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Home My WebLink AboutAPPROVED_Final Tree Retention Plan - 106th Ave SE_20240304 LAYTON TREE CONSULTING, LLC It’s all about trees…… PO BOX 572, SNOHOMISH, WA 98291-0572 * 425-220-5711 * bob@laytontreeconsulting.com FINAL TREE RETENTION PLAN 17018 AND 17022 106th Avenue SE Renton, WA Report Prepared by: Bob Layton Registered Consulting Arborist #670 Certified Arborist #PN-2714A March 4, 2024 JDing 06/05/2024 CURRENT PLANNING DEVELOPMENT ENGINEERING Michael Sippo 06/06/2024 Final Tree Plan – 106th Ave SE Project Page 2 Layton Tree Consulting LLC March 4, 2024 Table of Contents Assignment.................................................................................................................................................... 3 Description .................................................................................................................................................... 3 Methodology ................................................................................................................................................. 3 Judging Condition...................................................................................................................................... 4 Observations ................................................................................................................................................. 4 Discussion/Recommendations ...................................................................................................................... 5 General Tree Protection Guidelines .............................................................................................................. 5 General Tree Protection Measures ............................................................................................................... 6 Tree Density-Tree Replacement ................................................................................................................... 6 Arborist Disclosure Statement ...................................................................................................................... 7 Attachments Photos, pages 8 - 17 Tree Summary Table – Retained Trees Tree Plan Maps North Map South Map Final Tree Plan – 106th Ave SE Project Page 3 Layton Tree Consulting LLC March 4, 2024 Assignment Layton Tree Consulting, LLC was asked to compile the final tree retention plan for the 11-lot subdivision project in Renton, located at 17018 and 17022 106th Avenue SE. This is a condition of approval for the construction permit application per the Hearing Examiners Final Decision report. My assignment is to assess and report on the trees to be retained at the site, and to provide appropriate recommendations for the continued protection of retained trees during construction. Date of Field Examination: March 1, 2024 Description The final tree retention plan needs to comply with the Hearing Examiners (Preliminary Plat) Final Decision as follows: Tree Retention. As conditioned, adequate tree retention and mitigation is achieved. The applicant submitted a Conceptual Landscape and Tree Retention Plan (Ex. 8). A total of 69 significant trees were identified on the project site. Of these, 11 trees are located within areas of proposed right-of-way dedication, which results in 58 remaining significant trees on- site. Based on the City' s retention requirement of 30 percent, the applicant is required to retain or replace 17 trees on the project site. The applicant has identified 15 trees as viable for retention. The applicant is therefore required to for the removal of 2 significant trees through the installation of 12 2- inch caliper trees. The Conceptual Landscape Plan proposes the planting of 51 3- inch caliper trees, which exceeds the minimum tree replacement requirements. In addition, each lot includes the minimum two (2) trees required per 5, 000 square feet for compliance with the minimum tree density requirements. The site has been recently cleared and mass-graded. The majority of utilities have been installed. See pictures below. There are 20 significant trees remaining at the site. Five of these (Trees #105, #106, #107, #145 and #146) are not viable for retention. Their health and structural stability have been or will be compromised by house and/or driveway construction. 