§ 30-151. Landscape standards.

(a)

Intent.

(1)

Purpose. A transect-based landscape plan provides many aesthetic, ecological, functional and health and safety benefits. The standards of this section promote public health, safety and welfare by establishing minimum standards for the design, construction, and maintenance of landscape improvements for public frontages and private frontages, lots, buildings, civic spaces, thoroughfares and special requirements.

(2)

Aesthetics/walkability. These standards should enhance the overall aesthetic condition of communities, neighborhoods and the public realm with landscaping by:

a.

Coordinating public frontages and private frontages.

b.

Providing spatial definition to the public realm.

c.

Providing screening of unsightly places and/or mitigation of conditions that are incongruent with section 30-3, including, but not limited to, the edges of special districts.

(3)

Health/safety. These standards should enhance comfort, safety and utilization of the public realm by moderating the local microclimate through the application of trees and landscaping to:

a.

Improve air quality.

b.

Mitigate noise pollution.

c.

Provide seasonal shade, sun and temperature regulation.

d.

Reduce reflected light.

e.

Mitigate wind gusts.

f.

Provide a partial barrier between sidewalks and vehicular lanes.

g.

Provide areas for the convenient removal and storage of snow.

(4)

Ecology/energy. These standards should provide ecological benefits, including, but not limited to:

a.

Conservation of energy used in buildings though strategic shading and wind breaks.

b.

Interception of precipitation by vegetative canopies.

c.

Percolation of precipitation through pervious landscape areas.

d.

Reduction in the insulation of pavements and other hard surfaces associated with urban heat islands through vegetative canopy cover.

e.

Conservation of soil and prevention of soil erosion through vegetative cover, root growth and wind breaks.

f.

Conservation of water through xeriscape design strategies, including, but not limited to:

1.

The application and maintenance of landscape mulch to retain soil moisture.

2.

The selection of low-water-use and drought tolerant plants.

3.

The design and operation of efficient irrigation systems.

(b)

General to Zones T2, T3, T4, T4O, T5.

(1)

Landscape design standards.

a.

The spacing and placement of plants shall be adequate and appropriate for the typical size, shape and habit of the plant species at maturity.

b.

Proposed trees and understory trees shall be centered horizontally and minimally:

1.

Two feet from walkways, curbing, and other impervious pavements when planted in a tree well or continuous planter;

2.

Three feet from walkways, curbing and other impervious pavements when planted in a continuous swale;

3.

Five feet from street lights, underground utilities, utility meters and service lines, fences, walls and other ground level obstructions;

4.

Six feet from porch eaves, and awnings and similar overhead obstructions associated with the ground level of buildings;

5.

Eight feet from balconies, verandas, building eaves and cornices, and similar overhead obstructions associated with the upper stories of buildings.

c.

Proposed trees shall be a minimum height of ten feet and/or three inches in caliper.

d.

Proposed understory trees shall be a minimum of eight feet in height and/or 2.5 inches in caliper.

e.

Proposed shrubs shall be of a five-gallon container minimum. Shrubs shall be seventeen inches through 22 inches minimum clear from any sidewalk or pavement edge at the lot line.

f.

Ground vegetation or shrub plantings with spines, thorns or needles that may present hazards to pedestrians, bicyclists or vehicles are prohibited in the first two feet of the first layer.

g.

Bare and exposed ground on the site and/or in landscaped areas shall be covered with live plant materials and/or mulch, with the following exceptions:

1.

Naturally occurring creek beds, rock outcroppings or similar landscape features typically lacking in vegetation.

2.

Agricultural fields seasonally tilled for cultivation.

3.

Hiking trails and/or traces.

4.

Clay or sand surfaces associated with recreation fields and facilities.

h.

Artificial plants or artificial turf are prohibited, excluding active recreation sports fields that are typically subject to intense use and soil compaction which prohibits the establishment of turfgrass, and where paving or grass paving systems will not suffice given the area's purpose and level of use.

i.

All required landscape areas shall be irrigated by an automatic underground irrigation system.

1.

Where possible and practical, bubbler, drip irrigation, and soaker hose emitters shall be utilized.

2.

Each irrigation system shall be equipped with a meter, backflow preventer and a suitable controller.

j.

Constructed water features such as fountains, streams and ponds that operate with water recirculation systems shall be designed to prevent seepage and leaks.

k.

Buffers and screening elements shall be used to screen parking areas from public view, to screen service yards and other places that are unsightly.

(2)

Landscape construction standards.

a.

All plant materials shall meet with the minimum container size, class and other requirements outlined in American Standard for Nursery Stock (most recent edition) published by the American Nursery and Landscape Association (ANLA).

b.

The soil structure of planting strips shall be protected from compaction with a temporary construction fence. Standards of access, excavation, movement, storage and backfilling of soils in relation to the construction and maintenance of deep utilities and manholes shall be specified.

c.

The topsoil within the construction area's limits of disturbance shall be removed, stored and amended as recommended by a landscape soils test.

d.

Wind erosion shall be mitigated and controlled though dust abatement and similar practices during the period of site work and construction.

e.

Landscape soils that have been compacted during construction activities shall be loosened and aerated to a depth of at least six inches before planting.

f.

Plants shall have normal, well-developed branches and vigorous root systems.

g.

Temporary spray irrigation systems may be used to establish seeded areas for grass and groundcover.

(3)

Landscape maintenance.

a.

All grass and vegetation shall be lightly fertilized to avoid fertilizer pollution to groundwater, streams and ponds.

b.

