Chapter 18.35
DEVELOPMENT STANDARDS – LANDSCAPING
Sections:
18.35.040 Landscaping – Screen types and description.
18.35.045 Landscaping – General requirements.
18.35.050 Landscaping – Street trees for single-family subdivisions.
18.35.070 Landscaping – Surface parking areas.
18.35.080 Landscaping – General standards for all landscape areas.
18.35.090 Landscaping – Additional standards for required landscape areas.
18.35.100 Landscaping – Alternative options.
18.35.110 Landscaping – Plan design, design review, and installation.
18.35.130 Financial guarantees.
18.35.010 Purpose.
The purpose of this chapter is to preserve the aesthetic character of communities; to improve the aesthetic quality of the built environment; to promote retention and protection of existing vegetation; to promote water efficiency; to promote native wildlife; to reduce the impacts of development on drainage systems and natural habitats; and to increase privacy for residential zones by:
A. Providing visual relief from large expanses of parking areas and reduction of perceived building scale;
B. Providing physical separation between residential and nonresidential areas;
C. Providing visual screens and barriers as a transition between differing land uses;
D. Retaining existing vegetation and significant trees by incorporating them into the site design;
E. Providing increased areas of permeable surfaces to allow for:
1. Infiltration of surface water into groundwater resources;
2. Reduction in the quantity of stormwater discharge; and
3. Improvement in the quality of stormwater discharge;
F. Encouraging the use of native plant species by their retention or use in the landscape design;
G. Encouraging the use of a diversity of plant species which promote native wildlife habitat. [Ord. 11-0329 § 3 (Exh. 1).]
18.35.020 Application.
Except for wireless communication facilities regulated pursuant to Chapter 18.60 KMC, all new development shall be subject to the landscaping provisions of this chapter; provided, that specific landscaping and tree retention provisions for uses established through a conditional use permit or special use permit shall be determined during the applicable review process. [Ord. 16-0426 § 7 (Att. E); Ord. 11-0329 § 3 (Exh. 1).]
18.35.030 Land use grouping.
To facilitate the application of this chapter, land uses have been grouped in the following manner:
A. “Residential development” refers to residential land uses.
B. “Attached/group residences” refers to:
1. Multiple-family dwellings, except as provided in subsection (C)(1) of this section;
2. Single detached dwelling units developed on common property at a density of 12 or more units per acre;
3. Supportive living facilities;
4. Temporary lodging;
5. Adult family homes; and
6. Manufactured housing communities.
C. “Single-family development” refers to:
1. Residential subdivisions and short subdivisions, including attached and detached dwelling units on individually platted or short platted lots;
2. Any detached dwelling units located on a lot;
3. Family child-care homes; and
4. Type I community residential facilities.
D. “Commercial development” refers to:
1. Recreational/cultural land uses, except library, museum, park and trail;
2. General services land uses, except recycling centers, health care and social assistance, hospital, laboratory, educational service, day care I, and religious institution; and
3. Retail land uses.
E. “Industrial development” refers to:
1. Government/business services land uses, except public agency or utility office; public agency or utility yard; public agency archive; court; fire or police facility; utility facility; commuter parking lot; private stormwater management facility; and vactor waste receiving facility;
2. Manufacturing land uses; and
3. Mineral extraction and processing.
F. “Institutional development” refers to:
1. Library, museum and conference center;
2. Religious institution, hospital, health care and social assistance, ambulatory surgery center, laboratory, and educational service; and
3. Public agency or utility office; public agency or utility yard; public agency archive; court; fire or police facility; commuter parking lot; private stormwater management facility; and vactor waste receiving facility.
G. “Utility development” refers to utility facility, except private stormwater management facility and vactor waste receiving facility.
H. Uses that are not listed in this section shall not be subject to landscaping requirements except as specified in any applicable review of a conditional use or special use permit. [Ord. 19-0481 § 2 (Exh. A); Ord. 17-0438 § 2 (Att. A); Ord. 14-0391 § 2 (Exh. 1); Ord. 11-0329 § 3 (Exh. 1).]