15 trees are feasible for retention at the site. These are the subject of this report. Methodology Each tree in this report was visited. Tree diameters were measured by tape. Each tree was visually examined for defects and vigor. The tree assessment procedure involves the examination of many factors: • The crown or canopy of the tree is examined for current vigor/health by examining the foliage for appropriate color and density, the vegetative buds for color and size, and the branches for structural form and annual shoot growth; and the overall presence of limb dieback and/or any disease issues. • The trunk or main stem of the tree is inspected for decay, which includes cavities, wounds, fruiting bodies of decay (conks or mushrooms), seams, insect pests, bleeding or exudation of sap, callus development, broken or dead tops, structural defects and unnatural leans. Structural defects can include but are not limited to excessive or unnatural leans, crooks, forks with V-shaped crotches, multiple attachments. Final Tree Plan – 106th Ave SE Project Page 4 Layton Tree Consulting LLC March 4, 2024 • The root collar and exposed surface roots are inspected for the presence of decay, insect damage, as well as if they have been injured or wounded, undermined or exposed, or the original grade has been altered. Judging Condition The three condition categories are described as follows: Good – free of significant structural defects, no disease concerns, minor pest issues, no significant root issues, good structure/form with uniform crown or canopy, foliage of normal color and density, average or normal vigor, will be wind firm if isolated or left as part of a grouping or grove of trees, suitable for its location Fair – minor to moderate structural defects not expected to contribute to a failure in near future, no disease concerns, moderate pest issues, no significant root issues, asymmetric or unbalanced crown or canopy, average or normal vigor, foliage of normal color, moderate foliage density, will be wind firm if left as part of a grouping or grove of trees, cannot be isolated, suitable for its location Poor – major structural defects expected to cause fail in near future, disease or significant pest concerns, decline due to old age, significant root issues, asymmetric or unbalanced crown or canopy, sparse or abnormally small foliage, poor vigor, not suitable for its location The attached Tree Summary Table provides specific information on tree sizes and dripline measurements. Observations Trees to be retained are described as follows: Tree #101 is a semi-mature Douglas fir located in the back, northeast corner of the property. It has developed good structural form and is of decent vigor. Overall condition is rated as ‘fair-to-good’. There have been no impacts to the tree to date. Tree #108 is a semi-mature Western red cedar. It was topped many years ago at roughly 30-feet above ground. It has developed multiple new tops as a result of the past topping. New tops appear to be soundly attached. Vigor is good. Foliage is of normal color and density. Condition is ‘fair-to-good’. There have been no impacts to the tree to date. Trees #118, #119, #120, #121 and #124 are a grouping of semi-mature Douglas fir in the northwest corner of the site. All are of good vigor and have developed sound structural form. There has been some minor ground disturbance north of Tree #120. All are in ‘good’ condition. Trees #147, #148 and #149 are two semi-mature Douglas fir and an oak located on the east perimeter adjacent to 106th Avenue SE. These have been recently impacted on all sides by utility installations and grading. Impacts to date are significant but do not appear to have compromised the structural stability. These are in ‘fair-to-good’ condition. Final Tree Plan – 106th Ave SE Project Page 5 Layton Tree Consulting LLC March 4, 2024 Trees #159 > #162 are a row of four semi-mature Western red cedar. All are of good vigor with foliage of normal color and density. #159 and #160 were topped many years ago. They have developed multiple new tops as a result of the past topping. New tops appear to be soundly attached. Condition is ‘fair-to-good’. #161 and #162 are in good condition with no concerning issues. There has been some minor disturbance to outer north dripline areas where surface roots have been exposed and damaged. Tree #163 is a young to semi-mature variety of linden. It is comprised of three small-diameter stems that fork near ground level. Condition is ‘fair-to-good’. There have been no impacts to the tree to date. Discussion/Recommendations The 15 trees to be retained at the site are well-positioned for successful preservation and appear structurally stable at this time. Their stability has not been compromised by the recent removal of trees from the site. Most will not be significantly impacted by new improvements. The attached tree plan maps indicate