The following shall apply to all subdivision
and land development proposals:
A. All portions of a tract shall be designated as to
their use, such as lots, roads, open space, parking areas, etc.
B. Whenever possible, applicants shall preserve scenic
areas, historic sites, other community assets and landmarks, and natural
amenities such as trees and waterways.
C. Plans shall be designed to avoid excessive cut or
fill.
D. Floodplain land areas shall be governed by additional standards contained in this chapter, Chapter
176, Zoning, and the Borough's Building Code.
E. The applicant shall construct, install, and guarantee,
at no expense to the Borough all improvements required as part of
plan approval, including, but not limited to, streets, curbs, sidewalks,
water and sewage facilities, stormwater management facilities, streetlights,
fire hydrants, road signs, monuments, lot pins, utilities and shade
trees.
F. The Borough Council may request that development features
exceed these standards if conditions so warrant.
The Borough Council may grant a modification
of the requirements of this chapter, through a waiver, if strict application
of these requirements would be unreasonable, provided that such modification
will not be contrary to the public interest and that the purpose and
intent of the chapter is observed. All requests for modifications
shall:
A. Be in writing and be part of an application for subdivision
and/or land development;
B. State the grounds and facts of unreasonableness or
hardship on which the request is based;
C. List the provision(s) of the chapter involved; and
D. State the minimum modification necessary.
All new streets and extensions and widenings
of existing streets:
A. Shall be offered for dedication to the authority having
jurisdiction over the street at the time of plan approval. The Borough
may accept dedication of lands which are not accepted by other jurisdictions;
B. Shall conform with the circulation element of the
Borough Comprehensive Plan, as amended, Borough Ultimate Right-of-Way
Map, and county or state highway plans, and be coordinated with existing
streets;
C. Shall provide appropriate access between abutting
tracts of land for immediate or future use;
D. Shall create a road hierarchy among interior subdivision
and land development streets and exterior streets to insure proper
through-traffic flow, local access, and internal traffic distribution
and flow;
E. Shall be related closely to existing topography to
assure reasonable grades, alignment and drainage, appropriate access
to lots, and to minimize regrading and removal of vegetation;
F. Shall be designed to continue existing streets at
equal or greater right-of-way and cartway width, as recommended by
the Borough Engineer and Planning Commission.
Every street within the Borough shall be classified
by its function as one of the following and shall comply with the
requirements for its classification as contained herein.
A. Primary streets are the major traffic routes which
carry the highest volumes of traffic on an intercommunity, regional,
or higher level. Route 29 (Main Street) and Route 73 are the primary
streets in the Borough.
(1) Minimum right-of-way: 70 feet.
(2) Minimum cartway width: 40 feet.
(3) Construction requirements: PADOT standards. (See §
147-45.)
B. Local access streets are the minor streets which carry
the lowest volumes of traffic and serve primarily to provide vehicular
access and parking for adjacent land uses. All Borough streets that
are not primary or collector are local access streets.
(1) Minimum right-of-way: 50 feet.
(2) Minimum cartway width: 30 feet.
(3) Construction requirements: PADOT standards. (See §
147-45.)
Sight distance, horizontal and vertical curvature,
super-elevation, and maximum and minimum street grades shall be determined
by the Borough Engineer in compliance with the standards contained
in "A Policy on Geometric Design of Highways and Streets," published
by the American Association of State Highway Transportation Officials,
most recent edition, or PADOT standards and guidelines shall be complied
with.
A. Horizontal curvature for all local access streets
shall be not less than one-hundred-fifty-foot radius, measured along
the street center line.
B. Long radius, gentle curves are encouraged rather than
shorter radius curves connected by tangents.
C. Curve-tangent relationships shall follow accepted
engineering guidelines for safety and efficiency. For example, minimum
radius curves shall not be used at the ends of long tangents.
D. Street grades shall be measured along the center line
in accordance with the following:
(1) Minimum for all streets shall be 1%;
(2) Maximum grades for local access streets shall be 10%
for distances less than 1,500 feet;
(3) Street grades in excess of 5% should be avoided wherever
possible;
(4) Curve-grade combinations shall follow accepted engineering
guidelines for safety and efficiency. For example, minimum radius
horizontal curves will not be permitted in combination with maximum
grades;
(5) At all approaches to intersections, street grades
shall not exceed 4% for a minimum distance of 50 feet.
All street intersections shall be governed by
the standards of this section.
A. Number of streets. Not more than two streets shall
intersect at the same point.
B. Three-way/four-way intersections. Three-way or "T"
intersections should be used instead of four-way intersections unless
the four-way intersection can be justified in terms of necessary and
desirable traffic movements.
