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Home My WebLink AboutPlanning 2017-11-16 - TMC 18-54 Tree Regulations Work Session - Attachment A: Draft Revisions to DefinitionsTMC 18.06: Revised or New Definitions Note: New text is shown as underlined text; text proposed for deletion is shown in strikeout. This list of definitions includes existing definitions as well as proposed new definitions related to trees and landscaping. ######### At -Risk Tree "At -Risk Tree" means' a tree that is exposed to potential damage but can be retained during construction by use of appropriate tree protection measures as prescribed by a Qualified Tree Professional or by TMC Chapter 18.54. 18.06.125 Caliper "Caliper" means the . - _ • e - AmericanHorr accepted standard for measurement of trunk size of nursery stock. Caliper of the trunk for new trees shall be taken six6-inches above the ground for up to and including four -inch caliper size trees and 12 inches above ground for larger size trees.' 18.06.130 Canopy "Canopy" means an area encircling the base of a tree, the minimum extent of which is delineated by a vertical line extending from the outer limit of a tree's branch tips down to the ground. 18.06.135 Canopy Cover "Canopy Cover" means the extent of the canopy for an individual tree, or the cumulative areal extent of the canopy of all trees on a the site. When a tree trunk straddles a property line, 50% of the canopy shall be counted towards each property. The canopy coverage of immature trees and newly planted trees is determined using the projected canopy areas in the City's Recommended Tree List. 18.06-140 Certified Arborist: "Certified Arborist"-, see "Qualified Tree Professional" m ans an arborist certified by the International Society of Arboriculture or National Arborist Association. 18.06.145 Clearing "Clearing" means removal or causing to be removed, through either direct or indirect actions, any vegetation from a site. Actions considered to be clearing include, but are not limited to, causing irreversible damage to roots or trunks; poisoning; destroying the structural integrity; CL Page 1 of 8 11/8/2017 1:04 PM W:\SharePoint\\Long Range Projects\2016 Landscaping -Tree Code \ Definitions \New -Revised Definitions -edits addressed Commented [CL1]: This is a new definition from Lake Forest Park with revisions proposed by staff. Commented [CL2]: Current definition with revisions from Kirkland definition. Commented [CL3]: "AmericanHort" is the professional association formerly known as the American Nursery and Landscape Association, which merged with the Association of Horticultural Professionals to become AmericanHort. Commented [CL4]: This definition applies to nursery stock for new trees being planted and is distinguished from measuring diameter of existing trees. Existing trees are measured 4.5 feet from the ground, which is also referred to as "Diameter at Breast Height— DBH". Commented [CL5]: Current definition with additions from Lake Forest Park. Commented [CL6]: No change proposed. TMC 18.06: Revised or New Definitions and/or any filling, excavation, grading, or trenching in the root area of a tree which has the potential to cause irreversible damage to the tree. Critical Root]Zone "Critical Root Zone (CRZ)" means the area surrounding a tree at a distance from the trunk, which is equal to one foot for every inch of trunk diameter measured at four and one-half feet from grade (DBH) or otherwise determined by a qualified professional (example: a 24 -inch diameter tree would have a CRZ of 24 feet. The total protection zone, including trunk, would be 48 feet in diameter). Crown "Crown" means the area of a tree containing leaf- or needle -bearing branches Dead Tree "Dead Tree" means a tree with no live crown and no functioning vascular tissue. 18.06.199 Defective Tree "Defective Tree" means a tree that meets all of the following criteria: 1. A tree with a combination of structural defects and/or disease that makes it subject to a high probability of failure; and 2. A tree in proximity to moderate to high frequency targets (persons or property that can be damaged by tree failure); and 3. The hazard condition of the tree cannot be lessened with reasonable and proper arboricultural practices nor can the target be removed. Diameter at Breast Heigh (DBH) "Diameter at Breast Height (DBH)" means the diameter of existing Trees measured four and one-half feet above the ground. Dr[ Zine "Dripline" means the distance from the tree trunk that is equal to the furthest extent of the tree's crown or six-foot radius