Washington City Zoning Code

ARTICLE V

Landscaping, Screening and Buffer Yards

§ 350-26 Statement of intent.

It is intended that the application of the buffer yards, screening, and landscaping standards set forth in this chapter will reduce the visual and environmental impacts of any future use or parking lot on neighboring uses.

§ 350-27 Buffer yard requirements.

Vegetation within buffer yards.

Any existing trees within the required buffer yard that are a minimum of six inches in diameter at breast height (dbh) in accordance with American Nursery and Landscape Association standards shall count as required trees within the buffer yard. At no point, however, shall any existing trees and required trees be separated at a distance greater than the distance specified in the required buffer yard.

All trees required to be planted within the buffer yard shall be a minimum of 2.5 inches in diameter at breast height (dbh) in accordance with American Nursery and Landscape Association standards and shall be planted in accordance with accepted landscape conservation practices. All required trees shall be a minimum of six feet in height at the time of planting as measured from the ground adjacent to the planted tree to the top of the tree.

It shall be the responsibility of the landowner and/or developer to assure the continued growth of all required landscaping and/or to replace the same in the event of freezing, drought, vandalism, disease or other reasons for the discontinued growth of the required trees, shrubs and bushes.

A recommended plant listing for vegetation within buffer yards is included in Appendix A.[1]

Editor's Note: Said appendix is included as an attachment to this chapter.

Specific buffer yard requirements.

Buffer Yard A.

The minimum spacing and quantity of vegetation planted within Buffer Yard A shall be as prescribed by this section and as illustrated in Appendix B.[2]

Editor's Note: Said appendix is included as an attachment to this chapter.

No uses, buildings or structures, including, but not limited to, accessory structures, parking spaces, access drives and lighting devices may be located closer than 35 feet from any front, side or rear lot line; provided, however, that if the width of any such buffer yard would exceed more than 10% of the width or depth of the subject lot as it existed as of the effective date of this chapter, measured along a perpendicular line running from the relevant side or rear lot line, then the size of the buffer yard shall be established through the following formula:

On a lot with a width or depth of greater than 350 feet, the buffer yard for either the required front or the rear yard shall be 10% of that minimum dimension on that particular side of the lot. The buffer yard for the yard not selected of these two shall remain the minimum requirement of 35 feet. The buffer yards for the side yards shall remain the minimum requirement of 35 feet. In no event, however, shall the side or rear buffer yard be less than 25 feet except that access drives may be located in the front buffer yard or other buffer yard if required by the City or Borough's Subdivision and Land Development Ordinance,[3] as amended.

Editor's Note: See Ch. 315, Subdivision and Land Development.

Buffer Yard A shall contain two rows of planting. Each row shall consist of a mixture of 30% deciduous and 70% evergreen trees and a maximum spacing of 20 feet apart, measured from the vertical center line of adjacent trees.

In addition to the above-noted required tree spacing, a row of lower level evergreen shrubs or hedges shall be planted or earth mounding shall be constructed in the buffer yard which shall provide a year-round visual screen capable of acting as a barrier to light beams emanating from the headlights of vehicles. These lower level shrubs, hedges or mounds shall be a minimum of four feet in height. The length of an individual mound shall not be greater than 30% of the lot line to which the mound is adjacent. A variety of heights within and between mounds are recommended.

Buffer Yard B.

The minimum spacing and quantity of vegetation planted within Buffer Yard B shall be as prescribed by this section and as illustrated in Appendix B.[4]

Editor's Note: Said appendix is included as an attachment to this chapter.

No uses, buildings or structures, including, but not limited to, accessory structures, parking spaces, access drives and lighting devices, may be located any closer than 25 feet to any front, side or rear lot line except that access drives may be located in the front buffer yard or other buffer yard if required by the City's Subdivision and Land Development Ordinance,[5] as amended.

Editor's Note: See Ch. 315, Subdivision and Land Development.

Buffer Yard B shall contain a single row of planting which shall be comprised of a mixture of 30% deciduous and 70% evergreen trees. These trees shall be spaced 20 feet apart as measured from the center of the trees.

