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Matched Legal Cases: ['§ 1', '§ 7', '§ 7', '§ 6', '§ 12', '§ 1', '§ 1', '§ 2', '§ 5', '§ 1', '§ 7', '§ 8', '§ 6', '§ 12', '§ 3', '§ 3', '§ 2', '§ 7', '§ 1', '§ 7', '§ 6', '§ 12', '§ 2', '§ 4', '§ 5', '§ 1', '§ 7', '§ 2', '§ 1', '§ 7', '§ 12', '§ 4', '§ 3', '§ 1', '§ 7', '§ 3', '§ 3', '§ 1', '§ 5', '§ 7', '§ 3', '§ 3', '§ 1', '§ 7', '§ 4', '§ 4', '§ 1', '§ 7', '§ 1', '§ 7', '§ 1', '§ 7', '§ 1', '§ 7', '§ 1', '§ 7', '§ 1', '§ 5', '§ 7', '§ 1', '§ 8', '§ 2', '§ 1', '§ 2', '§ 1', '§ 2', '§ 1', '§ 2', '§ 3', '§ 1', '§ 2', '§ 1', '§ 2', '§ 1', '§ 1', '§ 7', '§ 9', '§ 12', '§ 4', '§ 30', '§ 2', '§ 1', '§ 2', '§ 3', '§ 1', '§ 7', '§ 1', '§ 7', '§ 12', '§ 31', '§ 1', '§ 7', '§ 6', '§ 12', '§ 7', '§ 21', '§ 5', '§ 1', '§ 7', '§ 12', '§ 1', '§ 7', '§ 12', '§ 9', '§ 1', '§ 1']

Chapter 18.12 LANDSCAPING AND TREE PRESERVATION
18.12.010 Purpose and intent.
18.12.030 Definitions.
18.12.040 Site evaluation, existing conditions and design considerations.
18.12.050 Landscape, tree, and irrigation plans.
18.12.060 Schedule – Landscape types by land use district.
18.12.070 Schedule – General requirements by landscape type.
18.12.100 Additional landscape requirements for parking areas.
18.12.105 Additional landscape requirements for parking structures.
18.12.110 Additional landscape requirements for outdoor storage.
18.12.115 Additional landscape requirements for outdoor sales display areas.
18.12.120 Additional landscape requirements for landscaping adjacent to critical areas and their associated buffers.
18.12.125 Additional landscape requirement for temporary landscaping.
18.12.130 Additional landscape requirements for fences, hedges, trash enclosures and mechanical equipment.
18.12.135 Additional landscape requirements for blank walls abutting public right-of-way and retaining walls.
18.12.136 Use of pesticides, herbicides and fertilizers.
General Provisions: Tree Preservation
18.12.1370 Minimum tree density requirements.
18.12.1375 Maximum tree removal on developed properties.
18.12.1376 Tree removal prohibited.
18.12.1380 Tree removal review.
18.12.1385 Tree retention requirements.
18.12.1390 Replacement trees.
18.12.141 Tree plan requirements.
18.12.145 Irrigation water budgeting requirements.
18.12.150 Landscape requirements on public properties and rights-of-way.
18.12.160 Maintenance – Landscape bond required and tree maintenance.
18.12.170 Administrative adjustment of standards – Landscaping.
18.12.175 Enforcement for landscape plans.
18.12.176 Violation, enforcement and penalties for noncompliance of tree preservation requirements.
18.12.180 City tree fund.
The purpose of this chapter is to establish standards for the regulation of landscaping and trees within the City of Issaquah. The intent is to establish general minimum landscape standards to provide beautification of the community by requiring well-designed green spaces that buffer high intensity urban uses and integrate good landscaping design principles. It is also the City’s intent to preserve the benefits that trees provide to the community, to mitigate where tree loss cannot be avoided, to maintain and enhance canopy coverage and to provide for the effective removal of hazard trees to protect public health and safety. The specific objectives of these regulations as they pertain to the environment, safety and aesthetics are as follows:
A. The Environment: Protect and enhance the environment including:
1. Improve and protect water quality and aesthetics of streams and wetlands;
2. Retain significant trees and preserve the natural forested character of Issaquah;
3. Minimize erosion and stormwater runoff;
4. Provide adequate spacing for proper growth and root development of trees and other vegetation;
5. Promote wise and efficient use of water;
6. Require retention of native vegetation and associated soils where appropriate and ensure that other required pervious surfaces include properly amended soils; and
7. Minimize the use of pesticides and other landscape chemicals in order to protect public health and the environment.
B. Safety: Provide the minimum requirements and standards to promote safety, including:
1. Promote pedestrian and vehicular safety;
2. Require adequate access for Fire and Police Departments; and
3. Require proper landscape maintenance practices to minimize landscape hazards; for example, proper tree pruning.
C. Aesthetics: Protect and enhance the aesthetic assets of the community, including:
1. Encourage healthy, attractive year-round landscapes throughout Issaquah;
2. Provide visual relief from large expanses of parking areas and reduction of perceived building scale;
3. Diminish impacts of noise, glare and heat;
4. Provide screening between incompatible land uses to reduce conflicts and to safeguard privacy;
5. Provide visual screens and barriers as a transition between differing land uses to protect the aesthetic assets of the dissimilar land uses;
6. Maintain and protect property values and enhance the general appearance of Issaquah; and
7. Provide shade in urban heat islands, filter air and reduce stormwater runoff. (Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007; Ord. 2481 § 7, 2006; Ord. 2383 § 6, 2004; Ord. 2108 § 12.1, 1996; Ord. 1877 § 1, 1991; Ord. 1859 §§ 1, 2, 1990; Ord. 1333 § 2, 1978).
A. Application of Provisions:
1. Landscaping: The provisions of this chapter shall apply to all zoned property and public rights-of-way in the City. Landscaping, irrigation, tree and vegetation resource plans are required for all public and private projects, except for existing lots in individual single family use; provided, that developer-installed landscaping in common areas of residential projects shall not be exempt. (See IMC 18.12.135 for additional landscape requirements for all zones regarding blank walls abutting public right-of-way and retaining walls.)
2. Tree Management: These provisions are applicable to all existing development, redevelopment, new development, and vacant or undeveloped lands within the City of Issaquah. No person shall remove, excessively prune, or top any protected, non-protected or significant tree except as provided by this chapter.
B. Nonconforming Landscaping Situations. When an addition, alteration, or repair of any existing building or structure exceeds fifty (50) percent of the value of an existing building or structure, such building or structure and the associated site shall be made to conform to the requirements of this chapter. When gross floor area with a value of fifty (50) percent or less of the existing structure value is added to a structure, said nonconforming structure and/or site shall be made to conform to the requirements of this chapter in a proportionate manner which shall be no less than a percentage of required landscaping area and plantings equal to the percentage of increase in gross floor area. The added landscaping may be required to be grouped into a single area with priority given to consistency with the required landscape types and visibility from a public street or other public area. This landscaping may be required to displace paving or other impervious material including one (1) or more parking spaces in excess of required parking.
C. Administrative Adjustment of Landscaping Standards. The Planning Director/Manager may approve exceptions to the regulations when all of the following are met:
1. The applicant can document that meeting the requirements would cause undue hardship due to pre-existing conditions on site, such as existing location of structures or vegetation.
2. The deviation from the standards meets the landscape requirements to the highest degree possible and is the minimum variation needed.
3. Other measures to meet the purpose and intent of this Landscape Code may be required to substitute for the required landscaping, such as decorative fencing, walls, arbors, or trellises, with appropriate vegetation.
4. The proposed landscaping represents an equal or better result than that which could be achieved by strictly following the requirements of this chapter. (Ord. 2549 § 5, 2009; Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007; Ord. 2481 § 8, 2006; Ord. 2383 § 6, 2004; Ord. 2108 § 12.2, 1996; Ord. 1859 § 3, 1990; Ord. 1333 § 3, 1978).
ANLA: American Nursery and Landscape Association, formerly the American Association of Nurserymen.
ANSI: American Standard for Nursery Stock (ANSI Z60.1-2004 or the most recent edition) published by the ANLA.
Arborist, certified: An individual who is trained in the art and science of planting, caring for and maintaining individual trees and certified by the International Society of Arboriculture (ISA) and with at least three (3) years of experience as a certified arborist.
Berm: An earthen mound designed to be planted and provide visual interest, screen undesirable views, and/or decrease noise.
Buffer: See IMC 18.02.040, Definitions – B.
Caliper: The American Nursery and Landscape Association standard for tree trunk measurement of nursery stock. Caliper of the trunk shall be the trunk diameter measured six (6) inches above the ground.
Canopy: The leaves and branches of a tree from the lowest branch on the trunk to the top.
Canopy cleaning: The removal of dead, dying, diseased, crowded, weakly attached, low-vigor branches, and watersprouts from a tree’s canopy.
Canopy raising: The removal of the lower branches of a tree in order to provide a height of up to eight (8) feet for pedestrian clearance and up to sixteen (16) feet for vehicular clearance or such other increased height as deemed appropriate for clearance by the City Arborist, provided it does not meet the definition of excessive pruning.
Canopy thinning: The selective removal of branches not to exceed more than twenty-five (25) percent of the leaf surface to increase light penetration and air movement, and to reduce weight.
Certified applicator: See WAC 16-228-1010, Definitions, “Certified applicator.”
Certified irrigation designer (CID): The certified irrigation designer prepares professional irrigation designs. They evaluate site conditions and determine net irrigation requirements based on the needs of the project and establish specifications and design drawings for the construction of an irrigation project. (Irrigation Association Water Management Committee, 2001, or the most recent edition).
Certified landscape irrigation auditor (CLIA): The certified landscape irrigation auditor analyzes landscape irrigation water usage. Auditors collect site data, make maintenance recommendations and perform water audits to develop irrigation base schedules. (Irrigation Association Water Management Committee, 2001, or the most recent edition).
City Arborist: City employee who is a certified arborist with a degree or extensive training in arboriculture, horticulture, forestry or a related field.
Clearing: See critical area regulations, IMC 18.10.390, Definitions – Clearing.
Contractor: That person or persons responsible for the installation of landscape designs.
Critical root zone: An area extending one (1) foot beyond the trunk for each inch of d.b.h.
Developable site area: See “Site area, developable.”
Development: See IMC 18.02.060, Definitions – D.
Diameter/diameter-breast-height (d.b.h.) or (dbh): The diameter of any tree trunk, measured at four and one-half (4.5) feet above average grade. For trees with multiple leaders at four and one-half (4.5) feet height, the d.b.h. shall be the combined cumulative total of branches greater than six (6) inches diameter at four and one-half (4.5) feet above the average grade. If a tree has been removed and only the stump remains that is below four and one-half (4.5) feet tall, the size of the tree shall be the diameter of the top of the stump.
Dripline: 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. (ANLA – A boundary on the soil surface delineated by the branch spread of a single plant or group of plants.)
Drought-tolerant plants: Plants that, once established, can survive with little or no supplemental water other than that from annual rainfall.
Excessive pruning: See “Pruning, excessive.”
Ground cover: One (1) or a number of low spreading planting(s) used in massed with the intent of total ground coverage within three (3) years of planting. Rocks, pebbles, sand and similar materials may be used as ground cover substitutes if approved by the Planning Director/Manager.
Hedge: A landscape barrier consisting of a continuous, dense planting of shrubs.
Herbicide: A chemical weed or plant killer, applied to leaves, foliage, roots or soil.
Hydrozone: A grouping of plant species used in a landscape that have similar irrigation watering needs.
Invasive plants: Plants (such as English ivy, Himalayan blackberry, Japanese knotweed, morning glory, and Scotch broom) that are exotic species and are able to gain dominance over other plants. Invasive plants include noxious weeds per the King County Noxious Weed Control Board as they are required to carry out the mandates of the State Weed Control Law, Chapter 17.10 RCW.
Irrigation plan: See “Plan, irrigation.”
Landscape: The presence of plant material, including lawn, ground covers, trees and shrubs. Landscape can also include decorative outdoor landscape elements such as rock, wood and other natural materials, land berming, pools, benches, fountains, sculptures, lighting and decorative paving surfaces. The intent is that these elements shall work together to create a landscaped environment which is both attractive and promotes the efficient use of natural resources, such as water.