from the trunk of the tree, whichever is greater (this from Lake Forest Park). CL Page 2 of 8 11/8/2017 1:04 PM W:\SharePoint\\Long Range Projects\2016 Landscaping -Tree Code\Definitions\New-Revised Definitions -edits addressed 94 Commented [CL7]: Lake Forest Park We propose using this term rather than "Essential Root Zone" Commented [CL8]: ISA source of definition Commented [CL9]: Lake Forest Park. Commented [COO]: This definition was added when the landscaping code was revised in March, 2017. Commented [CL11]: Lake Forest Park Commented [CL12]: From Kirkland and Lake Forest Park TMC 18.06: Revised or New Definitions C«entia1 Reet Tone "Essential root zone" m ans the ar a located on the ground between the tree trunk and 10 feet beyond the kanopy Exceptional Tree "Exceptional Tree" means a tree that is at least 1824 inches in diameter (DBH). For trees with two stems, if the stems have a combined total diameter of at least 24 inches, the tree shall be considered an Exceptional Tree. For trees with three or more stems, if the three largest stems have a combined total diameter of at least 1824 inches, the tree shall be considered an Exceptional Tree. 18.06.380 Groundcover "Groundcover" means trees, shrubs and any other plants or natural vegetation which covers or shades in whole or in part the earth's surface Hazardous Tree See "Defective Tree Heritage firee or Heritage Grove "Heritage Tree" means a tree, or group of trees comprising a grove, specifically designated by the City because of historical significance, special character, and/or community benefit. Invasive Plant and Tree List "Invasive Plant and Tree List" means the City list of plants and trees that are prohibited from being planted in landscaped areas subject to an approved landscape plan, and City properties and rights-of-way: Invasive Tree "Invasive Tree" means a non-native tree species, which is likely to spread and disrupt the balance of an eco -system. Landscape Design Professional "Landscape Design Professional" means a landscape architect persen licensed by the State of Washington to engage in the practice of landscape architecture as defined by RCW 18.98.030 or an individual who has graduated from an other accredited landscape design programofessionak CL Page 3 of 8 11/8/2017 1:04 PM W:\SharePoint\\Long Range Projects\2016 Landscaping -Tree Code\Definitions\New-Revised Definitions -edits addressed Commented [CL13]: Proposed using the term "Critical Root Zone" rather than this term. Commented [CL14]: Size of Exceptional Tree revised by Committee. Commented [CL15]: This definition revised when landscaping code revisions were adopted in March, 2017. Commented [CL16]: Issaquah Commented [AC17]: ISA source for definition. Commented [CL18]: This definition added to reflect new landscape code and text in TMC 18.52 that identifies those individuals who may prepare landscape plans for projects. TMC 18.06: Revised or New Definitions 18.06.185 13ndre3p.. Archuteet "Landscape architect" m ens a person licensed by the State of Washington to engage in the practice of landscape architecture as defined by RCW 18.96.030. 18.06.490 Landscaping or Landscaped Areas "Landscaping or Landscaped Areas" means natural vegetation such as trees, shrubs, groundcover, and other landscape materials arranged in a manner to produce an aesthetic effect appropriate for the use to which the land is put. In addition, landscaping or landscaped areas may also serve as bioswales to reduce storm water runoff, subject to the standards of this Chapter and TMC Chapter 14.30. Mulch "Mulch" means wood chips, bark or other organic material that covers the ground for weed control and water retention purposes. 18.06.586 Native Vegetation "Native vegetation" means vegetation with a genetic origin of Western Washington, Northern Oregon and Southern British Columbia, not including cultivars. Nuisance Tree "Nuisance Tree" means a tree that is causing obvious physical damage to structures, including, but not limited to sidewalks, curbs, the surfaces of streets, parking lots, or driveways, or building foundations. Nuisance Tree does not include trees that currently meet the definition of Hazardous or Defective Tree. 18.06.645 Protected Tree/Protected Vegetation "Protected tree/Protected Vegetation" means tree or area of understory vegetation identified on an approved landscape plan to be retained and protected during construction. 