In addition to the above-noted required tree spacing, a row of lower level evergreen shrubs or hedges shall be planted, or earth mounding shall be constructed in the buffer yard which shall provide a year-round visual screen capable of acting as a barrier to light beams emanating from the headlights of vehicles. These lower level shrubs, hedges or mounds shall be a minimum of four feet in height. The length of an individual mound shall not be greater than 30% of the lot line to which the mound is adjacent. A variety of mound heights are recommended.

Buffer Yard C.

The minimum spacing and quantity of vegetation planted within Buffer Yard C shall be as prescribed by this section and as illustrated in Appendix B.[6]

Editor's Note: Said appendix is included as an attachment to this chapter.

No uses, buildings or structures, including, but not limited to, accessory structures, parking spaces, access drives and lighting devices may be located any closer than 10 feet to any front, side or rear lot line except that access drives may be located in the front buffer yard or other buffer yard if required by the City's Subdivision and Land Development Ordinance,[7] as amended.

Editor's Note: See Ch. 315, Subdivision and Land Development.

This ten-foot buffer yard shall contain a row of planting which shall be comprised of a mixture of 30% deciduous and 70% evergreen trees. These trees shall be spaced 20 feet apart as measured from the center of the trees.

In addition to the above-noted required tree spacing, a row of lower level evergreen shrubs or hedges shall be planted, or earth mounding shall be constructed in the buffer yard which shall provide a year-round visual screen capable of acting as a barrier to light beams emanating from the headlights of vehicles. These low level shrubs, hedges or mounds shall be a minimum of four feet in height. The length of an individual mound shall not be greater than 30% of the lot line to which the mound is adjacent. A variety of mound heights are recommended.

Buffer Yard D.

The primary purpose of this buffer yard is to reduce the potential negative visual impacts of parked vehicles in two abutting parking lots located within 10 feet of a shared property line not along a public right-of-way.

The five-foot buffer yard width shall contain a row of plantings comprised of deciduous and/or evergreen shrubs.

The minimum height of shrubs shall be 3.5 feet by the third year after planting. Shrubs shall be spaced so that a continuous hedge exists after the third year after planting. See Appendix B.[8]

Editor's Note: Said appendix is included as an attachment to this chapter.

To maintain an adequate separation of uses, Table 501 provides the minimum buffer yard standards required.

Table 501: Buffer Yards
Use	A	B	C	D
	35'	25'	10'	5'
Multifamily Residential
Adjoining single-family		X
Adjoining multifamily			X
Adjoining any industrial	X
Adjoining primary roadways			X
Commercial and Institutional
Adjoining single-family		X
Adjoining multifamily			X
Adjoining any industrial			X
Adjoining primary roadways			X
Industrial
Adjoining Any residential	X
Adjoining any industrial			X
Adjoining primary roadways			X

Conflict between buffer yard and yard requirements. When the width of a required buffer yard is in conflict with the minimum yard requirements of this chapter, the greater distance shall apply. The landowner and/or developer shall adhere to the buffer yard planting requirement regardless of what the yard requirement is.

Existing structures in buffer yards. In instances where an existing building or structure houses the principal use of the lot, and is located within any required buffer yard, a buffer yard of not less than the minimum distance from the existing structure to the lot line shall be required. This reduced buffer yard width shall apply only to the yard area upon which the existing structure encroaches. If the existing building or structure is located within the required buffer yard on one side of the building or structure, the required buffer yard as determined by Table 501, Buffer Yards, of this chapter shall apply on all other yard areas. All planting requirements shall be adhered to regardless of the buffer yard width.

Stormwater management facilities within buffer yards. Stormwater management facilities and structures may be maintained within a buffer yard, but the existence of such facilities or structures shall not be a basis for a failure to meet the planting requirement.

§ 350-28 Parking lot landscaping.

Applicability.

No new parking lots shall hereafter be constructed or used unless landscaping is provided as required by the provisions of this article.

No parking lots shall be expanded, moved or removed and/or reconstructed unless the minimum landscaping required by the provisions of this article is provided for the property to the extent of its alteration or expansion, but not for the entire property unless required in § 350-27.

