Chapter 15.45 LANDSCAPING
15.45.010 Applicability and purpose.
15.45.060 Tree planting standards.
15.45.070 Materials, maintenance, and replacement.
15.45.090 Compliance with variances.
15.45.010 Applicability and purpose.
A. Applicability. This Chapter shall apply to all development in the City; provided, however, that single-family homes shall only be subject to Sections 15.45.080 and 15.45.090.
B. Purpose. The purpose of this Chapter is to require the preparation of landscape plans that contribute to visual quality and continuity within and between developments, provide screening and mitigation of potential conflicts between activity areas and site elements, ensure significant tree canopy shading to reduce heat build-up, enhance outdoor spaces and gathering areas, provide green space areas that support passive recreational uses, reduce erosion and stormwater runoff, and mitigate air pollution. (Ord. 2005-12)
A. Objectives. Every application for a Final Development Plan, Special Use Permit, Planned Unit Development, or Master Plan and any amendments thereto shall include a landscape plan that accomplishes the following objectives:
1. Protects existing trees, natural areas and topographical features including maintaining wetland and other habitat areas and the character of drainage channels;
2. Reinforces and extends any existing patterns of outdoor spaces and vegetation where practicable;
3. Supports functional purposes such as, visual screening, creation of privacy, management of microclimate or drainage;
4. Enhances the appearance of the development and the neighborhood;
5. Respects natural contours;
6. Complements the architecture of a development;
7. Provides buffers between conflicting land uses;
8. Creates year round visual interest;
9. Enhances the pedestrian environment;
10. Allows for adequate security and surveillance;
11. Avoids north side sun shadowing on driveways and sidewalks; and
12. Avoids reliance on excessive maintenance.
B. Xeriscape principles. All landscaping plans shall be designed to incorporate water conservation materials and techniques through application of the following xeriscape landscaping principles:
1. Grouping of plants with similar water requirements together on the same irrigation zones;
2. Limiting high-irrigation turf and plantings to appropriate areas that are highly visible or frequently used;
3. Use of low-water demanding plants and turf where practicable;
4. Use of efficient irrigation systems;
5. Incorporation of soil improvements;
6. Use of mulches;
7. Provision of regular and attentive maintenance; and
8. Exclusion of artificial turf or plants, mulched beds or areas without landscape plant material (including gravel), paving of areas not required for walkways, plazas or parking lots, bare ground, and weed covered or infested surfaces. (Ord. 2005-12)
A. Required elements. Landscape plans shall include the following elements:
1. Site plan. A plan reflecting the layout of the site showing existing and proposed buildings, parking areas and driveways, open space areas, walkways and other improvements, with circular symbols delineating existing and proposed trees and shrubs and stippling identifying ground covers. The circular symbols should represent the canopy size of the tree or shrub at five (5) to seven (7) years from the time of planting. The circular symbols should include a two or three letter abbreviation identifying the species type of individual plants or groups of plants of the same species.
2. Planting schedule. A table with a legend of the symbols used on the site plan for the proposed ground covers, trees, shrubs, or vines, the two or three letter abbreviation and matching species name, the number of each species to be planted, the size of the plant material at the time of planting.
3. Irrigation plan. A plan identifying the type and size of drip, spray head, or subsurface irrigation method proposed for each area of the site.
4. Elevation drawings. Elevation or cross-section drawings of proposed landscape screening of parking lots, parking structures, trash and mechanical equipment enclosures, or buffers of residential land uses to adjoining non-residential land uses.
B. Retaining walls. Landscaping material shall relate to the building in terms of color, materials, scale and architectural style of the building. Walls shall be tiered if they are more then four feet (4') in height and landscaping shall be used to break up the mass of the wall at each tier. The International Building Code requires that a professional engineer design retaining walls over four feet (4’) in height, including the foundation.
C. Coverage material.
1. General. Plant materials shall be water-conserving (xeriscape) varieties.
2. Turf grass. High-use areas shall be planted with irrigated turf grass. Turf in isolated areas of less than five feet (5') in width is discouraged.
