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115-14 - City and applicant's consulting arborist reports dated November 2013.pdfPrepared by Michael L. Bench, Consulting Arborist November 20, 2013 Michael L. Bench Consulting Arborist (831) 594-5151 7327 Langley Canyon Road Prunedale, California 93907 Inspection of the Root Damage to Neighboring Trees After Trenching At The Tate Development Project 10121 N. Foothill Boulevard Cupertino, California Assignment I was asked by Mr. George Schroeder, Planner, City of Cupertino to meet at the site with Mr. Ron Tate and Mr. Gessner, Consulting Arborist, and Mr. Schroeder to review the root damage after trenching to the neighboring trees on the West side of the property proposed by Mr. Tate for development at 10121 N. Foothill Boulevard, Cupertino, California. Observations I visited the site and met the parties involved on November 20, 2013. The trenches for proposed retaining walls and footings on the West side of this site had been cut prior to this observation. I observed no roots in the soil face of the cut near the neighboring Italian cypress Trees # 9-18. I observed no roots in the soil face of the cut near the neighboring Blue Atlas cedar Tree # 8. I observed no roots in the soil face of the cut near the neighboring Canary Island pine Tree # 7. I observed only 1 root, approximately 1 inch in diameter, in the soil face of the cut near the neighboring Deodar Cedar Trees # 6. This one root would not be significant root damage. Conclusions This observation makes it clear that the damage to the root systems of the neighboring Trees # 6-18 by the excavations at this site would be non-existent or insignificant. Respectfully submitted, Michael L. Bench, Consulting Arborist International Society of Arboriculture Certification # WE 1897A American Society of Consulting Arborists Member November 9, 2013 Ron Tate Tate Diversified Development, Inc. 22 S. Santa Cruz Avenue Los Gatos, CA 95030 Enclosed is the assessment of the trenching on 10121 N. Foothill Boulevard and the related influence on the trees located on 22576 and 22586 Silver Oak Way, Cupertino, CA 95014. There are three trees on 22576 and 22586 Silver Oak Way within close proximity to the proposed construction on 10121 N.Foothill Boulevard. The two species, Canary Island pine (Pinus canariensis) and deodar cedar (Cedrus deodara), have good tolerances to construction influences and root damage. The trench on 10121 N. Foothill Boulevard is outside the critical root zones and no roots from the trees were observed in the trench (Appendix A). With the limits of construction at the trench the influence the proposed construction will have on the trees is low. Assignment •Inspect the trenches located on 10121 N. Foothill Boulevard for tree roots. •Provide construction influence ratings regarding the two deodar cedar and one Canary Island pine. Limits of the assignment •No property boundaries or property ownership information was provided. •No tree risk assessments were performed. •No construction plans were provided. Purpose and use of the report The purpose of the report is to assess how the trenches on 10121 N. Foothill Boulevard may influence the neighboring trees located on 22576 and 22586 Silver Oak Way and how the future construction may affect them. The report is to be used by Tate Diversified Development, Inc. and the City of Cupertino to help determine the influence the project will have on the neighboring trees. 10121 N. Foothill Blvd - Tree and Trench Assessment November 9, 2013 Richard Gessner - Monarch Consulting Arborists LLC - (831) 331-8982 - rick@monarcharborist.com 1 P.O. Box 1010 Felton, CA 95018 Analysis No biological, environmental, or technical analysis was performed for this assignment. Observations Site The property located at 10121 N. Foothill Boulevard is located at the corner of N. Foothill Boulevard and Silver Oak Way. The site is an old gas station with two duplexes located directly to the west segregated by a concrete wall. The old parking area is level grade covered in asphalt to about ten feet from the concrete privacy wall. Approximately ten feet from the privacy wall is a steep upward slope with bare soil. The ground is dry with no irrigation and heavily compacted. Two Monterey pines (Pinus radiata) are growing on the slope toward the southwest corner with visible roots growing along the soil surface. No roots from the three trees on 22576 and 22586 Silver Oak Way were observed in the trench (See Site Sketch on Pg. 3). Deodar cedar one Deodara cedar number one is located in the northeast corner of the backyard