Landscape architect: A person licensed by the State of Washington to engage in the practice of landscape architecture as defined by RCW 18.96.030.
Landscape coverage, one hundred (100) percent: Means that trees and shrubs have grown and filled in so that the planting space appears full, not sparsely planted, and meets the appropriate buffer planting standards. One hundred (100) percent ground cover coverage shall mean that all areas within the planting space shall have ground cover planting and appear full, but that minor areas of mulch material may be visible.
Landscape plan: See “Plan, landscape.”
Landscape substitutions: Other methods to meet the purpose and intent of the Landscape Code shall be allowed to substitute such as decorative fencing, walls, arbors, trellises with appropriate vegetation, paving, patios, outdoor seating areas, pedestrian spaces and pedestrian walkways.
Landscaping: See IMC 18.02.140, Definitions – L.
LID Technical Guidance Manual: “Low Impact Development Technical Guidance Manual for Puget Sound,” prepared by the Puget Sound Action Team and the Washington State University Pierce County Extension Services, January 2005, as amended or subsequent guidance as authorized by the Public Works Engineering Director.
Low impact development (LID): Low impact development is a stormwater management strategy that emphasizes conservation and use of existing natural site features integrated with distributed, small-scale stormwater controls to more closely mimic natural hydrologic patterns in residential, commercial and industrial settings.
Low volume irrigation: A type of water system in which a precise amount of water is applied directly to the root zones of plants, typically measured in gallons per hour.
Mulch: An organic material such as bark, sawdust, wood shavings, straw or compost used on the soil surface for moisture retention, weed suppression, soil insulation, or decoration. Water permeable synthetic materials may be substituted as weed barriers but will generally be covered with organic mulch. Impermeable materials shall not be used as mulch or underneath mulch.
Multi-stemmed trees: See “Diameter/diameter-breast-height (d.b.h.) or (dbh).”
Native Growth Protection Easement (NGPE): See critical areas regulations, IMC 18.10.390, Definitions, Native Growth Protection Easement.
Native vegetation: See critical areas regulations, IMC 18.10.390, Definitions, Native vegetation.
Nursery stock: Plant material that meets the general specifications of the American Nursery and Landscape Association (ANLA).
Parking lot: For the purpose of this chapter, a parking lot is defined as an area not within or under a building where motor vehicles may be stored for the purposes of temporary, daily, or overnight off-street parking. The following does not constitute a parking lot:
A. Parking within the public street right-of-way.
B. Parking between the curbs of a private street.
C. On-site vehicular circulation which has parallel parking.
Pervious areas: See Chapter 18.02 IMC, Definitions, “Pervious surface,” and IMC 18.07.050, Impervious surface.
Pesticide: Any substance used for the control of insects, mites, mollusks, nematodes, weeds, fungi, bacteria, or rodents, or any substance used as a defoliant, desiccant or growth regulator.
Plan, irrigation: A plan which includes all pertinent irrigation and landscape components, including but not limited to irrigation zones, hydrozones, points of connection, valves, controllers, irrigation component specifications and other elements necessary to evaluate the irrigation plans.
Plan, landscape: A plan, drawn to scale, which clearly delineates existing and proposed landscape features and structures. Plant materials used shall be listed with common and botanical names and sizes given and all pertinent above-ground features such as detention vaults and ponds, fire hydrants, parking areas, light poles, utility boxes, etc.
Plant factor values (PF): PF represents the rate of evapotranspiration demand a particular plant species, or hydrozone, has in comparison to reference turf-grass. (PF is also known as “crop coefficient.”)
Planting area: An area of land to be planted such that it will be fully utilized under the conditions of this chapter.
Protected area: Includes all land within and surrounding the critical root zone of any trees to be preserved.
Protection measures: A temporary fence or other structural barrier installed to prevent permitted clearing or construction activity from adversely affecting vegetation which is approved for retention in a Tree Removal Permit.
Pruning: The proper selective removal of plant parts, including dead, damaged and diseased wood as well as any weak crossing branches per ANSI standards.
Pruning, excessive: Removal of more than one-quarter (1/4) of the functioning leaf and stem area of a tree in any twelve (12) month period, or removal of foliage so as to cause the unbalancing of a tree, unless greater pruning is approved by the City and is necessary for the health and safety of the tree.
Redevelopment: When a site modification, addition, alteration, or repair of any existing building or structure exceeds fifty (50) percent of the value of the existing building or structure, or the gross floor area of the use is expanded by ten (10) percent or greater.
Screen, visual: A method of reducing the impact of visual intrusions with less offensive or more harmonious elements, such as plants, berms, fences, walls, or any appropriate combination thereof.
Screening: See IMC 18.02.210, Definitions – S.
Shrubs: Woody plants, often multistemmed, generally less than fifteen (15) feet at maximum height, evergreen or deciduous.
Sight area: An area whose dimensions are a linear length by eight (8) feet in height or another unobstructed line of sight as determined by the City’s Street Standards.
Sight barrier, dense: The horizontal sight area to be of no less than ninety (90) percent obscured in three (3) years by the outline of the trees and shrubs during the winter months.
Site area, developable: The gross site area of a lot minus critical areas and buffers.
Snag: Standing dead tree often providing wildlife habitat.
Subgrade: The soil levels to support a structure, paving area or the landscape area.
Sustainable forestry: Management practices prioritizing the long-term health of a forest system.
Topsoil: The uppermost layer of soil, usually the top six (6) to eight (8) inches. It has the highest concentration of organic matter and microorganisms, and is where most of the Earth’s biological soil activity occurs. Plants generally concentrate their roots in, and obtain most of their nutrients from, this layer. Topsoil can be measured as the depth from the surface to the subgrade.
Tree: A large, woody plant having one (1) or several self-supporting stems or trunks and numerous branches and a potential minimum height of twenty (20) feet. May be classified as deciduous or evergreen. Trees include standing dead trees, also called snags.
Tree, conifer: A cone-bearing tree in the division Coniferophyta.
Tree, hazardous: A hazardous tree is one that is so affected by a significant structural defect or disease or in permanent decline that falling or failure appears imminent, and that otherwise currently poses a threat to life or property and the risk of failure per the most recent adopted ISA standard tree risk assessment evaluation must be rated greater than or equal to “high” as measured on the tree risk assessment form.
Tree, heritage: A tree or group of trees specifically designated by the City because of historical significance, special character or community benefit.
Tree, landmark: A tree greater than thirty (30) inches d.b.h.
Tree pit: An excavated hole dug so that the dimensions are three (3) times the diameter of the rootball of the tree to be planted and back-filled with appropriate soil amendment per the guidelines set forth in this chapter and adopted administrative rules available at the Permit Center.
Tree plan: An evaluation or site plan describing the tree and vegetation resources existing on the site, with information provided such as tree species, size, location, condition, plant community, health, and population estimate.
Tree, protected: Any tree in a greenbelt, Native Growth Protection Easement (NGPE), environmentally critical area, common area, approved landscape plan, right-of-way, City-owned property or protected by any other measure.
Tree, public: A tree located in a greenbelt, Native Growth Protection Easement (NGPE), environmentally critical areas on City property, including street rights-of-way, City parks, landscaped areas of City public buildings, and City-owned greenbelts and open space areas.
Tree, shade: Usually a broad-leafed deciduous tree – rarely an evergreen – planted primarily for its high crown of foliage or overhead canopy.
Tree, significant: A tree at least six (6) inches or greater at d.b.h. or an alder or cottonwood tree eight (8) inches or greater at d.b.h. Any trees that are listed on the King County complete weed list shall not be considered significant. The complete King County weed list includes: Class A noxious weeds, Class B noxious weeds, Class C noxious weeds, nonregulated noxious weeds or weeds of concern lists as adopted by King County noxious weed list, in accordance with Chapter 17.10 RCW and Chapter 16-750 WAC.
Tree, specimen: A particularly impressive or unusual example of a species due to its size, shade, age, or any other trait that epitomizes the character of the species, including Issaquah’s Centennial Tree, “Eddie’s White Wonder” Dogwood.
Tree stand: A group of three (3) or more trees of any size or species whose driplines touch. A “significant tree stand” is a tree stand that contains three (3) or more significant trees.
Tree topping: The significant cutting back of the leader stem or major branches, resulting in severely altering the growth potential of a tree as defined by the City Arborist. This definition does not apply when the sole purpose is to create a snag or snags for wildlife habitat.
Tree well: A tree pit in a paved sidewalk area with grating or other measure to prevent pedestrian traffic from damaging the root area.
Trees, deciduous: Woody plants with a minimum height generally greater than fifteen (15) feet which go dormant in winter and shed their foliage.
Trees, evergreen: Woody plants with a minimum height generally greater than fifteen (15) feet which retain at least one (1) year’s foliage during their winter dormant period.
Trees, multi-stemmed: See “Diameter/diameter-breast-height (d.b.h.) or (dbh).”
Vegetation, protected tree/vegetation: A tree or area of understory vegetation identified on an approved Tree Protection and Replacement Plan to be retained and protected during construction and/or permanently protected by easement, tract, or covenant restriction. A protected tree may be located outside or within an NGPE, critical area or critical area buffer.
Vegetation removal: Removal of a tree(s) or vegetation, through either direct or indirect actions including, but not limited to:
A. Clearing, cutting, causing irreversible damage to roots or trunks;
B. Poisoning; destroying the structural integrity; and/or
C. Any filling, excavation, compaction, grading, or trenching in the dripline area of a tree which has the potential to cause irreversible damage to the tree, or relocation of an existing tree.
Vegetation, understory: Small trees, shrubs, and ground cover plants, growing beneath and shaded by a significant tree which affect and are affected by the soil and hydrology of the area surrounding the significant tree roots.
Waterwise: Planting and irrigation practices that conserve water usage and protect the aquifer by employing water quality measures.
Weed: Thistles, grasses (such as Bermuda grass) or other plants that are a nuisance, hazard, tend to overgrow or choke out more desirable plants, or cause injury to people, animals or a desired flower, garden plant or lawn cover.
Woodlands, existing: Existing trees and shrubs of a number, size, and species that accomplish the same general function as new plantings.
Xeriscape: Landscape methods that conserve water through the use of drought-tolerant plants and planting techniques and efficient irrigation strategies.
Year-round sight barrier: The horizontal sight area to be no less than sixty (60) percent obscured in five (5) years by the outline of the trees and shrubs during the winter months. (Ord. 2596 §§ 2 (Exh. B1), 4 (Exh. B3), 2010; Ord. 2552 § 7, 2009; Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007; Ord. 2383 § 6, 2004; Ord. 2108 § 12.3, 1996; Ord. 1877 §§ 2, 3, 1991; Ord. 1859 §§ 4 – 19, 1990; Ord. 1333 § 5, 1978).
Information necessary to provide adequate design review and landscape plan evaluation shall be submitted with or before submittal of the landscape plan. This information is necessary to determine how to provide the most efficient use of the existing and proposed landscape elements. Landscape review and analysis shall be required for all projects and shall include the following site evaluations:
A. Tree Plan: A document and/or site plan shall be provided, describing the tree and vegetation resources on the site, with information provided from an inventory such as tree species, size, location, condition, plant community, structure, health, and population estimate.
B. Soil Analysis and Proposed Use of Existing Soil: A laboratory analysis of topsoil conditions with an evaluation of the practical use of the soil and/or proposed retention for use in the final landscape design shall be prepared and submitted with the tree plan and landscape plan.
C. Low Impact Stormwater Development (LID): Developments choosing to use LID techniques shall follow the guidelines of the LID Technical Guidance Manual, as amended. (Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007).
Landscape and irrigation plans are required for all projects except as required in IMC 18.12.020, Applicability. Tree plans are required for any clearing and grading permit, tree removal, subdivision, short subdivision, or other development permit and shall include a tree plan for the planting, removal and protection of trees. Vegetative mapping may be allowed in place of a detailed tree plan for lots greater than two (2) acres if landmark trees are identified and vegetation is characterized by dominant plant species and major undergrowth.