3. Native grass. Non-irrigated short grass, prairie grasses, or other adapted grasses may be established in remote, low-use, low visibility areas, including detention ponds. Such areas shall be irrigated until fully established, unless a waiver that includes a weed management plan is approved.
4. Perennial beds. Shrub and ground cover planting beds shall be separated from turf grass with edging and shall have open surface areas covered with mulch.
5. Annuals. Annual planting beds shall be limited to highly visible areas or areas with frequent pedestrian use.
6. Inorganic material. Rock, bark mulch, and other inorganic material may be used in limited decorative ways.
D. Parking lot landscaping. Parking lot landscaping shall meet the standards established in Section 15.44.050(H) in addition to the following minimum standards:
1. Islands. The interior of any parking lot in excess of twenty (20) spaces shall include interior landscaped islands to break up the expanse of asphalt, provide shade, and provide pedestrian connections between the parking area and the building. Every island shall include at least one (1) canopy shade tree or ornamental tree, be of a width greater than eight feet (8') in its smallest dimension, include at least eighty (80) square feet of ground area per tree to allow for root aeration, and have raised concrete curbs. Trees shall be located at least three feet (3') back from the curb and located to assure that their canopies do not interfere with parking lot and street light fixtures.
2. Screening. Parking lots with twenty (20) or more spaces shall be screened from adjacent uses and from the street. Screening from residential uses shall consist of a hedge, berm, or a fence or wall in combination with plant material, six feet (6') in height, and of sufficient year-round opacity to block at least ninety percent (90%) of light from vehicle headlights. Screening from the street and all non-residential uses shall consist of an earthen berm, plant material, planter, fence, or wall or a combination of such elements, each of which shall have a minimum height of thirty-six inches (36") above the level of the street or an adjacent property. Such screening shall extend a minimum of seventy percent (70%) of the length of the street frontage of the parking lot and also seventy percent (70%) of the length of any boundary of the parking lot that abuts any nonresidential use. Openings in the required screening shall be permitted for such features as access ways or drainage ways.
3. Visibility. To avoid blocking driver sight distance at driveway-street intersections, all landscaping shall comply with the sight visibility triangle requirements in Section 15.42.310.
E. Lighting. Landscape accent lighting shall not create glare onto adjacent properties or streets and shall not be used in areas that are directly adjacent to single-family residential properties. (Ord. 2005-12)
If the City Manager or designee determines that buffering between conflicting uses is necessary, one (1) or more of the following landscape buffering techniques shall be used to mitigate the conflicts:
1. Separate and screen with plant material: plant dense stands of evergreen trees, canopy shade trees, ornamental trees or shrubs.
2. Integrate plantings: incorporate trees, vines, planters or other plantings into the architectural theme of the buildings and their outdoor spaces to subdue differences in architecture and bulk and to avoid harsh edges.
3. Establish privacy: establish vertical landscaping elements to screen views into or between windows and defined outdoor spaces where privacy is important, such as where larger buildings are proposed next to side or rear yards of smaller buildings.
4. Visually integrate fences or walls: provide plant material in conjunction with a screen panel, arbor, garden wall, privacy fence or security fence to avoid the visual effect created by unattractive screening or security fences.
5. Landform shaping: utilize berms or other grade changes to alter views, subdue sound, change the sense of proximity and channel pedestrian movement. (Ord. 2005-12)
A. Trash and mechanical enclosures. To soften the appearance of trash and mechanical enclosures and provide a transition to surrounding landscaped areas, evergreen trees or upright evergreen shrubs shall be planted around the exterior of trash enclosures and mechanical enclosures, except the gate areas necessary for access. A minimum coverage of twenty percent (20%) of the enclosure walls shall be concealed with landscaping. Sections 15.43.110 and 15.43.120 shall also apply.
B. Loading and service areas. Evergreen trees shall be planted between a loading or service area and an adjacent street or property so as to screen from view at least forty percent (40%) of the loading or service area from the adjacent street or property. A screen wall may be used in lieu of landscape screening. Section 15.43.130 shall also apply.