No use shall be changed to another use for which this article requires additional parking over and above that required for the previous use, unless vehicular use area perimeter landscaping as required by this article is provided for such additional parking. The provisions of this section shall be effective regardless of whether or not new construction is necessary to meet the parking requirements for the new uses. Where the previous use had no required parking, perimeter landscaping shall be provided for the entire vehicular use area serving the new use. Interior landscaping shall not be required where only the use of the property is changed and no new addition, expansion, or exterior construction or reconstruction is proposed.

Perimeter landscaping.

Property line landscape buffers between adjacent land uses shall be provided in accordance to the requirements spelled out in § 350-27A of this article.

Any parking lot that is adjacent to a road or public right-of-way shall provide a landscaping area width based upon the following parking lot size:

Less than 6,000 square feet: five feet minimum landscape area width (Buffer Yard D).

Six thousand square feet or more: 10 feet minimum landscape area width (Buffer Yard C).

Grass or ground cover shall be planted on all portions of the landscape area not occupied by other landscape material.

Landscape plantings that are planted within the sight triangle near intersections shall conform to the following standards:

No trees shall be planted that have a main/stem/trunk greater than eight inches in diameter or have a dripline that falls below six feet six inches in height.

No shrubs or ground covers that exceed a height of 24 inches.

In all cases where significant natural vegetation exists, there will be limits of clearing/grading areas established to protect and preserve these natural areas. These natural areas will not be disturbed by the installation of any structures, utilities, storm and sanitary sewers, water lines, sediment and erosion control traps, stormwater management systems or signage. Existing landscape material which is proposed to be used to fulfill landscape requirements shall be shown in the required plan, and measures taken to protect these areas from disturbance during construction shall be identified.

Trees required as a part of the perimeter landscaping adjacent to a public right-of-way landscaping may be placed on the right-of-way adjoining such vehicular use area when approved by Council. Such trees shall be in addition to any street trees which may be required by the subdivision regulations.

In any parking lot perimeter landscaping area there shall be four-foot minimum distance to all trees from the edge of paving where vehicles overhang.

Parking lots shall include side and rear yard perimeter landscaping that include a continuous row of shrubs no less than 3 1/2 feet at planting and one canopy shade tree planted every 40 feet on center.

Interior landscaping.

For any new parking lot containing a minimum of 6,000 square feet of area or 15 or more spaces, interior landscaping shall be provided in addition to the previously required perimeter landscaping. Interior landscaping shall be contained in peninsulas or islands containing a minimum area of 160 square feet having a minimum width of eight and 1/2 feet and a minimum length of 18 feet. There shall be a minimum distance of four feet from the edge of paving to the base of all trees which may overhang parked vehicles. The minimum landscape area permitted shall be 10% of the parking area. Each island or peninsula shall be enclosed by appropriate curbing or a similar device at least six inches wide and six inches in height above the paving surface (wedge curbing is acceptable), unless this is in conflict with an approved best management practice, in which case the design of the approved stormwater plan shall apply.

Where a parking area is altered or expanded to increase the size to 6,000 or more square feet of area or 15 or more parking spaces, interior landscaping for the entire parking area shall be provided and not merely to the extent of its alteration or expansion.

Landscape islands or peninsulas; number required.

Each 10 parking spaces shall require an interior planting island.

All interior parking aisles shall end in a landscape island.

In no case shall there be more than 20 parking spaces in an unbroken row.

Maximum contiguous areas for interior parking lot landscaping. In order to encourage the required landscape areas to be reasonably distributed, no single required landscape island shall be larger than the following:

Three hundred fifty square feet in parking areas under 30,000 square feet.

One thousand five hundred square feet in parking areas over 30,000 square feet.

Minimum plant materials. A minimum of one shade tree for each five spaces of provided parking shall be required. The remaining area of the required landscaped area shall be landscaped with shrubs or ground cover not to exceed two feet in height. [See also § 350-28C(6), Shade trees in parking areas.]

Shade trees in parking areas.

Parking areas that are required to be paved must be shaded by deciduous trees (either retained or planted by the developer) that have or will have when fully mature a trunk at least 12 inches in diameter.

Each tree of the type described in Subsection C(6)(a) shall be presumed to shade a circular area having a radius of 15 feet with the trunk of the tree as the center, and there must be sufficient trees so that, using this standard, 20% of the vehicle parking area will be shaded.