on 22576 Silver Oak Way. The tree has a trunk diameter of 27 inches measured at 4.5 feet above grade and is approximately 55 feet tall. The north side of the tree has been stripped of its scaffold branches near the property boundary and the crown consists of multiple codominant tops. Foliar color, size, and density are normal for the species. The trench 12 feet from the retaining wall and approximately 15 feet from the trunk directly east and six feet from the retaining wall to the southeast and nine feet from the trunk. Canary Island pine two Canary Island pine number two is located in the southeast corner of the backyard on 22576 Silver Oak Way. The tree has a trunk diameter of 19 inches measured at 4.5 feet above grade and is approximately 50 feet tall. The crown consists of codominant tops with an abrupt angle attachment forming the east leader. Foliar, color, size, and density are normal for the species. The trench is fifteen feet from the retaining wall and approximately eighteen feet from the trunk. Deodar cedar three Deodar cedar number three is located in the southeast corner of the backyard on 22586 Silver Oak Way. The tree has a trunk diameter of 28 inches measured at 4.5 feet above grade and is approximately 55 feet tall. The crown is composed of one central leader with moderate sized scaffold branches and foliar size, color, and density are normal for the species. The trench is nine feet from the retaining wall directly east and eleven feet to the southeast with an additional four feet to the trunk beyond the wall. 10121 N. Foothill Blvd - Tree and Trench Assessment November 9, 2013 Richard Gessner - Monarch Consulting Arborists LLC - (831) 331-8982 - rick@monarcharborist.com 2 P.O. Box 1010 Felton, CA 95018 Site Sketch 22576 and 22586 Silver Oak Way 10121 N. Foothill Boulevard The oval represents the location of the trees and trench. 10121 N. Foothill Blvd - Tree and Trench Assessment November 9, 2013 Richard Gessner - Monarch Consulting Arborists LLC - (831) 331-8982 - rick@monarcharborist.com 3 P.O. Box 1010 Felton, CA 95018 #1#2#3 4ft.3ft.3ft. 13ft. 18ft.15ft. 9ft. Trench Wall Trees N Discussion Canary Island Pine Canary Island Pines (Pinus canariensis) grow naturally in the Canary Islands off the coast of Morocco. The trees grow 50 to 80 feet tall with a canopy spread of 25 feet. Canary Island pines cannot tolerate hard frost but are drought tolerant. The trees have been cultivated for timber production throughout the world and are grown as ornamentals in California. Canary Island pine trees are resistant to oak root fungus and Verticillium wilt but are susceptible to boring insects, Phytophthora root rot, and pitch canker. Canary Island pine trees rarely fail (Matheny and Clark, 1994). Canary Island pine trees have good tolerance to construction influences (Clark and Matheny, 1998). Deodar Cedar Deodar cedar (Cedrus deodara) is native to the Himalayas and is a fast growing tree reaching 80 feet tall and 40 feet wide. The trees are drought tolerant and have few pest problems, although they are susceptible to Phytophthora root rot and some types of bark beetles. Branch failure is usually associated with wind, hail, snow or ice (Matheny and Clark, 1994). Deodara cedar is tolerant of construction damage including both root and branch pruning. The trees cannot tolerate excessive soil moisture which may lead to Armillaria or Phytophthora (Clark and Matheny, 1998). Both species of trees have good tolerance to construction influences and root damage. Photo 1: Deodar cedar (Left), Canary Island pine (Right). Trees on 22576 Silver Oak Way. 10121 N. Foothill Blvd - Tree and Trench Assessment November 9, 2013 Richard Gessner - Monarch Consulting Arborists LLC - (831) 331-8982 - rick@monarcharborist.com 4 P.O. Box 1010 Felton, CA 95018 Critical Root Zone The critical root zone (CRZ) is the area of soil around the trunk of a tree where roots are located that provide stability and uptake of water and nutrients required for the tree’s survival. The CRZ is the minimum distance from the trunk that trenching or root cutting can occur and will be defined by the trunk diameter as a distance of three times the DBH in feet, and preferably, five times (Smiley, Fraedrich and Hendrickson, 2007). For example if the tree is two feet in diameter, the minimum CRZ distance would be six to ten feet from the stem on one side of the tree (Image 1). Because the trees have trunk diameters between 19 and 28 inches the critical root zone distances would range between 8 and 12 feet from the trunks. The trench is outside the CRZ of all the trees at the recommended five times the trunk diameter distance. One exception is the area near tree number one where the trench encroaches to nine feet, but is still outside the maximum encroachment of three times the trunk diameter. Furthermore there were no roots from any of the trees observed in the trench. This is not surprising because the ground was heavily compacted and dry, which is not a good environment for roots to grow or one that would encourage root growth. There is limited moisture on the slope and the privacy wall footing may further obstruct root growth on to 10121 N. Foothill Boulevard. Image 1: Critical Root Zone ©Copyright - Monarch Consulting Arborists LLC, 2012. 