C. Angle of intersections.
(1) All intersection approaches shall be designed at right
angles unless sufficient reason exists to justify a lesser angle.
However, no angle shall be less than 75º for intersections with
primary or secondary streets or 60º for intersections between
local access streets, measured at the center-line intersections.
(2) Where angled intersections are used it is preferable
to design them so that the heavier traffic flow will make the obliquely
angled turn rather than the acutely angled turn.
D. Corrective changes to existing intersections. When
existing streets intersect at odd angles or have more than four approaches,
the applicant shall contribute to corrective changes to bring the
intersection into compliance with this chapter, as required by the
Borough Council, who shall first seek the advice of the Borough Engineer
and Planning Commission and other technical advisors or agencies,
as appropriate. For state and county highways, corrective changes
shall comply with the requirements of the appropriate agency. The
extent of contribution shall depend on the proposal's use of the intersection.
E. Waiver of corrective changes. The Borough Council
may waive the above requirements for corrective changes under one
or more of the following conditions:
(1) When changes made on the applicant's land will not
improve the intersections deficiencies;
(2) When other road improvements are already planned which
would correct the problem without changes required of the applicant;
(3) When not required by PADOT on state roads.
F. Cul-de-sac intersections.
(1) Intersections with permanent cul-de-sac streets shall
be designed with the cul-de-sac street extending as a side street
from the throughstreet, rather than have a throughstreet extend through
an intersection to terminate as a cul-de-sac.
(2) Four-way intersections may be created using two permanent
cul-de-sac streets intersecting directly opposite one another along
a throughstreet, when the throughstreet is a local access street or
a collector.
G. Approaches to intersections. Approaches to intersections
shall follow a straight course for a minimum of 50 feet for local
access streets. All other streets shall follow a straight course in
accordance with accepted engineering standards, but in no case less
than 50 feet.
Street intersection spacing shall be done in
compliance with the regulations contained in this section, measured
from center line to center line.
A. The spacings listed in this section shall be considered
minimum spacings. Where greater spacing is required in compliance
with AASHTO or PADOT standards, the greater spacing distances shall
be applied, as determined by the Borough Engineer.
B. Primary streets.
(1) The following intersection spacings shall apply wherever
practicable, whether on the same or opposite sides of the street:
(a)
Primary streets: 400 feet.
(b)
Collector streets: 400 feet.
(c)
Local access streets: 300 feet.
(2) For intersections that would have to be spaced a lesser
distance apart, first preference should be given to locating the streets
opposite one another as a four-way intersection, otherwise the best
solution should be sought in terms of accepted traffic safety standards.
C. Offset intersections. In any case where the center
lines of street intersections are or would be within 150 feet of each
other, they shall be made to coincide by relocating the street within
the applicant's land, unless additional problems of sight-distance
or other safety-related problems would be created. As an alternative,
relocation further away from the offset intersection may be done in
compliance with the intersection spacing requirements contained herein,
when approved by the Borough Council.
Any street which is served by only one intersection
with a throughstreet shall be considered a single-access street, regardless
of the street's configuration within the proposed subdivision or land
development. Included in this classification of streets are cul-de-sac
streets (temporary and permanent); multiple cul-de-sac streets; single-access
loop streets and stub streets.
A. Single-access streets shall be subject to the requirements
for their classification of street, notwithstanding their single-access
status.
B. Permanent cul-de-sac streets:
(1) Shall be permanently closed at one end;
(2) Shall be provided with a vehicular turnaround at the
closed end with a right-of-way radius of at least 60 feet and a paving
radius of at least 48 feet;
(3) Shall not exceed 500 feet in length unless approved
by the Borough Council when warranted by special conditions:
(a)
Measurement of the length shall be made from
the edge of pavement of the throughstreet to the most distant point
on the edge of pavement of the turnaround, measured along the cul-de-sac
street's center line.
(b)
Special conditions may include, but not be limited
to:
[1]
Extreme topographical restrictions (slopes,
floodplains, etc.);
[2]
Oddly shaped tract configuration.
[3]
Lack of alternative outlets.
(4) Shall be served by an emergency accessway when required by the Borough Council, in compliance with §
147-26G herein.
C. Temporary cul-de-sac streets:
(1) May be temporarily closed at one end, with the intent
to extend the street onto the abutting tract upon its development;
(2) Shall be built to the tract boundary line at a location and grade that are logical for extension onto the abutting tract, but shall not exceed 750 feet in length, unless approved by the Borough Council when warranted by special conditions, as in §
147-26B(3)(b) herein;
(3) Shall not be extended as a cul-de-sac street, but shall be connected to another throughstreet, unless approved by the Borough Council when warranted by special conditions, as in §
147-26B(3)(b) herein;
(4) Shall form a logical step in the circulation pattern
of the superblock or area in which it is located;
(5) Shall be provided with a vehicular turnaround at the
closed end, abutting the tract boundary, with a paving radius of at
least 48 feet:
(a)
Construction shall meet the same requirements
as for a permanent cul-de-sac turnaround;
(b)
Those portions of the turnaround extending beyond
the street right-of-way shall be located on temporary access easements,
valid only until the road is extended;
(c)
Upon extension of the street, the full rights
and responsibilities for the area of the temporary easements shall
revert to the owners of the lots on which they were located.