No paving may be placed within eight feet (measured from the center of the trunk) of any tree retained to comply with Subsection C(6)(a), and new trees planted to comply with Subsection C(6)(a) shall be located so that they are surrounded by at least 200 square feet of unpaved area in a manner that will not encroach upon the projected dripline.

Parking areas shall be laid out and detailed to prevent vehicles from striking trees. Vehicles will be presumed to have a body overhang of three feet six inches.

Interior landscaping for parking areas shall be installed and continuously maintained by the owner according to the requirements contained in § 350-28 of this chapter.

Landscape material type and quality shall be in conformance with the requirements of § 350-28 of this chapter.

Whenever any property is affected by these parking area landscape requirements, the property owner or developer shall prepare a landscape plan for approval by Council.

§ 350-29 Screening.

All service structures shall be fully screened, except when located in an industrial zone. Service structures in an industrial zone shall be fully screened when located within 100 feet of any zone other than industrial. For the purposes of this article, service structures shall include propane tanks, dumpsters, air-conditioning units and condensers, electrical transformers and other equipment or elements providing service to a building or a site.

Location of screening. A continuous planting, hedge, fence, wall or earth mound shall enclose any service structure on all sides unless such structure must be frequently moved, in which case screening on all but one side is required. The average height of the screening material shall be one foot more than the height of the enclosed structure, but shall not be required to exceed eight feet in height. Whenever a service structure is located next to a building wall, perimeter landscaping material or vehicular use area, landscaping material of such walls or screening material may fulfill the screening requirement for that side of the service structure if that wall or screening material is of an average height sufficient to meet the height requirement set out in this section. Whenever service structures are screened by plant material, such material may count towards the fulfillment of required interior or perimeter landscaping. No interior landscaping shall be required within an area screened for service structures.

Protection of screening material. Whenever screening material is placed around any trash disposal unit or waste collection unit that is emptied or removed mechanically on a regular basis, a fixed barrier to contain the placement of the container shall be provided within the screening material on those sides where there is such material. The barrier shall be at least 18 inches from the material and shall be of sufficient strength to prevent possible damage to the screening when the container is moved or emptied. The minimum front opening of the screening material shall be 12 feet to allow service vehicles access to the container.

Washington City Zoning Code

ARTICLE V

Landscaping, Screening and Buffer Yards

§ 350-26 Statement of intent.

It is intended that the application of the buffer yards, screening, and landscaping standards set forth in this chapter will reduce the visual and environmental impacts of any future use or parking lot on neighboring uses.

§ 350-27 Buffer yard requirements.

Vegetation within buffer yards.

Any existing trees within the required buffer yard that are a minimum of six inches in diameter at breast height (dbh) in accordance with American Nursery and Landscape Association standards shall count as required trees within the buffer yard. At no point, however, shall any existing trees and required trees be separated at a distance greater than the distance specified in the required buffer yard.

All trees required to be planted within the buffer yard shall be a minimum of 2.5 inches in diameter at breast height (dbh) in accordance with American Nursery and Landscape Association standards and shall be planted in accordance with accepted landscape conservation practices. All required trees shall be a minimum of six feet in height at the time of planting as measured from the ground adjacent to the planted tree to the top of the tree.

It shall be the responsibility of the landowner and/or developer to assure the continued growth of all required landscaping and/or to replace the same in the event of freezing, drought, vandalism, disease or other reasons for the discontinued growth of the required trees, shrubs and bushes.

A recommended plant listing for vegetation within buffer yards is included in Appendix A.[1]

Editor's Note: Said appendix is included as an attachment to this chapter.

Specific buffer yard requirements.

Buffer Yard A.

The minimum spacing and quantity of vegetation planted within Buffer Yard A shall be as prescribed by this section and as illustrated in Appendix B.[2]

Editor's Note: Said appendix is included as an attachment to this chapter.

No uses, buildings or structures, including, but not limited to, accessory structures, parking spaces, access drives and lighting devices may be located closer than 35 feet from any front, side or rear lot line; provided, however, that if the width of any such buffer yard would exceed more than 10% of the width or depth of the subject lot as it existed as of the effective date of this chapter, measured along a perpendicular line running from the relevant side or rear lot line, then the size of the buffer yard shall be established through the following formula:

On a lot with a width or depth of greater than 350 feet, the buffer yard for either the required front or the rear yard shall be 10% of that minimum dimension on that particular side of the lot. The buffer yard for the yard not selected of these two shall remain the minimum requirement of 35 feet. The buffer yards for the side yards shall remain the minimum requirement of 35 feet. In no event, however, shall the side or rear buffer yard be less than 25 feet except that access drives may be located in the front buffer yard or other buffer yard if required by the City or Borough's Subdivision and Land Development Ordinance,[3] as amended.

