§ 6.3. REQUIRED BUFFERS

6.3.1. Buffer Defined

A buffer is a specified land area, located parallel to and within the outer perimeter of a lot or parcel and extending to the lot or parcel boundary line, together with the planting and landscaping required on the land. A buffer may also contain, or be required to contain, a barrier such as a berm, fence or wall, or combination thereof, where such additional screening is necessary to achieve the desired level of buffering between various land use activities. A buffer is not the same as the term "yard" or the term "stormwater management area."

6.3.2. Types of Required Buffers

There are two types of required buffers that may occur on any given development site, as follows.

A.

Street buffers; and

Commentary: Generally, a street buffer is located along the street(s) that border a development. The buffer requires a modest amount of landscaping, enhancing the "public" environment.

B.

Project boundary buffers.

Commentary: Generally, a project boundary buffer is located around the sides and rear of a development. This buffer ensures an appropriate transition between uses.
A buffer located around the perimeter of a nonresidential use is intended to protect adjoining land uses from noise, heat, dust, lights, and aesthetic impacts from more intense land uses.

6.3.3. Location

A.

Buffers shall be located within the outer perimeter of a lot or parcel, parallel to and extending to the lot or parcel boundary line. Buffers shall not be located on any portion of an existing, dedicated or reserved public or private street or right-of-way.

B.

Buffers may be located and constructed within any required yard.

6.3.4. Permitted Use of Buffer Area

A.

A buffer may be used for passive recreation and picnic facilities; and it may contain pedestrian, bike, or equestrian trails, provided that:

1.

Minimal existing plant material is eliminated;

2.

The total depth of the buffer is maintained; and

3.

All other requirements of these regulations are met.

B.

Other appurtenances which require high visibility and easy access, such as fire hydrants, public and emergency telephones, mail boxes, and school bus or other bus shelters or benches, are also permitted in a buffer. No screening of such appurtenances is required.

C.

A required buffer is encouraged to retain areas of native habitat and may incorporate water resources including stormwater detention/retention facilities designed as a natural-appearing amenity. However a minimum 10-foot contiguous width of the buffer shall be preserved as a planting area without stormwater facilities.

D.

Ingress and egress to the proposed use, and utility lines and appurtenances, may cross the buffer provided they minimize the amount of buffer taken.

E.

The buffer area may be included as part of the calculation of any required open space.

F.

Identification signs may be located within a buffer as specifically permitted in the Sign Ordinance. The landscape buffer shall be designed to address visibility of permitted ground signs.

G.

Lighting may be located within a buffer as specifically permitted in Section 6.9, Outdoor Lighting.

H.

Other activities and development required by this Ordinance or expressly authorized by the Planning Director.

6.3.5. Prohibited use of Buffer Area

A buffer area shall not be used for any building or use, accessory building or use, parking or loading area, storage area, or other principal or accessory uses except as specifically permitted in this Ordinance.

6.3.6. Planting in Easements

A.

Where required plantings are located in easements, the property owner shall be responsible for replacement of such required vegetation if maintenance or other utility requirements require their removal.

B.

No trees shall be planted in wet retention ponds, drainage maintenance easement, or any utility maintenance easements.

C.

Shrubs may be planted within easements, provided they are only within the outer three feet of the easement. No new trees may be planted in an easement.

D.

Existing trees may remain in dry retention ponds provided that the natural grade is undisturbed to the tree line, they are a species adapted to seasonal flooding and the pond is adequately maintained.

6.3.7. Determination of Buffer Requirements

To determine the type of buffer required between two adjoining lots or parcels, or between a lot or parcel and a street, the following procedure shall be followed:

A.

Street Buffers

Determine the appropriate street buffer based on Section 6.3.8.

B.

Project Boundary Buffers

Identify the zoning districts of the subject parcel and all adjoining properties. Determine the buffer opacity class required on each boundary (or segment thereof) of the subject parcel. Refer to the minimum project boundary buffer table in Section 6.3.9.

Commentary: Landscape plans should depict the basis for meeting planting requirements in 100 foot intervals.

6.3.8. Street Buffers

Street buffers shall be required and existing vegetation should be used to satisfy these planting requirements where possible (see Section 6.1.4, Existing Vegetation). No vegetation or fence shall interfere with a required clear sight triangle at a driveway or intersection (See Section 6.15). Berms constructed in accordance with Section 6.3.10.C, Berms with Vegetation, are encouraged as a component of any street buffer and the Planning Director may allow up to 25% reduction in the required buffer depth with a berm.

A.

Measurements

1.

Street buffers shall be measured along a perpendicular line from the future right-of-way line determined during site and development plan review. Buffer depth averaging may be used in conformance with paragraph 5, below.

2.

Required driveways may penetrate required street buffers.

3.

Driveway widths (measured at the inside edge of the buffer) shall not be counted in the calculation of the plant material required.

4.

Vehicular access easements shall not be treated as a street, but shall be buffered as a project boundary buffer outside the easement area. The buffer may be provided on either side of the easement.

5.

