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Home My WebLink AboutRS_Arborist_Report_170712_v1 ARBORIST REPORT/TREE PLAN FOR KENNYDALE PROJECT PARCELS 3342700415, --420, --425, --427 RENTON, WA February 9, 2016 American Forest Management 2/9/2016 Table of Contents 1. Introduction .............................................................................................................. 1 2. Description ............................................................................................................... 1 3. Methodology ............................................................................................................ 1 4. Observations ........................................................................................................... 2 5. Discussion ............................................................................................................... 2 6. Tree Protection Measures ........................................................................................ 3 7. Tree Replacement ................................................................................................... 3 Appendix Site/Tree Photos – pages 5 – 8 Tree Summary Tables - attached Tree Conditions Map - attached Tree Protection Plan – attached Tree retention Worksheet - attached General Tree Protection Fencing Detail - attached Kennydale Arborist Report Page 1 American Forest Management 2/9/2016 1. Introduction American Forest Management, Inc. was contacted by Jamie Schroeder of CPH Consultants, and was asked to compile an ‘Arborist Report’ for four parcels located within the City of Renton. The proposed subdivision encompasses parcels 3342700415, --420, --425, --427. Our assignment is to prepare a written report on present tree conditions, which is to be filed with the preliminary permit application. This report encompasses all of the criteria set forth under City of Renton code section 4-4-130. The tree retention requirement is 30% of significant trees. Date of Field Examination: August 27th, 2015 2. Description 40 significant trees were identified and assessed on the property. These are comprised of a mix of native species and planted ornamental species. A numbered aluminum tag was placed on the lower trunks of the subject trees by the surveying crew. These numbers were used for this assessment. Tree tag numbers correspond with the numbers on the Tree Summary Tables and attached maps. There are only a few issues with neighboring trees. The property is bounded on three sides by roads. There are only two neighboring tree issues on the south property lines which are not anticipated to be concerning. 3. Methodology Each tree in this report was visited. Tree diameters were measured by tape. The tree heights were measured using a Spiegel Relaskop. Each tree was visually examined for defects and vigor. The tree assessment procedure involves the examination of many factors:  The crown of the tree is examined for current vigor. This is comprised of inspecting the crown (foliage, buds and branches) for color, density, form, and annual shoot growth, limb dieback and disease. The percentage of live crown is estimated for coniferous species only and scored appropriately.  The bole or main stem of the tree is inspected for decay, which includes cavities, wounds, fruiting bodies of decay (conks or mushrooms), seams, insects, bleeding, callus development, broken or dead tops, structural defects and unnatural leans. Structural defects include crooks, forks with V-shaped crotches, multiple attachments, and excessive sweep.  The root collar and roots are inspected for the presence of decay, insects and/or damage, as well as if they have been injured, undermined or exposed, or original grade has been altered. Based on these factors a determination of viability is made. Trees considered ‘non-viable’ are trees that are in poor condition due to disease, extensive decay and/or cumulative structural defects, which exacerbate failure potential. A ‘viable’ tree is a tree found to be in good health, in a sound condition with minimal defects and is suitable for its location. Also, it will be wind firm if isolated or left as part of a grouping or grove of trees. A ‘borderline’ viable tree is a tree where its viability is in question. These are trees that are beginning to display symptoms of decline due to age and or species related problems. Borderline trees are not expected to positively contribute to the landscape for the long-term and are not recommended for