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Hazard Tree Removal Approval.pdfCITY OF EDMONDS 121 5th Avenue North, Edmonds WA 98020 Phone: 425.771.0220 o Fax: 425.771.0221 • Web: www.edmondswa.gov DEVELOPMENT SERVICES DEPARTMENT • PLANNING DIVISION I'I c . 18 9" November 27, 2019 Jola Stephenson 905 — 7th Avenue N Edmonds, WA 98020 Subject: Hazard Tree Removal Dear Ms. Stephenson, The City of Edmonds has received a request to remove Douglas fir tree from your property located at 905 — 7th Avenue North. The tree is located in your back yard approximately 67 feet from Shell Creek. Shell Creek is an anadromous fish bearing stream, which is a critical area with buffer of 100 feet pursuant to Chapters 23.90 of the Edmonds Community Development Code (ECDC). 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. In order to fall under the hazard tree provisions of ECDC 23.40.220.C.8.b a tree must be determined to be a high risk by a certified arborist. The request to remove the tree included an ISA Tree Risk Assessment form completed by certified arborist Zsofia Pasztor who found the tree to have an overall tree risk rating of "High". 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. It has been indicated that you propose to replace the Douglas fir a cascara tree (Rhamnus purshiana) and a vine maple (Acer circinatum). An exemption for the tree cutting is granted with the following conditions: 1. This approval only pertains to the Douglas fir tree identified in the attached materials. 2. Two tree must be planted to replace the subject Douglas fir tree. The replacement trees must be native and indigenous in accordance with ECDC 23.40.220.C.8.b.iv. The proposed replacement trees of cascara and vine maple are appropriate replacement tree species. Alternative species must be approved by the City of Edmonds. 3. Replacement trees must be planted within one year of removal of the hazard trees. Please notify the City once the replacement trees have been replanted for an inspection. Feel free to contact me if you have any questions at kernen.lien @edmondswa.gov, or 425-771-0220. Sincerely, 1 Kernen Lien Environmental Programs Manager Encl: Cover Letter ISA Tree Risk Assessment Form L.C. Lee & Associates, Inc. Technical Memorandum Site Plan Photos RECEIVED NOV 25 2 19 Jola Stephenson, property owner DEVELOPMENT SERVICES 905 7th Ave. N. Edmonds, WA 98020. COUNTER This tree is damaging property with it's roots and parts of it's root system is rotting. Tree poses a threat to property and persons should it fall. As you can see from the aerial photograph, Shell Creek is nearly completely obscured and shaded by a number of other trees on this property including 3 Western Red Cedars, a Broad leaf Maple, two Wild Black Cherries all located within 10 feet of Shell Creek. Other trees in this yard and a large Douglas Fir in the neighbors yard to the South also shade the creek. The tree needing removal is providing virtually no shade for the creek and it's base is located approximately 67 feet from the creek and near the high point of the property. Tree= Doug fir. Diameter 42 inches at 4.5 feet above ground (DBH) growiing in shallow sandy soil found throughout the property. Distance of tree to CMU (concrete masonry unit) foundation, 17 feet. Distance of tree to root up heaved concrete slab, 11 feet. Slab up heaved to CMIJ foundation. Distance of tree to sink hole, 12 feet. Sink hole is 6 feet diameter, 10 inches deep and has developed over the last two and a half years. During storms when hit with big gusts windward base of tree has been observed to raise. Tree is now leaning away from direction of wind of most storms (SE to SW) and towards house. Occupants will no longer sleep on main floor during wind storms due to danger of this tree falling. Sleeping in basement is not totally secure either as egress may be blocked by fallen tree. All trees fall eventually. Being able to choose when and how this dangerous tree will come down will eliminate the possibility of damage to property, personal injury and or loss of life. An ISA certified arborist has determined that this tree is a hazard citing roots and root collar section rotting, tree lifting in wind, Likelihood of Failure: Imminent. Entire tree Likelihood of Failure:Probable, Impact:High, Failure and Impact:Very Likely, Consequences: Severe Mitigations Options:Remove. Technical Memorandum prepared by geotech firm concurs that tree is a hazard and recommends removal. Two trees of native species (Cascara, Rhamnus purshiana and Vine maple, Acer circinatum) will be planted closer to the creek and away from the house. Basic Tree Risk Assessment Form Client vA Date ( 1 1il ��� - Time Address/Tree location Tree no, Sheet of Tree species •� dbh :�Height t�� Crown spread dia. Assessors) , - J Time frame ��.