1.
Required landscaping plan.
A.
Applicants shall submit a landscaping plan as part of the preliminary plan submission for all subdivisions and land developments, except for residential subdivisions of three lots or less. The landscaping plan shall be prepared by a certified planting professional (landscape architect, nurseryman, arborist, horticulturist, or urban forester). The Municipal Council may seek the advice of a certified planting professional regarding compliance with the ordinance standards.
B.
For residential subdivisions of no more than three lots, a formal landscaping plan is not required, but the applicant's plans shall be required to show compliance with the applicable planting requirements herein.
C.
Preservation of existing vegetation.
1)
All subdivisions and land developments shall be laid out in such a manner as to minimize the removal of healthy trees and shrubs. Special consideration shall be given to major specimen trees and ecologically significant woodlands.
2)
It shall be the responsibility of the applicant to demonstrate that existing healthy vegetation removal is minimized by showing that no alternative layouts are possible and that no alternative clearing or grading plan would reduce the loss of mature trees, tree masses and woodlands. If challenged by Norristown, the applicant shall produce evidence, such as written documents or plans certified by a registered landscape architect, showing that no alternative layouts are possible and that no alternative clearing or grading plan would reduce the loss of mature trees, tree masses, or woodlands.
3)
Each freestanding tree, mature tree, tree mass, or woodland on the site shall be designated "To Remain" or "To Be Removed."
4)
Existing vegetation to remain shall be identified "To Remain" on the landscape plan, erosion and sediment control plan and in the field prior to any clearing and physically protected during construction.
a.
A temporary physical barrier, such as a snow fence, shall be shown on the plan and erected a minimum of one foot outside the dripline on all sides of individual trees, tree masses, and woodlands prior to clearing and construction. The barrier shall be placed to prevent disturbance to or compaction of soil inside the barrier and shall remain until construction is complete. No construction materials or equipment shall be stored within the tree protection zone.
b.
It is recommended that trees to be preserved near portions of a site proposed to be developed are pruned and fertilized prior to the beginning of construction in order to ensure their health.
5)
Tree replacement planting requirements.
a.
Size requirements.
1.
Any individual trees proposed "to be removed" shall be replaced with two- to two-and-one-half-inch (measured by caliper as nursery stock) trees equal to the total number of trees removed.
2.
The total tree removal impact of woodland areas designated "To Be Removed" shall be measured by a forest density survey that calculates the approximate quantity of trees (with eight-inch or greater DBH) per square foot area. Calculated woodland tree removals and individual mature tree removals shall also be listed on the plan.
3.
Each mature tree of 16 inches or greater DBH designated "To Be Removed" shall be replaced with trees whose total trunk diameter (measured by caliper as nursery stock) equals the total inches in DBH of the tree removed.
b.
Replacement trees shall be planted on the site to mitigate for the existing trees removed, in addition to other landscaping requirements. Proposed replacement tree plantings shall be listed on the plan.
c.
If the site does not reasonably contain enough room for the required replacement trees, the governing body may accept an equivalent fee-in-lieu-of-plantings contribution for the Municipal Shade Tree Planting Fund.
d.
Calculation and estimation of existing trees shall be performed before any clearing commences and shall be documented on the plan.
e.
Calculation and estimation of the trees remaining after construction shall be performed and compared with the calculations of the approved plan. Any tree removals additional to those on the approved plan shall be replaced as required by this section prior to the issuing of any occupancy permits.
2.
Buffers and screens. Buffer plantings shall be installed in subdivisions and land developments to integrate new developments with surroundings, to separate incompatible land uses by providing screening, and to minimize or eliminate views to certain site elements.
A.
Buffer plantings shall be required for the following types of development and as otherwise specified in the Zoning Ordinance:
B.
An on-site investigation by the applicant shall determine the adjacent land uses along each property boundary. In the case of vacant land, the permitted zoning uses shall be used. The existing or zoned uses shall be noted on the plan. In the case of several permitted uses on a site, the most-restrictive landscaping requirements shall apply. Norristown shall have final approval of interpretation of land uses or the Zoning Map.
C.
Buffer area location and dimensions.
1)
A buffer planting area of not less than 10 feet in width shall be established along all property lines and external street boundaries of the site proposed for subdivision or land development, unless otherwise specified in the Zoning Ordinance.
2)
Unless otherwise specified in the Zoning Ordinance, the buffer area may be included within the front, side, or rear yard setback.
3)
The buffer area shall be a continuous pervious planting area consisting of tall canopy trees, small understory trees, and shrubs, with grass or ground cover. No paving shall be permitted within the buffer areas except for driveway crossings and/or walkways.