C. Small utility boxes and air conditioning units. Upright evergreen shrubs shall be used to screen small utility boxes and air conditioning units so as to screen from view at least eighty percent (80%) of the utility box or air conditioning unit from an adjacent street or property. Clearances around the units shall comply with the International Building Code. Section 15.43.110 shall also apply. (Ord. 2005-12)
15.45.060 Tree planting standards.
A. Tree canopy. All developments shall establish groves and belts of trees along all public streets, in and around parking lots, and in all landscape areas that are located within fifty feet (50') of any building or structure, to establish at least a partial urban tree canopy. The groves and belts may be combined or interspersed with other landscape areas in remaining portions of the development to accommodate views and functions such as active recreation and storm drainage.
B. Minimum planting. This Section requires a minimum tree canopy, but is not intended to limit additional tree plantings in any remaining portions of the development. Groves and belts of trees shall be required as follows:
1. Trees shall be planted in street rights-of-way adjacent to the development by one (1) or more of the methods described below:
a. In locations where the sidewalk is separated from the street by a parkway or tree-lawn at least five feet (5') wide, canopy shade trees shall be planted at between twenty-five (25) to forty (40) foot spacing dependent on the tree species mature canopy size. If the tree-lawn is less than five feet (5') wide, the trees shall be placed on the inside of the sidewalk.
b. In locations where the sidewalk is attached to the street, canopy shade trees shall be established in an area ranging from three feet (3') to seven feet (7') behind the sidewalk at the spacing intervals as required in subsection (a) hereof.
c. In locations where the sidewalk is attached to the street and the sidewalk is ten feet (10') or more in width, or extends from the curb to the property line, canopy shade trees shall be established in planting cutout areas of at least sixteen (16) square feet at thirty (30) foot to forty (40) foot spacing.
2. Tree plantings within sidewalks shall utilize appropriate soil amendments to support healthy tree growth.
C. Minimum species diversity. To prevent uniform insect or disease susceptibility and eventual elimination of the species at maturity on a development site or in the adjacent area or district, species diversity is required and extensive monocultures are prohibited. The minimum requirements outlined in Table 1.0 shall apply to any development plan.
Table 1.0. Species Diversity
Number of trees on site
Maximum percentage of any one species
10-19
80%
20-39
50%
40-59
33%
60 or more
25%
D. Prohibited species. The following tree species shall not be planted along public streets:
Box Elder (acer negundo)
Silver Maple (acer sccharinum)
Tree of Heaven (ailanthus altissima)
Cultivars of catalpa
Mulberrry (morus)
Poplar (populus)
Willow (salix)
Siberian Elm (ulmus pumila)
Russian Olive (elaeagnus augustafolia)
E. Minimum tree sizes. To ensure survivability and a high growth rate, the following minimum tree sizes outlined in Table 2.0 shall be required, except tree plantings in drainage channels:
Table 2.0. Tree Sizes
Type
Minimum Size
Canopy Shade Tree
3"-3.5" caliper* balled and burlapped or equivalent
Evergreen Tree
8'-10' height balled and burlapped or equivalent**
Ornamental Deciduous Tree
2"-2.5" caliper* balled and burlapped or equivalent
Upright Juniper
7 gallon or adequate size consistent with design intent
Shrubs
5 gallon or adequate size consistent with design intent
Vines
1 gallon
* caliper size is measured six inches (6") above the root ball.
** piñon pine, bristlecone pine, Bosnian pines, and any tree with a mature height of less than eighteen feet (18') shall be a maximum of six feet (6') in height.
F. Existing trees and shrubs. Depending on their quality and health, and to extent practicable, existing trees and shrubs shall be preserved in the redevelopment or modification of a site, and may be credited for required landscaping based on the size and species of the tree or shrub saved. (Ord. 2005-12)
15.45.070 Materials, maintenance, and replacement.
A. Plant materials and quality. The selection of plant materials shall be based on climate and site conditions. All plants shall be A-Grade or No. 1 Grade, free of any defects, of normal health, height, leaf density, and spread appropriate to the species as defined by American Association of Nurserymen standards.