trees to be retained and their driplines. Prior to commencing with home construction, the tree protection fencing shall be securely positioned around retained trees as shown on the attached maps. There have been recent impacts within the driplines of Trees #147, #148 and #149. Utility pipes have been installed at 8 to 10-feet west of the trunks, and there has been grading within the 8-feet of the trunks on the east side. The extent of the disturbance is unknown. Tree health shall be periodically monitored during the construction process. An inspection of tree health and risk is recommended just prior to the completion of the project. Other retained trees have not been significantly impacted to date. These can be expected to remain viable so long as the tree protection guidelines and measures as outlined below are adhered to. There have been minor disturbances to the outer dripline areas of Tres #162 and #163, which would have been eventually needed for dispersion trenches. Protection fencing can be positioned inside the driplines as shown on the attached map. The stability of Tree #108 will not be adversely affected by the removal of the adjacent cedar trees. The cut stumps of Trees #105, #106 and #107 shall be grinded down to below grade and not pulled. Pulling the stumps would cause unnecessary damage to Tree #108 whose roots will be intertwined with these trees. Maintain as much of the tree canopy on Tree #108 as possible so branches can continue to shade the lower trunk. Exposing the lower trunk to unfamiliar sun exposure will likely cause sun-scalding and cambium dieback on the southwest side, which will have a significant impact on future tree health. General Tree Protection Guidelines Tree protection fencing shall be positioned around any retained and/or protected trees prior to site demolition or bringing any heavy equipment onto the site. This will help to define clearing limits and protect soils and surface roots. Any roots damaged during site work outside of the tree protection fenced areas shall be pruned clean at sound tissue prior to backfilling or finishing areas. Sound tissue is where the root is undamaged and the bark is completely intact with the root. This will help roots to seal off potential decay and allow them to Final Tree Plan – 106th Ave SE Project Page 6 Layton Tree Consulting LLC March 4, 2024 sprout new growth. Any disturbed areas near protected trees shall be watered weekly during the dry season of June through September. This will help to create a favorable environment for new root growth and reduce the overall stress associated with root loss and disturbance. Simply finish the landscape within the driplines of retained trees by covering the ground with a 3 to 4- layer of organic mulch. Maintain the existing grades inside tree protection areas. Keep large plantings, irrigation trenching and construction of hardscapes outside of tree protection areas. All landscape work within the tree protection areas shall be completed by hand-labor only. General Tree Protection Measures The following guidelines are recommended to ensure that the designated space set aside for the retained trees is protected and construction impacts are kept to a minimum. Tree Protection Standards have been set forth under RMC 4-4-130 H. Performance Standards for Land Development/Building Permits; 10. Protection Measures During Construction. Review this code section prior to the start of work. • Tree protection fencing shall be erected per prior to moving any heavy equipment on site. Doing this will set clearing limits and avoid compaction of soils within root zones of retained trees. • Excavation limits shall be laid out in paint on the ground to avoid over excavating. • To establish sub grade for foundations, curbs and pavement sections near the trees, soil should be removed parallel to the roots and not at 90-degree angles to avoid breaking and tearing roots that lead back to the trunk within the drip-line. Any roots damaged during these excavations should be exposed to sound tissue and cut cleanly with a saw. • Areas excavated within the drip-line of retained trees should be thoroughly irrigated weekly during dry periods. • Preparations for final landscaping shall be accomplished by hand within the drip-lines of retained trees. Large equipment shall be kept outside of the tree protection zones at all times. Tree Density-Tree Replacement To my knowledge, the landscape or tree replacement plan for the project has not changed. The Conceptual Landscape Plan proposes the planting of 51 3- inch caliper trees, which exceeds the minimum tree replacement requirements. In