Editor's Note: See Ch. 315, Subdivision and Land Development.

Buffer Yard A shall contain two rows of planting. Each row shall consist of a mixture of 30% deciduous and 70% evergreen trees and a maximum spacing of 20 feet apart, measured from the vertical center line of adjacent trees.

In addition to the above-noted required tree spacing, a row of lower level evergreen shrubs or hedges shall be planted or earth mounding shall be constructed in the buffer yard which shall provide a year-round visual screen capable of acting as a barrier to light beams emanating from the headlights of vehicles. These lower level shrubs, hedges or mounds shall be a minimum of four feet in height. The length of an individual mound shall not be greater than 30% of the lot line to which the mound is adjacent. A variety of heights within and between mounds are recommended.

Buffer Yard B.

The minimum spacing and quantity of vegetation planted within Buffer Yard B shall be as prescribed by this section and as illustrated in Appendix B.[4]

Editor's Note: Said appendix is included as an attachment to this chapter.

No uses, buildings or structures, including, but not limited to, accessory structures, parking spaces, access drives and lighting devices, may be located any closer than 25 feet to any front, side or rear lot line except that access drives may be located in the front buffer yard or other buffer yard if required by the City's Subdivision and Land Development Ordinance,[5] as amended.

Editor's Note: See Ch. 315, Subdivision and Land Development.

Buffer Yard B shall contain a single row of planting which shall be comprised of a mixture of 30% deciduous and 70% evergreen trees. These trees shall be spaced 20 feet apart as measured from the center of the trees.

In addition to the above-noted required tree spacing, a row of lower level evergreen shrubs or hedges shall be planted, or earth mounding shall be constructed in the buffer yard which shall provide a year-round visual screen capable of acting as a barrier to light beams emanating from the headlights of vehicles. These lower level shrubs, hedges or mounds shall be a minimum of four feet in height. The length of an individual mound shall not be greater than 30% of the lot line to which the mound is adjacent. A variety of mound heights are recommended.

Buffer Yard C.

The minimum spacing and quantity of vegetation planted within Buffer Yard C shall be as prescribed by this section and as illustrated in Appendix B.[6]

Editor's Note: Said appendix is included as an attachment to this chapter.

No uses, buildings or structures, including, but not limited to, accessory structures, parking spaces, access drives and lighting devices may be located any closer than 10 feet to any front, side or rear lot line except that access drives may be located in the front buffer yard or other buffer yard if required by the City's Subdivision and Land Development Ordinance,[7] as amended.

Editor's Note: See Ch. 315, Subdivision and Land Development.

This ten-foot buffer yard shall contain a row of planting which shall be comprised of a mixture of 30% deciduous and 70% evergreen trees. These trees shall be spaced 20 feet apart as measured from the center of the trees.

In addition to the above-noted required tree spacing, a row of lower level evergreen shrubs or hedges shall be planted, or earth mounding shall be constructed in the buffer yard which shall provide a year-round visual screen capable of acting as a barrier to light beams emanating from the headlights of vehicles. These low level shrubs, hedges or mounds shall be a minimum of four feet in height. The length of an individual mound shall not be greater than 30% of the lot line to which the mound is adjacent. A variety of mound heights are recommended.

Buffer Yard D.

The primary purpose of this buffer yard is to reduce the potential negative visual impacts of parked vehicles in two abutting parking lots located within 10 feet of a shared property line not along a public right-of-way.

The five-foot buffer yard width shall contain a row of plantings comprised of deciduous and/or evergreen shrubs.

The minimum height of shrubs shall be 3.5 feet by the third year after planting. Shrubs shall be spaced so that a continuous hedge exists after the third year after planting. See Appendix B.[8]

Editor's Note: Said appendix is included as an attachment to this chapter.