(6) Shall be served by an emergency accessway when required by the Borough Council, in compliance with §
147-26G herein.
(7) The developer responsible for extension of the street
shall also be responsible for the following:
(a)
Removal of all curbing and paving of the temporary
turnaround beyond the width of the street's cartway;
(b)
Installation of new sidewalk, curbing, and cartway
paving to complete the street connection;
(c)
Extension of utilities as necessary;
(d)
Repair of any improvements damaged in this process;
(e)
Grading, installation, and/or restoration of
lawn areas where affected by this removal and construction process.
(8) Temporary cul-de-sac streets shall be built to the
standards for the classification of streets they will have when extended.
D. Multiple cul-de-sac streets:
(1) Are single-access streets which terminate in more
than one vehicular turnaround;
(2) Shall be avoided in favor of more desirable street
layouts;
(3) May be permitted where the length of cul-de-sac is
less than 500 feet, measured from the throughstreet intersection to
each turnaround;
(4) May be permitted to exceed the five hundred feet limit when approved by the Borough Council when warranted by special conditions, as in §
147-26B(3)(b) herein, or when qualified as a temporary cul-de-sac as regulated in §
147-26C herein;
(5) Shall be served by an emergency accessway when required by the Borough Council, in compliance with §
147-26G herein.
E. Single-access loop streets:
(1) Are single-access streets which do not terminate in
a vehicular turnaround, but instead loop back to intersect with themselves;
(2) Shall be discouraged but may be permitted when no
alternatives are determined to be feasible and preferable by the Borough
Council upon advice of the Borough Planning Commission and Engineer;
(3) When permitted, shall meet the following requirements:
(a)
Shall not under any circumstances exceed 2,000
feet in length, measured from the intersection with the throughstreet,
along the entire center line around to its intersection with itself;
(b)
Shall not contain or serve more than 45 residential
lots or dwelling units;
(c)
Shall be served by an emergency accessway when required by the Borough Council, in compliance with §
147-26G herein.
F. Stub streets:
(1) Shall be provided in appropriate locations for vehicular
access to abutting undeveloped lands when required by the Borough
Council, upon advice of the Borough Planning Commission and Engineer;
(2) Shall not be longer than:
(a)
The depth of one building lot abutting the street,
or;
(b)
The width of two building lots abutting the
street.
(3) Shall not be provided with a vehicular turnaround;
(4) Shall be constructed to the property line in accordance
with the standards of this chapter applicable to the classification
of street it will be upon extension.
G. Emergency accessways:
(1) Shall be constructed in compliance with the Borough's
Engineering Standards so that emergency vehicles shall have an alternative
access to a single-access street;
(2) Shall be constructed in a logical location in terms
of:
(b)
Relationship to normal access;
(c)
Street, driveway, or parking lot used to get
to the emergency accessway.
(3) Shall be marked by four-foot high posts, spaced 50
feet apart along one edge of the cartway.
Clear sight triangles shall be required to be
maintained along all approaches to all street intersections, and all
intersections of driveways with streets, in compliance with the standards
herein.
A. Clear sight triangles shall be measured along street
and driveway center lines, from their point of intersection;
B. Where differing classifications of streets intersect,
the higher classification of street shall determine the dimensions
used;
C. For driveways, the dimensions used shall be determined
by the classification of street being intersected;
D. The clear sight triangle legs shall each measure as
follows:
(1) Primary streets: 125 feet.
(2) Collector streets: 100 feet.
(3) Local access streets: 75 feet.
E. Within the area of clear sight triangles, obstructions
to visibility shall not be permitted within the following ranges of
height:
(1) For all streets, between 2 1/2 feet and 12 feet
above the edge of paving;
(2) Any plant materials placed within clear sight triangles
shall be properly maintained to continually comply with the height
restrictions herein. If not properly maintained, the Borough reserves
the right to trim or remove the plant materials, upon due notice to
the property owner;
(3) Exceptions may be made by the Borough Council to permit
the following items in a clear sight triangle:
(a)
One private sign or lamp post, provided that
the post does not exceed one foot square or diameter, and that the
sign or lamp itself is above the top height limitation;
(b)
One shade tree, provided that, as the tree matures,
its lower branches will be removed within the restricted height ranges;
(c)
Existing shade trees, provided that the lower
branches are removed within the restricted height ranges, and that
the size, number, and arrangement does not impede adequate visibility.
