10-07-08: STREET LANDSCAPE BUFFERS:

(1) Purpose: This article requires landscape buffers to be placed along streets as a means to improve the visual quality of the streetscape, to soften the visual impact of parking lots and their expanse of asphalt, to connect diverse architecture and land uses, and to promote attractive roadways and street beautification processes.

(2) Location: Street landscape buffers shall be located on private property beyond the street right of way and maintained by the property owner or a homeowners' association.

The measuring point for the street landscape buffer width associated with attached sidewalks shall be from the property line and not the sidewalk or curb. Exception: The buffer width associated with detached sidewalks may be measured from the front of curb when it can be demonstrated there is no opportunity for expansion of the street section within the right of way.

The required street landscape buffer width shall not include the sidewalk width. Fences are not permitted within required street landscape buffers. The area dedicated for right of way purpose is not credited toward the street landscape buffer width. Road dedication for right of way purpose is in addition to street buffer dedication requirements. The applicant shall landscape and maintain the areas intended for future right of way.

The road entrances into the subdivision shall be landscaped with a street landscape buffer, placed in a common platted lot for the length of the first developable lot's frontage, at a minimum.

(3) Applicability: Street landscape buffers shall be required along all residential, multi-family, commercial and industrial, development's boundaries that front on a public roadway. All commercial subdivision street landscape buffers shall be platted as either a common lot or placed in a permanent landscape easement shown on the plat and maintained in either dedication format by a homeowners' or business owners' association. All residential subdivision street landscape buffers shall be platted as a common lot and maintained by a homeowners' or business owners' association.

Common lot dedication is not intended to impede or conflict with a development's driveway or entrance access requirements. Placement of the street landscape buffer into a platted common lot shall not negate a property's zoning frontage requirement, rather the frontage along a common lot dedicated for landscape purpose will also be accepted as the abutting lot's frontage necessary to meet zoning frontage requirements.

The placement of landscape buffer into a platted common lot that is located between a street and a corner lot shall not change the status of the corner lot to an interior lot, rather the corner lot shall retain that designation, to include the corner lot dimensional requirements noted in the height, lot line setback and lot dimension schedule (see section 10-02-03 of this chapter).

Street landscape buffer dedication will not be required for a single-family or multi-family dwelling that is not part of a phased development, contain fewer than five (5) dwelling units, and not located in a local historical district, along a gateway street, the Indian Creek and the Boise River corridor or the I-84 corridor.

(4) Buffer Size: The required street landscape buffer width relative to type of roadway or land use:

Note:

1. Local streets, internal to a subdivision, are not required to have the 10 foot street landscape buffer. This landscape exclusion is based on the assumption that a homeowner/property owner will place lawn or other organic material in the residential front yard setback area for aesthetic purposes.

(5) Width Reduction: If the required street buffer width poses a hardship to the controller, they may submit a written request for a buffer modification to the community development director. The request must demonstrate evidence of a hardship and propose an alternative width or other means of resolving the landscape obligation. A hardship shall not be of the controller's own making. If the director denies the modification request, the controller may appeal that determination to the Caldwell planning and zoning commission or hearing examiner through the zoning variance process.

(6) Street Tree And Shrub Buffering Application: All required landscape street buffers shall be planted with a mixture of trees and shrubs, lawn, or other vegetative ground cover, with a minimum tree density equivalent to one tree per thirty-five (35) linear feet of buffer area. If this calculation results in a remaining buffer area of more than eighteen (18) linear feet, one additional tree shall be planted. Minimum shrub planting density shall be equivalent to one shrub per seven (7) linear feet of buffer area. Lawn coverage is optional for those areas planted with shrubs, spaced at intervals of seven feet (7') or less width.

(7) Tree Spacing: In order to promote design flexibility, trees may be grouped together or spaced evenly as desired. The presence of vision triangles, signage, driveways and above grade clearance shall be factors affecting actual placement of trees within buffer areas. The city forester is authorized to review and approve species and spacing variables in buffering areas to assure these factors are accommodated. However, trees shall not be spaced closer than eighty percent (80%) of the average mature width of the trees, as demonstrated in the following examples:

(Graphic courtesy of Meridian)

Note: Information about the average height, width and canopy of a tree at maturity is available from the nursery where the tree stock is obtained or through the city forester's office. The tree spacing associated with buildings located in the downtown area will be determined on a case by case basis.

(8) Parkways And Detached Sidewalks: If the controller proposes to install detached sidewalks and provided that construction application is acceptable to the city engineer, the controller must ensure that the minimum overall width of the parkway area is five feet (5'), unless the controller is matching a preexisting parkway width that differs from that measurement (as may be the case on a gateway street). On gateway streets, the parkway width will be established block by block, provided it is a minimum, three feet (3') wide. Tree plantings are restricted to class 2 trees (medium to large trees) within parkways less than ten feet (10') wide. This width provision is to ensure that the tree roots cause minimal disruption to underground utilities and the sidewalk (see section 10-08-02 of this chapter). The controller adjacent to the parkway will be responsible for its overall maintenance and upkeep.

(9) Impervious Surfaces Allowed In Street Buffer Area: Impervious surfaces allowed in the street buffer area include curb cuts, driveways, signs, fire hydrants, mailboxes, telephone poles, light poles and walkways. Other types of impervious surface are discouraged from placement there and are subject to approval on a case by case basis. The extension of development features, like patios into the street buffer area shall be compensated by a like amount of dedicated landscape area in the same location.

(10) Vehicles Located In Street Buffer Area: Vehicles are prohibited from parking within the street landscape buffer area.

(11) Berms Located In Street Landscape Buffers: See section 10-07-04 of this article for berm design requirements.

(12) Buffer Conflict: If there is a conflict between competing landscape buffer requirements, the more restrictive one shall apply. (Ord. 2533, 12-20-2004)