Loading...
STF20180045 Hazard Tree Removal.pdfCITY OF EDMONDS 121 5th Avenue North, Edmonds WA 98020 Phone: 425.771.0220 • Fax: 425.771.0221 a Web: www.edmondswa.gov DEVELOPMENT SERVICES DEPARTMENT • PLANNING DIVISION November 29, 2018 Tyler Zimmerman 21819 — 93d Place West Edmonds, WA 98020 Subject: Hazard Tree Removal Dear Mr. Zimmerman, You have contacted the city regarding the removal of two hazard trees on your property located at 21819 — 93rd Place West. The property at 21819 — 93`d Place West does not fall into exemptions from tree cutting permitting requirements of ECDC 18.45.030, the subject trees are located in a critical area and/or critical area buffer. Slopes on the adjacent property to the east exceed 40% and slopes on other portions where the trees are located exceed 25% according to the City's LiDAR information. These areas are consider potential landslide and erosions hazards pursuant to ECDC 23.80. Generally the removal of trees, or any vegetation, within a critical area or critical area buffer is not an allowed activity, unless, pursuant to ECDC 23.40.220.C.8, it involves the removal of invasive species or hazard trees. An arborist report prepared by Ms. Katy Bigelow has documented that two alder trees on your property may be considered hazardous and has recommended the trees be removed. Pursuant to ECDC 23.40.220.C.8.b.iv each hazard tree removed within a critical area or critical area buffer must be replaced with new trees at a ratio of two to one. With two trees being removed, four replacement trees are required. Ms. Bigelow has recommended that the two alders be replaced with vine maple (Acer circinatum) and weeping Alska cedar (Chamaecyparis nootkatensis). An exemption for the tree cutting is granted with the following conditions: 1. This approval only pertains to the two trees evaluated in the attached arborist report. Four replacement trees must be planted in the general vicinity of the trees removed. The replacement trees must be native and indigenous in accordance with ECDC 23.40.220.C.8.b.iv. Evergreen replacement trees must be at least six feet in height as measured from the top of the root ball and deciduous trees must be a minimum of one — two inches diameter at breast height. The replacement trees must be planted within one year of tree the tree cutting activity. Vine maple (Acer circinatum) and weeping Alska cedar (Chamaecyparis nootkatensis) have been proposed as replacement trees. Either of these tree species would be appropriate. Alternative species must be approved by the City of Edmonds. 3. Stumps of the tree cut must be left in place to provide slope stability and prevent erosion. 4. Replacement trees must be planted within one year of removal of the hazard trees. Feel free to contact me if you have any questions at kernen.lien@edmondswa.gov, or 425-771-0220. �S eerely, t ,ernen Lien Environmental Programs Manager Encl: Katy Bigelow Arborist Report Dated October 24, 2018 Katy Bigelow 206.351.1375 arboristkaty@gmail.com October 24, 2018 Tyler Zimmerman 21819 93rd Pl West Edmonds, WA 98020 Dear Mr. Zimmerman: 5rr�ot�bnoys ►4ECEIV, eo A'OV 19 2018 ®EVELOPA4ENT SE COUNTER RVICE�4 Thank you for asking me to assess trees on your property in Edmonds, WA. To evaluate the trees 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 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 Mr. Zimmerman to assess a small grove of red alder (Alnus rubra) trees growing on a short slope east of his home. I completed a Level 2 tree assessment on October 18, 2018. All levels of tree assessment are explained in an attachment to this report. The Zimmerman's property has many semi -mature and mature native trees, most of which grow on a short and gentle slope east of the home. The grove of alder trees was not planted but likely established some time after the home was built. Two of the trees in the grove have significant defects causing the trees to pose risk to the Zimmerman's property (Photos I & 2, Map I ). Tree 1: Red alder: 10" DBH (Diameter at Breast Height) —This alder is located approximately 30 feet east of the Zimmerman's home. The lower trunk has a small open wound with visible rot extending into the base of the trunk. Its crown leans heavily towards the west over the lawn, nearly reaching the home (Photo 3). There is a moderate probability that this tree will fail at its base and a moderately high probability this tree will fail in its upper trunk. In either type of failure, the target is likely the Zimmerman's yard and home, both high value targets. I recommend that this tree is removed to the ground. • Remove all branches and foliage from the site and leave processed wood chips on site. • Long lengths of trunk can be left on site for nurse log or slope retention purposes if desired. Tree risk assessment - Zimmerman 21819 93 d PI W, Edmonds, WA 10/24/ 18 • If possible, grind the stump and spread stump grindings out along the slope. Alder 2: Red alder 15.5" DBH — This tree also grows apgroximately 30 feet east of the home. Its lower trunk has a very large horizontal open wound with extensive trunk rot Photo 4 . The tree leans to the west towards the home. There is a moderately high probability that this tree will fail in the open wound area and a moderately high probability this tree will fail in its upper trunk. Both failures again would affect the Zimmerman's home and yard areas. • Remove all branches and foliage from the site or leave wood chips after processed on site. • Long lengths of trunk can be left on site for nurse log or slope retention purposes if desired. • If possible, grind the stump and spread stump grindings out along the slope. In my professional opinion, the removal of the trees as specified above will result in a small amount of canopy coverage reduction and a minimal loss of ground water absorption currently provided by the trees. The area in and near which the two trees I evaluated are growing is considered an Environmentally Critical Area (Map 2) 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, four trees are required to be replanted. Due to limited space in the area close to the trees, the best two species to plant close to where the trees are recommended for removal are vine maple (Acer circinatum) and weeping Alaska cedar (Chamaecyparis nootkatensis). Replacement trees shall 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. Planting in the fall or winter months and surrounding the base of new plants with a few inches of mulch 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, 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 <:` Prepared by Katy Bigelow Page 2 of 10 Tree risk assessment - Zimmerman 21819 93" PI W, Edmonds, WA 10/24/18 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. Prepared by Katy Bigelow Page 3 of 10 Tree risk assessment - Zimmerman 21819 93" PI W, Edmonds, WA 10/24/18 Site Maps North Map 1: Approximate alder locations. <k Prepared by Katy Bigelow Page 4 of 10 Tree risk assessment - Zimmerman 21819 93d PI W, Edmonds, WA 10/24/18 I 21805 #01 Map 2: Critical area designation shown as yellow and red shading. Prepared by Katy Bigelow Page 5 of 10 � i2'rr � 1 A 1r • r _ ����Pic 4f* Abe. k • � 4b. Tree risk assessment - Zimmerman 21819 93" PI W, Edmonds, WA 10/24/18 Assumptions, Limiting Conditions and General Waiver I, Katy Bigelo7, 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 PNWISA member # PN-6039B PNW Certified Tree Risk Assessor # 199 Registered ConsultingArborlst® #490 <:W Prepared by Katy Bigelow Page 10 of 10