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HomeMy WebLinkAboutArborist ReportMcKinley & Associates (818) 240-1358 Arborist Report 1512 South Santa Anita Avenue Arcadia, California Prepared for: Mr. Boris Li 2937 West Norwood Avenue Alhambra, CA 91803 Prepared by: William R. McKinley, Consulting Arborist American Society of Consulting Arborists Certified Arborist #WE-4578A International Society of Arboriculture 1734 Del Valle Avenue Glendale, CA 91208 Arborists and Environmental Consultants McKinley & Associates (818) 240-1358 October 4, 2021 Mr. Boris Li 2937 West Norwood Avenue Alhambra, CA 91803 Dear Mr. Li: Recently you contacted me concerning a plan to construct a new single-family home on a vacant lot located at 1512 South Santa Anita Avenue, Arcadia. I was told that the City of Arcadia was concerned about the impact that the project would have on the existing trees. I was requested to prepare an Arborist Report for the subject property. Background After reviewing the plans a proposal was sent to you for an Arborist Report on Monday, January 4, 2021. I received a signed, approved copy of the proposal back from you later that same day. An appointment was arranged for me to inspect the subject property on Wednesday, January 6, 2021 at 2:00 p.m. You were present at the time of my inspection. I was informed that in addition to the proposed driveway and house encroaching on the large Coast Live Oak, that a wall was planned to be constructed along the northern boundary of the subject property near the Coast Live Oak. The following observations were made during my site inspection. Tree/Site Inspection Tree #1 – Coast Live Oak or Quercus agrifolia. The tree measures approximately 48 inches in diameter at D.B.H. (Diameter Breast Height) as measured 54 inches above the soil grade. The tree has a drip line, which measures roughly 35 feet from the tree’s trunk. The spread of the tree is approximately 59 feet. The height of the tree is estimated to be roughly 35 feet tall. The tree is located near the northern boundary of the property. Canopy: (N)22’; (S)32’; (E)35’, (W)24’, (NE)28’, (NW)23’, (SE)34’, (SW)28’. The former building and structures have been demolished. The area near the tree has been disturbed. The tree is situated 65 feet east of South Santa Anita Avenue and along the northern boundary. There is no irrigation or landscape on the south side of the tree. Mexican Fan Palms grow east and west of the Oak tree’s trunk. They crowd the Oak and grow up through the crown of the Oak tree. The north side of the Oak on the neighboring property has an irrigated lawn and Camellia shrubs growing near the Oak. The tree’s crown has been pruned and raised. There is moderate Western Sycamore Borer insect Arborists and Environmental Consultants Page 1 McKinley & Associates (818) 240-1358 Tree/Site Inspection damage on the bark tissue on the lower trunk area. The crown is balanced with minor asymmetry. The Oak has 2 co-dominant stems which form a union at a point 5 feet above the ground. The stem union is normal and U-shaped. The foliage size and color appear normal. The crown density is normal. I would estimate that approximately 10% of the tree’s crown is composed of dead wood. The tree is in good condition. Rating: B Tree #2 – Southern Magnolia or Magnolia grandiflora. The tree measures approximately 15 inches in diameter at D.B.H. The tree has a drip line, which measures roughly 16 feet from the tree’s trunk. The spread of the tree is approximately 29 feet. The height of the tree is estimated to be roughly 40 feet tall. The tree is located near Santa Anita Avenue. Canopy: (N)12’; (S)14’; (E)13’, (W)16’, (NE)13’, (NW)14’, (SE)13’, (SW)15’. The tree is 55 feet south of the northern boundary and 8 feet east of Santa Anita Avenue. It is in the front of a vacant lot. There is no irrigation. Lantana and dry weeds grow nearby. The tree’s crown has been pruned and raised. The tree is balanced with minor asymmetry. It has multiple stems which form a union at a point 8 feet above the ground. Decay is visible in the old pruning wounds. The foliage size and color appear normal. The crown density is fair. I would estimate that approximately 20% of the tree’s crown is composed of dead wood. The tree is in average health and condition. Rating: C Tree #3 – Holly Oak or Quercus ilex. The tree measures approximately 10 inches in diameter at D.B.H. The tree has a drip line, which measures roughly 16 feet from the tree’s trunk. The spread of the tree is approximately 25 feet. The height of the tree is estimated to be roughly 35 feet tall. The tree is located near Santa Anita Avenue. Canopy: (N)9’; (S)14’; (E)9’, (W)16’, (NE)9’, (NW)12’, (SE)12’, (SW)15’. The tree is 43 feet south of Tree #2 and 8 feet east of Santa Anita Avenue. It is in the front of a vacant lot. There is no irrigation. Lantana and dry weeds grow nearby. The tree’s crown has been pruned and raised. The tree is balanced