addition, each lot includes the minimum two (2) trees required per 5, 000 square feet for compliance with the minimum tree density requirements. Final Tree Plan – 106th Ave SE Project Page 7 Layton Tree Consulting LLC March 4, 2024 Arborist Disclosure Statement Arborists are tree specialists who use their education, knowledge, training and experience to examine and assess trees, recommend measures to enhance the beauty and health of trees, and attempt to reduce the risks associated with living near trees. Clients may choose to accept or disregard the recommendations of the arborist, or to seek additional advice. Arborists cannot detect every condition that could possibly lead to the structural failure of a tree. Trees are living organisms that grow, respond to their environment, mature, decline and sometimes fail in ways we do not fully understand. Conditions are often hidden within trees and below ground. Arborists cannot guarantee that a tree will be healthy and/or safe under all circumstances, or for a specified period of time. Likewise, remedial treatments, like any medicine, cannot be guaranteed. Treatment, pruning and removal of trees may involve considerations beyond the scope of the arborist’s services such as property boundaries, property ownership, site lines, disputes between neighbors, and other issues. Arborists cannot take such considerations into account unless complete and accurate information is disclosed to the arborist. An arborist should then be expected to reasonably rely upon the completeness and accuracy of the information provided. Trees can be managed, but they cannot be controlled. To live near trees is to accept some degree of risk. The only way to eliminate all risk associated with trees is to eliminate all trees Final Tree Plan – 106th Ave SE Project Page 8 Layton Tree Consulting LLC March 4, 2024 Photo Documentation Tree #101 in back NE corner Tree #101 Final Tree Plan – 106th Ave SE Project Page 9 Layton Tree Consulting LLC March 4, 2024 Tree #108 on right Tree #108 on left Final Tree Plan – 106th Ave SE Project Page 10 Layton Tree Consulting LLC March 4, 2024 Tree #108 in foreground Trees #124, #120 and neighboring Tre #206 close to north property line Final Tree Plan – 106th Ave SE Project Page 11 Layton Tree Consulting LLC March 4, 2024 Trees #118 > #121 Upper crowns of trees pictured above Final Tree Plan – 106th Ave SE Project Page 12 Layton Tree Consulting LLC March 4, 2024 Looking northwest to Trees #118 > #121 Upper crowns of trees pictured above Final Tree Plan – 106th Ave SE Project Page 13 Layton Tree Consulting LLC March 4, 2024 Trees #147, #148 and #149 Recent utility work west of tree trunks Final Tree Plan – 106th Ave SE Project Page 14 Layton Tree Consulting LLC March 4, 2024 Recent grading work east of tree trunks (Trees #147, #148 and #149) Upper crowns of trees pictured above Final Tree Plan – 106th Ave SE Project Page 15 Layton Tree Consulting LLC March 4, 2024 Looking west down south property line to Trees #159 > #162 Trees #159 > #162 Final Tree Plan – 106th Ave SE Project Page 16 Layton Tree Consulting LLC March 4, 2024 Trees #159 > #162 on south perimeter Trees #160 > #162 Final Tree Plan – 106th Ave SE Project Page 17 Layton Tree Consulting LLC March 4, 2024 Tree #159 and #160, topped many years ago Tree #163 Layton Tree Consulting LLC For:Sapphire Homes Site:10718 106th Avenue SE - Renton Tree Summary Table Date: RETAINED TREES Tree/DBH Height Tag #Species (inches)(feet)Condition Comments N S E W 101 Douglas fir 23 95 10 12 10 16 Fair-Good foliage somewhat sparse 108 Western red cedar 36 75 18 20 12 20 Fair-Good topped in the past at +/-30-feet, multiple new tops 118 Douglas fir 28 110 8 10 12 10 Good good form and vigor 119 Douglas fir 29 120 6 14 10 6 Good good form and vigor 120 Douglas fir 23 90 14 12 10 16 Good good form and vigor 121 Douglas fir 16 80 6 10 12 6 Fair-Good minor crook 124 Douglas fir 31 120 12 8 12 12 Good good form and vigor 147 Douglas fir 30 120 16 8 12 14 Fair-Good recently impacted by utility work 148 Douglas fir 21 105 8 8 10 14 Fair-Good recently impacted by utility work 149 English oak 26 90 6 20 12 18 Fair-Good recently impacted by utility work 159 Western red cedar 20 45 14 12 8 12 Fair-Good topped in the past, multiple new tops 160 Western red cedar 17 50 14 10 10 8 Fair-Good topped in the past, multiple new tops 161 Western red cedar 22 55 12 12 10 10 Good good form and vigor 162 Western red cedar 25 60 12 12 10 6 Good good form and vigor 163 Linden 7,5,4 40 12 10 12 10 Fair-Good stems forked at base/root crown Dripline measurements from face of trunk Drip-Line (feet) 3/1/2024