource Group, Inc 15 of 17 November 2020 Tree Health Report Ramella-Pezza •J, CC `y Gic"Q-t Si � t i! ti j r �C