B. Installation. All landscaping shall be installed according to sound horticultural practices in a manner designed to encourage quick establishment and healthy growth.
C. Irrigation. All trees, shrubs, groundcovers, vines and sod areas shall be irrigated with drip or subsurface systems when possible. All native grass areas shall be irrigated until fully established.
D. Maintenance. Trees and vegetation, irrigation systems, fences, walls and other landscape elements shall be considered as elements of the project in the same manner as parking, building materials, and other site details. The applicant, landowner and successors in interest shall be jointly responsible for the regular maintenance of all landscaping elements. All landscaping shall be maintained free from disease, pests, weeds, and litter and shall be periodically trimmed to avoid obstruction of traffic signs or signals. All landscape structures such as fences and walls shall be repaired and replaced periodically to maintain a structurally sound condition. The determination as to whether maintenance has been adequate shall be made by the City Manager or designee, who shall consider the following criteria:
1. Whether the condition of the landscaping is in character with neighboring residences or commercial development;
2. Whether the condition of the landscaping may pose a fire hazard; and
3. Whether the condition of the landscaping may for any reason pose a danger to the health, safety or welfare of the general public.
E. Replacement. Any landscape element that dies or is otherwise removed shall be promptly replaced with a plant of the same or similar species and a size as set forth in Section 15.45.060(E). (Ord. 2005-12)
A. Applicability. This Section shall apply to all berms constructed or maintained in the City except those governed by Chapter 12.28.
B. Permit required. No new berm shall be constructed until a landscaping permit has been issued by the City Manager or designee.
C. General standards. Every berm shall comply with the following standards:
1. No berm shall exceed six feet (6') in height above natural grade.
2. No berm shall have a slope steeper than three feet (3') in the horizontal plane for each one foot (1') in the vertical plane (3:1 slope).
3. Berms shall be constructed solely of soil, and shall not contain concrete, brick, tires or other similar materials.
4. To provide visual relief, any berms exceeding ten feet (10') in length shall be curvilinear and shall vary in height.
5. All berms shall be designed so as not to disturb existing drainage patterns, unless otherwise approved by the City Manager or designee.
D. Landscaping. Except as otherwise provided in this Section, all berms shall be landscaped so that the berm coordinates with adjacent landscaping, subject to the following:
1. At least fifty percent (50%) of the berm area shall be landscaped with live plant material, which may include non-irrigated native grasses.
2. For every thirty (30) linear feet, there shall be planted at least one (1) tree and two (2) shrubs. When calculating the required number of trees and shrubs, fractions shall be rounded to the next greater whole number. Required trees and shrubs may be exchanged for one another with one (1) tree equaling five (5) shrubs.
3. For berms in commercial and multi-family residential zone districts and new single-family subdivisions, the tree size requirements established in Section 15.45.060(E) shall apply.
E. Exemptions. The following berms shall be exempt from the requirements of subsection (D) (2) hereof:
1. Berms of less than one foot (1') in height above natural grade;
2. Berms with a slope of less than five feet (5') in the horizontal plane for each one foot (1') in the vertical plane (5:1 slope); and
3. Berms in residential zone districts which are not visible from any public or private street or trail or are located at least fifty feet (50') from any public or private street or trail.
F. To provide visual relief, trees and shrubs shall be planted on both the top and the side slopes of the berm in a natural pattern.
G. Berms in the R-2.0 or R-2.5 zone districts may, as an alternative to the landscaping requirements of subsection (D) hereof, be landscaped with low water-use plant material, but only if at least fifty percent (50%) of the berm perimeter is adjacent to an area landscaped with low water-use plant material.
H. All landscaping shall be maintained to ensure the health and appearance of plant material. (Ord. 2005-12)
15.45.090 Compliance with variances.
Any landscaping installed on any property as a condition of a variance granted by the Board of Adjustments and Appeals shall be maintained in accordance with the conditions and plan approved by the Board. (Ord. 2005-12)