The Borough Council may require removal of one or more trees as necessary
to provide adequate visibility.
(4) Grading within a clear sight triangle shall not exceed
a 6% increase measured from the elevation of the edge of paving. Existing
grades in excess of 6% shall be regraded into compliance;
(5) Where street or driveway grades drop off from an intersection,
the Borough Council may modify these requirements as necessary to
improve visibility at the intersection.
Applicants shall submit tentative sketch plans
to the Borough Planning Commission, for their evaluation and advice,
in the following circumstances:
A. When five or more residential lots are proposed to
be subdivided along an existing Primary or Collector street.
B. For all nonresidential proposals which require a new
driveway or upgrading of an existing driveway to handle larger volumes
of traffic than that which exists at the time of plan submission.
C. For all proposals whose driveways would generate 25
or more vehicular trips per day, based on I.T.E. trip generation standards.
D. Issuance of permits.
(1) The Borough Planning Commission shall review the proposal in accordance with the procedures of Article
III of this chapter;
(2) Following evaluation by the Borough Planning Commission,
the applicant may submit plans to the state or Borough for formal
review and, as appropriate, approval and issuance of permits;
(3) No driveway location, classification, or design shall
be considered finally approved by the Borough unless permits have
been granted by the state and/or Borough and preliminary plan approval
has been granted by the Borough Council for the subdivision and/or
land development which the driveway(s) will serve.
Driveway intersections with streets shall be
subject to the PADOT permit process for state roads, the Borough's
permit process for Borough roads, and the additional requirements
of this chapter.
A. Driveway intersections with streets:
(1) Shall provide adequate sight distance in compliance
with AASHTO or PADOT standards;
(2) Shall not cause or contribute to:
(a)
Hazards to the free movement of normal street
traffic;
(b)
Traffic congestion on the street;
(c)
Interference with the design, maintenance, and/or
drainage of the street.
(3) Shall be designed and constructed in compliance with
PADOT standards when intersecting a state street;
(4) Shall be designed and constructed in compliance with
the Borough's Engineering Standards when intersecting a Borough street.
B. In order to facilitate safe and efficient access between
streets and driveways, the number of driveways permitted to serve
individual parcels of land shall be kept to the minimum needed to
adequately serve the parcel in question.
(1) Properties with frontages of 100 feet or less may
be permitted not more than one driveway intersection with a street;
(2) Not more than two driveway intersections with the
same street may be permitted for any parcel of land unless anticipated
traffic volumes warrant more than two, and then only when supported
by a traffic study prepared by a qualified engineer.
C. Driveway intersections serving individual parcels
of land may be prohibited by the Borough Council where such intersections
would create congestion, interference, and/or hazards to traffic flow
and safety by reason of street grades, land forms, vegetation, frequency
of driveway intersections, limited sight distances, and/or high speed
traffic flow. In such cases, the Borough Council may permit reasonable
alternative forms of vehicular access to the parcel of land by means
of:
(1) Marginal access streets or driveways;
(3) Reverse frontage lotting;
(4) Other means which are legally and technically suitable
in the opinions of the Borough Solicitor and Engineer.
D. Where driveway intersections are prohibited by the
Borough Council and alternative forms of vehicular access would cause
an undue burden upon an applicant, the Borough Council may permit
an alternative interim access solution in compliance with the following:
(1) It is the safest feasible alternative, acceptable
to the Borough Engineer and/or PADOT;
(2) Suitable provisions are made for a preferable permanent access solution, consistent with Subsection
C above, including legal agreements to enable implementation of the permanent solution.
E. Distance from street intersections. Driveways shall
be located as far from street intersections as is reasonably possible,
but not less than the following distances:
(1) Individual residential lots: 50 feet.
(2) Multifamily residential and nonresidential: 100 feet.
F. Choice of streets. When streets of different classes
are involved, the driveway shall provide access to the street of lesser
classification unless this requirement is waived by the Borough Council
for reasons of sight distance, incompatibility of traffic, grading,
drainage, or other major reasons.
G. Stopping areas. Regardless of the driveway classification,
all driveways shall be provided with a stopping area within which
the grade shall not exceed 6%. The stopping area shall be measured
as follows:
(1) The length of stopping area shall be a minimum of
20 feet, or the length of the longest vehicles anticipated to use
the driveway, whichever is greater.
(2) Stopping areas shall be measured from the ultimate
right-of-way line for primary and collector streets, and from the
edge of paving or curbline of local access streets.