10121 N. Foothill Blvd - Tree and Trench Assessment November 9, 2013 Richard Gessner - Monarch Consulting Arborists LLC - (831) 331-8982 - rick@monarcharborist.com 5 P.O. Box 1010 Felton, CA 95018 Influence Level Influence level defines how a tree may be affected by construction activity and proximity to the tree, and is described as low, moderate, or high (Table 1). The following scale defines the influence ratings: •Low = The construction activity will have little influence on the tree. •Moderate = The construction may cause future health or structural problems, and steps must be taken to protect the tree to reduce future problems. •High = Tree structure and health will be compromised and removal is recommended, or other actions must be taken for the tree to remain. The tree is located in the building envelope. Tree Number Trunk Diameter Critical Root Zone Comments Inﬂuence Rating Deodar cedar 1 27 12 feet Trench 15 feet and 9 feet from trunk Low Canary Island Pine 2 19 8 feet Trench 18 feet from trunk Low Deodar cedar 3 28 12 feet Trench 13 feet and 15 feet from trunk Low Table 1: Inﬂuence Ratings With the limits of construction where the trench is located the construction influence on the trees will be low and likely have no effect on the trees. There were no roots in the trench and it is outside the critical root zone of all the trees. The construction is also only on one side of any given tree with limited root area to be influenced regardless. Conclusion There are three trees within close proximity to the proposed construction on 10121 N. Foothill Boulevard. All three trees are located on 22576 and 22586 Silver Oak Way and the two species, Canary Island pine and deodar cedar, have good tolerances to construction influences and root damage. The trench on 10121 N. Foothill Boulevard is outside the critical root zone distance of three to five times the trunk diameter in feet, and no roots from the trees were observed in the trench. With the limits of construction at the trench the influence the proposed construction will have on the trees will be low. Recommendations 1.Exclude equipment and personnel from accessing the area between the trench and retaining wall. 2.Submit this report and findings to the City of Cupertino for planning review or peer review. 10121 N. Foothill Blvd - Tree and Trench Assessment November 9, 2013 Richard Gessner - Monarch Consulting Arborists LLC - (831) 331-8982 - rick@monarcharborist.com 6 P.O. Box 1010 Felton, CA 95018 Bibliography Clark, James R., and Nelda P. Matheny. A Photographic Guide to the Evaluation of Hazard Trees in Urban Areas. Bedminster, PA: International Society Of Arboriculture, 1994. Print. Matheny, Nelda P. Trees and development: A technical guide to preservation of trees during land development. Bedminster, PA: International Society of Arboriculture, 1998. Print. Smiley, E. Thomas, Fraedrich, Bruce R., and Hendrickson, Neil. Tree Risk Management. 2nd ed. Charlotte, NC: Bartlett Tree Research Laboratories, 2007. 10121 N. Foothill Blvd - Tree and Trench Assessment November 9, 2013 Richard Gessner - Monarch Consulting Arborists LLC - (831) 331-8982 - rick@monarcharborist.com 7 P.O. Box 1010 Felton, CA 95018 Appendix A: Photographs A1: Southend of trench The photo above is of the southern end of the trench. The large roots in the trench are from the Monterey pine trees. 