To maintain an adequate separation of uses, Table 501 provides the minimum buffer yard standards required.

Table 501: Buffer Yards
Use	A	B	C	D
	35'	25'	10'	5'
Multifamily Residential
Adjoining single-family		X
Adjoining multifamily			X
Adjoining any industrial	X
Adjoining primary roadways			X
Commercial and Institutional
Adjoining single-family		X
Adjoining multifamily			X
Adjoining any industrial			X
Adjoining primary roadways			X
Industrial
Adjoining Any residential	X
Adjoining any industrial			X
Adjoining primary roadways			X

Conflict between buffer yard and yard requirements. When the width of a required buffer yard is in conflict with the minimum yard requirements of this chapter, the greater distance shall apply. The landowner and/or developer shall adhere to the buffer yard planting requirement regardless of what the yard requirement is.

Existing structures in buffer yards. In instances where an existing building or structure houses the principal use of the lot, and is located within any required buffer yard, a buffer yard of not less than the minimum distance from the existing structure to the lot line shall be required. This reduced buffer yard width shall apply only to the yard area upon which the existing structure encroaches. If the existing building or structure is located within the required buffer yard on one side of the building or structure, the required buffer yard as determined by Table 501, Buffer Yards, of this chapter shall apply on all other yard areas. All planting requirements shall be adhered to regardless of the buffer yard width.

Stormwater management facilities within buffer yards. Stormwater management facilities and structures may be maintained within a buffer yard, but the existence of such facilities or structures shall not be a basis for a failure to meet the planting requirement.

§ 350-28 Parking lot landscaping.

Applicability.

No new parking lots shall hereafter be constructed or used unless landscaping is provided as required by the provisions of this article.

No parking lots shall be expanded, moved or removed and/or reconstructed unless the minimum landscaping required by the provisions of this article is provided for the property to the extent of its alteration or expansion, but not for the entire property unless required in § 350-27.

No use shall be changed to another use for which this article requires additional parking over and above that required for the previous use, unless vehicular use area perimeter landscaping as required by this article is provided for such additional parking. The provisions of this section shall be effective regardless of whether or not new construction is necessary to meet the parking requirements for the new uses. Where the previous use had no required parking, perimeter landscaping shall be provided for the entire vehicular use area serving the new use. Interior landscaping shall not be required where only the use of the property is changed and no new addition, expansion, or exterior construction or reconstruction is proposed.

Perimeter landscaping.

Property line landscape buffers between adjacent land uses shall be provided in accordance to the requirements spelled out in § 350-27A of this article.

Any parking lot that is adjacent to a road or public right-of-way shall provide a landscaping area width based upon the following parking lot size:

Less than 6,000 square feet: five feet minimum landscape area width (Buffer Yard D).

Six thousand square feet or more: 10 feet minimum landscape area width (Buffer Yard C).

Grass or ground cover shall be planted on all portions of the landscape area not occupied by other landscape material.

Landscape plantings that are planted within the sight triangle near intersections shall conform to the following standards:

No trees shall be planted that have a main/stem/trunk greater than eight inches in diameter or have a dripline that falls below six feet six inches in height.

No shrubs or ground covers that exceed a height of 24 inches.

In all cases where significant natural vegetation exists, there will be limits of clearing/grading areas established to protect and preserve these natural areas. These natural areas will not be disturbed by the installation of any structures, utilities, storm and sanitary sewers, water lines, sediment and erosion control traps, stormwater management systems or signage. Existing landscape material which is proposed to be used to fulfill landscape requirements shall be shown in the required plan, and measures taken to protect these areas from disturbance during construction shall be identified.

Trees required as a part of the perimeter landscaping adjacent to a public right-of-way landscaping may be placed on the right-of-way adjoining such vehicular use area when approved by Council. Such trees shall be in addition to any street trees which may be required by the subdivision regulations.

In any parking lot perimeter landscaping area there shall be four-foot minimum distance to all trees from the edge of paving where vehicles overhang.

Parking lots shall include side and rear yard perimeter landscaping that include a continuous row of shrubs no less than 3 1/2 feet at planting and one canopy shade tree planted every 40 feet on center.

Interior landscaping.