A. Preparation and Submittal:
1. The landscape plan shall be designed or approved by a landscape architect, Washington-certified nurseryman/landscaper or other qualified landscape designer as authorized by the City, signed by the party accepting responsibility and liability for the proposed plan, and be submitted to the Permit Center at the time of initial project submittal.
2. The irrigation plan shall be designed or reviewed and approved by a certified irrigation designer, or other qualified irrigation designer as approved by the City and submitted for review to the Permit Center with the building plans.
3. All tree plans shall be designed or approved by a certified arborist, unless the requirement is waived by the Planning Director/Manager. For hazardous trees a qualified arborist must possess the ability to perform tree risk assessments per the International Society of Arboriculture (ISA) standards and prescribe appropriate measures necessary for the preservation of trees during land development. Tree plan requirements are established in IMC 18.12.141, Tree plan requirements.
B. Content: All plans shall provide the minimum standards as established by this chapter and shall be drawn to scale and identify the following:
1. Landscape and Tree Plan:
a. Identify the project boundaries and acreage of the site; include address, adjacent streets, north arrow and scale;
b. Total landscape area, topographic elevations and separate hydrozones;
c. Location, size and description of all landscape and hardscape materials (new and existing). Indicate existing significant trees and other landscape features, botanical/common name and applicable size and plant spacing;
d. Delineate construction zone limits and provide a protection program defining construction methods that will be incorporated to protect trees and other vegetation during and after construction. Methods should include but not be limited to barriers, signs, soil stabilization and contractor notices;
e. Property lines including dimensions and distances to all buildings and landscape features;
g. Impervious surfaces, clearly delineating all existing and proposed buildings and parking spaces or other vehicular use areas, access aisles, and driveways;
h. All existing natural features and vegetation. Areas to be left in their natural state are to be delineated on the site plan and identified on the construction site for protection from development impacts. These sites shall be required to be kept natural and free of invasive, exotic plants;
i. Location of lighting and mechanical equipment and vaults;
j. Proposed and existing underground utilities (a utility plan may be shown on a separate plan unless required for clarity);
k. The plan shall also include all permanent above-ground features such as utility lines and poles, detention vaults, fire hydrants, roads, etc.; and
l. The use of rock, wood and other natural materials, land berming, pools, fountains, sculptures, benches, lighting and decorative paving shall be identified and described.
2. Irrigation Plan:
a. Location and size of separate water meters for the landscape, if required by the design of the irrigation plan. A separate water meter is not required per this section, but the irrigation plan and any installed meters must meet the minimum utility requirements;
b. Location, type and size of all required components of the irrigation system, including point(s) of connection, master control valve, automatic controllers, main and lateral lines, valves, sprinkler heads, moisture sensing devices, rain switches, quick couplers, backflow prevention devices and pressure reducing valves;
c. Static water pressure at the point of connection to the public water supply;
d. Flow rate (gallons per minute), application rate (inches per hour) and design operating pressure (pounds per square inch) for each station; and
e. Irrigation water budget and estimated water use calculations (see IMC 18.12.145). Also see IMC 18.12.140(D), Irrigation, for standards and specification details, and IMC 18.12.140(Q), Soil Amendments.
f. The Planning Director/Manager may require outside review of irrigation plans. Sufficient fees shall be charged to the applicant to cover the cost of the review.
C. Planting and Irrigation Details: Planting details are adopted through administrative rules approved by the Planning Director/Manager. All planting and irrigation plans, details and plant materials shall conform to the guidelines set forth in this chapter and administrative rules available at the Permit Center.
D. Landscape and Irrigation Plan Revision: Landscape and irrigation plan revisions shall be approved by the Planning Director/Manager, and installed according to the revised plan. Revised plans shall show all changes including different plant types, sizes, quantities, locations, irrigation, and all other landscape and irrigation elements. All revisions to landscape and irrigation plans shall be approved prior to installation.
E. Certificate of Occupancy: The final landscape and irrigation installation shall be approved prior to temporary or permanent Certificate of Occupancy. (Ord. 2596 § 2 (Exh. B1), 2010; Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007; Ord. 2108 § 12.4, 1996. Formerly 18.12.040).
The schedule set forth in IMC Table 18.12.060 indicates those areas where landscaping shall be required and maintained and the type of landscaping required to meet the purpose and intent of this section.
Table 18.12.060(A) Schedule
– Landscape Types by Land Use Districts
Landscaping Buffers Abutting Less Intense Land Use District
Comment/Appropriate Section
(Additional requirements as defined in this section shall also apply for all zones)
Low intensity use: C‑Rec and TP-NRCA
Landscape standards shall be consistent with the Parks, Open Space and Recreation Plan
Landscape standards shall be consistent with the most restrictive adjacent zoning
SF-E, SF-S, SF-SL, SF‑D, C‑Res
Street trees are to be planted and maintained as required in IMC 18.12.150, Landscape requirements on public properties and rights-of-way
Multifamily or nonresidential uses in all multifamily and single family zones: C-Res, SF‑E, SF-S, SF-SL, SF‑D, MUR, MF-M, MF-H
Type 2 (All single family zones, C-Rec and TP-NRCA)
Cultural and Business District: CBD
*Refer to Olde Town Design Standards
Professional Office (PO) and Retail (R)
(MF zones, SF zones, or CBD)
Intensive Commercial (IC)
(MFR, SFR, or CBD)
Table 18.12.060(B)
– Schedule – Landscape Types by Land Use Districts
Parking (IMC 18.12.100) > twenty-five (25) required spaces
IMC 18.12.100, Additional landscape requirements for parking areas
Parking (IMC 18.12.100) < twenty-five (25) required spaces
IMC 18.12.105, Additional landscape requirements for parking structures
Outdoor storage or loading areas
IMC 18.12.110, Additional landscape requirements for outdoor storage
Outdoor sales or display areas
IMC 18.12.115, Additional landscape requirements for outdoor sales display areas
Trash enclosures, mechanical/electrical equipment
IMC 18.12.130, Additional landscape requirements for fences, hedges, trash enclosures and mechanical equipment
Blank walls abutting right-of-way and retaining walls
IMC 18.12.135, Additional landscape requirements for blank walls abutting public right-of-way and retaining walls
(Ord. 2624 § 4 (Exh. A3a), 2011; Ord. 2562 § 3 (Exh. B2), 2009; Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007).
A. General regulations, required for all landscape areas, are defined in IMC 18.12.140, Landscape standards and specifications.
B. The following regulations shall apply to all landscape areas based on the type of required landscaping as defined in IMC 18.12.060, Schedule – Landscape types by land use district.
Table 18.12.070(B)(1)
– Schedule – General Requirements by Landscape Type
Type 1 Dense Year-Round Sight Barrier
Purpose: To provide a dense sight barrier to significantly separate uses and land use districts, typically required between residential and nonresidential uses, or for screening of outdoor storage, mechanical equipment, trash receptacles, etc.
Minimum 90% evergreen
Rows spaced an average of thirty (30) feet on center depending on species with a minimum of four (4) trees per 5,000 square feet
A minimum of six (6) to eight (8) feet high for conifers and 2.5-inch caliper for deciduous and evergreen broad-leaf trees when planted
Minimum 80% evergreen
Triangulated rows: Large shrubs spaced per IMC 18.12.140(G)(2), Plant Sizes and Spacing – Shrubs
Large shrubs a minimum of five (5) gallon pot or balled and burlapped equivalent when planted
Spacing is dependent on the type and size of the plant material and must be adequate to provide total coverage of the landscape area within three (3) years. See IMC 18.12.140(G)(1).
Type 1 Criteria:
Where the required setback is greater than ten (10) feet, the ten (10) feet of the setback area adjacent to the property line shall be landscaped. Where the required setback is ten (10) feet or less, the entire setback area shall be landscaped. The landscaping shall be a combination of large evergreen and deciduous material to provide a 90% sight-obscuring screen within three (3) years, or a combination of approximately 70% evergreen trees backed by a 100% sight-obscuring fence softened or accented with landscaping.
Table 18.12.070(B)(2)
Type 2 Visual Screen
Purpose: To provide a visual screen to separate uses and land use districts, typically found between commercial and industrial zones, multifamily and single family zones, or commercial and residential zones
Minimum 50% evergreen
Medium trees spaced an average of twenty-five (25) to thirty (30) feet on center depending on species, with a minimum of four (4) trees per 5,000 square feet
Minimum of six (6) to eight (8) feet for conifers and two (2) inch caliper for deciduous and evergreen broad-leaf trees when planted
Triangulated rows: Medium shrubs spaced per IMC 18.12.140(G)(2), Plant Sizes and Spacing – Shrubs
Minimum two (2) to three (3) gallon pot or balled and burlapped equivalent when planted
Spacing is dependent on the type and size of the plant material and must be adequate to provide total coverage of the landscape area within three (3) years. See IMC 18.12.140(G)(1), Plant Sizes and Spacing – Ground Covers.
Type 2 Criteria:
Where the required setback is greater than ten (10) feet, the ten (10) feet of the setback area adjacent to the property line shall be landscaped. Where the required setback is ten (10) feet or less, the entire setback area shall be landscaped. The landscaping shall be a combination of medium to large evergreen and deciduous material to provide a visual screen within three (3) years and with shrubs and ground cover providing 100% coverage in three (3) years, or a combination of approximately 30% evergreen trees backed by a 70% sight-obscuring fence softened or accented with landscaping.
Table 18.12.070(B)(3)
Type 3 Visual Buffer
Purpose: To provide a visual buffer to separate and soften the appearance of uses and land use districts, typically found along street frontage or between multifamily developments
Minimum 30% evergreen
Small to medium trees spaced an average of twenty (20) feet on center depending on species with a minimum of four (4) trees per 5,000 square feet
A minimum of six (6) to eight (8) feet for conifers and 1.5-inch caliper for deciduous and evergreen broad-leaf trees when planted
Triangulated rows: Small shrubs spaced per IMC 18.12.140(G)(2), Plant Sizes and Spacing – Shrubs
Minimum one (1) gallon pot or balled and burlapped equivalent
Type 3 Criteria:
Where the required setback is greater than ten (10) feet, the ten (10) feet of the setback area adjacent to the property line shall be landscaped. Where the required setback is ten (10) feet or less, the entire setback area shall be landscaped. The landscaping shall be a combination of evergreen and deciduous material to provide a visual buffer within three (3) years and with shrubs and ground cover providing 100% coverage in three (3) years.
(Ord. 2624 § 3 (Exh. A2b), 2011; Ord. 2562 § 3 (Exh. B2), 2009; Ord. 2546 § 1, 2008; Ord. 2525 § 5, 2008; Ord. 2497 § 7, 2007).
A. Purpose: To provide a low dense sight barrier and adequate shade in parking areas by:
1. Breaking up large areas of impervious surfaces;
2. Mitigating adverse impacts created by vehicle use areas including noise, glare and increases in heat reflection by buffering uses, screening adjacent properties, providing shade, facilitating movement of traffic and improving the physical appearance of vehicle use areas.
B. Street Frontage, Pedestrian Walkways and Parking Lots near Sidewalks: Along street frontage and between pedestrian walkways and parking areas, a planting area along the right-of-way or pedestrian walkway, except for driveways, shall be planted with a mixture of evergreen and deciduous trees based on the size of the parking lot as required for the identified landscape type identified in IMC 18.12.070, Schedule – General requirements by landscape type.
C. Screening Wall: Screen walls shall consist of a solid three (3) foot high evergreen hedge and/or fence with landscaping to soften the fence on the street side. Trellising with climbing vines above a solid wall may be substituted for the fencing.
D. Vegetation Coverage: The parking landscape area shall contain shrubs and ground cover that shall be spaced to achieve one hundred (100) percent coverage in three (3) years.
E. Landscape Islands/Strips:
1. Landscape islands or peninsulas within the parking lot shall be a minimum of nine (9) feet wide.
2. Planting islands with trees shall be at the ends of each row and located midway between the ends. A span of no more than ten (10) parking spaces shall be allowed between planting islands (six (6) if spaces are double backed). Planting islands located midway between the end islands may run perpendicular or parallel with the rows.
