15.4.1.6: BUFFER YARDS:
   A.   Determination Of Buffer Requirements: Buffers shall be required for all new development and redevelopment except as provided in subsections A5 and A6 of this section. The table of buffer requirements (see table in subsection C2 of this section) describes the type of buffer required as determined by the type of proposed use and the type of use which is designated, approved, or existing on lands adjacent to the proposed project. In order to determine the type of buffer required, the following procedures shall be followed:
      1.   Identify the type of use for the proposed project.
      2.   On sites with extensive tree cover or large tracts of land, an aerial photograph depicting impacted/nonimpacted areas may be submitted with a survey of a representative area no less than one-half (0.5) acre in size.
      3.   Where an abutting property has a lawful nonconforming use of less intensity than the allowable use of the property, buffering shall be based upon the allowable use.
      4.   Refer to the table of buffer requirements in subsection C2 of this section, for buffer requirements on each property boundary or portion thereof and select the required buffer option for the specified type of buffer from those outlined in subsection B of this section.
      5.   The following developments are not required to provide buffers:
         a.   Construction of single-family homes or duplexes.
         b.   Passive agriculture activities such as livestock grazing, orchards, silviculture, or croplands.
         c.   Passive recreation such as golf courses, hiking/equestrian/bicycle trails, or boardwalks.
         d.   Conservation lands.
      6.   Buffers are also not required in the following circumstances:
         a.   When the property line abuts a railroad right of way.
         b.   Within fifteen feet (15') of the edge of a street surface or curb line to prevent obstructing visibility.
         c.   When the nonresidential use is compatible with a residential use, such as cropland, forests, parks, etc. (The parking lot or active recreational area of a park requires a buffer yard.)
         d.   When the use of a property changes from one nonresidential or high density residential use to another nonresidential or high density residential use and the new use is not expanded in the direction of or parallel to a residential use and when the new use does not result in an increase in noise or light reaching a residential use that would otherwise be required to be protected by a buffer yard.
         e.   When natural features of the property provide the required screening and buffer yard.
         f.   Existing legal nonresidential uses or proposed uses that have an approved site plan on file on the effective date hereof, unless expansion beyond that approved as of the effective date hereof occurs in the direction of or parallel to a residential use.
      7.   When it is determined to be in the public interest, the buffer yard requirement may be waived by the city council when a senior citizen housing conversion development is established as a special use in an R-1 zone.
   B.   Types Of Buffers: Required buffer types shall consist of A, B, and C. Trees in buffers of ten feet (10') or less should be understory trees. Trees in buffers of more than ten feet (10') may be canopy or understory trees provided however, at least one- half (1/2) of the required trees shall be canopy trees.
      1.   Landscape Credits: Landscape credits for buffers shall be determined from the following table:
      LANDSCAPE CREDIT UNIT (LCU) VALUES
Deciduous (Minimum Caliper)
Evergreen Or Ornamental
(Minimum Height)
LCU Value
Deciduous (Minimum Caliper)
Evergreen Or Ornamental
(Minimum Height)
LCU Value
New planting:
 
 
 
    Trees
       3 inches
10 feet
9
 
       2.5 inches
9 feet
6
 
       2 inches
8 feet
5
 
       1.5 inches
6 feet
3
    Shrub
18 inches height or spread
2
    Ornamental grasses or perennial beds
1 gallon size
1
 
Minimum Caliper
LCU Value
Existing tree:
 
 
    Mature
>13 inches
15
    Large
11 to 13 inches
12
    Medium
6 to 10 inches
8
    Small
3 to 5 inches
5
 
      2.   Type A Buffer: A type A buffer shall be at least ten feet (10') in width and shall have plant materials equal to twenty (20) landscape credits per one hundred feet (100') with a visual screen four feet (4') high consisting of evergreen plantings, fences, walls or a combination thereof.
      3.   Type B Buffer: A type B buffer shall be at least fifteen feet (15') in width and shall have plant materials equal to thirty (30) landscape credits per one hundred feet (100') with a visual screen five feet (5') high consisting of evergreen plantings, fences, walls or a combination thereof.
      4.   Type C Buffer: A type C buffer shall be at least twenty feet (20') in width and shall have plant materials equal to forty (40) landscape credits per one hundred feet (100') with a visual screen six feet (6') high consisting of evergreen plantings, fences, walls or a combination thereof.
      5.   Buffers Along Sidewalks: Where a public street separates a land use required to install a buffer from the protected land use and where the land use required to install the buffer will include a parking lot adjoining that street, the required buffer shall be broken into two (2) parts:
         a.   A buffer five feet (5') wide shall be established between the parking area and the public street or sidewalk; such buffer shall have plant materials with ten (10) landscape credits per one hundred feet (100') and a visual screen no more than thirty inches (30") high;
         b.   An additional buffer meeting the standards required by this section less five feet (5') in width and ten (10) landscape credits per one hundred feet (100') shall be installed on the other side of the parking lot, providing visual separation between the use required to include the buffer and the protected use, with the parking lot and the smaller buffer in between.
   C.   Required Buffers:
      1.   Purpose/Principles: The intent of this subsection is to require a more intensive use to provide a landscaped buffer to provide visual screening, separation and some sound buffering between it and a nearby protected use. (Ord. 2013-20)
      2.   Buffer Table: Any use falling in a zoning district listed across the top of the following table shall be required to install a buffer as designated by the letters A, B or C to separate it from any use or land located in a zoning district listed down the left side of the table; if the cell reflecting the intersection between two (2) districts is blank, no buffer between them is required.
   