10121 N. Foothill Blvd - Tree and Trench Assessment November 9, 2013 Richard Gessner - Monarch Consulting Arborists LLC - (831) 331-8982 - rick@monarcharborist.com 8 P.O. Box 1010 Felton, CA 95018 A2: Trench with deodar cedar number three The photo above is of the southern end of the trench with deodar cedar number three in the background beyond the wall. 10121 N. Foothill Blvd - Tree and Trench Assessment November 9, 2013 Richard Gessner - Monarch Consulting Arborists LLC - (831) 331-8982 - rick@monarcharborist.com 9 P.O. Box 1010 Felton, CA 95018 A3: Trench with cedar one and Canary Island pine two The photo above is of the central portion of the trench near trees one and two. 10121 N. Foothill Blvd - Tree and Trench Assessment November 9, 2013 Richard Gessner - Monarch Consulting Arborists LLC - (831) 331-8982 - rick@monarcharborist.com 10 P.O. Box 1010 Felton, CA 95018 Qualiﬁcations, Assumptions, and Limiting Conditions Any legal description provided to the consultant is assumed to be correct. Any titles or ownership of properties are assumed to be good and marketable. All property is appraised or evaluated as though free and clear, under responsible ownership and competent management. All property is presumed to be in conformance with applicable codes, ordinances, statutes, or other regulations. Care has been taken to obtain information from reliable sources. However, the consultant cannot be responsible for the accuracy of information provided by others. The consultant shall not be required to give testimony or attend meetings, hearings, conferences, mediations, arbitration, or trials by reason of this report unless subsequent contractual arrangements are made, including payment of an additional fee for such services. This report and any appraisal value expressed herein represent the opinion of the consultant, and the consultant’s fee is not contingent upon the reporting of a specified appraisal value, a stipulated result, or the occurrence of a subsequent event. Sketches, drawings, and photographs in this report are intended for use as visual aids, are not necessarily to scale, and should not be construed as engineering or architectural reports or surveys. The reproduction of information generated by architects, engineers, or other consultants on any sketches, drawings, or photographs is only for coordination and ease of reference. Inclusion of said information with any drawings or other documents does not constitute a representation as to the sufficiency or accuracy of said information. Unless otherwise expressed: a) this report covers only examined items and their condition at the time of inspection; and b) 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 structural problems or deficiencies of plants or property may not arise in the future. 10121 N. Foothill Blvd - Tree and Trench Assessment November 9, 2013 Richard Gessner - Monarch Consulting Arborists LLC - (831) 331-8982 - rick@monarcharborist.com 11 P.O. Box 1010 Felton, CA 95018 Certiﬁcation of Performance I Richard Gessner, Certify: That I have personally inspected the tree(s) and/or the property referred to in this report, and have stated my findings accurately. The extent of the evaluation and/or appraisal is stated in the attached report and Terms of Assignment; That I have no current or prospective interest in the vegetation or the property that is the subject of this report, and I have no personal interest or bias with respect to the parties involved; That the analysis, opinions and conclusions stated herein are my own; That my analysis, opinions, and conclusions were developed and this report has been prepared according to commonly accepted Arboricultural practices; That no one provided significant professional assistance to the consultant, except as indicated within the report. That my compensation is not contingent upon the reporting of a predetermined conclusion that favors the cause of the client or any other party, nor upon the results of the assessment, the attainment of stipulated results, or the occurrence of any other subsequent events; I further certify that I am a Registered Consulting Arborist® with the American Society of Consulting Arborists, and that I acknowledge, accept and adhere to the ASCA Standards of Professional Practice. I am an International Society of Arboriculture Board Certified Master Arborist® and Tree Risk Assessor Qualified. I have been involved with the practice of Arboriculture and the care and study of trees since 1998. Richard J. Gessner ASCA Registered Consulting Arborist® #496 ISA Board Certified Master Arborist® WE-4341B ISA Tree Risk Assessor Qualified Copyright © Copyright 2013, Monarch Consulting Arborists LLC. Other than specific exception granted for copies made by the client for the express uses stated in this report, no parts of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, recording, or otherwise without the express, written permission of the author. 10121 N. Foothill Blvd - Tree and Trench Assessment November 9, 2013 Richard Gessner - Monarch Consulting Arborists LLC - (831) 331-8982 - rick@monarcharborist.com 12 P.O. Box 1010 Felton, CA 95018