H. Clear sight triangles. Clear sight triangles shall be provided where driveways intersect streets, in compliance with the standards of §
147-27, Clear sight triangles.
Sidewalks, curbs, and storm sewers shall be
installed along all proposed streets, common driveways, and common
parking areas except when this requirement is waived at the discretion
of the Borough Council upon recommendation of the Borough Planning
Commission and Engineer. Engineering design and construction standards
shall be those contained in the Borough's Engineering Standards.
A. The Borough Council may waive the sidewalk requirement
under one or more of the following conditions:
(1) Where proposed residential lot widths will be 125
feet or greater;
(2) There is clearly no destination to be reached by pedestrians
(e.g., shopping center, bus stop, employment, schools), or none anticipated
in the foreseeable future;
(3) The sidewalk(s) would not be an extension of an existing
network which provides neighborhood or village circulation;
(4) An alternative pedestrian circulation concept can
be shown to be more desirable, especially when using open space areas,
provided that appropriate walks are provided between the open space
walkways and the pedestrian origins and destinations;
(5) The character, density of the area and/or small size
of the proposal preclude the purposeful use of sidewalks.
B. The Borough Council may waive the curb and/or storm
sewer requirement under one or more of the following conditions:
(1) The curbs and storm sewer would not be an extension
of existing curbs and storm sewers;
(2) When an alternative system of protecting the pavement
edge, and collecting and handling stormwater can be shown to be equal
or superior to the use of curbs and storm sewers;
(3) When topographic conditions and/or low intensity of
development do not require their use.
C. Regardless of the small-size of a land development
or subdivision proposal, sidewalks, curbs and storm sewers shall be
required wherever they fill a gap in an existing network.
D. If for any reason an interim waiver of these requirements is made, a sufficient guarantee shall be posted for the eventual installation of these items, subject to approval by the Borough Council upon recommendation of the Borough Engineer and Solicitor, in accordance with §
147-49 of this chapter.
E. Sidewalks shall be not less than four feet in width,
although the Borough Council may require additional width in commercial,
industrial, office, or higher density residential areas where higher
volumes of pedestrian traffic are anticipated.
F. The edge of sidewalks shall be located six inches
from the right-of-way line, toward the street, with the sidewalk extending
toward the streets.
G. Sidewalks shall be provided in appropriate locations
to provide safe and efficient pedestrian access between parking areas
and buildings.
H. Additional sidewalks shall be required where deemed
necessary by the Borough Council to provide access to schools, churches,
parks, community facilities, and commercial or employment centers,
and to provide necessary pedestrian circulation within land development
and/or subdivisions where otherwise required sidewalks would not be
sufficient for public safety and convenience. Such additional sidewalks
may be constructed of alternative materials, in compliance with the
Borough's Engineering Standards.
I. Sidewalks shall be designed to facilitate access and
use by the handicapped, in compliance with the Borough's Engineering
Standards and the Americans with Disabilities Act.
J. Driveway crossings shall be designed in compliance
with the Borough's Engineering Standards.
Parking and related internal driveways shall
be governed by the following regulations:
A. General.
(1) Off-street parking facilities shall be provided in compliance with the parking requirements of Chapter
176, Zoning, and the regulations contained herein;
(2) Angled or perpendicular parking shall not be permitted
along public or private streets, except where specifically permitted
by this or other ordinances;
(3) The terms "parking lot," "parking area," and "parking"
are interchangeable. "Parking" includes the driveway which provides
direct access to the parking spaces.
B. All parking lots.
(1) Parking shall not be permitted along driveways which
serve as the entrance(s) or exit(s) to parking areas with a capacity
of 50 cars or more;
(2) Parking areas shall not be located closer than 20 feet from any tract boundary line, nor less than 15 feet from any ultimate right-of-way line. These setback areas shall be landscaped in accordance with the requirements of §
147-39, General planting requirements;
(3) Where the edge of a parking area is located close to a street, driveway, or other parking area, and the provisions of Subsection
B(2) above do not apply, a minimum separation of 10 feet shall be provided between these features. This spacing shall consist of a raised landscaped area, preferably curbed, with planting in conformance with §
147-39C herein;
(4) Parking spaces shall not be located closer than 20
feet from a building to provide potential access space for fire fighters
and equipment. Driveways providing access to parking spaces may be
located within that twenty-foot setback, but shall not be closer than
three feet from the edge of the building.
(5) Dead-ended parking areas shall be discouraged when
the required parking capacity can be accommodated in a layout that
permits more convenient vehicular movements. However, extraneous through-traffic
flow should be avoided.