   City of Carbondale   REQUIRED BUFFERS
District Required To Provide Buffer
Protected
District
F
AG
RR
R-1
R-1-D
R-2
R-3
PAR
PA
SB
BPL
BWA
LI
GI
District Required To Provide Buffer
Protected
District
F
AG
RR
R-1
R-1-D
R-2
R-3
PAR
PA
SB
BPL
BWA
LI
GI
    F
A
B
B
B
B
B
B
C
C
    AG
A
B
B
B
B
B
B
C
C
    RR
A
B
B
B
B
B
B
C
C
    R-1
A
B
B
B
B
B
B
C
C
    R-1-D
A
B
B
B
B
B
B
C
C
    R-2
B
B
B
B
B
B
C
C
    R-3
B
B
B
B
B
C
C
    PAR
    PA
    SB
    BPL
    BWA
    BPR
    LI
    GI
 
(Ord. 2013-31)
      3.   Exceptions: Where a use that would be required by this section to provide a buffer is separated from the use that would be protected by any of the following, no buffer is required:
         a.   A railroad track in active use;
         b.   A state highway; or
         c.   A public street with at least fifty feet (50') of right of way.
   D.   Modifications To Buffer Requirements:
      1.   A proposed development may be allowed a fifty percent (50%) reduction in the required buffer width in no case to allow a required buffer to be less than five feet (5') in width providing one of the following conditions exists and is indicated on the plan for the proposed development or project:
         a.   The adjacent property is designated with a nonresidential land use district and is vacant;
         b.   The adjacent property has an existing required landscaped buffer; or
         c.   The adjacent property has existing vegetation sufficient in size, types of plantings, and location that serve in the same capacity as a required buffer.
      2.   For projects that propose to retain an undisturbed open space area between the extent of the development and the property line, if the director of development services finds that such area will substantially serve the purpose of a buffer, the director of development services may give credit to the owner or owner's designee for part or all of the undisturbed open space toward the buffer requirements of this section. This exemption does not apply to industrial, extractive, or outdoor recreation uses. Additionally, the plan must show the undisturbed area has an existing mixture of grass, trees, and shrubs, and other vegetation that would serve in the same capacity as the required buffer.
      3.   For projects that are required to provide a buffer to adjacent residentially designated property that is currently vacant, the owner or owner's designee may plant the required buffer at the proper density and configuration. All plants utilized shall be of a type that the growth will reach the required height criteria within a three (3) year period from the time of planting.
      4.   Alternative designs for required buffers may be approved by the director of development services upon a finding that the required buffer will require alterations of the existing improvements on the property.
   E.   Use And Location Of Buffers:
      1.   Allowed Uses: Areas set aside as required buffers may also be used as follows:
         a.   Satisfaction of minimum setback requirements, if any.
         b.   Satisfaction of minimum open space requirements, if any.
         c.   May contain stormwater retention or detention areas, so long as the required buffer plantings are provided and the design and landscaping of the buffer does not interfere with proper functioning of the drainage system and the design water depth does not harm the viability of the plantings.
         d.   Passive recreation such as pedestrian, bicycle, or equestrian trails subject to the following limitations:
            (1)   No plant material is eliminated.
            (2)   There is a minimum width of ten feet (10') of pervious material at all points in the buffer, after subtracting any part of a trail covered with impervious material.
            (3)   The total width of the buffer is maintained.
            (4)   All other requirements of this zoning ordinance are met.
         e.   Installation of underground utilities, so long as the location and use of the utility lines does not interfere with required buffer plantings.
      2.   Prohibited Uses: The following uses shall not be allowed in a required buffer: principal structures, accessory structures, play fields, stables, swimming pools, tennis courts, or similar active recreation uses; storage facilities, or parking facilities.
      3.   Location And Design:
         a.   Buffers shall be located on the outer perimeter of a lot or parcel, extending the entire length of the lot or parcel boundary line.
         b.   Buffers shall not be located on any portion of an existing, dedicated, proposed right of way, road easement, or private street.
         c.   Where an existing utility easement is partially or wholly within a required buffer, the developer shall design the buffer to eliminate or minimize plantings within the easement. Such design may require a buffer with more land area (see subsection B of this section).
         d.   Where a proposed development is a mixed use project, buffers shall not be required between various constituent parts except that any nonresidential use shall be separated from the residential use by internal landscaping. (Note: It is the intent to allow flexibility of design within the confines of a mixed use development, but to nevertheless require landscaping for the residential portion of the project from potential negative impact of a proposed nonresidential portion of the project.)
         e.   All general landscape requirements of section 15.4.1.3 of this chapter shall be met.
   F.   Fencing Within Buffers: Fencing for the purpose of security or protection is allowable within all buffers provided the fence is in compliance with applicable standards of section 15.4.2 of this chapter. Developments proposing a privacy fence five feet (5') or more in height within a required buffer, may be allowed a fifty percent (50%) reduction in the density of plantings required. Such request shall be submitted in writing by the owner or owner's agent and shall include provisions by the owner for maintenance of the buffer and the fencing. This reduction does not apply to industrial, extractive, or active outdoor recreational uses. (Ord. 2013-20)