18.35.040 Landscaping – Screen types and description.
The three types of landscaping screens are described and applied as follows:
A. Type I Landscaping Screen.
1. Type I landscaping is a “full screen” that functions as a visual barrier.
2. Type I landscaping shall minimally consist of:
a. A mix of primarily evergreen trees and shrubs generally interspersed throughout the landscape strip and spaced to form a continuous screen;
b. Between 70 and 90 percent evergreen trees;
c. Trees provided at the rate of one per 10 linear feet of landscape strip and spaced no more than 30 feet apart on center;
d. Evergreen shrubs provided at the rate of one per four linear feet of landscape strip and spaced no more than eight feet apart on center; and
e. Ground cover pursuant to KMC 18.35.090;
3. Landscape-based stormwater management facilities are permitted within Type I landscaping screen areas; provided, that the screening objectives in subsections (A)(1) and (2) of this section are achieved.
B. Type II Landscaping Screen.
1. Type II landscaping is a “filtered screen” that functions as a visual separator.
2. Type II landscaping shall minimally consist of:
a. A mix of evergreen and deciduous trees and shrubs generally interspersed throughout the landscape strip spaced to create a filtered screen;
b. At least 50 percent deciduous trees and at least 30 percent evergreen trees;
c. Trees provided at the rate of one per 20 linear feet of landscape strip and spaced no more than 30 feet apart on center;
d. Shrubs provided at the rate of one per four linear feet of landscape strip and spaced no more than eight feet apart on center; and
e. Ground cover pursuant to KMC 18.35.090;
3. Landscape-based stormwater management facilities are permitted within Type II landscaping screen areas; provided, that the screening objectives in subsections (B)(1) and (2) of this section are achieved.
C. Type III Landscaping Screen.
1. Type III landscaping is a “see-through screen” that functions as a partial visual separator to soften the appearance of parking areas and building elevations.
2. Type III landscaping shall minimally consist of:
a. A mix of evergreen and deciduous trees generally interspersed throughout the landscape strip and spaced to create a continuous canopy;
b. At least 70 percent deciduous trees;
c. Trees provided at the rate of one per 25 linear feet of landscape strip and spaced no more than 30 feet apart on center;
d. Shrubs provided at the rate of one per four linear feet of landscape strip and spaced no more than eight feet apart on center; and
e. Ground cover pursuant to KMC 18.35.090.
3. Landscape-based stormwater management facilities are permitted within Type III landscaping screen areas; provided, that the screening objectives in subsections (C)(1) and (2) of this section are achieved. [Ord. 16-0428 § 13 (Att. I); Ord. 11-0329 § 3 (Exh. 1).]
18.35.045 Landscaping – General requirements.
|
|
Street frontage perimeter landscaping (average width)9 |
Interior lot line perimeter landscaping (average width)14 |
Surface parking lots of 10 or more stalls |
|---|---|---|---|
|
Residential development1 |
10' Type III8 |
5' Type II8 10' Type II11 |
20 sq. ft. per stall in common parking areas. |
|
Commercial development2 |
10' Type III |
20' Type I10 |
20 sq. ft. per stall if 10 – 30 stalls provided; 25 sq. ft. per stall if 31 or more stalls provided. |
|
Industrial development3 |
10' Type II |
10' Type II12 20' Type I10 |
20 sq. ft. per stall if 10 – 30 stalls provided; 25 sq. ft. per stall if 31 or more stalls provided. |
|
Institutional development4 |
20' Type II6 |
10' Type II |
20 sq. ft. per stall if 10 – 30 stalls provided; 25 sq. ft. per stall if 31 or more stalls provided. |
|
Utility development5 |
10' Type II7 |
10' Type II13 |
20 sq. ft. per stall if 10 – 30 stalls provided; 25 sq. ft. per stall if 31 or more stalls provided. |
1 As described in KMC 18.35.030(A).
2 As described in KMC 18.35.030(D).
3 As described in KMC 18.35.030(E).
4 As described in KMC 18.35.030(F).
5 As described in KMC 18.35.030(G).
6 Excluding playgrounds and playfields.
7 For an above-ground utility facilities development only, excluding distribution and transmission corridors.
8 Only for attached/group residence development as described in KMC 18.35.030(B).
9 For all zones except the UR, DC and DR zones. In the CB zone, where street frontage setbacks are required, the area within the setback must contain Type II landscaping.