with minor asymmetry. The foliage size and color appear normal. The crown density is normal. There is minor dead wood in the tree’s crown. The tree is in slightly above average health and condition. Rating: C+ Observations The subject property is located in a single family home residential neighborhood. It is located along a major boulevard with substantial traffic. At the present time the site is a vacant lot. The previous existing structures have all been demolished. The proposed site plan shows a circular concrete driveway in the front, a new single-family home, another concrete driveway running near the north boundary and accessory structure and a CMU wall running along the north boundary of the subject property. The site plan shows that both Tree #2 and Tree #3 will be preserved. Both these trees appear to be City of Arcadia Arborists and Environmental Consultants Page 2 McKinley & Associates (818) 240-1358 Observations-Continued Street Trees. The southern driveway entrance appears to be encroaching on the root zone of Tree #3. Care must be taken to minimize damage to the tree and the tree roots. Root pruning may be necessary where roots are torn or otherwise damaged during driveway construction. The proposed concrete driveway on the north side of the subject property will be located within the root zone of Tree #1. Care must be taken to minimize damage to the tree’s roots during driveway construction. Root pruning may be necessary where roots are encountered during driveway construction. Work within the tree protection zone should be performed using hand tools. No tractors, vehicles or heavy equipment should be permitted to work within the tree protection zone. The proposed CMU wall along the northern boundary must utilize a bridge type footing within the tree protection zone. A pier and beam type footing is commonly used in cases where bridging over tree roots is necessary. Since the tree’s trunk is directly in the path of the proposed wall it will be necessary to stop the wall roughly 6 feet away from the tree’s trunk on either side. A wood type fence can then be attached to the wall and modified as necessary to span the distance between both sections of the wall. The wood can be cut or modified to accommodate the Oak tree trunk. The crown of Tree #1 will also require pruning in order to provide the necessary clearance over the new driveway as well as the new house. Side trimming the Oak tree’s crown may also be necessary. Tree Protection Plan After inspecting the subject trees and property and studying the proposed building plan it is my professional opinion that it is possible to implement this design without significantly impacting the health and or safety of either tree. The following tree protection mitigation measures are recommended in order to preserve these trees: 1) The single family home construction will encroach upon the tree protection zones of 3 trees. All trees to be preserved and protected during construction must have free standing T-Panel chain-link fence placed at the drip line of each tree or farthest point possible. Orange plastic fencing should be attached to the chain-link for added visibility. The placement of the tree protection fence shall be approved by a Certified Arborist or the designated representative of the City. 2) Protective fencing shall remain around the trees until written authorization is received from the City. This fencing shall be maintained in a vertical position throughout the construction period and shall not be removed or relocated without written authorization from the City and any relocation of the protective fence shall be done under the supervision of a Certified Arborist. Arborists and Environmental Consultants Page 3 McKinley & Associates (818) 240-1358 Tree Protection Plan-Continued 3) Prohibit dumping of paints, solvents, stucco, cement, concrete, mortar, excess soil and other foreign materials within the area defined as five feet beyond the drip line or tree protection zone of the trees to be preserved. 4) Avoid or minimize grading (cutting or adding soil), storage of vehicles and building materials within the area defined as five feet beyond the drip line or protected zone of all the trees to be preserved on the subject property. 5) Minimize trenching or continuous digging for utilities, plumbing or electrical or footings and foundations within the area defined as the drip line of all trees to be preserved. Such footings or foundations must be hand-dug and minimize cutting of large roots two inches diameter and larger. If possible, a pier and beam footing should be designed and built in areas within the drip line of Tree #1. 6) Roots, which are encountered during excavation, should be avoided if possible. Roots, which are cut, torn or damaged, must be pruned back to the side of the excavation with a clean, sharp pruning tool. Root ends must be kept moist. Where possible cover the root ends with moist burlap or cloth until back-fill can occur. Water exposed root ends 2 to 3 times per day until back-fill can occur to prevent the root ends from drying out. Root pruning should be done under the supervision of a Certified Arborist. 