(a)
Up to 30 parking spaces may be located in a
dead-ended parking area if there is not a more desirable alternative
feasible and sufficient backup areas are provided for the end stalls;
(b)
More than 30 parking spaces may be located in
a dead-ended parking area only if a turnaround area is provided at
the closed end, suitable for passenger car turning. The turnaround
area may be circular, "T" or "Y" shaped, or other configuration acceptable
to the Borough Council.
C. Residential parking lots.
(1) Parallel rows of parking spaces, which are not separated by a driveway, shall be separated by a raised and/or curbed planting strip, a minimum of 10 feet wide, landscaped in accordance with §
147-39C herein;
(2) A single row of parking spaces located parallel to and between two driveways, shall be separated from one of the driveways by a raised and/or curbed planting strip, a minimum of five feet wide, landscaped in accordance with §
147-39C herein;
(3) Parking lots shall be divided into sections of not more than 20 cars each, with the sections separated by raised and/or curbed planting strips, a minimum of 10 feet wide, landscaped in accordance with §
147-39C herein;
(4) The entire parking lot perimeter shall be landscaped in compliance with §
147-39C herein.
D. Nonresidential parking lots.
(1) Parking lots with a capacity of from 10 to 30 cars shall require a raised and/or curbed planting strip, a minimum of 10 feet wide, landscaped in accordance with §
147-39C herein, around the entire perimeter;
(2) Parking lots with a capacity of from 31 to 100 cars shall require a perimeter planting strip as in Subsection
D(1) above, and, within the perimeter of the lot, an additional planted area equal to 10% of the parking lot area, landscaped in accordance with §
147-39C herein. Minimum dimensions of any area used as part of the 10% shall be 10 feet by 20 feet, however, larger areas are encouraged;
(3) Parking lots for more than 100 cars shall require a perimeter planting strip as in Subsection
D(1) above and shall be divided into sections by raised and/or curbed planting strips, a minimum of 10 feet wide, landscaped in accordance with §
147-39C herein:
(a)
These planting strips shall be located parallel
to the rows of parking, to serve the following purposes:
[1]
To separate main access (entrance-exit) driveways
from rows of parking spaces;
[2]
To separate other major driveways from rows
of parking spaces (service drives, general internal circulation);
[3]
To separate large parking areas into smaller
units at intervals of not more than four rows of parking stalls with
each unit capacity not greater than 100 cars;
[4]
To add visual character and improve the appearance
of large parking areas by reducing their massiveness into smaller
units;
[5]
To provide shade for parked cars;
[6]
To reduce random vehicular flow across parking
area;.
[7]
To permit a high level of visibility for those
uses (stores, offices) for which visibility is an important factor;
[8]
To facilitate snow removal and storm drainage,
and to conserve energy in construction and resurfacing operations,
by permitting relatively large units of paving surface, not obstructed
by numerous, small, barrier island areas;
(b)
The ends of rows of parking shall be marked
as islands by means of painted lines or the use of different paving
materials such as paving blocks, bricks, or round stones.
[1]
Marked end islands shall be equal in size to
one parking space for each row of spaces;
[2]
Parking shall be prohibited on these islands;
[3]
The first parking space abutting the end of
each island shall be reserved and marked for handicapped parking,
at the end of the row closest to the building. Ramps shall be provided
at convenient intervals for access between parking surface and sidewalks.
The following requirements apply to driveways
within sites proposed for land development as well as other sites
proposed for development which will provide parking capacity for 50
or more cars:
A. A smooth transition in horizontal and vertical alignment
shall be provided between the driveway section required for access
to a public street and the driveway(s) required for internal site
circulation;
B. Main access driveways (entrance-exit) and service
driveways handling large trucks shall be a minimum paved width of
30 feet, with one lane in each direction;
C. Access driveways for cars and other small vehicles
which are clearly secondary in importance may be reduced to 26 feet
in paved width;
D. Storefront driveway in shopping centers shall be a
minimum paved width of 35 feet, to allow one lane in each direction
and a dropoff/pickup lane along the sidewalks;
E. Driveways along other nonresidential buildings shall
be a minimum paved width of 26 feet, except where a dropoff/pickup
lane is proposed the width shall be 35 feet;
F. Parking access driveways (as defined) shall be a minimum
of 22 feet wide with two-way traffic flow for convenience and efficiency;
G. One-way driveways and/or parking at less than right
angles may be permitted only when:
(1) Right-angled parking and two-way driveways are not
feasible because of site characteristics; or
(2) They are proven by the applicant to be superior for
the particular development proposal.
H. Wherever feasible, internal circulation driveways
shall extend from access drives in locations which permit and encourage
entering traffic to turn and enter the parking aisles without first
traveling along a building-front driveway. This feature is intended
to reduce the volume of vehicular traffic along a building-front driveway
to make it safer for pedestrian traffic.