10 Along any portion adjacent to a residential development as described in KMC 18.35.030(A).
11 Along portions of an attached/group residence development as described in KMC 18.35.030(B) adjacent to property developed with single detached residences or vacant property that is zoned R-1 through R-6.
12 Along any portion adjacent to a commercial or institutional development as described in KMC 18.35.030(D) and (F).
13 Excluding distribution or transmission corridors.
14 In the DC zone, where interior setbacks are required and/or provided, setbacks shall be landscaped with Type II landscaping. In the CB zone, where interior setbacks are required and/or provided, setbacks shall be landscaped with Type II landscaping.
[Ord. 23-0574 § 2 (Exh. A); Ord. 11-0329 § 3 (Exh. 1).]
18.35.050 Landscaping – Street trees for single-family subdivisions.
For single-family subdivisions:
A. Trees shall be planted at the rate of one tree for every 40 feet of frontage along a neighborhood collector street or arterial street. Native vegetation cultivars are preferred;
B. The trees shall be:
1. Located within the street right-of-way if permitted by the City;
2. No more than 20 feet from the street right-of-way line if located within a lot;
3. Maintained by the adjacent landowner unless part of a City maintenance program; and
4. A species approved by the City if located within the street right-of-way and compatible with overhead utility lines;
C. The trees may be spaced at irregular intervals to accommodate sight distance requirements for driveways and intersections. [Ord. 16-0428 § 13 (Att. I); Ord. 11-0329 § 3 (Exh. 1).]
18.35.060 Landscaping along the Burke-Gilman public trail.
Repealed by Ord. 14-0391. [Ord. 11-0329 § 3 (Exh. 1).]
18.35.070 Landscaping – Surface parking areas.
A. Trees shall be provided and distributed throughout the parking area at a rate of:
1. One tree for every three parking stalls for a commercial or industrial development; and
2. One tree for every five parking stalls for residential or institutional development;
B. The maximum distance between any parking stall and landscaping shall be no more than 100 feet;
C. Permanent curbs or structural barriers shall be provided to protect the plantings from vehicle overhang;
D. Landscaping around the perimeter of a site that is in addition to the perimeter landscaping required by KMC 18.35.045 may count toward 10 percent of the required surface parking area landscaping in all zones except the DC, DR, and UR zones, or RB-zoned properties that are not subject to P-suffix condition NS-P4, and which lie north of NE 175th Street (see subsection F of this section), if it is adjacent to the parking area;
E. Parking area landscaping shall consist of:
1. Canopy-type deciduous trees, evergreen trees, evergreen shrubs and ground covers planted in islands or strips. Native vegetation cultivars are preferred;
2. Internal parking lot landscaping shall be configured as landscape-based stormwater management feature unless infeasible;
3. Shrubs that do not exceed a maintained height of 42 inches;
4. Plantings contained in planting islands or strips having an area of at least 100 square feet and with a minimum dimension of not less than five feet;
5. Ground cover in accordance with KMC 18.35.090; and
6. At least 70 percent of trees are deciduous;
F. Standards for perimeter landscaping and screening of surface parking lots for the DC, DR, and UR zones, or RB-zoned properties that are not subject to P-suffix condition NS-P4, and which lie north of NE 175th Street, are defined in Chapter 18.52 KMC, Design Standards. All other landscape requirements for surface parking lot landscaping in this section apply to the DC, DR, and UR zones, and RB-zoned properties that are not subject to P-suffix condition NS-P4, and which lie north of NE 175th Street. [Ord. 23-0574 § 2 (Exh. A); Ord. 16-0428 § 13 (Att. I); Ord. 14-0391 § 2 (Exh. 1); Ord. 11-0329 § 3 (Exh. 1).]