� Tools used / Target Assessment Target description Target zone Occupanry late 1-rJf2 a -occasional 3—frequent 4 —constant pp � P M t— >< ii 3 \ '� 4 Site racw,a t Topography Flat❑ Slope lam/ % Aspect History of failures Aspect Site changes None Grade change Site clearing Changed soil hydrology Rootcuts❑ Describe Soil conditions Limited volump ❑ Saturated ❑ Shallows Compacted ❑ Pavement over roots.'Q % Describe Prevailing wind direction. �' Common weather Strong winds QR Snow ❑ Heavy rain Describe Tree Health and Species Profile Vigor Low ❑ Normal.0S High ❑ Foliage None (seasonal) ❑ None (dead) ❑ Normal ) % Chlorotic % Necrotic % Pests Ablotic Species failure profile Branched• Trunkl�Roots Describe Load Factors Wlnd exposure Protected ❑ Partials Full ❑ Wind funneling ❑ Relative crown size Small ❑ Mediu Large ❑ Crowndensity SparseO NormV6 Dens70 Interior branches Few❑ • Ns[tnal Den e❑ Vigs/Mistletoe/M*qss Recent or planned change In load factors ' IA A T� Tree Defects and Conditions Affecting the Likelihood of Failure Crown and Branches — Unbalanced crown LCR% Cracks ❑ Lightning damage ❑ Dead twigs/branches ❑%overall Max. dia. Codominant ❑ Inducted bark ❑ Broken/Hangers Number Max. dia. Weak attachments Cavity/Nest hole _ry`p-circ. Over -extended branches ❑ Previous branch failures` jnk J& 't Similar branches presf 7 ❑ Pruning history Dead/Missing bark ❑ Cankers/Galls/Burls ❑ Sapwood damage/decay O Crown cleaned ❑ Thinned ❑ Raised ❑ Conks ❑ Heartwood decay ❑ Reduced ❑ Topped ❑ Lion -tailed ❑ Flush cuts ❑ Other Response growth pp Main concern(s) t''-'-'-"—� t ` LAI load on defect N/A ❑ Minor ❑ , Moderate ❑ Significantsl Likelihood of failure Improbable ❑ Possiblp� Probable ❑ Imminent ❑ —Trunk — — Roots and Root Collar — Dead/Missing bark ❑ Abnormal bark texture/color ❑ Collar buried/Not visible ❑ Depth Stem girdling ❑ Codominant stems ❑ included bark ❑ Cracks ❑ Dead ❑ Decay ❑ Conks/Mushrooms ❑ Sapwood damage/decay ❑ Cankers/Galls/Buris❑ sap ooze ❑ Ooze ❑ Cavity ❑ %clrc. Lightning damage ❑ Heartwood decay ❑ Conks/Mushrooms ❑ Cracks ❑ Cut/Damaged roots ❑ Distance from trunk Cavity/Nest hole %circ. Depth Poortaper ❑ Root plate lifting Soil weakness Lean " Corrected? _ Response growth Response growth Main concern(s) Main concern s) L�l �l (A1 `) �M Load on defect N/A ❑ Minor ❑ Moderate ❑ Significant ❑ Load on defect N/A ❑ Minor ❑ Moderate ❑ Significantt likelihood of failure Likelihood of failure Improbable ❑ Possible ❑ Probable ❑ Imminent ❑ Improbable ❑ Possible ❑ Probable ❑ Immine Pa OP- 1 of 2 Risk Categorization IMMIX mi, I ■■0■■■��■i9!lll.�3 mmm�mmonommimomm MEMO MEN WMM�0000000 0000000MM Matrix 1. Likelihood matrbc. Likelihood of Failure Likelihood of Impacting Target Very low Low Medium High Imminent Unlikely Somewhat likely Likely Very likely Probable Unlikely Unlikely Somewhat likely Likely . Possible Unlikely Unlikely Unlikely Somewhat likely Improbable Unlikely Unlikely Unlikely Unlikely Matrix2. Risk rating matrix. Likelihood of Failure & Impact Consequences of Failure Negligible Minor Significant Severe Very likely Low Moderate High Extreme Likely I Low Moderate High High Somewhat likely Low Low Moderate Moderate Unlikely Low Low Low Low Notes, explanations, North ->t Mitigation options A 4Residrisk risk Residual risk Residual risk Overall tree risk rating Low ❑ Moderate ❑ 1,1!61 O' Extreme ❑ Work priority 1X'2 ❑ 3 ❑ 4 ❑ Overall residual risk Lov;,G Moderate ❑ High ❑ Extreme ❑ Recommended inspection interval Data�ifinal ❑ Preliminary Advanced assessment needed)Ex/No ❑Yes-Type/Reason Inspection Ilmitations�None ❑Visibility ❑Access ❑Vines ❑Root collar buried Describe This datasheet was produced by the International Society of Arboriculture (ISA) and is intended for use by Tree Risk Assessment Qualified (TRAQ) arborists — 2013 Page 2 of 2 L.C. Lee & Associates, Inc. 421 North Forest Street Bellingham, Washington 98225 Tel: 206.979.5633 Email. flyndon@lcleeinc.com] Technical Memorandum November 12, 2019 To: Ms. Jola Stephenson 905 