[Amended 4-11-2002 by Ord. No. 311; 4-8-2004 by Ord. No. 320]
Parking spaces shall be a minimum of nine feet
by 18 feet, except that where vehicles may overhang a planting strip,
a three-foot widening of the planting strip shall permit a three-foot
reduction of parking space length to 15 feet. Parking lot dimensions
shall be as shown in Figure 2, herein.
Rear lots, as defined herein, may be permitted
by the Borough Council, in accordance with the following standards
and criteria:
A. Purposes of rear lotting.
(1) To permit reasonable subdivision of land which is
physically constrained by unusual configuration of the tract or limited
road frontage and which could not be subdivided in a desirable manner
using conventional streets and lotting patterns;
(2) To permit an alternative to the use of local access
streets where such streets cannot be justified in terms of the number
of lots served, volumes of traffic generated and/or the need to extend,
supplement or otherwise support or reinforce an established road pattern
or traffic circulation plan for the area surrounding the proposed
subdivision:
(a)
As an interim alternative where future subdivision
will result in appropriate street construction.
(b)
As a permanent alternative.
B. Parts of a rear lot. Rear lots shall be comprised
of two parts, the access strip and the body of the lot, in compliance
with the following standards:
(1) The access strip shall be a minimum of 25 feet wide
for its entire length, including that portion which abuts a public
street right-of-way for access;
(2) When necessary or desirable for grading, drainage,
or preservation of natural features, such as trees, the access strip
shall be widened beyond the 25 foot minimum as necessary. Fifty feet
is suggested as a maximum width;
(3) When the body of the rear lot is capable of being
further subdivided into additional lots, the minimum width for its
access strip shall be 50 feet, for future use as a road right-of-way,
unless further subdivision is prohibited by a deed restriction or
other legal instrument approved by the Borough Solicitor;
(4) The access strip shall be a fee-simple part of the
rear lot and shall not be a separate parcel or easement;
(5) The body of a rear lot shall comply with all the minimum
dimensional requirements of the zoning district in which it is located.
The area of the access strip shall not be counted toward the minimum
lot area requirement.
C. Review factors. In reviewing applications for rear
lots, the following factors will be considered by the Borough Council
Planning Commission and Engineer:
(1) The amount of road frontage and configuration of the
property being subdivided;
(2) The sizes and number of lots proposed, including both
the total number of lots and the number of rear lots;
(3) The type and character of road which the tract abuts;
(4) The topography of the parcel being subdivided, with
an emphasis on trees and slopes;
(5) The physical characteristics of the surrounding area,
and whether or not the subdivision site is distinguishable from it;
(6) The development status of the surrounding sites;
(7) The visual character preferred for the tract; that
is, whether it's better to see a lot of houses abutting the road,
or to "hide" some in rear areas to reduce the perceivable density
of development;
(8) Whether rear lots would set an undesirable precedent
for nearby sites;
(9) The economic impact of requiring road construction
as compared to using rear lots;
(10)
The visual and physical impacts of road construction
as compared to the use of access strips.
D. Design standards for rear lots.
(1) The length of the access strip shall be kept to a
minimum, and, as a guide, the preferred length is approximately equal
to the depth of one lot which complies with the minimum lot width
and area requirements of the district in which it is located;
(2) The location of the access strip should be logical
relative to the body of the rear lot, surrounding property configurations,
and natural features of the land, and it shall intersect the public
street at a safe, visible location;
(3) Turns greater than 60º should be avoided in access
strips:
(a)
It may be necessary to widen the access strip
at such sharp turns to accommodate grading, drainage, or tree preservation;
(b)
For access strips that may become roads, the
Borough Council may require turns to be designed to accommodate horizontal
curves required for roads.
(4) Driveways serving access strips shall comply with
the Borough's Engineering Standards for drainage and cartways, from
the edge of road pavement to a distance of 50 feet beyond the ultimate
right-of-way line of the road;
(5) When two access strips abut, they should share a common
access point and driveway from the edge of pavement to a distance
of 50 feet beyond the ultimate right-of-way line of the road, from
which point either one common driveway or two individual driveways
may continue. The shared portion shall be a minimum of 18 feet wide;
(6) When more than two access strips would abut one another,
the Borough Council may require, instead, the use of a public street,
in accordance with the standards of this chapter.
E. Provisions for future roads. The Borough Council may
permit the use of rear lots where one or more access strips are intended
to serve as a right-of-way for a road which will serve future lotting.
