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Arborist Peer Review Report - 7752 Orion June 2022 June 13, 2022 Brianne Harkousha City of Cupertino H O R T J C I E N C E 10300 Torre Avenue 9ARTlETT CONSULTING Cupertino CA, 95014 Subject: Tree Removal Report Peer Review 7752 Orion Lane, Cupertino, CA Dear Ms. Harkousha: The City of Cupertino requested that HortScience I Bartlett Consulting, Divisions of The F. A. Bartlett Tree Expert Company, provide a peer review of the Arborist Report prepared by Bo Firestone Consulting & Design (dated April 15, 2022) and Planting Plan prepared by Gregory Lewis Landscape Architect dated March 5, 2022. The report reviews the applicant's request to remove and replace one tree due to sidewalk improvements planned at the parcel. You asked that I provide professional opinions to verify: 1. If removal is recommended and assess the trees proposed to be removed. Are they dead and should be removed with this permit? Is removal justified, please explain why or why not. 2. If the replacement plan is acceptable/supported per your expertise of tree replacements, to ensure that the tree being removed is adequately replaced. 3. If the replacement plan includes trees planted at grade level and that the trees being replaced are located near or at similar locations as the ones removed. 4. That the timing for replacements would be sufficient and would ensure a healthy tree will be grown. Please recommend specific timing for replacements. 5. Conduct a site visit to support analysis and findings. The following summarizes my observations and assessment. I visited the site on April 22, 2022 and preformed a visual inspection from the ground. 1. Verify if removal is necessary based on the impacts and assess the trees proposed to be removed. The arborist report lists one 30-inch diameter deodar cedar tree for removal and replacement. Removal is being recommended based on proposed impacts which would be significant and beyond the tolerance of the tree. The arborist report indicated the tree was in fair condition; however, I would rate the tree in good condition. A sidewalk is planned that is located about 6 feet south of the trunk of the tree (Figure 1). On the north side of the tree, the structure is proposed to be located at about 12 to 15 feet from the tree. I agree with the arborist that root loss on the southern side of the tree where sidewalk is proposed, is likely to be significant. However, large roots are unlikely to be located in the area of the existing structure on the northern side and impacts there will likely be minimal. The proposed covered porch will affect a small part of the root area and should not be the deciding factor in the impact evaluation. The application does not specify other factors that could impact the tree's preservation such as grade changes, utility locations (existing and proposed) and underground irrigation lines. Nor does it address design modifications to reduce impacts to the trees. For instance, could the sidewalk be narrowed in the area of the tree or left at the sidewalk where both the HortScience I Bartlett Consulting . Divisions of The F.A. Bartlett Tree Expert Company 325 Ray St. Pleasanton,CA . 925.484.0211 . www.hortscience.com Tree Removal Permit Peer Review City of Cupertino— 7752 Orion Lane, Cupertino, CA Page 2 adjacent properties will and have sidewalk located? Were other options explored prior to the determination that tree removal was the best course of action? Figure 1. Detail of I applicant's landscape plans showing the location of the tree and adjacent construction. I ee +h1 �� 4 JrA LLME 20' dar C d g DCOVER> ❑ 0 6 C 1'oEZCH LY Y LY lQx D 1 D HYD 1 PAF F 0 LB L LB MC LB LB D Y❑ 1 El ( LM LM LM LM n Mq However, based on the City of Cupertino's Tree Protection ordinance removal could be approved based on criteria 14.18.180#4 which allows removal of a mature protected tree based on the replacement meeting the following matrix. In this case the 30-inch Deodar cedar is proposed to be replaced with a 36-inch box tree. This meets the criteria matrix below. Diameter of Trunk Size of Removed Tree Replacement Trees (Measured 4'/feet above grade) Up to 12 inches* One 24"box tree Over 12 inches and up to 18 inches Two 24"box trees or One 36"box tree Over 18 inches and up to 36 inches Over 36 inches One 36"box tree Heritage tree One 48"box tree *Does not apply to R1,Al,A,RHS,and R2 zones except required privacy plantings trees in R1 zones 2, Verify if the replacement plan is acceptable/supported per your expertise of tree replacements, to ensure that the tree being removed is adequately replaced. Based on the 30-inch trunk diameter, the applicant is required to plant two 24-inch box trees or one 36-inch box tree. The applicant's plan showed planting one 36-inch box bigleaf maple (Acer macrophyllum) in the back yard of the parcel. Bigleaf maple is a native deciduous tree primarily found in streambeds with dense shade. The tree has a maximum height of 75 feet and canopy width of 30-50 feet. I would not recommend the planting of bigleaf maple in this landscape setting. If the applicant would like to plant a native tree, I recommend planting naive species coast live oak (Quercus agrifolia)or valley oak (Quercus lobata)., There are several other options for large canopy trees that would enhance the property. HortScience I Bartlett Consulting • Divisions of The F.A. Bartlett Tree Expert Company Tree Removal Permit Peer Review City of Cupertino— 7752 Orion Lane, Cupertino, CA Page 3 3. Verify if the replacement plan includes trees planted at grade level and that the trees being replaced are located near or at similar locations as the ones removed. The tree is proposed to be removed from the front yard. The replacement tree will be planted in the rear yard at grade. However, the applicant is proposing to plant a strawberry tree (Arbutus marina) in the front yard close to where the deodar is proposed for removal. This tree is smaller in size than the deodar but will be better suited for a small front yard planting than the large deodar cedar. Please verify that the timing for replacements would be sufficient and would ensure a healthy tree will be grown. Please recommend specific timing for replacements. Planting more trees will provide more benefits to the project. I recommend trees be installed after work is complete to avoid construction impact on the young trees. Summary and Recommendations Based on my field inspection, review of the arborist report and plans, I recommend the City investigate further if the sidewalk could be relocated to adjacent to the curb therefore preserving the deodar cedar. However, the applicant has met the replacement findings. Replacement with one 36-inch box large canopy tree in the rear yard and smaller canopy 24- inch box strawberry tree be planted in the front yard. All trees should be planted in accordance with American National Standards Institute A300 part 6 specifications for planting and Best Management Practices, Tree Planting, 2"d Ed. (International Society of Arboriculture 2014). No root barriers surrounding the root ball should be installed. Please contact me if you have any questions regarding my opinions. Sincerely, HortScience I Bartlett Consulting Darya Barar, Managing Consulting Urban Forester ISA Certified Arborist No. WE-6757A Registered Consulting Arborist#693 ISA Tree Risk Assessment Qualified HortScience I Bartlett Consulting • Divisions of The F.A. Bartlett Tree Expert Company