18.06.650 Protection Measure "Protection Measure" means the practice or combination of practices (e.g. construction barriers, protective fencing, tree wells, etc.) used to control construction or development activity, where such activity may impact vegetation which is approved for retention in a Tree CI wring Permit. CL Page 4 of 8 11/8/2017 1:04 PM W:\SharePoint\\Long Range Projects\2016 Landscaping -Tree Code\Definitions\New-Revised Definitions -edits addressed 96 Commented [CL19]: Propose using "Landscape Design Professional" Commented [CL20]: Amended definition to reflect new landscaping code, which allows bioswales to substitute as landscaped areas if certain criteria are met. TMC 18.06: Revised or New Definitions 18.06.651 Protective Fencing) "Protective Fencing" means a non -flexible, temporary fence or other structural barrier installed to prevent permitted clearing or construction activity from adversely affecting vegetation, which is approved for retention required by +R a Tree CI wring Permit or approved landscaping plan. Prunin "Pruning" means the cutting or limbing of tree or shrub branches. Pruning does not include the removal of any portion of the top of the tree, sometimes referred to as "topping". Qualified Tree Professional: an individual who is a certified professional with academic and field experience that makes them a recognized expert in urban forestry and tree protection. A Qualified Tree Professional shall be a member of the International Society of Arboriculture (ISA) and/or the Association of Consulting Arborists, and shall have specific experience with urban tree management in the state of Washington. Arborists preparing tree valuations shall have the necessary training and experience to use and apply the appraisal methodology prescribed in the most recent edition of the ISA Plant Appraisal Guide. Risk: "Risk" means, in the context of urban forestry and trees, the likelihood of tree failure causing damage to a Target such as property or persons. 18.06.705 Screening: "Screening" means a continuous fence and/or evergreen landscaped planting that effectively conceals the property it encloses. 18.06.775 Significant Tree "Significant Tree" means a single -trunked tree {Cottonwood excluded} which is four -4 inches or more in diameter as measured (DBH) geode or a multi -trunked tree with a diameter of two -inches or more on any trunk (such as willows or vine maple). 12.06.776 Significant Tree Shoreline• a height of 1 feet above the ground or a multi trunked tree with a diameter of 2 inches or more {such as willows or vine maple). CL Page 5 of 8 11/8/2017 1:04 PM W:\SharePoint\\Long Range Projects\2016 Landscaping -Tree Code\Definitions\New-Revised Definitions -edits addressed Commented [CL21]: Current definition, with proposed revisions. Commented [CL22]: New definition, primarily from Portland, with staff additions. Commented [CL23]: Modified from Lake Forest Park Commented [CL24]: Modified from Lake Forest Park with City revisions. Commented [CL25]: Revised to reconcile this definition with the definition for a "Significant Tree" in the shoreline jurisdiction. TMC 18.06: Revised or New Definitions 18.06.777 Significant Vegetation (Removal "Significant Vegetation Removal" means the removal or alteration of trees, shrubs, and/or ground cover by clearing, grading, cutting, burning, chemical means, or other activity that causes significant ecological impacts to functions provided by such vegetation. The removal of invasive or noxious weeds does not constitute significant vegetation removal. Tree pruning, not including tree topping, where it does not affect ecological functions, does not constitute significant vegetation removal. Site Disturbance: "Site Disturbance" means any development, construction, or related operation that could alter the subject property, including, but not limited to, soil compaction including foot traffic, tree or stump removal, road, driveway or building construction, installation of utilities, or grading. through and unobscurcd pcnctration of sight or light. Street Tree "Street Tree" means a tree located within the public right-of-way, or easement for street use granted to the City, provided that, if the trunk of the tree straddles the boundary line of the public right-of-way and the abutting property, it shall be considered to be on the abutting property. Target or Risk Target,: "Target or Risk Target" means, as used in the context of urban forestry or trees, people, property, or activities that could be injured, damaged, or disrupted by a tree. Tree Risk Assessment "Tree Risk Assessment" means the systematic process to identify, analyze and evaluate tree risk, -prepared in accordance with the latest version of the ISA Best