Chapter 17.70
LANDSCAPE REQUIREMENTS
Sections:
17.70.030 Landscape plan requirements.
17.70.040 Landscape development – General requirements.
17.70.050 Plant size, height and spacing requirements.
17.70.060 Landscape types – Perimeter landscaping.
17.70.070 Landscape standards – Single-family development.
17.70.080 Landscape standards – Multifamily, commercial, industrial and utility park development.
17.70.090 Landscape standards – Parking lots.
17.70.100 Landscape standards – Planned unit development.
17.70.110 Existing vegetation in lieu of landscape development.
17.70.120 Modification to standards.
17.70.130 Maintenance of plant materials.
17.70.140 Performance assurance.
17.70.010 Purpose.
The purpose of this chapter is to provide guidelines and regulations which will:
A. Maintain and protect property values;
B. Create a well designed landscaped environment which measurably improves the overall quality of the project and enhances the visual appearance of the community;
C. Preserve the natural landscape character of the Pacific Northwest and promote the use native and drought tolerant plantings;
D. Provide a smooth transition between adjacent properties and buffer conflicting land uses;
E. Provide screening for such unsightly areas as parking lots, storage areas, utility boxes or service yards so as to minimize the negative visual impact to the public. (Ord. 1198 § 22 (Exh. D), 2017; Ord. 744 § 2, 1995).
17.70.020 Applicability.
A. A landscape plan is required and shall be submitted to the city with all zoning applications and/or for a building permit for the following:
1. Residential subdivisions with respect to public right-of-way, open space or utility tract landscaping;
2. Multifamily residential uses;
3. Planned unit developments;
4. Commercial uses;
5. Industrial uses;
6. Conservation/resource district uses.
B. Review of a landscape plan submitted with a building permit that does not include any other land use approval shall be approved by the director. Landscape plan review required as part of any other land use decision shall be processed as part of that land use decision.
C. Any subdivision, planned unit development, mobile home park, or structure legally existing in the city on the effective date of this code shall be exempt from compliance with these landscape regulations. (Ord. 1198 § 22 (Exh. D), 2017; Ord. 769 § 29, 1996; Ord. 744 § 2, 1995).
17.70.030 Landscape plan requirements.
The applicant has the option of submitting a preliminary landscape plan prior to final approval. The preliminary landscape plan need not include the detail required for final approval, although areas of proposed landscaping should be shown and should indicate the type of landscaping proposed. The final landscape plan shall include the following information:
A. Three sets of landscape plans drawn to a scale of 1" = 50' or larger (e.g., 1" = 30', 1" = 20'). The plan should include a bar scale for reference;
B. Name and address or location of the project;
C. Vicinity map;
D. Scale, north arrow and date of the plan;
E. All property lines, easements, rights-of-way, streets, walks, vehicular drives, parking lots, existing and proposed structures, building entrances, freestanding lights, service or loading areas, signs, open spaces, plazas and recreation amenities with materials noted;
F. Existing and proposed contours (minimum five-foot intervals), elevations, and critical spot elevations;
G. Location, sizes and species of existing significant trees and heritage trees within required landscape areas. Natural areas should be designated as such;
H. Dimensioned landscaped areas;
I. Location of all trees, shrubs and ground cover to be planted;
J. Any proposed or existing physical elements (such as fencing, walls, curbing, benches) that may affect the overall landscape;
K. Parking layout, including circulation, driveway location, parking stalls and curbing;
L. Location of irrigation system. The source of water and type of irrigation system shall be noted;
M. A legend shall be included which shows symbols and type of plant;
N. All plant materials shall be shown on the landscaping plan at three-quarters mature size in appropriate relation to the chosen scale of the plan;
O. The plan shall state the estimated date for installation and completion of all plantings and finish materials;
P. Construction drawings for landscaping shall be submitted when requested by the city;
Q. The landscape plan shall identify the location and dimensions of any designated critical areas and required critical area buffers;
R. Such other submissions consistent with this chapter as may be required by the director;
S. A plant schedule shall be included which indicates the scientific and common names, quantities, sizes and spacing for all plants in the landscape plan. Quantities are not required on a preliminary landscape plan;
T. Location of areas of soil that will be protected from disturbance, location of areas of disturbed soils that will be amended, and specifications for soil preparation. (Ord. 1198 § 22 (Exh. D), 2017; Ord. 744 § 2, 1995).
17.70.040 Landscape development – General requirements.
General requirements for required landscaped areas are as follows:
A. Arrangements of plants shall enhance building designs and attractively screen parked vehicles and unsightly areas, soften visual impact of structures and enhance views and vistas.
B. At least 30 percent of required landscape plantings, other than street trees, shall be comprised of native vegetation.