While the buffer depth is normally calculated as parallel to the property line, design variations are allowed and are calculated on the average depth of the buffer per 100 feet of linear width measured along the property line. Minimum depth of buffer in any case shall not be less than 50% the required depth of the buffer chosen. Maximum depth shall not be more than 150% the required depth of the buffer chosen.

B.

Collector or Thoroughfare Street Buffers

All development located along either a collector or thoroughfare street shall be required to provide one of the following buffers along the entire street frontage.

1.

One canopy tree per 100 linear feet of property frontage, located within a twenty-foot landscape buffer; OR

2.

Two understory trees per 100 linear feet of property frontage, located within a twenty-foot landscape buffer; OR

3.

Under utility lines only, two understory trees per 100 linear feet of property frontage, located within a 20-foot landscape buffer. No trees under utility lines shall have a natural height over 25 feet.

C.

Local Street Buffers

With the exception of one- or two-family dwellings on a single lot or parcel, all development across a local street from a Residential district or use shall require a buffer with a minimum opacity of .2 (see Section 6.3.9.A.2, Measurements) and a depth of 15 feet.

6.3.9. Project Boundary Buffers

Commentary: Project Boundary Buffers ensure a landscaped transition between different types of uses and/or zoning districts. At first glance, the following method may seem complicated. In reality, this is a fairly easy approach to implement. A few simple steps will provide the total amount of plants that are required to be in a buffer as well as the buffer depth.
This approach also addresses the following criticisms that are raised when the County requires buffers and landscaping.
1. What about unusual site circumstances? The table provides a number of alternative approaches to achieving the requirements.
2. Why do I have to put all the plants in - the lot next to me is vacant? This approach anticipates this type of situation. The initial developer will have a reduced buffer requirement.
3. What if I want to put in a narrower buffer? The developer may select Alternative 3, Canopy and Wall or may install a berm. This will allow the developer to reduce the buffer depth while still providing appropriate screening.
4. There are already plants there - why do I have to put in new plants? Credit is given for existing plants (that meet a minimum size requirement) on a one-for-one basis.

A.

Required Project Boundary Buffer Table

1.

Description

i.

The buffer standards in the table below address the opacity of the buffer that is required on the property boundary between zoning districts, and in some instances within a zoning district.

ii.

An opacity of 0.2 screens 20% of an object, and an opacity of 1.0 would fully screen the adjoining development during summer months after five years of growth.

2.

Measurements

Project boundary buffers shall be measured along a perpendicular line from the lot line.

3.

How to Read the Buffer Table

i.

The required opacity of project boundary buffers is represented in the Table below by two numbers (for example, .2/.6).

ii.

The second number represents the total required buffer opacity between any two properties.

iii.

Where the proposed project adjoins vacant property, the first number represents the applicant's required buffer opacity.

iv.

Where the adjoining property is already developed with no buffer, the proposed project is responsible for providing the total required opacity (the second number).

[See Buffer Alternatives Table]

v.

Where the adjoining property is already developed with a partial buffer, the proposed project is responsible for providing the remaining opacity required.

vi.

A zero means no project boundary buffer is required.

ZONING DISTRICT of SUBJECT PROPERTY	ZONING DISTRICT of ADJOINING PROPERTY
	Rural Low Density Residential	R-7500, R-6000, and SBR-6000	MR-3200 and N-C	C-I	C-LD and RU-I	I-G
Rural Residential	0 /0	.2/.2	.4/.6	.2/.8	.2/.8	.2/1.0
R-7500, R-6000, and SBR-6000	.2/.2	0 /0	.2/.4	.2/.6	.2/.6	.2/1.0
MR-3200 and N-C	.4/.6	.2/.4	0 /0	.2/.6	.2/.6	.2/1.0
C-I	.6/.8	.4/.6	.4/.6	0/0	.2/.4	.2/1.0
C-LD and RU-I	.6/.8	.4/.6	.4/.6	.2/.4	0/0	.2/1.0
I-G	.8/1.0	.8/1.0	.6/1.0	.6/1.0	.4/.6	0/0
Non-residential uses locating next to vacant property shall be required to provide a 0.2 buffer.
When locating a non-residential use in a Rural Residential, R-7500, R-6000, SBR-6000, MR-3200, NC, C-LD, or RU-I Zoning District next to an existing residential developed property, a 0.4 buffer shall be required. Non-residential uses locating next to other non-residential uses are not required to provide a buffer.

 

Commentary: A .2/.4 requires a 20% opaque buffer for property adjacent to vacant land or a 40% opaque buffer when adjacent to existing development. A .4/.4 requires a 40 percent opaque buffer property adjacent to either vacant or developed land. A zero means no project boundary buffer is required.
 
Example: A new development in the C-I District abutting a developed R-7500 District would be required to provide a buffer with an opacity of .6 (60% opaque) If the adjacent property were vacant, the requirement would be .4 since the adjacent property is vacant.

4.

Buffer Alternatives

The table below shows the required buffer depth (average) and plantings required for a project boundary buffer to satisfy the required opacity. Existing vegetation should be used to satisfy these planting requirements where possible (see Section 6.1.4, Existing Vegetation). Credit may also be given for use of best management practices and exceptional design.