18.35.080 Landscaping – General standards for all landscape areas.
All new landscape areas proposed for a development shall be subject to the following provisions:
A. Berms shall not exceed a slope of two horizontal feet to one vertical foot (2:1).
B. All new turf areas, except all-weather, sand-based athletic fields, shall:
1. Be augmented with a two-inch layer of organic material cultivated a minimum of six inches deep; or
2. Have an organic content of five percent or more to a depth of six inches.
C. Except as specifically outlined for turf areas in subsection B of this section, the organic content of soils in any landscape area shall be as necessary to provide adequate nutrient and moisture-retention levels for the establishment of plantings.
D. Landscape areas, except turf or areas of established ground cover, shall be covered with at least two inches of mulch to minimize evaporation.
E. Plants having similar water use characteristics shall be grouped together in distinct hydrozones.
F. Plant selection shall consider adaptability to climatic, geologic, and topographical conditions of the site. Preservation of existing vegetation is encouraged.
G. Landscape areas proposed as stormwater management facilities shall be designed in accordance with the Kenmore stormwater management standards. [Ord. 16-0428 § 13 (Att. I); Ord. 11-0329 § 3 (Exh. 1).]
18.35.090 Landscaping – Additional standards for required landscape areas.
In addition to the general standards of KMC 18.35.080, landscape areas required pursuant to KMC 18.35.045 through 18.35.070 shall conform to the following standards:
A. All plants shall conform to American Association of Nurserymen (AAN) grades and standards as published in the “American Standard for Nursery Stock” manual; provided, that existing healthy vegetation used to augment new plantings shall not be required to meet the standards of this manual;
B. Single-stemmed trees required pursuant to this chapter shall at the time of planting conform to the following standards:
1. In parking area landscaping and in street rights-of-way:
a. Deciduous trees shall have a minimum caliper of one and three-quarters inches and a height of 10 feet in all zones except the DC and DR zones, or RB-zoned properties that are not subject to P-suffix condition NS-P4, and which lie north of NE 175th Street between 65th Avenue NE extended and 73rd Avenue NE, which shall have a minimum caliper of three inches, and
b. Coniferous and broadleaf evergreen trees shall be at least five feet in height;
2. In all other required landscape areas:
a. Deciduous trees shall have a minimum caliper of one and one-half inches and a height of 10 feet in all zones except the DC and DR zones, or RB-zoned properties that are not subject to P-suffix condition NS-P4, and which lie north of NE 175th
Street between 65th Avenue NE extended and 73rd Avenue NE, which shall have a minimum caliper of three inches, and
b. Coniferous and broadleaf evergreen trees shall be at least five feet in height except in the DC and DR zones, or RB-zoned properties that are not subject to P-suffix condition NS-P4, and which lie north of NE 175th Street between 65th Avenue NE extended and 73rd Avenue NE, where they shall be at least 10 feet in height;
C. Multiple-stemmed trees shall be permitted as an option to single-stemmed trees in all zones except the DC and DR zones, or RB-zoned properties that are not subject to P-suffix condition NS-P4, and which lie north of NE 175th Street between 65th Avenue NE extended and 73rd Avenue NE; provided, that such multiple-stemmed trees are:
1. At least six feet in height, and
2. Not allowed within street rights-of-way;
D. When the width of any landscape strip is 20 feet or greater, the required trees shall be staggered in two or more rows;
E. Shrubs shall be:
1. At least an AAN container class No. 2 (two-gallon) size at time of planting in Types II, III and parking area landscaping,
2. At least 24 inches in height at the time of planting for Type I landscaping, and
3. Maintained at a height not exceeding 42 inches when located in Type III or parking area landscaping except in the DC and DR zones where they shall not exceed a maximum height of 48 inches;
F. Ground covers shall be planted and spaced to result in total coverage of the majority of the required landscape area within three years;
G. All fences shall be placed on the inward side of any required perimeter landscaping along the street frontage;
H. Required street landscaping may be placed within City street rights-of-way subject to the City street design standards, provided adequate space is maintained along the street line to replant the required landscaping should subsequent street improvements require the removal of landscaping within the rights-of-way;
I. Required street landscaping may be placed within Washington State rights-of-way subject to permission of the Washington State Department of Transportation; and
J. New landscape material provided within areas of undisturbed vegetation or within the protected area of significant trees shall give preference to utilizing indigenous plant species. [Ord. 11-0329 § 3 (Exh. 1).]