C. At least 50 percent of required landscape plantings shall be comprised of drought tolerant species.
D. Existing vegetation may be included in the landscape plan to augment new plantings.
E. Landscape plans shall incorporate pedestrian and bicycle trails in conformance with a pedestrian and/or bicycle circulation plan adopted by the city.
F. Where wetlands, shorelines and other environmentally critical areas affect a proposed development, the landscape plan shall include measures for their protection and enhancement.
G. All landscaped areas shall be graded to prevent erosion and to facilitate the installation, growth and maintenance of the landscaping. Berms or mounds should be no steeper than 3 (H): 1 (V). All turf areas located in public rights-of-way shall have a grade of no greater than 3:1.
H. Trees and very large shrubs should be located with consideration to underground and overhead utility lines or public improvements.
I. Landscaping shall be designed to ensure adequate visibility and safety of vehicular traffic, bicyclists, pedestrians and other users, on and off the proposed site. Evergreen trees shall not be located where they will prevent pedestrian movement or where they will obstruct the visual line of sight of a public right-of-way.
J. The applicant shall retain all significant trees and heritage trees which will not constitute a safety hazard as determined by an ISA-certified arborist, and approved by the director. Areas devoted to access and areas to be cleared for required roads, utilities, sidewalks, trails or storm drainage improvements may be exempt from this requirement if approved by the director.
K. Plants that are not allowed in landscaped areas include, but are not limited to, ivy, holly, and noxious weeds on the King County noxious weed list. (Ord. 1198 § 22 (Exh. D), 2017; Ord. 744 § 2, 1995).
17.70.050 Plant size, height and spacing requirements.
The following standards apply to all landscaping required by this chapter:
A. Minimum sizes at installation are as follows:
1. One-and-three-quarter-inch caliper street trees;
2. One-and-one-half-inch caliper other deciduous trees;
3. Eight-foot minimum height vine maples and other multi-stemmed trees;
4. Six-foot minimum height evergreen trees;
5. Two-foot minimum height for medium and tall shrubs.
B. Maximum Size. Species approved within a landscape plan shall have a growth pattern in scale with the development and be consistent with the preservation of significant views and the preservation of significant trees. (Ord. 1198 § 22 (Exh. D), 2017; Ord. 744 § 2, 1995).
17.70.060 Landscape types – Perimeter landscaping.
The following landscape types shall be required along perimeter lot lines for all abutting compatible uses and abutting uses in transition areas, as specified in Table 1; and along street frontages as specified in SMC 17.70.080:
A. Type I Full Screen.
1. Purpose. To provide a “full screen” that functions as a visual barrier between incompatible uses and adjacent to freeways.
2. Type I landscaping shall consist of:
a. A mix of primarily evergreen trees and shrubs placed to form a continuous screen;
b. At least 70 percent evergreen trees;
c. Evergreen trees spaced no more than 15 feet on center;
d. Deciduous trees spaced no more than 20 feet on center;
e. Evergreen shrubs that achieve a height of four to six feet within three years spaced no more than four feet apart; and
f. Living ground cover planted to achieve full coverage of the ground surface within three years.
B. Type II Filtered Screen.
1. Purpose. To provide a “filtered screen” that functions as a visual separator between commercial and industrial uses; between differing types of residential development; and to screen industrial uses from the street.
2. Type II landscaping shall consist of:
a. A mix of evergreen and deciduous trees and shrubs spaced to create a filtered screen;
b. At least 50 percent deciduous trees and at least 30 percent evergreen trees;
c. Evergreen trees spaced no more than 15 feet on center;
d. Deciduous trees spaced no more than 20 feet on center;
e. A mix of evergreen and deciduous shrubs that achieve a height of four to six feet within three years spaced no more than five feet apart; and
f. Living ground cover planted to achieve full coverage of the ground surface within three years.
C. Type III Visual Buffer.
1. Purpose. To provide a visual separation of uses from streets and a visual separation of compatible uses to soften the appearance of street, parking areas and building facades.
2. Type III landscaping shall consist of:
a. A mix of evergreen and deciduous trees spaced to create a continuous canopy;
b. At least 60 percent deciduous trees and at least 20 percent evergreen trees;
c. Evergreen and deciduous trees spaced no more than 25 feet on center;
d. A mix of evergreen and deciduous shrubs that do not exceed a height of four to six feet at maturity spaced no more than four feet apart. Shrubs greater than four feet in height should not impair sight distances or create a safety hazard; and
e. Living ground cover planted to achieve full coverage of the ground surface within three years.