retention. The attached Tree Conditions Map indicates the viability of the subject trees. Kennydale Arborist Report Page 2 American Forest Management 2/9/2016 4. Observations The subject trees are comprised of a mix of native and planted species. Native species are comprised of red alder, Scouler’s willow, pacific madrone, Douglas-fir and black cottonwood. Planted species include redwood, Ponderosa pine, fruit trees, Colorado blue spruce, dogwood and Norway maple. Five of the 40 assessed trees are in poor condition and considered non-viable. These are described as follows: Tree #7866 is an over-mature apple variety. The lower trunk is extensively decayed. The subject will likely collapse within the next few years. Tree #7614 is another over-mature apple variety. Its productive life span is compromised by decay and disease. Tree #7217 is an over-mature purple-leaf plum or cherry plum, Prunus cerasifera. It is approximately 98% dead. The trunk and large laterals are cracked. Its structure is compromised by extensive internal decay. The subject will likely collapse within the next few years. See picture below. Tree #7771 is an over-mature red alder. It also has major basal and internal decay/rot. See picture below. The subject is high risk with a high potential for complete trunk failure. Tree #7777 is a semi-mature cluster of Scouler’s willow. Many of the stems are in premature decline. Most have developed advanced decay in the lower stems. Productive life span is likely less than five years. Additionally, five of the subject trees are considered ‘borderline’ viable, which are not recommended for retention. These are native pioneer hardwood species of black cottonwood, Scouler’s willow and red alder all with significant defects. These are not expected to positively contribute to the landscape for the next decade. 5. Discussion Of the 40 trees assessed, 30 are in a sound and healthy condition, and considered viable. Significant trees are scattered across the site. Five trees are proposed for retention/protection. These are primarily found on the south perimeter of the site. In order to properly protect retained trees, existing grades shall be maintained around them to the fullest extent possible. After review of the proposed design, the subject trees selected for retention can be successfully preserved in good condition, so long as the proper tree protection measures are taken. The drip-lines (farthest reaching branches) for the subject trees can be found on the tree summary tables at the back of this report. These have also been delineated on a copy of the development plan for trees proposed for retention. The information plotted on the attached plan may need to be transferred to a final tree retention/protection plan to meet City submittal requirements. The trees that are to be removed shall be shown “X’d” out on the final plan. The Limits of Disturbance (LOD) measurements can also be found on the tree summary table. This is the recommended distance of the closest impact (soil excavation or fill) to the trunk face. These should be referenced when determining tree retention feasibility. The LOD measurements are based on species, age, condition, drip-line, prior improvements, proposed impacts and the anticipated cumulative impacts to the entire root zone. Tree Protection fencing shall be initially located a few feet beyond the drip-line edge of retained trees per the attached plan, and only moved back to the LOD when work is authorized and ready to commence. The proposed water main line northwest of the large redwood tree #7819 is approximately 18’ from the trunk face. The recommended LOD is 16’. Any roots greater than 2” in diameter encountered during utility work shall be pruned clean to sound tissue prior to backfilling. Kennydale Arborist Report Page 3 American Forest Management 2/9/2016 The new sidewalk adjacent to Lake WA Blvd will be designed to afford Tree #7520 more space. The proposed sidewalk is outside of the recommended LOD. Impacts to the subject tree related to sidewalk improvements are not expected to be significant. There are no major conflicts concerning neighboring trees. The property is bounded on three sides by roads. Subject trees #7790 and #109 situated on the south perimeter are well positioned for retention. For Tree #7790, maintain existing grades within 8’ of the property line and 5’ for Tree #109. Keep retaining walls outside of tree protection zones. Finished landscaping work within the drip-lines of retained trees shall maintain existing grades and not disturb fine root mass at the ground surface. Finish landscape with beauty bark or new lawn on top of existing grade. Add no more than 2” to 4” of mulch/beauty bark or 2” of composted soil to establish new lawn. Raising the grade more than a few inches will have adverse impacts on fine roots by cutting off oxygen causing suffocation. 