18.35.100 Landscaping – Alternative options.
The following alternative landscape options may be allowed, subject to City approval, only if they accomplish equal or better levels of screening, or when existing conditions on or adjacent to the site, such as significant topographic differences, vegetation, structures or utilities would render application of this chapter ineffective or result in scenic view obstruction:
A. The amount of required landscape area may be reduced to ensure that the total area for required landscaping, and/or the area remaining undisturbed for the purpose of wildlife habitat or corridors does not exceed 15 percent of the net developable area of the site. For the purpose of this subsection, the net developable area of the site shall not include areas deemed unbuildable due to their location within critical areas and any associated buffers;
B. The average width of the perimeter landscape strip may be reduced up to 25 percent along any portion where:
1. Berms at least three feet in height or architectural barriers at least six feet in height are incorporated into the landscape design; or
2. The landscape materials are incorporated elsewhere on-site;
C. Where a local or subarea plan with design guidelines has been adopted, the city manager shall base the landscaping modifications on the policies and guidelines of such plan;
D. When an existing structure precludes installation of the total amount of required site perimeter landscaping, such landscaping material shall be incorporated on another portion of the site;
E. Single-stemmed deciduous tree species that cannot generally be planted and established in larger sizes may have a caliper of less than one and one-half inches;
F. The number of trees and shrubs to be provided in required perimeter and parking area landscaping may be reduced up to 25 percent when a development uses landscaping materials consisting of species typically associated with the Puget Sound Basin in the following proportions:
1. Seventy-five percent of ground cover and shrubs, and
2. Fifty percent of trees;
G. In the DC and DR zones, alternative landscape requirements may be proposed in order to retain trees (over 12 inches DBH if deciduous or eight inches DBH if evergreen, measured as average trunk diameter at chest height; measured four and one-half feet above grade). This alternative requirement applies only to trees which are beyond what is already required in the City’s significant tree ordinance. Interior parking lot landscape requirements may be reduced at a 1:1 ratio equal to the land area within the drip line of the tree being retained. [Ord. 11-0329 § 3 (Exh. 1).]
18.35.110 Landscaping – Plan design, design review, and installation.
A. The landscape plan submitted to the department shall be drawn on the same base map as the development plans and shall identify the following:
1. Total landscape area and separate hydrozones;
2. Landscape materials botanical/common name and applicable size;
3. Property lines;
4. Impervious surfaces;
5. Natural or manmade water features or bodies;
6. Existing or proposed structures, fences, and retaining walls;
7. Natural features or vegetation left in natural state; and
8. Designated recreational open space areas.
B. The proposed landscape plan shall be certified by a Washington State registered landscape architect, Washington State certified nurseryman, or Washington State certified landscaper.
C. An affidavit signed by an individual specified in subsection B of this section, certifying that the landscaping has been installed consistent with the approved landscaping plan, shall be submitted to the department within 30 days of installation completion, unless the installed landscaping has been inspected and accepted by the department.
D. The required landscaping shall be installed no later than three months after issuance of a certificate of occupancy for the project or project phase. However, the time limit for compliance may be extended to allow installation of such required landscaping during the next appropriate planting season. A financial guarantee shall be required prior to issuance of the certificate of occupancy, if landscaping is not installed and inspected prior to occupancy. [Ord. 11-0329 § 3 (Exh. 1).]
18.35.120 Maintenance.
A. All landscaping shall be maintained for the life of the project;
B. All landscape materials shall be pruned and trimmed as necessary to maintain a healthy growing condition or to prevent primary limb failure;
C. With the exception of dead, diseased or damaged trees specifically retained to provide wildlife habitat, other dead, diseased, damaged or stolen plantings shall be replaced within three months or during the next planting season if the loss does not occur in a planting season; and
D. Landscape areas shall be kept free of trash. [Ord. 11-0329 § 3 (Exh. 1).]
18.35.130 Financial guarantees.
Financial guarantees shall be required consistent with the provisions of KMC Title 21. This time period may be extended to one year by the city manager, if necessary to cover a planting and growing season. [Ord. 11-0329 § 3 (Exh. 1).]