T" Avenue North Edmonds, Washington 98020 From: Lyndon C. Lee, Ph.D., PWS L.C. Lee & Associates, Inc. CC: LCLA/cf Ref. Hazard Tree Removal R1EcEiido=® I)EVELOPWIENT SERVICES MINTER This Technical Memorandum has been prepared at the request of Ms. Jola Stephenson. She resides at 905 7"' Avenue North, Edmonds, Washington 98020. The Snohomish County Tax Parcel Number for the lot is 27032400201000. This parcel is located within the Shell Creek Watershed. The western portion of the lot includes a reach of the main channel of Shell Creek and its riparian zone and Critical Area Buffer. Shell Creek is a fish bearing stream with documented runs of Coho and Chum salmon in its lower reaches. On September 18, 2019, Ms. Stephenson received a Basic Tree Risk Assessment from ISA arborists. They concluded that the large Douglas -fir (Pseudotsuga rnenziesii) specimen in her back yard has a high risk rating and should be removed to protect nearby houses and their residents, fences, and other infrastructure. I have examined this tree several times and agree with the ISA assessment. In particular, I am concerned that the tree is large and rooted on moderately sloping and historically graded terrain that forms the transition from Ms. Stephenson's backyard lawn to the riparian zone and main channel of Shell Creek. NRCS maps soils in this location as "Alderwood — Urban Land Complex" (Map Unit 5). The historic grading of these Alderwood soils for construction of housing removed significant amounts of the recessional glacial till (upper) soil horizons and created a situation where there is almost immediate contact to highly compacted advance till layers. Consequently, in Ms. Stephenson's back yard, I have observed that there is limited soil water storage capacity in the upper parts of the soil horizon. During the wet season, I have also observed that this lower hillslope location saturates quickly and remains saturated for very long durations. It is my opinion that during high wind events, the combination of the size of the tree and the fact that it is located on relatively shallow and saturated soils within and immediately proximate to the Shell Creek riparian zone presents a significant blowdown hazard risk. I recommend therefore that consistent with the City of Edmonds Tree and Vegetation Protection and Removal guidelines, the tree should be cut down as soon as possible and replaced with at Table 1. Candidate Native Trees and Shrubs for Ms. Jola Stephenson's Planting. Candidate Native Scientific Name Recommended Trees Stock Big Leaf Maple Acer macro h llum 1 gallon pots Cascara Rhamnus urshiana 1 gallon pots Crabapple Malusfusca 1 gallon pots Douglas -fir Pseudotsuga Bare root "2/0" of menziesd Jumbo stock Grand fir Abies grandis Bare root "2/0" of Jumbo stock Oregon ash Fraxinus latifolia 1 gallon pots or live cuttin s Paper birch Betula pa vri era 1 gallon pots Sitka spruce Picea sitchensis Bare root "2/0" of Jumbo stock Western hemlock Tsuga heterophylla Bare root "2/0" of Jumbo stock Western red cedar Thuja plicata Bare root "2/0" of Jumbo stock Scouler's Willow Salix scouleriana Live cuttings from local stock Candidate Native Shrubs Black current Ribes hudsonianum 1 gallon pots Elderberry Sambucus racemosa 1 gallon pots or live cuttings from local stock Indian plum Oemlaria 1 gallon pots cerasiformis Red twig dogwood Corpus stolonifera Live cuttings from local stock Vine maple Acer circinatum I 1 gallon pots least a 2:1 planting of native trees or a combination of native tree and shrub species. Table 1 below offers candidate native tree and shrub species that are fit for conditions in Ms. Stephenson's back yard. Because Ms. Stephenson's property includes a portion of the Shell Creek riparian zone and main channel system, plantings should be planned and installed in a manner that will provide shade to the stream and allow development of a vigorous fine root biomass, which will add shear strength to the soils located within the riparian zone. Timing for plantings should coincide with the onset of early spring, for example any time after mid - February to early March and no later than April 15 in any given year. LCLA Technical Memorandum - Jola Stephenson, November 12, 2019�� 3 1w, h4v Ilk) EFVGOMMOTIOR IS RESPONSIBLE FOR OWN EFl 8ION 0010HOL AND DRAINAM 10 x� -llo' I P12vpb's� p MQA&Erov tr►.fi, �1.'i. 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