18.50.040 Landscape development standards

18.50.040 Landscape development standards.

A. General Location for Landscape Improvements. Landscaping shall be provided in the following locations for all types of development, unless the city determines that the required landscape is not necessary to fulfill the purposes of this chapter:

1. Perimeter Areas. All areas that abut a street or residential property shall be landscaped in compliance with this chapter, except where occupied by a primary building, walk or driveway. Minimum landscape areas are listed in Tables 18.50.040(A) and (B).

2. Unused Areas. All areas of a multifamily or nonresidential project site not intended for a specific use (including areas planned for future phases of a phased development) shall be landscaped with existing natural vegetation, native grasses or similar.

3. Parking/Loading Areas. Parking lots, and where loading areas are visible from a public street, shall be landscaped in compliance with this chapter.

4. Outdoor Storage Areas, Recreational Vehicle Parking, and Refuse Areas. All outdoor storage areas, recreational vehicle parking, and refuse areas, when visible from adjoining properties or public streets, shall be landscaped in compliance with this chapter.

5. Storm Water Low Impact Development (LID) Facilities. Areas of vegetation planted in storm water LID facilities (not permanently inundated or ponded areas) and for which there is a city-approved maintenance plan as prescribed in the city’s Engineering Design Standards Manual shall count towards the minimum landscape coverage areas outlined in subsection B of this section.

B. Landscape Area Requirements by Zones. Minimum landscape area requirements are listed below by zones consistent with ACC 18.02.070.

Table 18.50.040(A). Minimum Landscape Requirements by Zoning District
Zones	Minimum Landscape Coverage¹	Minimum Landscape Planter Width – Perimeter Areas²
Zones	Minimum Landscape Coverage¹	Abutting Street³	Abutting Residential Property
Residential Zones
RC, R-1, R-5, and R-7 Residential Zones⁴	N/A	N/A	N/A
R-10, R-16 and R-20 Zones⁵	20%	6 ft.	10 ft.
Nonresidential Zones
C-2	10%	0 ft.	6 ft.
C-1, C-N	10%	6 ft.	10 ft.
C-3, I, P-1	15%	6 ft.	10 ft.
M-1	10%	10 ft.	10 ft.
M-2	10%	10 ft.	25 ft.
Other
RO⁶/RO-H⁶	N/A	N/A	N/A
DUC⁷	N/A	N/A	N/A

1Minimum landscape coverage required is the minimum percentage of net lot area that must be maintained with a vegetated pervious surface. Vegetated bioretention cells or water quality treatment swales (not permanently inundated or ponded areas) may be included in the required landscape coverage percentage. Preference shall first be given to retention of areas of existing native coniferous vegetation. For sites that do not have existing native coniferous vegetation, landscape coverage can be achieved through planting of native species.

2Listed planter widths shall be located entirely on private property.

3The minimum landscape planter abutting a street may be reduced in size using the provision contained in ACC 18.50.080, Alternative landscaping plan. The reduced landscape planter shall have an average width of the requirement contained in Table 18.50.040(A).

4Landscaping shall only be required in conjunction with an administrative or conditional use permit. The type and amount of landscaping shall be determined at that time the administrative or conditional use permit is approved.

5Refer to ACC 18.31.200, Architectural and site design review standards and regulations, for additional requirements.

6Landscaping within the RO/RO-H zone is not required unless site development includes the demolition of existing structure(s) together with new construction. Under this scenario the minimum landscape requirements of the C-1 zone shall be met.

7Landscaping within the DUC zone shall be provided as defined in the Downtown Urban Center Design Standards; see reference to ACC 18.29.070.

C. Landscape Design and Planting Requirements. Landscape design and construction for new development or redevelopment shall be compatible with the surrounding urban and natural environment. Landscape plantings shall comply with the plant type, size, and spacing provisions listed below.

1. Landscape Design. Landscaping shall be designed as an integral part of the overall site plan with the purpose of enhancing building design, public views and spaces, supporting storm water low impact development facilities, and providing buffers, transitions, and screening.

a. All required planting areas shall be covered with a mixture of trees, shrubs, and groundcover plants. Sodded lawn (not seed) may be substituted for some but not all of shrubs or groundcover plants. If sodded lawn is used it cannot cover more than 20 percent of the site and those portions of the lawn area must be served by an automatic irrigation system.

b. Planting design shall have focal points at project entries, plaza areas, and other areas of interest using distinct planting and/or landscape features.

c. As appropriate, building and site design shall include the use of landscaping against buildings to visually break up expanses of wall, soften appearance, and create visual interest through the use of planting areas, wall planters, hanging gardens, and/or raised planters. Loose rock, gravel, decorative rock or stone shall not exceed 20 percent of the planting area.

2. Plant Types. Landscape planting shall be compatible with the character and climate of the Pacific Northwest and complement the architectural design of structures on the site.

a. Native Landscaping. Landscaping materials installed shall include species native to the Puget Sound lowland region of the Pacific Northwest or noninvasive species that have adapted to the climactic conditions of the region in the following minimum amounts:

i. Fifty percent of trees.

ii. Fifty percent of groundcover and shrubs.

b. Trees. Trees planted within 10 feet of a public street, sidewalk, paved trail, or walkway shall be a deep-rooted species and shall be separated from hardscapes by a root barrier to prevent physical damage to public improvements.