3. Decorative mulches or unit pavers may be used in areas of heavy foot traffic but may not cover more than five (5) percent of the required landscaping.
4. A curb or wheel stop must be installed to protect planting from parked cars.
F. Clustering: Clustering of landscaping is permitted to encourage larger planting areas for LID.
Table 18.12.100
– Additional Landscape Requirements for Parking Areas
Trees – Shading
Parking: Greater than or equal to twenty-five (25) required spaces
Type 1 Landscaping of the planting strip with medium to large trees
When parking lots are within fifteen (15) feet of a less intense land use district, a six (6) foot high wall is required with Type 2 screening of the wall
Twenty-five (25) square feet of landscaping must be provided for every parking space
Interior parking areas shall have:
1. One (1) tree for every six (6) parking spaces – a minimum of ten (10) feet high and two (2) inch caliper when planted. The trees shall be 100% large broad-leaf canopy trees.
2. Planting islands with trees shall be at the ends of each row and located midway between the ends.
3. A span of no more than ten (10) parking spaces shall be allowed between planting islands (six (6) if spaces are double backed).
Parking: Less than twenty-five (25) required spaces
Type 2 Landscaping of the planting strip with medium trees
When parking lots are within fifteen (15) feet of less intense land use districts, a six (6) foot high wall or evergreen hedge with shrubs spaced three (3) feet on center is required
Eighteen (18) square feet of landscaping must be provided for every parking space
Frontage will be required to have a three (3) foot high wall or solid evergreen hedge.
Visual access to meet CPTED standards will be allowed where necessary as determined by the Planning Director/Manager.
Island widths shall be a minimum of nine (9) feet wide.
Parking lot design criteria:
Interior design criteria: Landscape areas shall be provided at the entries of buildings and between parking areas and buildings. Said areas shall be a minimum of five (5) feet wide and may be clustered to accommodate pedestrian circulation and parking layout.
Hedges: Planting and pruning of shrubs for hedges along street frontages shall be adequate to allow the plants to fill in between shrubs to create a screen that reduces headlight glare to surrounding properties and streets.
Preservation of tree function (shade): Upkeep of the landscape shall allow the trees to reach a size and shape to provide the intended shading of the parking surface. The Landscape Plan shall set a predetermined minimum height for trees. Once the desired height is reached they shall not be pruned below that height. At no times shall pruning reduce the tree canopy below 25% of the tree.
(Ord. 2624 § 3 (Exh. A2c), 2011; Ord. 2562 § 3 (Exh. B2), 2009; Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007).
A. Purpose: To provide a dense sight barrier for parking structures by mitigating adverse impacts created by vehicle use areas including noise and glare by buffering uses, screening adjacent properties, facilitating movement of traffic and improving the physical appearance of vehicle use areas.
B. Vegetation Coverage: The parking structure landscape area shall contain shrubs and ground cover that shall be spaced to achieve one hundred (100) percent coverage in three (3) years.
C. Perimeter Screening: In addition to required landscaping of the setback area, one (1) of the following shall be provided around and adjacent to the entire parking structure except for driveways, pedestrian walkways, and emergency access points:
1. A ten (10) foot wide planting area with Type 1 Landscaping; or
2. A five (5) foot wide planting area with Type 2 Landscaping with trellising and climbing vines as described in IMC 18.12.135(A)(2), Additional landscape requirements for blank walls abutting public right-of-way and retaining walls.
D. Interior Design Criteria: Landscape areas shall be provided at the entries of buildings and between parking structures and buildings when the parking structure is a separate structure. Said areas shall be a minimum of five (5) feet wide and may be clustered to accommodate pedestrian circulation and parking layout.
E. Screening Wall: Screen walls shall consist of a solid three (3) foot high evergreen hedge and/or fence with landscaping to soften the fence on the street side. Trellising with climbing vines above a solid wall may be substituted for the fencing.
F. CPTED: Visual access to meet CPTED standards will be allowed where necessary as determined by the Planning Director/Manager. (Ord. 2624 § 4 (Exh. A3b), 2011).
A. Landscape Requirements in Outdoor Storage Areas: Outdoor storage areas and recreational vehicle parking areas shall be screened with a wall or fence six (6) feet in height. The wall/fence shall be softened or accented with additional landscaping buffer a minimum of three (3) feet wide. The combined height of the wall or fence and the landscaping shall be at least one (1) foot above the height of the items to be screened. See also IMC Table 18.12.070(B)(1) – Schedule – General Requirements by Landscape Type.
B. Alternative: A landscape buffer a minimum of ten (10) feet wide consisting of a hedge which could achieve a height of at least five (5) feet within three (3) years of planting and additional planting to fill in the buffer area one hundred (100) percent within three (3) years. (Ord. 2596 § 4 (Exh. B3), 2010; Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007).
A. Landscape Requirements for Outdoor Sales and Display Areas: Outdoor sales areas shall be landscaped as Type 2 landscaping but shall be allowed the use of one hundred (100) percent deciduous trees in the street frontage area.
B. Outdoor pedestrian-oriented areas are exempt from additional screening standards. (Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007).
Native vegetation shall be retained adjacent to critical areas and their associated buffers wherever possible. Where native vegetation cannot be retained, all vegetation shall be planted and maintained so that no plant material or runoff of irrigation water and fertilizers will be diverted into the critical areas or their associated buffers. Nonnative, invasive plants shall be kept out of the buffers. (Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007).
When an approved development site is cleared and construction is delayed more than six (6) months, the Planning Director/Manager may require temporary vegetative cover and removal of invasive plants in support of IMC 16.30.050 (erosion and sediment control review requirements). (Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007).
A. Fencing: When fencing is installed, other than on a property line, planting shall be on the side of the fence that has the greatest public use. All fences are subject to the street intersection sight obstruction requirements as established by the Issaquah Street Standards and Specifications. See general standards for fences in IMC 18.07.120, Fences.
B. Hedges: Hedges that are used for screening shall be pruned and maintained as necessary to comply with screening and sight area requirements and be at least one (1) foot above the height of the material being screened.
C. Trash Enclosures: All trash containers shall be maintained inside of a minimum six (6) foot high enclosure designed to extend a minimum of one (1) foot above the height of the container and shall provide a one hundred (100) percent sight-obscuring fence or wall and appropriate landscape screen (Type 1 landscaping, minimum three (3) to five (5) feet wide) on all sides abutting adjacent properties, the street or public areas, except for vehicular access side.
D. Mechanical Equipment: All mechanical equipment areas outside of the access requirements for the utility shall be screened from view of the public right-of-way through the use of hedges or fencing on all sides abutting adjacent properties, the street or public areas, except for vehicular access side (Type 1 landscaping a minimum of five (5) feet wide). (Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007).
A. Blank Walls along Right-of-Way: Blank walls that front public areas or street frontages shall be treated to provide visual relief from large blank surfaces and to reduce the perceived scale of the structure by one (1) of the following ways:
1. Planting shall incorporate the use of a triangulated row of large trees an average of twenty (20) feet on center which may be clustered to screen where necessary. A dense evergreen hedge shall also be planted to screen the view from the right-of-way (Type 1 landscaping); or
2. Type 2 landscaping may be substituted for blank walls along right-of-way that employs a variety of texture, setbacks, colors and materials to break up the wall’s surface or install a vertical trellis in front of the wall with climbing vines or plant material. See Chapter 18.07 IMC, Appendix 2, Design Standards, C. Design Harmony and Compatibility.
B. Retaining Walls: Large retaining walls over four (4) feet tall, including walls in single family subdivisions and plats, shall be landscaped and terraced where possible or the use of decorative wall material or raised planter beds shall be incorporated to obscure the wall’s surface. See Chapter 18.07 IMC, Appendix 2, Design Standards, C. Design Harmony and Compatibility. (Ord. 2546 § 1, 2008; Ord. 2525 § 5, 2008; Ord. 2497 § 7, 2007).
In CARA Class 1 and 2 areas, proposed developments with maintained landscape areas greater than ten thousand (10,000) square feet in total area shall prepare an operations and maintenance manual plan using best management practices (BMPs) and integrated pest management (IPM) for fertilizer and pesticide/herbicide applications. The BMPs shall include recommendations on the quantity, timing and type of fertilizers applied to lawns and gardens to protect groundwater quality. The City shall issue guidelines for IPM in CARA Class 1 and 2 areas that shall be based on the following principles:
A. Use of chemical applications shall be kept at the minimum level required by the chemical information sheet; and
B. Selective applications of chemicals will be used rather than broad-based chemical applications. (Ord. 2546 § 1, 2008; Ord. 2500 § 8, 2007).
A. Minimum Tree Density: A minimum tree density shall be maintained in the developable site area of all developed sites. The tree density may consist of existing significant trees, replacement trees, or a combination of both.
IMC 18.12.1370(A): Minimum Tree Density Requirements
Minimum Tree Density
4 significant trees2 per 5,000 sq. ft.1
Commercial, Retail and Facilities
2 significant trees2 per 5,000 sq.ft.1
1Calculated based on developable site area of the lot(s)
2Or their equivalent size in caliper inches at dbh.
(Ord. 2596 § 2 (Exh. B1), 2010; Ord. 2546 § 1, 2008).
The following provisions apply to trees outside of environmentally critical areas and associated buffers. Standards for tree removal in critical areas are in Chapter 18.10 IMC, Environmental Protection.
A. Existing Single Family Lots: Single family homeowners may remove significant, nonprotected, non-landmark trees without a permit based on the following:
18.12.1375(A) Maximum Tree Removal on Existing Single Family Lots without a Permit
Maximum number of significant trees* allowed to be removed in one year without a permit
Maximum number of significant trees* allowed to be removed in 5 years without a permit
Lots up to 10,000 sq. ft.
Lots 10,001 to 20,000 sq. ft.
Lots 20,001 sq. ft. or greater
*Except landmark trees (greater than 30-inch dbh) shall not be removed without permit approval as established in IMC 18.12.1380(B), tree removal review.
B. Existing Non-Single Family Lots: Tree removal requests for non-single family lots shall be required to meet the minimum tree density requirements and maintenance requirements of this chapter. Tree removal shall comply with the approval criteria of the applicable landscape plan or with the intent of the Landscape Code and design criteria if no plans are available. The City may require a bond to ensure the survival of replacement trees. (Ord. 2596 § 2 (Exh. B1), 2010; Ord. 2546 § 1, 2008).
A. Protected Trees: Removal of protected trees is prohibited, except as provided in IMC 18.12.1380(C), Tree Removal – Hazardous Trees, or through the approved modification of a Landscape Plan (IMC 18.04.320, Thresholds – Level 0, and IMC 18.04.360, Thresholds – Level 1).
B. Vacant Lots: Removal of trees from a vacant lot prior to a project development is prohibited except as provided for in IMC 18.12.1380(C), Tree Removal – Hazardous Trees.
C. Demolitions: Tree removal shall be prohibited as part of a permitted demolition except as required to reasonably conduct demolition activities subject to approval of the Planning Director. Tree replacement may be required for removed trees.
D. In critical areas and in all natural growth protection easements, tree removal is prohibited except as allowed per Chapter 18.10 IMC, Environmental Protection. (Ord. 2596 § 2 (Exh. B1), 2010; Ord. 2546 § 1, 2008).
A. Tree Removal Form on a Single Family Lot: A tree removal form shall be submitted to the City prior to the removal of any significant (non-landmark) tree(s) on existing single family lots when all conditions are met:
1. The number of significant trees to be removed shall not exceed the maximum as established in IMC 18.12.1375(A), maximum tree removal on existing single family lots; and
2. No removal of landmark tree(s) is proposed; and
3. Replacement Trees:
a. No replacement trees are required if property retains the minimum tree density as established in IMC 18.12.1370, Minimum tree density requirements; or
b. If replacement trees are required because property does not meet the minimum tree density, as established in IMC 18.12.1370(A), minimum tree density requirements, the applicant agrees to plant replacement trees.