4)
Parking is not permitted in the buffer area unless a shared parking and/or access arrangement exists.
5)
Stormwater management facilities are permitted in the buffer area, provided that the visual screening requirement of the buffer is still met.
D.
The minimum planting requirements shall be determined by the intensity of the proposed land use and the adjacent land use, vacant land, or zoning district, according to Figure 4.17.[1]
1)
Screening buffers must be adequate to visually screen the proposed land use or development from off-site view. Several different planting options could be used to create an effective buffer. Grading treatments and architectural features, such as walls, fences, and/or naturally undulating berms, may be necessary in addition to the minimum planting quantities in order to effectively provide a visual screen. The sufficiency of the buffer shall be determined by the Municipal Council upon recommendation of the Norristown Planning Commission.
2)
The limited area buffer can be used in older developed areas where space for planting is severely restricted. The planting screen would be equivalent to an evergreen hedge planting. Alternative planting arrangements, such as shade or flowering trees with deciduous shrubs, could be considered in conjunction with a fence or wall, at the discretion of the Municipal Council.
[1]
Editor's Note: Figure 4.17 is included at the end of this chapter.
E.
Minimum plant material requirements. In accordance with Figure 4.17,[2] for every one 100 linear feet of property line and external street boundaries of the site proposed for subdivision or land development to be buffered, the minimum quantities, types, and sizes of plant material shown in Figure 4.18 shall be required.[3] These are minimum standards; additional plant material, grading treatments, or architectural elements may be included in the plan, at the applicant's discretion. Generalized illustrations of buffer types are presented in Figures 4.19 through 4.21.[4] Species shall be selected from Appendix A, Recommend Plant Materials List.[5]
[2]
Editor's Note: Figure 4.17 is included at the end of this chapter.
[3]
Editor's Note: Figure 4.18 is included at the end of this chapter.
[4]
Editor's Note: Figures 4.19 through 4.21 are included at the end of this chapter.
[5]
Editor's Note: Appendix A is included at the end of this chapter.
F.
Mitigation of visual impacts. The use of a screening buffer shall be required to mitigate the adverse visual impacts which proposed land uses or site elements will have on the subject tract, adjoining properties and the community in general. In addition to the requirements for buffer plantings as listed in Figure 4.19,[6] the following proposed land uses and site elements shall be screened from off-site with a screening buffer:
1)
Dumpsters, trash disposal, recycling areas, and mechanical equipment.
2)
Service and loading docks.
3)
Outdoor storage areas.
4)
Sewage treatment plants and pump stations.
[6]
Editor's Note: Figure 4.19 is included at the end of this chapter.
G.
Plant material that has been classified as invasive, destructive or is no longer recommended for use is prohibited. The plant material listed in Appendix B is not permitted in Norristown.[7]
[7]
Editor's Note: Appendix B is included at the end of this chapter.
H.
Existing healthy trees, shrubs, or woodlands may be substituted for part or all of the required plant material, at the discretion of the Municipal Council. The minimum quantities and/or visual effect of the existing vegetation shall be equal to or exceed that of the required screen.
I.
Existing topography, such as embankments or berms, may be substituted for part or the entire required site element screen, at the discretion of the Municipal Council. The minimum visual effect shall be equal to or exceed that of the required screen.
J.
The applicant may propose the use of alternative screen types or changes in plant materials or designs which fulfill the intent of these regulations, with the approval of the Municipal Council. Plant materials shall meet the specifications in the Technical and Engineering Standards, and plant materials shall be from the List of Recommended Plant Material.
3.
Street trees.
A.
Street trees shall be required:
1)
Along all existing streets when they abut or lie within the proposed subdivision or land development, except where existing trees serve to meet the planting requirement.
2)
Along all proposed streets.
3)
Along access driveways which serve two or more residential dwelling units.
4)
Along access driveways that serve nonresidential properties.
5)
Along major walkways through parking lots and between nonresidential buildings.
B.
Street trees shall be located between the ultimate right-of-way line and the building setback line and shall meet these standards:
1)
Trees shall be planted at a rate of at least one tree per 40 linear feet of frontage or fraction thereof. Trees shall be distributed along the entire frontage of the property.
2)
Trees shall be planted a minimum distance of five feet and a maximum distance of 10 feet from the ultimate right-of-way line. However, in certain cases, as follows, the Municipal Council may permit trees to be planted within the legal right-of-way:
3)
In nonresidential developments, trees shall be located within a planting area within the front yard setback, at least 10 feet in width, planted in grass or ground cover. In areas where wider sidewalks are desirable, or space is limited, tree planting pits may be used.