6. Tree Protection Measures The following general guidelines are recommended to ensure that the designated space set aside for the preserved trees are protected and construction impacts are kept to a minimum. 1. Tree protection fencing should be erected around retained trees and positioned just beyond the drip-line edge 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. 2. Any existing infrastructure to be removed within the drip-line or tree protection zone shall be removed by hand or utilizing a tracked mini-excavator. 3. Excavation limits should be laid out in paint on the ground to avoid over excavating. 4. Excavations within the drip-lines shall be monitored by a qualified tree professional so necessary precautions can be taken to decrease impacts to tree parts. A qualified tree professional shall monitor excavations when work is required and allowed within the “limits of disturbance”. 5. 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. Cutting tools should be sterilized with alcohol. 6. Areas excavated within the drip-line of retained trees should be thoroughly irrigated weekly during dry periods. 7. 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. Simply finish landscape within 10’ of retained trees with a 2” to 4” layer of organic mulch. 7. Tree Replacement Supplemental trees will likely be necessary to meet the retention requirement, given the low potential for successful tree retention. The tree retention calculation is based on 26 significant trees, not including high-risk or danger trees (6), or trees within proposed public streets (8). The retention requirement for the site is 30%, therefore, a total of 8 trees are required for retention per code. The following replacement requirements are necessary when retained/protected trees do not meet the minimum requirement per 4-4-130 H. Performance Standards for Land Development/Building Permits: e. Replacement Requirements: As an alternative to retaining trees, the Administrator may authorize the planting of replacement trees on the site if it can be demonstrated to the Administrator’s satisfaction that an insufficient number of trees can be retained. Kennydale Arborist Report Page 4 American Forest Management 2/9/2016 i. Replacement Ratio: When the required number of protected trees cannot be retained, replacement trees, with at least a two-inch (2") caliper or an evergreen at least six feet (6') tall, shall be planted at a rate of twelve (12) caliper inches of new trees to replace each protected tree removed. Up to fifty percent (50%) of trees required pursuant to RMC 4-4-070, Landscaping, may contribute to replacement trees. The City may require a surety or bond to ensure the survival of replacement trees. The proposal is to retain or protect five significant trees, therefore three will need to be replaced per the above. This will require the supplemental planting of 18 – 2” caliper replacement trees for a total replacement of 36 caliper inches (3 X 12). Nine of these will be satisfied by landscaping requirements so an additional nine will be required above the minimum density requirement of two trees per lot. The Tree Retention Worksheet is attached. New tree plantings shall be given the appropriate space for the species and their growing characteristics. Confer with the City’s Urban Forester for appropriate replacement species. For planting and maintenance specifications, refer to municipal code 4-4-070 Landscaping. There is no warranty suggested for any of the trees subject to this report. Weather, latent tree conditions, and future man-caused activities could cause physiologic changes and deteriorating tree condition. Over time, deteriorating tree conditions may appear and there may be conditions, which are not now visible which, could cause tree failure. This report or the verbal comments made at the site in no way warrant the structural stability or long term condition of any tree, but represent my opinion based on the observations made. Nearly all trees in any condition standing within reach of improvements or human use areas represent hazards that could lead to damage or injury. Please call if you have any questions or I can be of further