B. Tree Removal Permit on Commercial or Multifamily Lots or for Removal on Single Family Lots as Defined Below (Level 0 Review): The following actions require the Tree Removal Permit to be approved by the Planning Director/Manager and are subject to the criteria in subsection (B)(3) of this section:
1. Existing developed single family lot:
a. Removal of a landmark tree; or
b. Removal of significant trees over the maximum number of trees established in IMC 18.12.1375(A), Existing Single Family Lots.
2. Existing non-single family development with or without an approved landscape plan:
b. Removal of a significant tree; or
c. Substantial alterations to the landscape area as a result of any tree removal.
3. Approval Criteria and Conditions of Removal:
a. A Tree Removal Permit may be granted when one (1) or more of the following criteria are met:
(1) Removal of tree(s) causing obvious physical damage to structures including but not limited to building foundations, driveways or parking lots. Routine maintenance of roofs that is required due to leaf fall does not constitute obvious physical damage to structures.
(2) Removal of tree(s) providing solar access to buildings incorporating active solar devices. Windows are solar devices only when they are south-facing and include special storage elements to distribute heat energy.
(3) Removal of tree(s) for the purposes of thinning a heavily wooded area where remaining trees may benefit by thinning and the site’s overall appearance or function is maintained.
(4) Removal of tree(s) that are part of an approved landscape plan for the purpose of replacing unhealthy or diseased trees.
b. Conditions of Removal:
(1) The tree removal shall not create soil disturbance greater than allowed in Chapter 16.26 IMC, Clearing and Grading, or if soil disturbance is greater, a Clearing and Grading Permit is issued.
(2) Tree removal and any required replanting shall meet the intent of the approved landscape plan or, if there is not an approved landscape plan, then removal shall meet the intent of the Landscape Code and/or the design criteria checklist, whichever is greater. A revised landscape plan and replanting may be required for multifamily and commercial properties.
4. Additional Permits Required:
a. Substantial change to an approved landscape plan area (or existing landscaping if no approved landscape plan exists) may require a Level 1 Review (IMC 18.04.360, Thresholds – Level 1).
b. A Clearing and Grading Permit may be required if clearing, grading or filling actions associated with tree removal exceed Chapter 16.26 IMC, Clearing and Grading.
C. Tree Removal – Hazardous Trees: The purpose of this section is to provide clarity to property owners and to developers and to provide a process and standards for the removal of hazardous trees on both developed and undeveloped properties and to discourage the unnecessary removal of trees.
1. No person shall remove any protected tree that is hazardous without first obtaining a tree removal form or permit as established per this section. For emergency tree removal see subsection (D)(4) of this section, Emergency Removal.
2. Application Requirements: In determining whether a Hazardous Tree Removal Permit is to be approved, approved with conditions, or denied, the City may require:
a. An evaluation of the tree in writing by a certified arborist per the International Society of Arboriculture (ISA) standards if the nature of the risk of the tree is not apparent.
b. The submittal of a tree plan per IMC 18.12.050, Landscape, tree, and irrigation plans.
3. Hazardous Trees on City Property: Upon notice from the public, the City will evaluate the condition of potentially hazardous trees located on City property and take appropriate actions.
4. Preventive Measure Evaluation: An evaluation of preventive measures by an arborist in lieu of removing the tree and potential impacts of tree removal may be required. If required, this evaluation shall include the following measures:
a. Avoid Disturbing Tree: Avoid disturbing the tree at all unless it represents a hazard as determined by an arborist;
b. Stabilize Tree: Stabilize the tree, if possible, using approved arboricultural methods such as cable and bracing in conjunction with other practices to rejuvenate the tree such as repairing damaged bark and trunk wounds, mulching, application of fertilizer, and improving aeration of the tree root zones;
c. Pruning: Remove limbs from the tree, such as removing dead or broken branches, or by reducing branch end weights. If needed, remove up to one-quarter (1/4) of the branches from the canopy and main trunk only in small amounts, unless greater pruning is needed by approval of the arborist;
d. Wildlife Tree: Create a wildlife tree or snag, or cut the tree down to a safe condition, without disturbing the roots, where the tree no longer poses a hazard. To create snags, remove all branches from the canopy, girdle deciduous trees, and leave the main trunk standing. Wildlife trees or snags are most appropriate in greenbelts, NPGEs, vacant property, and environmentally critical areas;
e. Steep Slopes: Removal of tree roots on steep slopes may require a geotechnical evaluation;
f. Creeks and Lakes: Trees fallen into creeks and lakes are to remain in place unless they create a hazard; and
g. Provide professional recommendations on:
(1) The necessity of removal, including alternative measures to removal;
(2) The lowest-impact approach to removal;
(3) A replacement tree plan, if required.
D. Tree Removal Exemptions: A tree removal form or permit is not required for:
1. Removal of non-significant trees that are not protected by any other means.
2. Removal of trees in association with right-of-way and easements. Tree removal by a public agency or a franchised utility within a public right-of-way or upon an easement, for the purpose of installing and maintaining water, storm, sewer, power, gas or communication lines, or motorized or non-motorized streets or paths. Notification to the City by the public agency or franchised utility is required prior to tree maintenance or removal within City-owned rights-of-way.
3. Tree removal in association with mineral resource extraction or processing in a mineral resource zone regulated under IMC 18.07.525, Mineral Resource Zone (“M”) development standards.
4. Emergency Removal: Any number of hazardous protected and nonprotected trees may be removed under emergency conditions. Emergency conditions include immediate danger to life or dwellings or similar stationary and valuable property, including the presence of a target. Emergency removal may occur and all the following conditions shall be met:
a. The City is notified the following business day of the unpermitted action;
b. Visual documentation (i.e., photographs, video, etc.) is made available; and
c. The felled tree remains on site for City inspection.
d. Replacement required.
(1) Non-Single Family Use: The property owner will be required to provide replacement trees as established in IMC 18.12.1390, Replacement trees.
(2) Single Family Use: The property owner will not be required to provide replacement trees.
e. Should the City determine that the tree(s) did not pose an emergency condition, the owner shall be cited for a violation of the terms of this chapter. (Ord. 2596 § 2 (Exh. B1), 2010; Ord. 2562 § 3 (Exh. B2), 2009; Ord. 2546 § 1, 2008).
A. Tree Retention Requirements:
1. General Tree Retention Requirements: Significant trees on lots proposed for project development or redevelopment shall be retained as follows:
IMC 18.12.1385(A) Tree Retention Requirements for Proposed Project Development
Retention Required:
Single family, duplex, short plats, or subdivision development (SF-E, SF-S, SF-SL, SF-D, C-Res)
30% of the total caliper (dbh) of all significant trees in developable site area
Commercial and multifamily development (Multifamily (MUR, MF-M, MF-H), Professional Office (PO), Cultural and Business District (CBD), Retail (R) and Intensive Commercial (IC), and Urban Village (UV))
25% of the total caliper (dbh) of all significant trees in developable site area
2. Urban Village Tree Retention Requirements: Tree Retention standards do not apply to the Issaquah Highlands and Talus Urban Villages. These tree retention standards will apply to future Urban Village designations unless other tree retention standards are specifically included in the Urban Village Development Agreement.
3. Priority of Tree Retention Requirements: Significant trees shall be retained in the following priority order:
a. Priority One:
(1) Significant trees which form a continuous canopy;
(2) Significant trees on slopes greater than twenty (20) percent;
(3) Significant trees adjacent to critical areas and their associated buffers;
(4) Significant trees over sixty (60) feet in height or greater than eighteen (18) inches dbh.
b. Priority Two:
(1) Healthy tree groupings whose associated undergrowth can be preserved;
(2) Other significant native evergreen or deciduous trees; and
(3) Other significant nonnative trees.
c. Priority Three: Alders and cottonwoods shall be retained when all other trees have been evaluated for retention and are not able to be retained except where adjacent to open space, wetlands or creek buffers.
B. Modification to Tree Retention Requirements: A reduction of up to fifty (50) percent of the tree retention requirements of all development may be approved by the Planning Director/Manager through a Level 2 Review process, or a Level 1 Review process for individual single family projects, provided the following criteria are met:
1. The modification is consistent with the purpose and intent of this chapter, Chapter 18.12 IMC, Landscaping and Tree Preservation; and
2. The modification incorporates the retention of a grouping(s) of smaller trees that make up the equivalent diameter inches and retains other natural vegetation occurring in association with the smaller tree grouping(s); and
3. The modification is necessary because the size, shape, topography, or location of the subject property may jeopardize the reasonable use of the property and reasonable alternatives do not exist; and
4. The modification is necessary because the required ingress/egress, existing and proposed utility locations, trails, storm drainage improvements or similar constraints may jeopardize the reasonable use of the property and reasonable alternatives do not exist; and
5. The modification is necessary to provide solar access to a building that incorporates active solar devices. Windows are solar devices only when they are south-facing and include special storage elements to distribute heat energy.
C. Additional Tree Protection: The Planning Director/Manager may approve an administrative adjustment of standards, including but not limited to IMC 18.07.330, Setbacks, and IMC 18.09.060, Administrative adjustment of parking standards, in order to retain existing healthy significant tree(s). (Ord. 2596 § 2 (Exh. B1), 2010; Ord. 2546 § 1, 2008).
A. Replacement Tree Requirement: Trees removed pursuant to the provisions of this chapter shall be replaced per the following criteria:
1. For tree removal associated with a commercial or multifamily revision to an approved landscape plan, replacement may be calculated based on meeting the landscape plan purpose and intent. This may include: adjustments to the timing of replacement up to six (6) months, or to the size of replacement trees up to one (1) inch, when justification can be provided that the changes meet or exceed the original landscape plan.
2. For All Other Tree Removal: One (1) replacement tree for every six (6) inches of caliper at dbh of trees removed if remaining tree density is below the minimum requirements in IMC 18.12.1370, Minimum tree density requirements.
3. All replacement trees shall be:
a. A minimum of two (2) inch caliper for deciduous trees and seven (7) to eight (8) feet tall for conifers for multifamily and commercial lots;
b. A minimum of five (5) gallon for existing single family lots.
4. Tree replacement must be completed the end of the calendar year the tree is removed.
5. Single Family Lots: Replacement for hazardous tree removal is not required.
B. Replacement Tree Maintenance and Quality: Replacement trees shall be State Department of Agriculture Nursery Grade No. 1 or better and must be consistent with the approved tree plan. Replacement trees must be staked, fertilized, mulched and protected as required in IMC 18.12.140(N), Tree and Vegetation Protection. Fifty (50) percent of replacement trees must be evergreens for the replacement of evergreen trees or deciduous if a deciduous tree is removed.
C. Replacement Tree Location: The applicant’s proposed location of transplanted or replacement trees shall be subject to approval of the Planning Director/Manager as part of the tree replacement plan.
1. Location On Site: To the extent feasible, trees shall be relocated or replaced on site.
2. Relocation or Replacement Off Site: Where it is not feasible to relocate or replace trees on site, relocation or replacement shall be made at another Director- or Manager-approved location in the City.
D. City Tree Fund: Where it is not feasible to relocate or replace trees on site or off site as established in the approved tree plan, the applicant may be required to pay into the City tree fund an amount of money approximating the current market value of the replacement trees and the labor to install them.
E. Value: The value of significant and protected trees shall be established according to the formula outlined in the most recent edition of the Guide for Plant Appraisal, published by the Council of Tree and Landscape Appraisers. This value shall be determined by the City. (Ord. 2596 § 2 (Exh. B1), 2010; Ord. 2546 § 1, 2008).
The following landscape standards and specifications shall apply to all landscaping required under this chapter or other requirement of City ordinance. The Planning Director/Manager or City Horticulturist is authorized to make adjustments to the following standards on a case-by-case basis using best professional judgment.
A. Centennial Tree: “Eddie’s White Wonder” Dogwood (Cornus “Eddie’s White Wonder”) has been chosen as Issaquah’s official Centennial Tree. Developers are therefore encouraged to use it as a single specimen or in small group plantings.