No disturbed ground shall be left exposed. Turfgrass and other approved and appropriate groundcovers or mulch shall cover all non-paved and non-built developed areas.

c.

It shall be the responsibility of the property owner or his assigned agent to:

1.

Maintain and keep all screening and fencing in good condition at all times;

2.

Maintain landscaping by keeping turfgrass lawns properly mowed and edged, plants properly pruned and disease-free, and planting beds mulched, groomed and weeded, except in T1, T2, and areas of naturally occurring vegetation and undergrowth; and

3.

Replace any required planting which are significantly damaged, removed, infested, disease ridden, or dead within one year or the next planting season, whichever occurs first, except in the T1 Zone, the T2 Zone and other areas of naturally occurring vegetation and undergrowth.

(c)

Specific to Zones T2, T3, T4.

(1)

The first layer may not be paved, with the exception of driveways as specified in this article.

(2)

The minimum required landscape area shall be 30 percent of the first layer of the principal frontage and the secondary frontage. The second layer shall not have less than 20 percent landscaped area for the entire site.

(3)

Preservation of on-site existing trees and vegetation is encouraged and may be used to fulfill the landscape requirements.

a.

The root zones of existing trees and vegetation to be preserved shall be protected from clearing or construction activities.

b.

Natural communities and areas of naturalized vegetation may be exempt from the installation irrigation systems.

c.

The size and limits of existing vegetation shall be indicated on the landscape plan.

d.

Priority shall be given to preserving and protecting significant trees that provide screening, buffering, wildlife habitat and/or linkages to wildlife habitat.

1.

The applicant may remove mature, healthy, noninvasive trees only within areas of a lot that are inside the proposed footprint of the primary structure.

2.

The applicant shall replace mature trees that are removed on the site with trees of the same or similar species whose combined caliper dimensions equal that of the tree removed.

e.

During construction, the root zone of existing vegetation to be preserved shall be enclosed by a temporary protective fence.

(4)

Open spaces and civic space shall remain fenced and protected during all adjacent site work and construction activities unless alterations to them are otherwise specified by the plans.

(5)

All landscape areas compacted during construction activities shall be re-tilled and reconditioned to provide an arable topsoil layer that can support the long-term health and vitality of landscaping.

(6)

The topsoil within the construction area's limits of disturbance shall be removed, stored and amended with organic soil additives as recommended by a landscape soils test prior to being redistributed.

(d)

Specific to Zone T3.

(1)

One tree shall be planted within the first layer for every 800 square feet of landscape area or any portion thereof (Table 23d).

a.

Substitutions.

1.

One tree may be substituted for two understory trees;

2.

One understory tree may be substituted for ten shrubs.

b.

Tree preservation credit.

1.

One tree may be substituted for an existing tree to be preserved provided that it:

(i)

Is four inches DBH or greater;

(ii)

Possesses a healthy and full canopy;

(iii)

Has an unmolested CRZ;

(iv)

Has incurred no damage that would undermine its long-term vitality and quality.

2.

One additional tree may be substituted for each additional three inches DBH of existing tree to be preserved in accordance with subsection (d)(1)b.1 of this section.

(2)

Trees may be of single or multiple species.

(3)

Trees shall be naturalistically clustered in conjunction with adjacent street trees.

(e)

Specific to Zone T4.

(1)

A minimum of one understory tree or ten shrubs shall be planted within the first layer for every 500 square feet of first layer landscape area (Table 23.d).

(2)

Trees, if planted, should match the species of adjacent street trees on the public frontage.

(3)

Parking spaces shall be broken with landscape islands every 20 spaces.

(4)

The landscape islands shall be distributed throughout the lot and may be combined as a component of a stormwater management plan to facilitate water harvesting. Landscape islands may be omitted for solar panel installations or other shading structures of equal or greater coverage.

(5)

Parking areas that exceed 120 spaces shall include a minimum of eight-foot-wide pedestrian walkway. The pavements of such walkways shall be differentiated from parking area pavement through a change in surface texture, material, style, and/or color.

(6)

Porous paving materials are encouraged in order to increase stormwater infiltration on site.

(f)

Specific to Zones T4O, T5.

(1)

Landscape islands in interior parking lots shall only occur at the end of drive aisles. Islands should be the minimum size for healthy growth for the specific species of tree.

(2)

Porous paving materials should be used in order to increase stormwater infiltration on site.

(g)

Specific to special districts.

(1)

Buffers and screening elements shall be used to screen parking areas from public view, to screen service yards and other places that are unsightly, and to buffer between the special district and the adjacent transect zone.

a.

A frontage landscape buffer, which may also include the sidewalk, shall be a minimum of ten feet in depth, measured from the frontage line and running its full width.

1.

A minimum of one tree shall be planted within the first layer for every 700 square feet of frontage landscape buffer.

2.

Fifty percent or more of the frontage landscape buffer must have shrubs and vegetative cover.

b.

An interior landscape buffer located along common property lines shall be required between a special district and an adjacent T-zone.

1.

A minimum of one tree shall be planted within the side and rear setbacks for every 700 square feet of interior landscape buffer.

2.

Fifty percent of the interior landscape buffer shall be covered with vegetation.

(2)

Shrubs shall be five-gallon container and 24 inches height minimum, and of a type that, at maturity, will provide a continuous opaque screen at least 36 inches in height.

(3)

Trees shall be four inches caliper minimum, or in the case of evergreen trees, 12 feet minimum height.

(Code 2003, § 31-38; Ord. No. 13-04, § 1(exh. A), 2-21-2013)