assistance. Sincerely, Bob Layton ISA Certified Arborist #PN-2714A Tree Risk Assessment Qualified (TRAQ) Kennydale Arborist Report Page 5 American Forest Management 2/9/2016 Tree #7771 – Non-viable Tree #7217 – Non-viable Kennydale Arborist Report Page 6 American Forest Management 2/9/2016 Tree #7785 (left), neighboring tree #7790 (right) Neighboring Tree #7172 Kennydale Arborist Report Page 7 American Forest Management 2/9/2016 Southwest portion of property Overview of property looking west Kennydale Arborist Report Page 8 American Forest Management 2/9/2016 Large girdling root on tree 7962 Tree Summary Table American Forest Management, Inc. For:Kennydale Project Date:8/27/2015 Renton Inspector:Layton Native/ Planted/ Tree/Tag #Species VolunteerDBH Height Condition Viability Comments N S E W 7785 burgundy Norway maple P 35 63 27/16 25/NA 25/15 24/15 FAIR-GOOD VIABLE LARGE SPREADING CROWN 7217 purple-leaf plum P 16 22 X X X X POOR NON-VIABLE 95% DEAD, CRACKED 7696 Pacific madrone N 12 22 14/10 5/10 8/8 13/10 FAIR-GOOD VIABLE YOUNG, NATURAL LEAN 101 Pacific madrone N 11 24 12/8 10/8 10/8 8/8 GOOD VIABLE YOUNG 102 big leaf maple N 10 32 14/8 12/8 12/8 12/8 FAIR VIABLE YOUNG, FORKED TOP 7962 black cottonwood N 17 52 18/14 16/14 13/10 15/12 FAIR-POOR BORDERLINE LARGE GIRDLING ROOT, CROOKED TRUNK 7520 western red cedar N 22 46 14/12 18/16 14/12 18/14 GOOD VIABLE NO CONCERNS 103 European white birch V 11 44 10/8 12/8 8/8 10/8 FAIR VIABLE TYPICAL 7783 Douglas-fir P 15 41 14/10 14/10 14/10 12/10 GOOD VIABLE YOUNG, FULL CROWN 7784 Douglas-fir P 15 45 14/10 14/10 8/10 12/10 GOOD VIABLE YOUNG, FULL CROWN 7772 red alder N 15 48 14/10 10/10 14/10 14/10 FAIR-POOR BORDERLINE LARGE CAVITY, SIGNIFCANT DECAY 7771 red alder N 23 50 X X X X POOR NON-VIABLE EXTENSIVE TRUNK ROT, DYING TOP, HIGH RISK 7780 Scouler's willow N 14 43 12/10 12/10 8/8 10/8 FAIR VIABLE TYPICAL 7778 black cottonwood N 11 43 6/8 6/8 6/8 8/8 FAIR VIABLE YOUNG, POOR FORM 7777 Scouler's willow N 6"-8"40 X X X X POOR NON-VIABLE CLUSTER, DECAY, DECLINE 7782 western red cedar N 15 40 10/6 12/10 10/10 10/10 FAIR VIABLE BROKEN TOP, GOOD COLOR 7770 Colorado blue spruce P 12 28 8/6 10/10 8/8 8/8 FAIR-GOOD VIABLE NATURAL LEAN SOUTH, TYPICAL 7765 red alder N 13,11 48 16/10 8/10 16/10 12/10 FAIR-POOR BORDERLINE FORKED AT ROOT CROWN, WEAKLY ATTACHED 104 weeping willow P 12 33 16/10 10/10 16/10 12/10 FAIR VIABLE INJURED TRUNK, OKAY FOR NOW 7766 Douglas-fir N 21 56 16/14 18/16 14/12 16/14 GOOD VIABLE YOUNG TO SEMI-MATURE 105 Italian plum V 6"-12"32 12/10 16/10 14/10 16/12 FAIR-POOR BORDERLINE HEAVY LEANS, SOME DECLINE, SUPPRESSED 7536 redwood P 35,38 86 20/16 23/18 24/18 20/18 GOOD VIABLE LARGE SPECIMENS 7866 apple P 16 30 X X X X POOR NON-VIABLE EXTENSIVE ROT, MATURE 7865 apple P 12,12 30 10/10 12/10 8/10 12/10 FAIR VIABLE TYPICAL 7535 Ponderosa pine P 28 82 16/12 25/16 12/12 12/12 FAIR VIABLE FORKED TOP, MODERATE RISK 7534 Ponderosa pine P 19 76 13/10 14/12 8/10 10/10 FAIR VIABLE FORKED TOP, MODERATE RISK 106 pear P 10,9 14 6/8 10/8 8/8 10/8 FAIR VIABLE HEAVILY PRUNED 7532 Ponderosa pine P 22 72 12/14 12/14 12/12 10/12 FAIR VIABLE TYPICAL 7531 European white birch V 13 56 10/10 14/10 10/10 8/10 FAIR VIABLE TYPICAL Drip-Line measurements from face of trunk Drip-Line (feet) Tree Summary Table American Forest Management, Inc. For:Kennydale Project Date:8/27/2015 Renton Inspector:Layton Native/ Planted/ Tree/Tag #Species VolunteerDBH Height Condition Viability Comments N S E W 7530 Ponderosa pine P 34 82 18/14 24/16 12/14 16/14 GOOD VIABLE NO CONCERNS 7529 Colorado blue spruce P 15 34 12/12 10/12 14/12 10/12 GOOD VIABLE YOUNG 7528 pacific madrone N 12 25 10/10 16/12 8/10 12/10 FAIR VIABLE TYPICAL 7614 apple P 16 18 X X X X POOR NON-VIABLE OVER-MATURE 107 noble fir P 10 30 6/7 5/7 5/7 6/7 FAIR VIABLE LARGE FROST CRACK 108 dogwood P 10 18 8/8 10/8 10/8 8/8 FAIR VIABLE TOPPED IN PAST 7657 apple P 12 22 8/8 12/NA 10/8 13/10 FAIR VIABLE HEAVILY PRUNED 7819 redwood P 56 73 28/18 NA 26/18 22/16 GOOD VIABLE TYPICAL 7820 European white birch V 9,11 51 16/8 NA 10/8 8/10 FAIR VIABLE TYPICAL 7821 Colorado blue spruce P 25 70 14/12 NA 12/10 14/14 GOOD VIABLE NO CONCERNS 110 Scouler's willow N 4"-7"30 18/12 16/12 14/10 12/12 FAIR BORDERLINE LARGE CLUSTER, SHORT-LIVED 7172 big leaf maple N 16 40 13/8 NA 19/12 15/12 FAIR VIABLE MULTIPLE TRUNKS 7790 black locust V 15,10,12 68 10/8 NA 10/10 16/12 FAIR VIABLE MATURE 109 Japanese maple P 8 24 10/8 NA 8/8 12/10 FAIR VIABLE TYPICAL Drip-Line measurements from face of trunk Drip-Line (feet) NEIGHBORING TREES