B. Drainage: All landscapes shall have adequate drainage, either through natural percolation or through an installed drainage system. A percolation rate of one-half (1/2) inch of water per hour is acceptable. Wetland and riparian landscapes choosing to use LID techniques, as part of a LID stormwater element, shall follow the guidelines of the LID Technical Guidance Manual, as amended.
C. Use of Chemical Applications: The use of plant material or maintenance practices requiring excessive fertilizer, pesticide or herbicide applications to be kept healthy and attractive shall not be allowed. Integrated pest management (IPM) strategies shall be incorporated into landscape design and maintenance whenever possible.
1. Fertilizer, pesticide and herbicide applications, only when necessary, shall be done with herbicide classified as safe for aquatic environments and shall be made in a manner that will prevent their entry into waterways and wetlands and minimize their entry into storm drains. No applications shall be made within fifty (50) feet of a waterway or wetland, or its associated buffer as established by the City codes, such as the critical areas regulations (Chapter 18.10 IMC, Environmental Protection), unless done so by a state-certified applicator with prior City approval.
2. All applications to turf or trees and shrubs shall follow Washington State University Extension Office, National Arborist Association or other accepted agronomic or horticultural guidelines as well as the product guidelines.
D. Irrigation: A permanent, efficient irrigation system shall be installed in all landscapes unless exempted pursuant to this section. The system shall be designed to conserve water by using best available conservation technology and irrigation best management practices. These techniques may include, but are not limited to: subsurface or drip irrigation to minimize evaporation loss, moisture sensors or rain sensors to prevent irrigation during rainy periods, weather-based automatic controllers to ensure proper duration of watering, sprinkler head selection and spacing designed to minimize overspray, use of plants with similar water needs, soil moisture sensors and separate zones for turf and shrub hydrozones and microclimates to meet watering needs of different sections of the landscape. Exceptions to the irrigation requirement, as approved by the Planning Director/Manager or designated official, may be made for: street-tree-only plantings, approved xeriscape (low water usage) plantings, landscaping using drought-tolerant plants, established indigenous plant material, landscaping in conjunction with low impact development stormwater systems or landscapes where natural appearance is acceptable or desirable to the City. In those situations where irrigation is necessary, the following shall be required for all landscape irrigation areas:
1. Irrigation systems shall be designed to avoid runoff, low-head drainage, overspray, or other similar conditions where irrigation water flows onto adjacent property, nonirrigated area, or impervious surfaces by:
a. Considering soil type and infiltration rates;
b. Using proper irrigation equipment and schedules, including such features as repeat cycles, and matched precipitation and infiltration rates; and
c. Considering special problems posed by irrigation on slopes, in median strips, and in narrow hydrozones.
2. Irrigation systems shall be designed and installed to have a minimum distribution uniformity of 0.65 or greater per IMC 18.12.145(E), Irrigation System Review and Audit at Installation.
3. Landscape water features shall use nonpotable water unless the water feature is designed to both minimize water loss and recirculate water used in operation (required for all landscapes).
4. Irrigation systems shall utilize a master control valve connected to a flow sensor and irrigation controller.
5. Irrigation systems shall include a rain or soil moisture sensor designed to shut off or override watering during rainfall events.
6. Irrigation systems in right-of-way medians, curb strips, parking lots or other landscape strips of less than five (5) feet in width or turf-grass exceeding a slope of three horizontal feet to one vertical foot (3:1) provided through a low-volume, subsurface irrigation system providing a distribution uniformity of not less than 0.90.
7. Irrigation systems shall be designed with provisions for winterization by providing either:
a. Manual drains (automatic valves are not permitted) at all low points; or
b. Method to blow out irrigation system pipes with pressurized air.
8. Irrigation Maintenance: Irrigation systems shall be maintained and inspected periodically to assure proper functioning, adjust scheduling and to meet irrigation water budget requirements. Replacement of components shall be original specified parts or materials, or their equivalents.
E. Waterwise Planting Requirements, Mulches and Soil Amendments: The following planting, mulching and topsoil amendments shall be required for all landscape areas:
1. Plants having similar water use characteristics (hydrozones) shall be grouped together.
2. Soil amendments may be necessary to produce a healthy growing medium, which will increase the survival rate for new planting and reduce ongoing maintenance requirements.
3. Incorporate water and nutrient holding materials into the soil as deep as possible (a minimum of twelve (12) inches). Use fully composted organic material.
4. Mulch new planting areas to minimize evaporation, suppress weed growth and reduce erosion. Use fully composted material. All mulches used in planter beds shall be feathered to the base of the plants and kept at least six (6) inches away from the crowns of shrubs or trunks of trees.
5. Water tubes can also be added to the tree plantings to allow water to penetrate the soil.
6. The Planning Director/Manager may exempt a project from some or all of the required irrigation plan in exchange for the proper installation of mulches, soil amendments and plantings. A temporary irrigation system may be required until the planting material is established.
F. Plant Selection: All plants shall be adapted to their sites (sun exposure, cold hardiness, moisture requirements, soil type, soil pH, etc.). Plants with differing environmental/cultural requirements shall not be used together if desirable circumstances cannot be provided for both. New plant materials shall consist of native or drought-tolerant varieties or nonnative species that have adapted to the climate conditions of the greater Issaquah region (see the list of native trees and shrubs for wildlife habitat in the Issaquah area available at Permit Center). All plants shall be selected taking into consideration the mature size of the plant and the space allowed for the plant to grow unobstructed (i.e., large native conifers are not appropriate in densely built areas and narrow planter beds). Plants shall be selected that are appropriate for the provided space in order to minimize persistent pruning. No plants shall be allowed that are determined to be noxious weeds per the King County Noxious Weed Control Board pursuant to the State Weed Control Law, Chapter 17.10 RCW.
G. Plant Sizes and Spacing: Standard plant sizes and spacing requirements for new landscape areas shall follow the guidelines for selection and spacing based on the ultimate size and growth habits of the plants as defined in the ANSI Z60.1-2004 or the most recent edition of the guide. Flexibility with the general spacing requirements below may be approved by the Planning Director/Manager if the applicant can show that the overall effect of the landscape plan can meet the purpose of the landscape requirements per IMC 18.12.010, Purpose and intent. Spacing shall be as follows:
1. Ground Covers: Spacing is dependent on the type and size of the plant material used and must be adequate to provide total coverage of the landscape area within three (3) years. In existing woodlands, the spacing of ground covers may be allowed to be spaced further apart per the approval of the Planning Director/Manager. In general:
a. Four (4) inch pots shall be spaced twelve (12) inches on center in a triangular planting arrangement.
b. One (1) gallon pots shall be spaced eighteen (18) inches in a triangular planting arrangement or to cover in three (3) years.
c. All mulched ground cover areas shall have ground cover established and covering the area with growing plant material within three (3) years.
2. Shrubs: Spacing is dependent on the type and size of the plant material used and must be adequate to provide total coverage of the landscape area within three (3) years. In general:
a. Low Shrub: Mature size under three (3) feet tall. Minimum size at planting: one (1) or two (2) gallon pot or balled and burlapped equivalent, spacing eighteen (18) inches on center to cover in three (3) years.
b. Medium Shrub: Mature size from three (3) feet to six (6) feet tall. Minimum size at planting: two (2) or three (3) gallon pot or balled and burlapped equivalent, spacing twenty-four (24) inches on center or to cover within three (3) years if used for mass effect.
c. Large Shrub: Mature size over six (6) feet tall. Minimum size at planting: five (5) gallon pot or balled and burlapped equivalent, spacing three (3) feet on center or to cover within three (3) years if used for mass effect.
3. Trees: Spacing is dependent on the type and size of the trees used and will depend on the landscape type that is required per the approved landscape plan. One (1) tree shall be provided for each one thousand (1,000) square feet of area to be landscaped. In general:
a. Small Tree: A tree whose ultimate height is less than thirty (30) feet under normal urban growing conditions. When planted, they shall be no smaller than one and one-half (1-1/2) inch caliper, six (6) to eight (8) feet in height, spacing no more than an average of twenty (20) feet on center.
b. Medium Tree: A tree whose ultimate height is between thirty (30) and fifty (50) feet under normal urban growing conditions. When planted, they shall be no smaller than two (2) inch caliper, ten (10) feet to twelve (12) feet high and shall be spaced no more than an average of thirty (30) feet on center.
c. Large Tree: A tree whose ultimate height is over fifty (50) feet under normal urban growing conditions. When planted, a deciduous tree shall be no smaller than two and one-half (2-1/2) inch caliper, twelve (12) feet to fourteen (14) feet in height and shall be spaced no more than an average of forty (40) feet on center.
d. Narrow Tree: A tree whose maximum width is less than fifteen (15) feet. Spacing shall be reduced to accommodate the reduced width of the tree species.
e. Coniferous tree: When planted, they shall be six (6) to eight (8) feet high as measured per the ANSI Standards; spacing is dependent on species and landscape type.
f. Multistemmed trees shall be a minimum of eight (8) to ten (10) feet high when planted.
g. Street trees when planted shall be a minimum of two (2) inch caliper regardless of ultimate size.
H. Berms: If berms are used, they shall be planted with trees, shrubs and living ground cover and must be adequately planted to prevent erosion.
1. Berms planted with sod lawn shall be no steeper than a three to one (3:1) ratio.
2. Planted slopes with erosion control plants and ground covers shall be no steeper than a two to one (2:1) ratio.
3. Any berms over two to one (2:1) must have erosion control netting or matting installed in addition to the required plantings.
I. Plant Standards: All plant materials used shall meet the most recent American Association of Nurseryman Standards (ANSI Z60.1) for nursery stock.
a. Branches interfering with utility lines.
b. Significant crown dieback has occurred.
K. Shrub Pruning: Shrubs used for screening purposes shall have a predetermined minimum desired height shown on the landscape plan. The shrubbery shall be required to fill in and create an adequate screen to reduce headlight glare to surrounding properties. Once the desired height is reached, they shall not be pruned below that height. Shearing is allowed for hedges, but specimen plants are to be selectively pruned according to their plant type, not sheared. Visual access to meet CPTED standards shall be incorporated where necessary as shown on the landscape plan.
L. Pedestrian Pathways: Grass or other ground covers tolerant to foot traffic shall be used in areas of pedestrian traffic flow. In areas where there is heavy pedestrian traffic flow, dense shrubbery shall be required to direct pedestrian traffic flow onto designated pathways.
M. Landscaping Area Size Requirements:
1. Larger planting beds are more likely to be successful than small ones. Therefore, planting bed size shall be as large as practical for each site. All required tree planting areas shall be a minimum of one hundred (100) square feet with a minimum width of five (5) feet.
2. Island planting beds in parking lots or similar situations shall have a minimum dimension of eight (8) feet from inside of curb.
3. Tree wells shall be a minimum of twenty-four (24) square feet depending on size potential of the tree; however, the use of continuous landscape beds or lawns is considered preferable to individual tree wells.
4. Planting holes shall be three (3) times the diameter of the rootball of the plant material and shall be back-filled following planting guidelines available at the Permit Center.
N. Tree and Vegetation Protection: In order to provide adequate protection of trees and the landscaping area, the landscape design shall comply with the following standards:
1. Protective devices such as bollards, trunk guards, root guards, etc., may be required to direct pedestrian or vehicular traffic away from the trees and their associated vegetation areas.
a. Mulch may not be placed against the tree trunk above the soil line.
b. Trees in lawn areas are required to have a mulched bed extending a minimum of twenty-four (24) inches in all directions from the base of the tree.
2. Where vehicles may overhang into required landscaping areas, trees shall be located such that they will not be damaged by vehicles pulling in and out of parking stalls. Permanent curbing shall be provided in all landscaping areas within or abutting parking areas except where based upon appropriate surface water considerations; other structural barriers may be substituted for curbing, such as concrete wheel stops.
3. Trees shall be sized appropriately and not be placed in areas where they will require excessive pruning (greater than twenty-five (25) percent of the canopy) such as in the sight line of project sign locations.