D. Type IV Parking Area Landscaping.
1. Purpose. To provide shade and visual relief while maintaining clear sight lines within parking areas.
2. Type IV landscaping shall consist of:
a. Deciduous trees or evergreen trees;
b. Evergreen or deciduous shrubs that do not exceed a height of four feet at maturity spaced no more than four feet apart. Shrubs greater than four feet in height should not impair sight distances or create a safety hazard;
c. Living ground cover planted to achieve full coverage of the ground surface within three years; and
d. At least 70 percent of the required trees shall be deciduous unless submitted plans show adequate soil preparation and volume to support additional evergreen trees. (Ord. 1198 § 22 (Exh. D), 2017; Ord. 744 § 2, 1995).
17.70.070 Landscape standards – Single-family development.
The following standards apply to residential subdivisions on property located within the R-C, R-1-4, R-1-7.5, PR and MU districts:
A. Residential Streets. Trees shall be provided along all public streets as follows:
1. Trees shall be spaced no more than 40 feet apart on arterials.
2. Trees shall be spaced no more than 50 feet apart on collector and local access streets.
3. Street trees shall be planted prior to final plan approval. The director shall approve spacing and species.
4. Trees may be spaced at irregular intervals in order to accommodate sight distance requirements for driveways and installation of LID BMPs. However, when this is proposed, the required number of street trees based on the maximum spacing must still be installed in the overall street tree planting areas.
5. No street tree shall be planted with less than 300 cubic feet of total soil volume.
B. Other Reserve Tracts and Open Space.
1. Preserve existing vegetation to the maximum extent possible.
2. The director may require enhancement of existing vegetation if necessary to screen proposed uses or adjacent to such tract.
C. When street trees are removed or severely damaged, trees greater than six inches DBH shall be replaced at a ratio of two new trees per removed tree, while all trees less than six inches DBH shall be replaced at a ratio of one new tree per removed tree. Where new street trees cannot be planted due to portions of rights-of-way having been previously paved or otherwise rendered unsuitable to plant trees, a fee-in-lieu of planting is required. Such fee shall be determined by the city arborist per city policy and deposited into the city street tree account. (Ord. 1198 § 22 (Exh. D), 2017; Ord. 744 § 2, 1995).
17.70.080 Landscape standards – Multifamily, commercial, industrial and utility park development.
In addition to other requirements of this chapter, the following standards shall apply in the R-2, R-3, B, OP, PCI, I and MU districts:
A. Street Trees.
1. Trees shall be provided along all public streets, spaced as follows:
a. No more than 40 feet apart on arterial streets;
b. No more than 50 feet apart on collectors and local access streets.
2. Trees shall be:
a. Located within the street right-of-way if permitted by the city or other custodial state or local agency; or
b. Located no more than 10 feet from the street line when located within a lot.
3. Trees may be spaced at irregular intervals in order to accommodate sight distance requirements for driveways and intersections and installation of LID BMPs.
4. Street trees shall be planted prior to final plan approval. The director shall approve spacing and species.
5. No street tree shall be planted with less than 300 cubic feet of total soil volume.
B. Perimeter Landscape Areas. See Table 1.
C. Street Frontage. The required landscaped areas shall be equal to the front yard setback specified for the applicable zoning district and shall consist of Type III landscaping.
D. When street trees are removed or severely damaged, trees greater than six inches DBH shall be replaced at a ratio of two new trees per removed tree, while all trees less than six inches in diameter DBH shall be replaced at a ratio of one new tree per removed tree. Where new street trees cannot be planted due to portions of rights-of-way having been previously paved or otherwise rendered unsuitable to plant trees, a fee-in-lieu of planting is required. Such fee shall be determined by the city arborist per city policy and deposited into the city street tree account. (Ord. 1198 § 22 (Exh. D), 2017; Ord. 744 § 2, 1995).
17.70.090 Landscape standards – Parking lots.
A. Type IV landscaping shall be provided within all surface parking containing 10 or more parking stalls or 3,000 square feet of vehicle use area.
B. Vehicle use area includes the parking lot, driveways and service areas.
C. For parking lots with 10 to 30 stalls, 10 percent of the vehicle use area shall be landscaped.
D. For parking lots with 31 or more stalls, 15 percent of the vehicle use area shall be landscaped.
E. At the discretion of the director, required parking lot landscaping area percentages may be reduced for development within historic overlay zones if the applicant cannot meet minimum parking requirements (See Chapters 17.35 and 17.37 SMC).
F. The minimum area per planting segment shall be 100 square feet, with minimum dimensions of not less than six feet on any side, and not less than 300 cubic feet of soil, in planters containing trees.
G. Planting areas shall be distributed throughout the parking lot. The maximum distance between any parking stall and required parking area landscaping shall be no more than 50 feet.
H. Shade trees shall be provided at the rate of a minimum of one per planter and/or one per 100 square feet of planter. Planting areas incorporated into LID BMPs may be exempted from the requirement for shade trees, up to a maximum of 10 percent of the landscaping area required to have shade trees.