7) Pruning of tree branches should be done under the supervision of a Certified Arborist. Pruning will be necessary to provide clearance for the new house, vehicles, equipment and pedestrians. Pruning should attempt to eliminate dead wood, enhance the structure, eliminate defects and provide clearance. In general, the goal is avoid unnecessary cuts over 2 inches in diameter and not remove more than 30% of a tree’s foliage at one-time. In the case of Coast Live Oak trees, they should have no more than 25% of the live wood removed at the time of pruning. Tree pruning must conform to International Society of Arboriculture Guidelines and ANSI A-300 Pruning Standards. 8) Timing of pruning is very important. It is important to know the pruning requirements of your trees. A Certified Arborist can assist you with identifying trees and their individual needs. Prune evergreen native Oaks such as Coast Live Oak in summer. Pruning the trees at the correct time of year prevents disease and insect infestation. Arborists and Environmental Consultants Page 4 McKinley & Associates (818) 240-1358 Tree Protection Plan-Continued 9) Landscape and irrigation plans should be reviewed by an I.S.A Certified Arborist to ensure that they are compatible with the needs of the native Oak tree. It is important not to water the Oak tree trunk or any tree trunk. Irrigation can be applied near the drip line of the trees. Native California shrubs such as Toyon, Lemonade Berry, Sugar Bush, Ceanothus, Manzanita and Ribes may be used as landscaping near the Coast Live Oak tree since these plants are compatible with the water requirements of native Oaks. 10) The proposed new driveway areas will encroach upon the tree protection zone of Tree #1 and Tree #3. Tree #1 is a privately owned native Coast Live Oak and Tree #3 is a City Street Tree, Holly Oak. An Encroachment Permit must be obtained from the City of Arcadia before this work can begin within the tree protection zones of these trees. A copy of this tree report must be submitted with the encroachment permit application. 11) An I.S.A. Certified Arborist should be retained to supervise and monitor all construction activities near the subject trees during construction to ensure that the tree protection plan is being followed. Summary/Conclusion After reviewing the site and development plans and inspecting the trees it appears that it will be necessary to encroach upon the tree protection zone of Tree #1 and Tree #3. An Oak tree encroachment permit application must be filled-out and submitted with a copy of this Arborist Report. The southern circular driveway entrance will be constructed south of Tree #3 within the tree protection zone. Care must be taken to minimize root damage while constructing the driveway entrance. The driveway running north of the proposed new house will be constructed within the tree protection zone of Tree #1. Once again care must be taken to minimize root damage. The proposed CMU wall running along the northern boundary will need to stop at a point 6 feet on either side of the trunk of Tree #1. A wood fence can be constructed between both sections of the CMU wall. The wood fence can be carefully constructed around the trunk of the Oak tree. The portions of the CMU wall which encroach within the tree protection zone must be on pier and beam footings in order to bridge over the roots of Tree #1. All work within the tree protection zones should be performed using hand tools. No tractors or vehicles should be permitted to work within the tree protection zones. It will be necessary to prune, raise and side trim Tree #1 in order to provide adequate clearance for the house and driveway. Arborists and Environmental Consultants Page 5 McKinley & Associates (818) 240-1358 Summary/Conclusion-Continued I.S.A. Certified Arborist should be hired to supervise and monitor all construction activities near the subject trees during construction. The latest modified design will have less impact to the trees than the earlier design. If the above stated tree protection recommendations are followed then the remaining trees on and near the property should survive and contribute to the beauty of the subject property and the surrounding neighborhood for many years to come. Thank you for the opportunity to serve you and your environmental and horticultural needs. If you have any questions, please feel free to contact me on my business cell phone at (818) 426-2432 or you may call my office at (818) 240-1358. Yours truly, William R. McKinley William R. McKinley, Consulting Arborist American Society of Consulting Arborists Certified Arborist #WE-4578A International Society of Arboriculture Arborists and Environmental Consultants Page 6