4. For significant trees, tree stands and existing vegetation, the following additional requirements shall be met to protect vegetation from development impacts during construction:
a. The applicant shall not fill, excavate, stack or store any equipment or compact the earth in any way within the area defined by the dripline of any tree to be retained.
b. The applicant shall construct a temporary but immovable four (4) foot high sturdy fence around each tree or native vegetated area to be retained generally corresponding to the critical root zone of the trees.
c. The applicant may not install impervious surface material within the area defined by the dripline of any trees to be retained unless specifically approved by the Planning Director/Manager.
d. The grade level around any tree to be retained may not be lowered by more than two-thirds (2/3) of the area defined by the critical root zone of the tree. If the grade level around a tree to be retained is to be raised, the applicant shall construct a dry rock wall or rock well around the tree. The diameter of this wall or well must be equal to the diameter of the tree’s dripline.
O. Waterway and Wetland Landscaping: Native plant species and plants deemed suitable for riparian habitat (as specified by the approved plant list available at the Permit Center) shall be used along streams and wetland buffer zones.
P. Soil Porosity: Soils in planting areas shall have adequate porosity to allow root growth. Soils which have been compacted to a density greater than eighty-five (85) percent compaction shall be loosened (ripped) to increase aeration to a minimum depth of eighteen (18) inches or to the depth of the largest plant rootball, whichever is greater. A minimum of eight (8) inches of topsoil, amended as appropriate for soil conditions and plant material selection, shall be tilled into soils in four (4) inch lifts to prevent a distinct soil interface from forming. After soil preparation is completed, motorized vehicles shall be kept off to prevent excessive compaction and underground pipe damage.
Q. Soil Amendments – Compost, Topsoil and Seed Mix Specifications: All new landscape areas shall be required to amend soils to improve soil health and nutrient availability, increase porosity, infiltration and moisture holding capacity and shall meet minimum specifications for soils, compost, mulches and seed mixes.
1. Subgrade shall be a minimum of eight (8) inches below finish grade. Substandard soils shall be removed prior to adding amendments.
2. A soils analysis shall be completed for all new planting areas and shall include:
a. A determination of soil texture, indicating percentage of organic matter.
b. An approximated soil infiltration rate either measured or derived from soil/texture/infiltration rate tables.
c. A measure of pH value.
3. Soils for use in projects applying low impact development (LID) standards shall follow the LID Technical Guidance Manual for Puget Sound, Section 6.2, Amending Construction Site Soils.
4. For soils that will not adequately percolate to provide proper drainage for plant materials, a plan to correct the situation shall be developed by the landscape architect and approved by the Planning Director/Manager.
5. Guidelines for meeting minimum standards are available at the Permit Center and shall follow the Washington State University King County Extension Services guidelines for soil conditions and plant selection.
R. Native Soil Protection: The conservation and use of on-site native soil and vegetation for stormwater management is a central principle of LID design. For management of native vegetation and soil protection areas for LID design see the LID Technical Guidance Manual (Chapter 4, Vegetation Protection, Reforestation and Maintenance, and Section 6.2, Amending Construction Site Soils).
1. The duff layer and native topsoils shall be retained in an undisturbed state to the maximum extent practicable. Any duff layer or topsoil removed during grading shall be stockpiled on site in a designated, controlled area not adjacent to public resources and critical areas. The material shall be reapplied to other portions of the site where feasible.
2. Areas that have been cleared and graded or subject to prior disturbance shall be amended. Prior disturbance shall include soil compaction or removal of some or all of the duff layer or underlying topsoil. Replaced topsoil shall be a minimum of eight (8) to twelve (12) inches in depth, unless the applicant demonstrates that a different thickness will provide conditions equivalent to the soil moisture holding capacity native to the site. Replacement topsoil shall have an organic content of ten (10) percent dry weight and a pH between 5.5 and 7.0. The intent of amending disturbed soils is to restore the moisture holding capacity of the original undisturbed native soil to the maximum extent practicable.
3. This section does not apply to areas that would harm existing trees proposed for retention, or that, at project completion, are covered by an impervious surface, incorporated into a drainage facility or engineered as structural fill or slope. (Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007; Ord. 2481 § 9, 2006; Ord. 2108 § 12.16, 1996; Ord. 1877 §§ 4 – 6, 1991; Ord. 1859 § 30, 1990. Formerly 18.12.160).
A. Tree Plan Required: Applications for any clearing and grading permit, subdivision, short subdivision, or other development permit shall include a tree plan for the planting, removal and protection of trees. Vegetative mapping may be allowed in place of a detailed tree plan for lots greater than two (2) acres if landmark trees are identified and vegetation is characterized by dominant plant species and major undergrowth.
1. The following note shall be on all plans: “A tree designated for retention shall not have the soil grade altered within its dripline or within fifteen (15) feet of its trunk whichever is greater.”
2. While it is recognized that trees will be removed in the course of construction, no tree shall be removed for the purpose of view enhancement. Retention of trees is required as established in IMC 18.12.1385(A), Tree Retention Requirements, for proposed project development.
3. Trees may be removed to provide solar access to buildings incorporating active or passive solar devices. Windows will be considered solar devices only when they are south-facing and include special storage elements to distribute heat energy.
C. Submittal Requirements:
1. The required tree plan shall be submitted separately or incorporated with a grading, drainage and erosion control plan, as applicable. All tree plans must be certified by a certified arborist.
2. Commencement of site construction or any tree removal shall not occur until after the tree plan is approved.
3. A plan review/permitting/inspection fee shall be charged as specified in IMC 3.64.010, Fees imposed.
D. Plan Requirements for Development Projects:
1. Identify the project boundaries and acreage of the site; include address, adjacent streets, north arrow and scale.
2. Identify the location, size and species of all significant trees or groups of trees. Trees shall be identified by botanical/common names and applicable size.
3. Trees to be removed or altered in any way shall be marked in the field and matched on the tree plan. Number of trees, species and sizes (dbh) shall be identified on the plan.
4. Delineation of all construction zone limits.
5. Provide a protection program defining construction methods that will be incorporated to protect trees during and after construction. Methods should include but not be limited to barriers, signs, soil stabilization, and contractor notices.
6. Identify the size, location and number of replacement plantings.
7. Provide plans for supervising and/or monitoring implementation of any required tree protection or replacement measures.
8. The name and qualifications of the person responsible for preparing the tree plan.
9. An assessment of the condition of the trees. A tree risk assessment evaluation per subsection (E) of this section, Plan Requirements for Hazard Tree Removal, must be submitted for any trees to be exempted from retention because of a hazardous condition.
E. Plan Requirements for Hazard Tree Removal: Whether as a part of a development project or as part of a tree removal request, an abbreviated tree plan is allowed for identification of trees that may pose a high risk. An evaluation of the trees must be made by an arborist certified by ISA as a tree risk assessor. The evaluation must show that the risk of failure of the tree is high per a standard tree risk assessment evaluation. The hazard tree plan shall at a minimum include:
1. Name and qualification of arborist;
2. Date of evaluation;
3. Description of type, size, location, and condition of tree(s);
4. The tree unit density if removal of the tree(s) is approved;
5. Description of the potential hazard and target;
6. Evaluate preventive measures in lieu of removing the tree and potential impacts of tree removal as provided in IMC 18.12.1380(C), Tree Removal – Hazardous Trees;
7. The most recent ISA tree risk assessment checklist completed for the project.
F. Provide a separate plan for supervising and/or monitoring implementation of any required tree protection or replacement measures. (Ord. 2596 § 2 (Exh. B1), 2010; Ord. 2546 § 1, 2008).
Irrigation water budgeting requirements shall apply to all landscaping required under this chapter or other requirement of City ordinance. Irrigation systems shall conform to landscape standards and specifications as outlined in IMC 18.12.140, Landscape standards and specifications. The Planning Director/Manager is authorized to make adjustments to standards on a case-by-case basis using best professional judgment.
A. Irrigation Water Budget: A landscape design’s irrigation water budget (IWB) shall be calculated based upon the total square footage of the proposed landscape area and including landscape water features (such as decorative ponds, pools or fountains) and excluding impervious surfaces and sensitive areas and their buffers. The irrigation water budget shall be calculated as described in the “Irrigation Water Budgeting Requirements” handout available at the Permit Center.
B. Irrigation Design Estimated Water Use: A landscape design’s estimated water use (EWU) shall be calculated by determining the estimated water use for each hydrozone and adding the EWU for all hydrozones together. The sum of the EWU for all hydrozones is the landscape’s total EWU. The formula used to determine the estimated water use for each hydrozone is available in the “Irrigation Water Budgeting Requirements” handout available at the Permit Center.
C. Plant Factor Values: Plant factor values shall be used for all plant species selected for use in a landscape. The plant factor value for the hydrozone shall be that of the plant species with the highest plant factor value within the hydrozone. Plant factor values assigned shall reflect the plant species’ actual water demand as planted according to the final landscape design and plan.
D. Irrigation System Efficiency Values: Irrigation system efficiency values (IE) shall be assigned in calculating the estimated water use for each hydrozone of a landscape. Determination of the IE shall be as described in the “Irrigation Water Budgeting Requirements” handout available at the Permit Center.
E. Irrigation System Review and Audit at Installation: The irrigation system shall be designed, installed and maintained in such a manner as to meet a minimum distribution uniformity of not less than 0.65. Prior to final approval of the irrigation and landscape, all installed irrigation systems must successfully pass an irrigation system audit and meet a minimum distribution uniformity of 0.65. The irrigation system audit shall be performed by an Irrigation Association certified landscape irrigation auditor (CLIA), registered landscape architect or professional engineer with irrigation design experience. Irrigation system audit certification shall be submitted for review and approval prior to approval of the landscape and irrigation.
F. Irrigation Schedule: An irrigation schedule shall be submitted with the irrigation plan. (Ord. 2596 § 2 (Exh. B1), 2010; Ord. 2587 § 3 (Exh. B2), 2010; Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007).
A. The City shall have an Approved Street Tree List and Master Street Tree Plan from which developers may select trees. Any trees selected for use on public property which are not on the list shall require approval by the City. This list shall be subject to periodic updating by the City and shall be available at the Permit Center.
B. The City shall have an approved set of specifications from which developers may select grass seed combinations (including sod) for use on public property. Any seed combination not on the list shall require approval by the City. Alternative cross-sections of the planting strip on City right-of-way for the use of trees, shrubs and drought-tolerant materials to replace sod shall require approval by the Planning Director/Manager.
C. The City shall be responsible for the maintenance of all developed landscape areas owned by the City, except for right-of-way, unless otherwise agreed upon by the City.
D. Maintenance of landscape areas (including irrigation systems, ornamental plantings and other landscape elements) on City right-of-way shall be the responsibility of the abutting property owner unless the City has accepted maintenance responsibility for that right-of-way. Any tree removal shall require City approval (see Issaquah Street Standards and Specifications, Chapter 12.04 IMC).
E. Permission by the City shall be required before any plant may be planted or removed from City property or public right-of-way.
F. Plant location and spacing on City right-of-way must meet all sight obstruction requirements (see Issaquah City Street Standards and Specifications). Plantings on City right-of-way shall not obstruct the visibility or accessibility of any fire hydrant (see Fire Hydrant Construction Standards) or traffic control device. The trees may be spaced at irregular intervals in order to accommodate sight distance requirements for driveways, intersections or traffic control devices.
G. Street trees shall have a minimum overhead clearance of seven (7) feet over pedestrian pathways and fourteen (14) feet over streets at maturity. Street trees shall be centered a minimum of three (3) feet from curbs and two (2) feet from sidewalks or as otherwise approved by the City.
H. Street trees planted in tree wells in sidewalks shall have a minimum of two and one-half (2-1/2) feet of pedestrian clearance around the tree unless otherwise approved by the City (see Issaquah City
Street Standards and Specifications, Chapter 12.04 IMC). Tree grates may be required to meet ADA accessibility requirements.
I. Street trees shall be planted in a planting strip with a minimum of five (5) feet between the sidewalk and the back of the curb. Permanent or temporary irrigation shall be required for a minimum of three (3) years.
J. Trees planted under overhead utility wires shall be of a small variety (as specified by the Approved Street Tree List) which will not grow up to interfere with the wires.