MINIMUM REQUIRED PROJECT BOUNDARY BUFFER
Buffer Depth and Plants Required Per 100 Linear Feet
Required Opacity	Alternative 1 Plantings	Alternative 2 Plantings	Alternative 3 Plantings + 6-Foot (Height) Fence	Alternative 4 Plantings + 6-Foot (Height) Wall
0.2	10 feet 1 canopy 1 understory 7 shrubs	10 feet 1 canopy 2 understory 3 shrubs	Not available	Not available
0.4	20 feet 2 canopy 4 understory 25 shrubs	20 feet 2 canopy 6 understory 9 shrubs	15 feet width 3 understory 3 shrubs	10 feet width 3 understory 3 shrubs
0.6	30 feet 3 canopy 6 understory 34 shrubs	30 feet 3 canopy 8 understory 13 shrubs	20 feet width 0 canopy 3 understory 3 shrubs	15 feet width 0 canopy 3 understory 3 shrubs
0.8	50 feet 5 canopy 7 understory 43 shrubs	50 feet 4 canopy 10 understory 17 shrubs	35 feet width 0 canopy 5 understory 7 shrubs	25 feet width 0 canopy 5 understory 7 shrubs
1.0	80 feet 5 canopy 8 understory 49 shrubs	80 feet 4 canopy 11 understory 19 shrubs	60 feet width 0 canopy 5 understory 7 shrubs	40 feet width 0 canopy 5 understory 7 shrubs
Notes:
Required Opacity x 100 = % Required Opacity (e.g., .2 times 100 = 20% Required Opacity).
When Alternative 3 is selected, the fence type must be 100% opaque and comprised of either wooden or vinyl material.
When Alternative 4 is selected, the wall must be designed in conformance with Section 6.3.10.A Walls, and Section 6.3.10, Walls, Berms, and Fences within Buffers.

 

Commentary: Suppose you are required to install a buffer with an opacity of 0.6 and you elect to use Alternative 1. Your buffer would have to be 30 feet deep (on average) and you would have to plant 3 canopy tress, 6 understory trees, and 34 shrubs for every 100 feet of buffer length.

5.

In lieu of a project boundary buffer, the Street Buffer applies (See Section 6.3.8) when both a 1) recorded easement for ingress and egress or a right-of-way exists (whether developed or undeveloped) and 2) a zoning district designation of the adjacent parcel(s) is different than that of the subject parcel.

6.

When proposed residential units adjoin an existing bona fide farming activity in a Voluntary Agricultural District, the minimum buffer depth shall be 50 feet, with a minimum opacity of 0.2.

B.

Hardship Relief

The buffer requirement may be modified by the Planning Director upon a finding that a modification would be consistent with the purpose and intent of this Article, with any adopted land use plans, that such modification would not adversely affect the land use compatibility or public interest, and complies with one or more of the following criteria:

1.

The affected buffer is parallel to and adjoins an existing utility or drainage easement of at least 50 feet in width;

2.

The affected buffer is between uses that are to be developed under a common development plan or series of development plans; or

3.

The affected buffer adjoins a property that has a joint use agreement with the parcel under site plan;

4.

When buffering the adjoining property would serve no practical purpose due to the nature and/or use of the property, such as undevelopable land (wetlands, etc.), industrial use, public or private utility, etc.

6.3.10. Walls, Berms and Fences in Buffers

Where walls, berms or fences are built within any required buffer, they shall meet the following requirements.

A.

Walls

1.

A finished side of the wall shall face off site.

2.

All required plantings should be placed along the interior side of the wall (facing the developed area of the subject property).

B.

Fences

1.

A finished side of the fence shall face off site and see Note 2 in Buffer Alternatives Table (Section 6.3.9.A.4) for allowed fence types.

2.

Fencing shall be between six to ten feet in height.

3.

Fences shall be maintained in a structurally safe and attractive condition and with a finished face located towards the adjoining property.

4.

All required plantings should be placed along the interior side of the fence (facing the developed area of the subject property).

C.

Berm with Vegetation

1.

The Planning Director may allow a reduction of up to 25% of the required buffer depth when a berm meeting these requirements is provided.

2.

An earthen berm may be used in conjunction with planted vegetation provided that the combined height of the berm and planted vegetation shall be at least six feet and provide approximately 75% opacity within one year of planting.

3.

The slope of the berm shall be stabilized with vegetation and no steeper than 3:1. The height of the berm may not exceed six feet, with a level or rounded area on top of the berm. The berm shall be constructed of compacted earth.

4.

Prior to issuance of the first certificate of compliance, berms shall be planted to ensure coverage by live plant material within three to five years.

5.

When berms are planned to be installed within required buffers, storm drainage plans submitted with an application shall be designed to anticipate a 100-year storm event.

Commentary: Berms can dramatically alter the drainage patterns in an area, and result in significant flooding both within a development and in areas abutting a development. Therefore, it is important to understand any potential impacts.