Management Practices Guide by a Qualified Tree Professional. Tree Risk Assessor: "Tree Risk Assessor" means a Qualified Tree Professional with a Tree Risk Assessment Qualification, who identifies subject tree(s) and site conditions, evaluates and classifies the CL Page 6 of 8 11/8/2017 1:04 PM W:\SharePoint\\Long Range Projects\2016 Landscaping -Tree Code\Definitions\New-Revised Definitions -edits addressed 98 Commented [CL26]: No changes proposed to this definition. Commented [CL27]: New definition— Kirkland. Commented [CL28]: In searching the code, I do not find the term "Solid Planting" used; TMC 18.52.020 D defines "Type III -Heavy Perimeter Screening", which is essentially a solid planting, so this definition is not needed. Commented [CL29]: This definition from Kirkland. Street tree is also defined in TMC 11.04.040 883 as "any trees located on any street or public right-of-way". It is not defined in the new TMC 18.52 ordinance. Commented [CL30]: Modified from Lake Forest Park. Commented [CL31]: Modified from Lake Forest Park. TMC 18.06: Revised or New Definitions likelihood of failure, estimates the consequences of tree(s) hitting a Target and determines options for treatment or mitigation. 18.06.845 hTreel "Tree" means any self-supporting woody plant which at maturity is usually 20 fcct or more in height and generally has one main trunk, with a potential diameter br ast height of 2 inches or more characterized by one main trunk, or for certain species, multiple trunks, typically reaching 12-15 feet in height at maturity that is recognized as a Tree in the nursery and arboricultural industries. 18.06.850 Tree RemovalClcaring Permit: "Tree Removal CI aring Permit" means a permit issued by the Director authorizing tree cl aring removal activities, or work that may impact the Critical Root onel, pursuant to the general permit provisions of this Title. Tree Removal: "Tree Removal" means the direct or indirect removal of a tree through actions including, but not limited to: clearing, cutting, girdling, topping, or causing irreversible damage to roots or stems, destroying the structural integrity of trees through improper pruning, poisoning, or filling, excavating, grading, or trenching within the dripline that results in the loss of more than 20 percent of the tree's root system; or the removal through any of these processes of greater than 50 percent of the live crown of the tree. LToppin• "Topping" means the inappropriate pruning practice - - e used to reduce tree height by cutting to a predetermined crown limit without regard to tree health or structural integrity. Topping does not use acceptable pruning practices as described in the American National Standards Institute (ANSI) "A 300 Pruning Standards" and companion "Best Management Practices for Tree Pruning" published by the International Society of Arboriculture, such as crown reduction, utility pruning, or crown cleaning to remove a safety hazard, dead or diseased material. 18.06.860 Understory Vegetation: "Understory vegetation" means small trees, shrubs, and groundcover plants, growing beneath and shaded by the canopy of a significant tree, which affect and are affected by the soil and hydrology of the area surrounding the significant tree roots. CL Page 7 of 8 11/8/2017 1:04 PM W:\SharePoint\\Long Range Projects\2016 Landscaping -Tree Code\Definitions\New-Revised Definitions -edits addressed Commented [CL32]: Current definition with revisions from Lake Forest Park. Commented [CL33]: This phrase added by staff to reflect change in permit title by Advisory Committee and the various circumstances that may trigger a Tree Permit. Commented [CL34]: New definition from Lake Forest Park. Commented [CL35]: Revised from Portland TMC 18.06: Revised or New Definitions 18.06.910 Vegetation: "Vegetation" means living trees, shrubs or groundcover plants. Viable tree': "Viable Tree" means a Significant Tree that a Qualified Tree Professional has determined to be in good health with a low risk of failure, is relatively Windfirm if isolated or exposed, and is a species that is suitable for its location and is therefore worthy of long-term retention. �Nindfirml: "Windfirm" means a tree that is healthy and well -rooted and that a Qualified Tree Professional has evaluated and determined that can withstand normal winter storms or surrounding tree removal. CL Page 8 of 8 11/8/2017 1:04 PM W:\SharePoint\\Long Range Projects\2016 Landscaping -Tree Code\Definitions\New-Revised Definitions -edits addressed 100 Commented 1CL36]: Lake Forest Park Commented [CL37]: Lake Forest Park