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STF20200002 hazard tree removalCITY OF EDMONDS 121 5t" Avenue North, Edmonds WA 98020 Phone: 425.771.0220 • Fax: 425.771.0221 • Web: www.edmondswa. DEVELOPMENT SERVICES DEPARTMENT • PLANNING DIVISION /pc. 189v January 29, 2020 Stacee Franks 8732 2091" PI SW Edmonds, WA 98026 Subject: Hazard Tree Removal (STF20200002) Dear Stacee, You contacted the City of Edmonds regarding removal of a birch tree at the top of a steep slope at your property at 8732 209t" PI SW. The slope on the east side of your lot is considered to be a critical area (geological hazard) with a slope in excess of 25% (approximately 45%). The removal of trees or vegetation from within a critical area or critical area buffer is not an allowed activity unless it involves the removal of invasive species or hazard trees pursuant to Section 23.40.220.C.8 of the Edmonds Community Development Code (ECDC). Normal maintenance of vegetation is an exempt activity in critical areas, however. "Normal maintenance of vegetation" is defined as "removal of shrubs/nonwoody vegetation and trees (less than four -inch diameter at breast height) that occurs at least every other year. Maintenance also may include tree topping that has been previously approved by the city in the past five years." In this case, the tree is in excess of four inches in diameter (8.5") and has not been maintained recently so it is subject to the hazard tree documentation requirement in ECDC 23.40.220.C.8.b. According to the submitted report prepared by certified arborist Katy Bigelow, the birch is infested with bronze birch borer and the canopy of the tree is dead. Removal of the birch at ground level is recommended to mitigate the hazard. An exemption for hazard tree removal is granted with the following conditions: 1. The subject birch tree may be removed using a ground -level cut. 2. All downed wood should be removed from the site to minimize possible pest transmission. 3. Tree replacement must be at a minimum 2:1 ratio near the birch location (or elsewhere on the site if the birch area is already well vegetated). The species recommended in the report may be used or similar tree species native to the Pacific Northwest may be substituted. Replacement trees must be a minimum of one to two inches in diameter at breast height (dbh) for deciduous trees and a minimum of six feet in height for evergreen trees as measured from the top of the root ball. 4. The replacement trees must be planted within one year of removal of the hazard birch. Call for an inspection once the replacement trees have been installed. If you have any questions, please let me know at either michael.clugston@edmondswa.gov or 425-771-0220. Sincerely, Mike Clugston, AICP Senior Planner Encl: Arborist report received January 28, 2020 Katy Bigelow 206.351.1375 arboristkaty@gmail.com January 23, 2020 Stacee Franks 8732 209th Pl. SW Edmonds, WA 98026 Dear Mrs. Franks: Thank you for asking me to assess trees on your property in Edmonds, WA. To evaluate the tree addressed in this letter I combined my field experience and education with the current accepted practices as defined by the American National Standards Institute (ANSI) and the International Society of Arboriculture (ISA). The tools I use to make an assessment are limited to a rubber mallet, binoculars, compass, laser pointer, diameter tape and hand trowel unless otherwise noted. A visual tree assessment and other methods are only conclusive for the day of inspection and do not guarantee that conditions will remain the same in the future. I was asked by Mrs. Franks to assess one birch (Betula pendula) tree growing at the top of a slope east of her home (Photo 1). I completed a Level 2 tree assessment on January 17, 2020. All levels of tree assessment are explained in an attachment to this report. The Franks' property is densely vegetated with mature native tree species and dense understory. The property is flat on the western portion and then steeply slopes to the east. One non-native ornamental birch tree stands just northeast of the corner of the home, at the tope of the slope. It is very young and measures 8.5" DBH (Diameter at Breast Height). It is approximately 25' tall. I previously inspected this tree for a prior property owner in January 2018. Since that time the tree has become infested with bronze birch borer, a serious pest to birch trees. The top of the tree (crown) has now died down approximately eight feet (Photo 2) though I observed boring sites as low down on the trunk as seven feet. Bronze birch borer will ultimately kill the tree. There is a high probability dead pieces of the upper trunk will (as they already have started to) fail onto the area around the tree. This type of failure could damage the homes roof, gutters, an off property deck structure, nearby good condition trees and shrubs or people below. Although the size of pieces that will fail right now are relatively small, the progression of death in this tree Tree risk assessment - Franks 8732 209th P1 SW, Edmonds, WA 1/23/20 has been fast and can be expected to continue along this time line. This means that larger and larger pieces and, eventually the entire tree, will fail. Creating a snag out of this tree is not recommended due to the limited planting area on this site. If the tree is allowed to be removed entirely, new trees can be planted close by to mitigate its removal and establish quickly to fill in the site. At this point I recommend that the tree is removed to the ground and debris removed from the site to prevent tinder buildup close to the home in an already densely vegetated area. • Remove all branches and foliage from the site. • Leave processed wood chips on site if desired. • Leave long lengths of logs on site if desired. In my professional opinion, the removal of the tree as specified above will result in a small percentage of canopy