4)
Trees shall be located so as not to interfere with the installation and maintenance of sidewalks and utilities. Trees shall be planted a minimum of three feet from curbs and sidewalks, 12 feet from overhead lines, and six feet from underground utilities.
5)
Tree species shall be selected from the list in Appendix A[8] based on appropriate growth rates and mature heights for use beneath and adjacent to overhead utility lines.
[8]
Editor's Note: Appendix A is included at the end of this chapter.
4.
Trail and pathway landscaping.
A.
A filtering buffer as described in Figure 4.20[9] shall buffer the trail from adjacent land uses. Upon recommendation of the Norristown Planning Commission, the Municipal Council may permit breaks in the filtering buffer where adjacent land uses do not require a full buffer.
[9]
Editor's Note: Figure 4.20 is included at the end of this chapter.
B.
Trees and shrubs shall be set back six feet from the trail surface. Figure 4.22 illustrates a generalized concept of trail landscaping.[10]
[10]
Editor's Note: Figure 4.22 is included at the end of this chapter.
C.
If not required as a visual buffer, evergreen trees shall not be planted on the southern side of the trail to allow for winter sun exposure. To fulfill buffering requirements, evergreen trees shall be replaced by an equal mix of canopy trees, understory trees, and shrubs of the size described in Figure 4.18.[11]
[11]
Editor's Note: Figure 4.18 is included at the end of this chapter.
D.
Entrances to trails and intersections between trails shall be delineated with post-and-rail fencing or other suitable material.
5.
Parking lot landscaping. All parking lots shall be designed according to § 282-430 and landscaped according to the following regulations:
A.
Parking lots shall be effectively landscaped with trees and shrubs to reduce the visual impact of glare, headlights, and parking lot lights, to delineate driving lanes, and to define rows of parking. Furthermore, parking lots should be adequately landscaped to provide shade in order to reduce the amount of reflected heat and to improve the aesthetics of parking lots.
B.
All parking lots in Norristown with 10 or more stalls shall be landscaped according to the following:
1)
One planting island shall be provided for every 10 parking stalls. There shall be no more than 10 continuous parking stalls in a row without a planting island.
2)
In residential developments, parking lots shall be divided into smaller parking areas of no more than 40 parking stalls by planting strips.
3)
Planting strips shall be a minimum of eight feet wide and run the length of the parking row and shall be protected with curbing, wheel stops, or bollards and planted with one canopy tree every 25 feet plus shrubs and/or ground cover to cover the entire area at maturity. Species shall be selected from Appendix A.[12]
[12]
Editor's Note: Appendix A is included at the end of this chapter.
4)
Planting islands shall be a minimum of nine feet by 18 feet in area and shall be protected with curbing, wheel stops, or bollards, and each planting island shall contain at least one shade tree plus shrubs and/or ground cover to cover the entire area.
5)
Planting strips and planting islands may contain stormwater management facilities, such bioretention swales, filtering strips, and rain gardens. When planting areas also serve as bioretention facilities, curbing may be reduced or eliminated to facilitate stormwater infiltration, as approved by the Municipal Engineer.
6)
The placement of light standards shall be coordinated with the landscape design to avoid a conflict with the operation of light fixtures.
7)
Additional planting is encouraged and may include a variety of ornamental trees, shrubs, and ground covers, chosen from the list of plant materials in Appendix A,[13] provided that:
a.
At the ends of planting strips at driveway intersections, drivers' visibility shall be maintained by limited plantings within 35 feet of the intersection.
b.
At the ends of planting strips between rows of parking spaces, visibility shall be maintained by limited plantings within 20 feet of the intersection.
[13]
Editor's Note: Appendix A is included at the end of this chapter.
8)
Where perimeter landscaping is required, planting strips shall be planted with a filtering buffer as per Figure 4.20.[14]
[14]
Editor's Note: Figure 4.20 is included at the end of this chapter.
9)
Whenever a parking lot abuts a primary arterial street, it shall be screened by a four-foot-tall fence constructed of wood, vinyl designed to look like wood, brick, stone, stucco over concrete block (capped with brick, slate, or stone), or ornamental iron (or ornamental aluminum, steel, or vinyl designed to look like iron), as consistent with local character. This will be in addition to filtering buffer requirements. The design shall require the approval of the Municipal Council upon recommendation of the Norristown Planning Commission.
6.
Additional plantings.
A.
All proposed nonresidential structures shall incorporate the following minimum plant materials in the landscaping areas adjacent to the proposed structure:
1)
One canopy tree (two to 2 1/2 inches' minimum caliper) or two understory trees (eight feet minimum height) shall be planted for every 50 feet of proposed building facade facing a public street.