I. Permanent curbs or structural barriers shall be provided to protect the landscape plantings from vehicle overhang, except where curb cuts are placed to allow water to enter LID BMPs.
J. Landscape planting areas shall project out into the pavement as peninsulas or islands (surrounded on at least two sides by pavement).
K. Trees shall be planted at least four feet from the outside edge of the planting area. (Ord. 1198 § 22 (Exh. D), 2017; Ord. 744 § 2, 1995).
17.70.100 Landscape standards – Planned unit development.
The applicable standards of SMC 17.70.080 and 17.70.090 shall apply as minimums depending upon the uses proposed in the PUD. (Ord. 1198 § 22 (Exh. D), 2017; Ord. 744 § 2, 1995).
17.70.110 Existing vegetation in lieu of landscape development.
If the proposal is required to provide natural vegetative buffers for critical areas located on or adjacent to the project site, the director may waive the landscape area and planting requirements of SMC 17.70.060 through 17.70.100 and may permit the use of vegetation that exists within a critical area buffer required by Chapter 19.12 SMC in lieu of landscape development if the width of that vegetated area equals at least twice the dimension required by Table 1. Supplemental compatible landscaping may be added adjacent to the critical area buffer to create the necessary width. (Ord. 1198 § 22 (Exh. D), 2017; Ord. 744 § 2, 1995).
17.70.120 Modification to standards.
A. Request for Modifications. The applicant may request a modification of the landscaping requirements set forth in this chapter; provided, that modifications shall not allow disturbance of protected or environmentally critical areas and that street frontage landscaping shall be maintained.
B. Review. For any landscape plan that does not include any other land use approval, the director may approve modifications to the standards set forth in SMC 17.70.060 through 17.70.140 if the proposed landscaping is superior to that which could be achieved by strict compliance with those standards. For modifications proposed in landscape plans submitted with any other land use approval, those modifications shall be reviewed as part of that associated land use decision.
C. Findings. In approving modifications to the standards set forth in SMC 17.70.060 through 17.70.140, the director or other land use decisionmaker shall prepare written findings that the proposed modification is justified based on one of the following:
1. The modifications retain significant trees equal in number to what would otherwise be required; or
2. The modifications retain existing vegetation in consolidated locations promoting the natural vegetated character of the site; or
3. The modifications better accommodate or improve the existing physical conditions of the subject property; or
4. The modifications incorporate elements to provide for wind protection or to maintain solar access. (Ord. 1198 § 22 (Exh. D), 2017; Ord. 769 § 30, 1996; Ord. 744 § 2, 1995).
17.70.130 Maintenance of plant materials.
A. Replacement. The property owner shall replace any unhealthy or dead plant materials in conformance with the approved landscape plan per SMC 17.70.030 and shall maintain all landscape plant material.
B. Maintenance Assurance. The director shall require a maintenance assurance device for a period of two years from the completion of planting in order to ensure compliance with the requirements of this section. (Ord. 1198 § 22 (Exh. D), 2017; Ord. 744 § 2, 1995).
17.70.140 Performance assurance.
A. The required landscaping must be installed prior to issuance of the certificate of zoning compliance unless the director determines that a performance assurance device, for a period of not more than one year, will adequately protect the interests of the city. In no case may the property owner delay performance for more than one year.
B. If a performance assurance device is permitted under this section, the director shall require an assurance device in conformance with SMC 17.05.100(B). (Ord. 1198 § 22 (Exh. D), 2017; Ord. 744 § 2, 1995).
Table 1
Required Landscaping for Perimeter Lot Lines
|
|
Transition Areas |
|||||
|---|---|---|---|---|---|---|
|
Subject Property Zone |
Abutting Compatible Use |
Abutting Single-Family |
Abutting Multifamily |
Abutting Comm./Indust. |
Abutting Utility Park |
Abutting Parks/Open Space |
|
Nonresidential Uses in R-1, R-2 zones |
10' Type III |
20' Type I |
15' Type I |
10' Type II |
10' Type I |
20' Type II |
|
R-2 Duplex/Triplex |
10' Type III |
10' Type II |
10' Type II |
10' Type II |
10' Type I |
10' Type II |
|
R-3 Multifamily |
10' Type II |
20' Type II |
10' Type II |
10' Type I |
10' Type I |
10' Type II |
|
Commercial Industrial |
10' Type III |
30' Type I |
20' Type I |
10' Type III |
10' Type II |
20' Type II |
|
Utility Park |
|
30' Type I |
30' Type I |
30' Type I |
|
40' Type I |
|
Parks and Open Space |
|
** |
** |
** |
** |
** |
**To be determined by the director.
(Ord. 1198 § 22 (Exh. D), 2017).