coverage reduction from the entire site and a minimal loss of ground water absorption currently provided by the tree. The area near which the tree I evaluated is growing is considered an Environmentally Critical Area (Map 1) as designated by the City of Edmonds and a permit is required before trees are removed in these areas. Replanting to mitigate live tree removal in Environmentally Critical Areas is currently specified at 2:1 (replaced: removed) ratio. In this case, two trees are required to be replanted. Replacement trees should be a minimum of one to two inches D13H for deciduous trees and a minimum of six feet in height for evergreen trees as measured from the top of the root ball. Due to limited space on the entire property that is not already vegetated, the best species to use for replanting include dogwood species (Cornus species), vine maple (Acer circinatum), small cultivars of Western red cedar (Thuja plicata) and weeping Alaska cedar (Chamaecyparis nootkatensis). Planting in the fall or winter months and surrounding the base of new plants with a few inches of mulch (wood, not bark chips) can help new trees establish. Water should be provided to keep at least the top three inches of soil moist during summer months within the first year after trees are planted. If planted near each other or near an existing tree, leave at least ten feet between each new tree. Thank you very much for calling me for your arboricultural concerns. Katy Bigelow Board Master Certified Arborist PNW ISA member # PN-6039B PNW Certified Tree Risk Assessor # 199 Registered Consulting Arborist® #490 43P Prepared by Katy Bigelow Page 2 of 7 Tree risk assessment - Franks 8732 209th PI SW, Edmonds, WA 1/23/20 Levels of Tree Assessment LEVEL 1: The Level 1 assessment is a visual assessment from a specified perspective of an individual tree or a population of trees near specified targets to identify obvious defects or specified conditions. A limited visual assessment typically focuses on identifying trees with an imminent and/or probable likelihood of failure. Limited visual assessments are the fastest but least thorough means of assessment and are intended primarily for large populations of trees. LEVEL 2: This is a basic assessment completing a detailed visual inspection of a tree and surrounding site, and a synthesis of the information collected. This assessment requires that a tree risk assessor walk completely around the tree looking at the site, buttress roots, trunk, and branches. A basic assessment may include the use of simple tools to gain additional information about the tree or defects. Basic is the standard assessment that is performed by arborists in response to a client's request for tree risk assessment. Simple tools may be used for measuring the tree and acquiring more information about the tree or defects. However, the use of these tools is not mandatory unless specified in the Scope of Work. LEVEL 3: Advanced assessments are performed to provide detailed information about specific tree parts, defects, targets, or site conditions. They are usually conducted in conjunction with or after a basic assessment if the tree risk assessor needs additional information and the client approves the additional service. Specialized equipment, data collection and analysis, and/or expertise are usually required for advanced assessments. These assessments are therefore generally more time intensive and more expensive. ' t' Prepared by Katy Bigelow Page 3 of 7 Tree risk assessment - Franks 8732 209th PI SW, Edmonds, WA 1/23/20 Site Map 1 North Map 1: Steep slope designation shown in red. Approximate tree location shown by the star. ' t' Prepared by Katy Bigelow Page 4 of 7 Tree risk assessment - Franks 8732 209th PI SW, Edmonds, WA 1/23/20 Assumptions, Limiting Conditions and General Waiver I, Katy Bigelow, certify that: I have personally inspected the tree(s) and or the property referred to in this report; I have no current or prospective financial or other interest in the vegetation or the property which is the subject of this report and have no personal interest or bias in favor of or against any of the involved parties or their respective position(s), if any; The analysis, opinions and conclusions stated herein are the product of my independent professional judgment and based on current scientific procedures and facts, and the foregoing report was prepared according to commercially reasonable and generally accepted arboricultural standards and practices for the Pacific Northwest and Puget Sound areas; The information included in this report covers only those trees that were examined and reflects the condition of the trees as of the time and date of inspection; This report and the opinions expressed herein are not intended, nor should they be construed, as any type of warranty or guarantee regarding the condition of the subject trees in the future; Covenants, Conditions, and Restrictions ("CC&Rs") may restrict the number, type and height of vegetation on the subject property, and I have made no investigation regarding whether the property is subject to such CC&Rs; and To the best of my knowledge and belief, all statements and information in this report are true and correct and information provided by others is assumed to be true and correct. I am not an attorney or engineer. This report does not cover these areas of expertise and represents advice only of arboricultural nature. Without limiting the generality of the preceding sentence, it is specifically understood that nothing contained in this report is intended as legal advice, or advice or opinions regarding soil stability or zoning laws, and this report should not be relied upon to take the place of such advice. Katy Bigelow Board Master Certified Arborist PNW ISA member # PN-6039B PNW Certified Tree Risk Assessor # 199 Registered Consulting Arborist® #490 Prepared by Katy Bigelow Page 7 of 7