2)
Five deciduous or evergreen shrubs (18 inches' minimum height) shall be planted for every 20 feet of proposed building facade facing a public street.
3)
Planting areas shall be a minimum of 150 square feet with a minimum ten-foot width.
4)
A minimum of 25% of the area between the building facade and the property frontage shall consist of pervious planting areas.
B.
All proposed residential lots shall plant at least one canopy tree per 10,000 square feet, or portion thereof, of lot area. Existing trees to remain may satisfy part or all of this planting requirement.
C.
All proposed attached residential units shall plant a minimum of one canopy tree for every two dwelling units.
D.
At the discretion of the Municipal Council, if sufficient planting space is not available immediately adjacent to the proposed structure, required building facade plantings may be located on the other areas of the tract.
7.
Stormwater basins and associated facilities. Landscaping shall be required in and around all stormwater management basins according to the following and as generally presented in Figure 4.23:[15]
A.
All areas of stormwater management basins, including basin floors, side slopes, berms, impoundment structures, or other earth structures, shall be planted with suitable vegetation, such as naturalized meadow plantings specifically suited for stormwater basins and as recommended in Appendix A.[16] Landscape designs for the basin should require minimal overall maintenance.
1)
Trees and shrubs shall be planted in and around stormwater basins. A minimum planting of two trees and 10 shrubs per 100 linear feet of basin perimeter shall be planted in and around the basin. No woody vegetation shall be planted within 30 feet of an outlet/drain structure, emergency spillway, or berm.
2)
Naturalized ground cover plant species, such as native wildflowers, meadows, and nonaggressive grasses specifically designed for the permanently wet, intermittently wet, and usually dry areas of stormwater basins, shall be seeded in the floors and slopes of the basin and meet the following requirements:
3)
Mown turf grass is permitted only in the emergency spillway, on top of berms, on the outside face of berms, on specified walking paths within the basin, and on access paths to allow maintenance of inflow and outflow structures. Any other areas proposed for turf grass requiring regular mowing should be reviewed by the Norristown Engineer.
a.
Areas of the naturalized basin containing lawn grass (including the top and outside berm) shall be sodded or hydroseeded to minimize erosion during the establishment period; and once established, these areas shall be maintained at a height of not more than six inches.
[16]
Editor's Note: Appendix A is included at the end of this chapter.
B.
Once established, a singular annual mowing of the meadow/naturalized grass areas should be sufficient to maintain a wet meadow and/or basin floor. A full description of basin maintenance responsibilities should be included on the recorded subdivision plan, and a notation outlining the basin maintenance responsibilities of the basin owner should be placed on the property deed.
C.
Signage at basins to educate the public and/or designate the limits of mowing is encouraged.
D.
Low-flow concrete channels are not permitted with stormwater management facilities.
E.
Stormwater basins shall be screened from adjacent properties using the buffer plantings standards for a filtering buffer as described in Figure 4.18 and Figure 4.20.[17]
[17]
Editor's Note: Figures 4.18 and 4.20 are included at the end of this chapter.
[15]
Editor's Note: Figure 4.23 is included at the end of this chapter.
8.
Landscape design criteria.
A.
Plantings shall be placed in arrangements and locations to best mitigate the adverse impacts of proposed site development. The required plant material shall be distributed over the entire length and width of any required buffer area.
B.
Plantings shall be spaced to comply with the visual mitigation requirements, with consideration given to the provision for the future growth habits and mature sizes of selected plant species.
C.
Plant species selection shall be based on the following considerations:
1)
Existing site conditions and their suitability for the selected plants based on the site's soils, hydrology and microclimate.
2)
Specific functional objectives of the plantings, which may include but not be limited to visual screening, noise abatement, energy conservation, wildlife habitat, erosion control, stormwater management, and aesthetic value.
3)
Maintenance and replacement considerations, such as hardiness, resistance to insects and disease, longevity, availability and cost of plant materials.
4)
A minimum variety of tree species is required as follows:
Number of Trees | Minimum Number of Tree Species | Maximum Percentage of Any 1 Species | |
|---|---|---|---|
0-5 | 1 | 100% | |
6-15 | 2 | 50% | |
16-30 | 3 | 40% | |
31-50 | 4 | 30% | |
51+ | 6 | 20% |
D.
Existing healthy trees, shrubs, or woodlands may be substituted for part or all of the required plant material, at the discretion of the Municipal Council. The minimum quantities and/or visual effect of the existing vegetation shall be equal to or exceed that of the required buffer. In order for existing vegetation to qualify for required buffer plantings, proof must be demonstrated that adequate protection measures, particularly in the plant's root zone, are incorporated into the plan.