3. Planting Size and Spacing. In order to balance both an immediate effect of a landscape installation and to allow sustained growth of planting materials, minimum plant material sizes and plant spacing are as follows:

a. Trees. Trees shall be a minimum of one and one-half inches in diameter breast height (dbh) at the time of planting. Evergreen trees shall be a minimum of four to six feet in height at the time of planting and may include either broadleaf or conifer. Tree spacing within the perimeter planters along streets and abutting residential property shall be planted no further apart on center than the mature diameter of the proposed species.

b. Shrubs. Shrubs shall be a minimum of 18 inches in height, or two-gallon size containers, at the time of planting.

c. Groundcover. Groundcover means low evergreen or deciduous plantings and shall be planted from either four-inch pot with 12-inch spacing or one-gallon pot with 18-inch spacing. Alternative spacing of particular species may be approved by the city if documentation concerning the effectiveness of the groundcover is submitted with the landscape plan.

i. Tree size and spacing at installation shall be increased by the city where needed to ensure visual access for vehicles and pedestrians and provide clear vision at street, access tracts and driveway intersections (sight distance triangles).

ii. Trees or shrubs with a full-grown height equal to or greater than 30 inches shall not be planted in any sight distance triangle. Sight distance triangles are determined in conformance with the city of Auburn engineering design standards, Chapter 10.

iii. A minimum distance of 15 feet is required from the mature diameter of trees and the center of street light standards.

4. Landscaping Requirements for Parking Areas.

a. General Parking Lot Landscaping Standards.

i. All parking lot landscape areas shall be protected with vertical or extruded concrete curbs, or equivalent barriers. Tire blocks shall not be used as a substitute for curbing and boundary around the landscaped area unless they are integral to a storm water LID facility design as approved by the city engineer or designee.

ii. All parking lot landscaping must be located between parking stalls, at the end of rows of parking, or between the end of rows of stalls and the property line.

iii. The maximum distance between any parking stall and required parking area landscaping shall be no more than 50 feet.

iv. Shrubs, groundcover or lawn shall be planted to cover each parking lot planting area using the planting size and spacing requirements specific in subsection (C)(3) of this section. All groundcover shall have a mature height of not more than 24 inches.

v. Modifications to protect drainage features, easements, or utility facilities may be allowed. Modifications that reduce landscape area or plant material shall be made up elsewhere on site, if possible.

vi. The requirements of this section shall not apply to parking garages or to display areas for automotive and equipment sales and rentals that are specifically designed, approved and constructed for the display purpose and that do not reduce required landscape areas.

b. Specific Parking Lot Landscaping Standards.

Table 18.50.040(B). Specific Parking Lot Landscaping Standards
	Landscaped Area Required	Planting Area Design Requirements	Plantings Required
12 parking stalls or less	No requirement
13 – 75 parking stalls	7% of surface parking stalls (exclusive of circulation)	Minimum planter width: 6 feet	Trees shall be provided at the rate of a minimum of one per planter and/or one per 100 square feet of planter.
76 parking stalls or more	10% of surface parking stalls (exclusive of circulation)	Minimum planter width: 6 feet	Trees shall be provided at the rate of a minimum of one per planter and/or one per 100 square feet of planter.

5. Landscaping for Outdoor Storage Areas, Recreational Vehicle Parking and Refuse Areas.

a. Outdoor storage areas and recreational vehicle parking areas must be screened from view from adjacent streets and from all residentially zoned land by a minimum six-foot-wide landscape buffer. This landscape buffer shall contain evergreen trees or tall shrubs, a minimum of six feet in height at the time of planting, which will provide a 100 percent sight-obscuring screen within three years from the time of planting is required; or a combination of evergreen trees or deciduous trees, planted 20 feet on center with no more than 30 percent being deciduous and backed by a 100 percent sight-obscuring fence. In addition to the trees, shrubs shall be planted at four-foot spacing, in all directions, and groundcover provided.

b. Outdoor storage areas abutting the Interurban Trail (regardless of the zoning of the Interurban Trail) and other future trails connecting to the Interurban Trail shall have a minimum 10-foot-wide landscape buffer containing the planting materials specified in subsection (C)(5)(a) of this section.

c. Trash containers, dumpsters, trash compactors, and recycling bins associated with multiplex, multi-unit residential, and nonresidential uses must be screened from public view on all sides with a solid fence, wall, or gate constructed of cedar, redwood, masonry, or other similar building material reflecting the overall design of the site, and be appropriately landscaped (e.g., climbing vines, arborvitae, etc.).

6. Irrigation. No portion of any landscaped area shall be located further away than 50 feet from a source of water adequate to irrigate the landscaping. The source of water may be a manual (hose connection) or an automatic irrigation system. (Ord. 6885 § 1 (Exh. A), 2022; Ord. 6617 § 29, 2016; Ord. 6387 § 1, 2011; Ord. 4914 § 1, 1996; Ord. 4304 § 1(34), (35), 1988; Ord. 4229 § 2, 1987.)