K. Street trees shall be required in all rights-of-way unless an exception is approved by the Planning Director/Manager and shall be a minimum of two (2) inch caliper at the time of planting unless they are of a small variety (as specified by the Approved Street Tree List or specified in the Master Street Tree Plan) or an exception has been granted by the City. Street trees shall be limbed up a minimum of five (5) feet when planted, following the standards provided in ANSI Z133.1-2004. The minimum tree pit size in a tree well shall be sixteen (16) square feet and the minimum tree pit shall be three (3) times the size of the rootball. If a street tree or other tree or shrub on City property is removed, broken or otherwise damaged it shall be considered a violation of subsection E of this section and subject to fine. (Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007; Ord. 2108 § 12.17, 1996; Ord. 1859 § 31, 1990. Formerly 18.12.170).
A. Landscape Bond Required and Procedures:
1. All landscapes need to be maintained in a safe, healthy and attractive manner in perpetuity. All existing landscapes within the City shall also be kept weed and litter free and the plant material shall be maintained in good growing condition. The property owner shall replace any unhealthy or dead plant materials in conformance with the approved landscape plans and shall maintain all landscape material. The property owner is the responsible entity to ensure the landscaping is maintained in an appropriate manner, regardless of any second party landscape maintenance agreements.
2. To insure that all plant material used in landscapes shall be maintained in a healthy growing condition, a cash deposit or other acceptable security worth fifty (50) percent of the value of the landscaped plant material, cost of labor, irrigation and materials shall be posted with the City prior to receipt of a temporary or final Certificate of Occupancy. The cash deposit will be returned in three (3) years if the plants remain in a healthy growing condition and have achieved full coverage (replacement of all plants will not be required if full coverage has been met). The Planning Director/Manager may accept other suitable security as permitted in Chapter 18.04 IMC, Procedures.
3. If any portion of the required landscaping dies within three (3) years, the City shall notify the property owner, in writing, and require replacement within sixty (60) days. If the landscape is not replaced within the specified time period, the City may use whatever portion of the deposit is needed to replace the dead landscaping. The City may use either City employees or private contractors to replace the landscaping, and may assess the property owner all actual costs against the deposit, if it is sufficient. An additional three (3) year cash deposit or other security device at fifty (50) percent of the value of the landscaping may be required at the discretion of the Planning Director/Manager if a significant amount of the plants need to be replaced.
4. Regular maintenance procedures shall be as follows:
a. Litter pickup;
b. Mowing turf;
c. Edging turf;
d. Weeding planting beds;
e. Sweeping;
g. Fertilization as needed per manufacturer’s specifications to keep plants healthy and actively growing;
h. All mulches used in planter beds shall be kept at least six (6) inches away from the crown of shrubs and trees;
i. Pruning to required heights and widths; and
j. Pest and disease control (all chemical products and application methods shall be approved by the City Parks Department).
5. It is recognized that these procedures may vary due to weather conditions, seasonal events, etc. The above guidelines are to serve as a standard for normal maintenance operations.
B. Tree Maintenance: The following regulations shall apply to all significant and protected trees. The City Arborist is authorized to make adjustments to the standards and requirements on a case-by-case basis using best professional judgment.
1. An irrigation method, approved by the City, shall be provided to all newly planted protected trees through an establishment period.
2. All pruning shall be done to the most recent ANSI standards (A300-1995 and Z133.1-1994). Canopy raising, canopy cleaning, and canopy thinning as defined in IMC 18.12.030, Definitions, are permitted; provided, that they do not meet the definition of excessive pruning in IMC 18.12.030, Definitions. No permit shall be required for maintenance pruning.
3. Tree topping is prohibited, except under the following circumstances:
b. Significant canopy dieback has occurred.
If illegal tree topping has occurred, the property owner shall have a certified arborist develop and implement a five (5) year pruning schedule in addition to monetary fines and required tree replacement.
4. Excessive Pruning: Excessive pruning as defined in IMC 18.12.030, Definitions, is a violation of this chapter. (Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007; Ord. 2283 § 6, 2000; Ord. 2108 § 12.5, 1996; Ord. 1877 § 7, 1991; Ord. 1859 § 21, 1990; Ord. 1333 § 5, 1978. Formerly 18.12.050).
A. Unless otherwise specified, the Planning Department may vary the specific requirements of this chapter as set forth in the Administrative Adjustment of Standards (AAS) process.
B. AAS Purpose: The purpose and intent of Administrative Adjustment of landscaping standards is to provide the flexibility to reduce or modify standards in all zoning districts at the administrative level, without permitting an adjustment that negatively impacts the surrounding neighborhood. This provision requires a Level 2 Review, regardless of street frontage or parcel size, with public notification to adjacent property owners.
C. AAS Process: The Planning Director/Manager has the authority to make the final decision regarding Administrative Adjustment of Standards for all levels of review. The Director/Manager shall consider the application information regarding the approval criteria which has been provided by the applicant and any public comment which has been received within the comment period. The Director/Manager may request input from the Chair of the Development Commission during the comment period; however, this is not required. The Planning Director/Manager’s decision on the Administrative Adjustment of Standards is final unless appealed. Appeals to Administrative Adjustment of Standards are addressed in Chapter 18.04 IMC.
D. AAS Approval Criteria: Approval must be based on a determination that the adjustment is consistent with the purpose and intent of this Code and of the development standards. The following approval criteria, in addition to the approval criteria for a Level 2 Review, shall be used to determine whether an Administrative Adjustment shall be granted for landscape standards:
1. The adjustment(s) will be equal to, or superior in, fulfilling the intent and purpose of the landscape requirements; and
2. The adjustment(s) does not negatively impact the adjacent property owners; and
3. The landscape adjustment(s) shall provide consistency with the intent, scale and character of the zoning district involved; and
4. The intent and purpose of the required screening and/or buffering of uses or specific areas (for example, dumpsters and parking areas) are not jeopardized. (Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007; Ord. 2108 § 12.14, 1996. Formerly 18.12.140).
A. Responsibility: The ultimate responsibility for any landscaping shall be borne by the legal owner of the property on which the landscaping is located. The Building Official or his/her designee may require, when necessary, that the property owner or agent be party to, or applicant for, any required landscaping permit.
B. Authority: The Building Official is authorized and directed to enforce all provisions of this chapter and is empowered to promulgate such rules and regulations as may from time to time be necessary to accomplish the purpose of this chapter, subject to City Council approval.
C. Violations: Violations of any portion of this chapter shall be subject to the applicable code enforcement and penalty provisions set out in Chapter 18.05 IMC, Enforcement. Violations include:
1. The unauthorized removal of plant material from an approved or revised landscape planting. If a tree has been removed and only the stump remains, the size of the tree shall be the diameter of the top of the stump.
2. Excessive pruning of vegetation, such as topping of trees. (Ord. 2546 § 1, 2008; Ord. 2497 § 7, 2007; Ord. 2108 § 12.15, 1996; Ord. 1333 § 9, 1978. Formerly 18.12.150).
A. Noncompliance with any other section of this chapter constitutes a violation of this Code.
B. Enforcement Authority: It shall be the duty of the Planning Director to enforce this Code. The Director may call upon the police and other appropriate City officials or departments to assist in enforcing this Code. It is unlawful to violate any of the provisions of this Code and violators shall be punished in accordance with IMC 1.06.010, General penalties.
C. General Provisions for Enforcement and Penalties:
1. The enforcement provisions for tree protection are intended to encourage compliance and protect the City’s significant and protected trees. To achieve these ends, violators will not only be required to restore damaged or removed protected trees to the extent possible, but will incur a civil and/or criminal penalty for the redress of community ecological, aesthetic, and economic values lost or damaged.
2. The owner of the land on which the violation occurs shall be named as a party to the violation, except in cases of trespass. In addition to any other persons who may be liable for violations, the owner shall be jointly and severally liable for the restoration of a site and payment of any penalties imposed.
3. Each violation of this Code, or any rule or regulation adopted, or any permit, permit condition, or order issued pursuant to this Code, shall be a separate offense.
4. Aiding or Abetting: Any person who, through an act of commission or omission, procures, aids or abets in the violation shall be considered to have committed a violation for the purposes of the penalty.
1. Criminal Penalties: Any person violating any provisions of this chapter is subject to criminal penalties. A violation of this chapter is a gross misdemeanor and is punishable by a fine not to exceed $5,000 and imprisonment not to exceed one (1) year. Additionally, the City may be entitled to restitution for up to three (3) times the value of the trees removed or damaged as well as costs in replacing and restoring the damaged area and any other reasonable expenses incurred.
2. Civil Penalties: Any person violating any provisions of this chapter shall have committed a civil infraction and may be subject to civil penalties in addition to any criminal penalties. Pursuant to Chapter 64.12 RCW, the City may be entitled to triple the amount of civil damages claimed or assessed. The extent of the penalty shall be determined according to one or more of the following:
a. An amount reasonably determined by the Director to be equivalent to the costs estimated by the City to investigate and administer the infraction;
b. The economic benefit that the violator derives from the violation (as measured by the greater of the resulting increase in market value of the property or the value received by the violator or savings of construction costs realized by the violator performing any act in violation of this chapter);
c. The value lost of the trees removed versus that recovered through replacement plantings; and
d. The cost of replacing and replanting the trees and restoring the disturbed area according to a specific plan approved by the City. Violators of this chapter or of a permit issued thereunder shall be responsible for restoring unlawfully damaged areas in conformance with a plan, approved by the Director, that provides for repair of any environmental and property damage, and restoration of the site; and which results in a site condition that, to the greatest extent practical, is equivalent to the site condition that would have existed in the absence of the violation(s). In cases where the violator intentionally or knowingly violated this chapter or has committed previous violations of this chapter, restoration costs may be based on the City-appraised tree value of the subject trees on which the violation occurred. If diameter of removed tree is unknown, determination of the diameter size shall be made by the City Arborist by comparing size of stump and species to similar trees in similar growing conditions.
e. If illegal tree topping has occurred, the property owner shall be required to have a certified arborist develop and implement a five (5) year pruning schedule in addition to monetary fines and required tree replacement.
3. Civil penalties under this section shall be imposed by a notice in writing, either by certified mail with return receipt requested or by personal service, to the person incurring the same from the City. The notice shall describe the violation, approximate the date(s) of violation, and shall order the acts constituting the violation to cease and desist, or, in appropriate cases, require necessary corrective action within a specific time.
4. Any fiscal penalty recovered under this section shall be deposited in the City’s tree fund as established in IMC 18.12.180, City tree fund.
E. Notices and Citations: The Director is authorized to issue notices and administrative orders, levy fines, and/or institute legal actions in court.
1. Recourse to any single remedy shall not preclude recourse to any of the other remedies.
2. The Director may issue a stop work order for any approved development activity for the property on which or adjacent to which a violation of this chapter occurred if the owner of such property, agent, employee, contractor, or other party with interest in the property committed the violation. A stop work order issued for violation of the provisions of this chapter shall remain in effect until such time that penalties imposed by the violation have been paid, restoration has been performed, and mitigation has been performed for environmental damage resulting therefrom, to the satisfaction of the Director.
a. The order shall set forth and contain a description of the nature of the violation.
b. The stop work order issued under this section shall become effective immediately upon receipt by the person to whom the order is directed.
c. Failure to comply with the terms of a stop work order can result in enforcement actions including, but not limited to, criminal penalties.
d. Orders and penalties issued pursuant to this subsection may be appealed as provided for in IMC 18.04.250 through 18.04.260, appeals. (Ord. 2546 § 1, 2008).
There is hereby created a City tree fund which shall be administered by the Finance Department. All funds received from civil penalties resulting from violations of this chapter shall be deposited in the fund which shall be used only for the purpose of paying all or part of the cost and expense of enforcing and implementing this chapter and may be used for the purpose of acquiring, maintaining, and preserving wooded areas, for planting and maintaining trees on publicly owned property within the City, and for urban forestry education. Monies in said fund not needed for immediate expenditure shall be invested for the benefit of the City tree fund pursuant to RCW 36.29.020. For investment purposes, the Director of Finance is hereby designated the fund manager. (Ord. 2546 § 1, 2008).