For any new parking lot containing a minimum of 6,000 square feet of area or 15 or more spaces, interior landscaping shall be provided in addition to the previously required perimeter landscaping. Interior landscaping shall be contained in peninsulas or islands containing a minimum area of 160 square feet having a minimum width of eight and 1/2 feet and a minimum length of 18 feet. There shall be a minimum distance of four feet from the edge of paving to the base of all trees which may overhang parked vehicles. The minimum landscape area permitted shall be 10% of the parking area. Each island or peninsula shall be enclosed by appropriate curbing or a similar device at least six inches wide and six inches in height above the paving surface (wedge curbing is acceptable), unless this is in conflict with an approved best management practice, in which case the design of the approved stormwater plan shall apply.

Where a parking area is altered or expanded to increase the size to 6,000 or more square feet of area or 15 or more parking spaces, interior landscaping for the entire parking area shall be provided and not merely to the extent of its alteration or expansion.

Landscape islands or peninsulas; number required.

Each 10 parking spaces shall require an interior planting island.

All interior parking aisles shall end in a landscape island.

In no case shall there be more than 20 parking spaces in an unbroken row.

Maximum contiguous areas for interior parking lot landscaping. In order to encourage the required landscape areas to be reasonably distributed, no single required landscape island shall be larger than the following:

Three hundred fifty square feet in parking areas under 30,000 square feet.

One thousand five hundred square feet in parking areas over 30,000 square feet.

Minimum plant materials. A minimum of one shade tree for each five spaces of provided parking shall be required. The remaining area of the required landscaped area shall be landscaped with shrubs or ground cover not to exceed two feet in height. [See also § 350-28C(6), Shade trees in parking areas.]

Shade trees in parking areas.

Parking areas that are required to be paved must be shaded by deciduous trees (either retained or planted by the developer) that have or will have when fully mature a trunk at least 12 inches in diameter.

Each tree of the type described in Subsection C(6)(a) shall be presumed to shade a circular area having a radius of 15 feet with the trunk of the tree as the center, and there must be sufficient trees so that, using this standard, 20% of the vehicle parking area will be shaded.

No paving may be placed within eight feet (measured from the center of the trunk) of any tree retained to comply with Subsection C(6)(a), and new trees planted to comply with Subsection C(6)(a) shall be located so that they are surrounded by at least 200 square feet of unpaved area in a manner that will not encroach upon the projected dripline.

Parking areas shall be laid out and detailed to prevent vehicles from striking trees. Vehicles will be presumed to have a body overhang of three feet six inches.

Interior landscaping for parking areas shall be installed and continuously maintained by the owner according to the requirements contained in § 350-28 of this chapter.

Landscape material type and quality shall be in conformance with the requirements of § 350-28 of this chapter.

Whenever any property is affected by these parking area landscape requirements, the property owner or developer shall prepare a landscape plan for approval by Council.

§ 350-29 Screening.

All service structures shall be fully screened, except when located in an industrial zone. Service structures in an industrial zone shall be fully screened when located within 100 feet of any zone other than industrial. For the purposes of this article, service structures shall include propane tanks, dumpsters, air-conditioning units and condensers, electrical transformers and other equipment or elements providing service to a building or a site.

Location of screening. A continuous planting, hedge, fence, wall or earth mound shall enclose any service structure on all sides unless such structure must be frequently moved, in which case screening on all but one side is required. The average height of the screening material shall be one foot more than the height of the enclosed structure, but shall not be required to exceed eight feet in height. Whenever a service structure is located next to a building wall, perimeter landscaping material or vehicular use area, landscaping material of such walls or screening material may fulfill the screening requirement for that side of the service structure if that wall or screening material is of an average height sufficient to meet the height requirement set out in this section. Whenever service structures are screened by plant material, such material may count towards the fulfillment of required interior or perimeter landscaping. No interior landscaping shall be required within an area screened for service structures.

Protection of screening material. Whenever screening material is placed around any trash disposal unit or waste collection unit that is emptied or removed mechanically on a regular basis, a fixed barrier to contain the placement of the container shall be provided within the screening material on those sides where there is such material. The barrier shall be at least 18 inches from the material and shall be of sufficient strength to prevent possible damage to the screening when the container is moved or emptied. The minimum front opening of the screening material shall be 12 feet to allow service vehicles access to the container.