The following regulations shall apply:
(1) Legal guarantees shall be provided to assure future
use of any access strip proposed for future use as a road, subject
to approval of the Borough Solicitor;
(2) The road shall be constructed or financially guaranteed
at the applicant's expense;
(3) Access strips legally and financially guaranteed for
future use as roads may comprise the legal and physical access to
otherwise landlocked residual parcels only if the access is irrevocably
guaranteed;
(4) An overall tentative sketch plan shall be submitted
as part of the proposed subdivision, to show how the rear lotting
and reservation of access strips for future roads forms a logical
and appropriate first phase in subdivision of the entire tract and/or
how it will allow interconnection with adjacent tracts;
(5) When the road is constructed, any access strips which
are no longer needed shall revert to the owners of the abutting lots,
in accordance with the terms agreed to as part of the original preliminary
plan approval which created the access strips.
The regulations contained herein shall apply in those areas identified as flood-prone in Chapter
176, Zoning. The Flood Boundary and Floodway Map shall be available in the Borough Office for inspection. In regard to the adopted Floodplain Conservation District, the regulations contained herein shall apply to those areas defined and established as floodplain and not in conflict with the information provided in the Flood Insurance Study.
A. The Regulations contained herein are intended to conform
to the requirements of the National Flood Insurance Program, P.L.
93-234, and the Pennsylvania Flood Plain Management Act, P.L. 851,
No. 166 of 1978, and as either is amended. Furthermore, it is the purpose
of these regulations to:
(1) Regulate the subdivision and development of floodplain
areas in order to promote the general health, welfare, and safety
of the community;
(2) Require that each subdivision lot or development site
in floodplain areas be provided with a safe building site with adequate
access; and that public facilities which serve such sites be designed
and installed to preclude flood damage at the time of initial construction;
(3) Protect individuals from buying lands which are unsuitable
for use because of flood hazards by prohibiting the subdivision and
development of unprotected floodplain areas;
(4) Maintain the certification of Schwenksville Borough
and the eligibility of the property owners in the Borough for the
benefits of the National Flood Insurance Program, P.L. 93-234.
B. Prospective developers shall consult with the Zoning
Officer to make a determination as to whether or not the proposed
subdivision or land development is located within an identified floodplain.
C. Where not prohibited by this or any other codes or
ordinances, land located in a floodplain may be subdivided or developed
in accordance with this and any other codes or ordinances regulating
such development.
D. The finished elevation of proposed streets within
floodplain areas shall be a minimum of two feet above the base flood
elevation. Drainage openings shall be sufficient to discharge flood
flows without increasing flood heights onto lands of other property
owners.
E. Storm drainage facilities shall be designed to convey
the one-hundred-year flow without risk to persons or property. The
drainage system shall ensure drainage at all points along streets,
and ensure conveyance of drainage away from buildings.
F. The Borough Council may require in a floodplain an
underground system to accommodate a one-hundred-year flood and a secondary
surface system to accommodate larger, less frequent floods. Drainage
plans shall be consistent with local and regional drainage plans.
The facilities shall be designed to prevent the discharge of increased
runoff onto adjacent properties.
G. All new or replacement sanitary sewer systems, whether
public or private, located in floodplain areas shall be floodproofed,
and all appurtenances thereto (including, but not limited to, pumping
stations) shall be floodproofed up to a point 1 1/2 feet above
the base flood elevation.
H. All new or replacement water systems, whether public
or private, in floodplain areas shall be floodproofed up to a point
1 1/2 feet above the base flood elevation;
I. All other new or replacement public or private utilities
and facilities in floodplain areas shall be elevated or floodproofed
to a point 1 1/2 feet above the base flood elevation.
J. Waivers. Guidelines for relaxation from the requirements
set forth in this section are as follows:
(1) A waiver shall not be issued within any designated
regulatory floodway if any increase in flood levels during the base
flood discharge would result.
(2) A waiver shall only be issued if there is:
(a)
A determination that failure to relax the requirements
would result in exceptional hardship to the applicant;
(b)
A determination that the relaxing of a requirement
will not result in increased flood heights, additional threats to
public safety, extraordinary public expense, create nuisances, cause
fraud on or victimization of the public, or conflict with existing
local laws or ordinances;
(c)
A determination that relaxing of a requirement
will not result in any adverse impact on adjacent landowners either
upstream or downstream.
(3) A waiver shall only be issued upon a determination
that the waiver is the minimum necessary, considering the flood hazard,
to afford relief.
(4) The Borough shall maintain a record of all waivers,
including justification for their issuance, and report such decisions
issued in its annual report submitted to the Federal Insurance Administrator.
K. Where the subdivision or land development lies partially
or completely in a floodplain or where the subdivision or land development
borders on a floodplain, the plan shall include detailed information
identifying the following:
(1) Location and elevation of existing and proposed streets,
water supply and sanitary facilities, and any other permitted improvements,
soil types, and proposed floodproofing measures;
(2) Boundaries of the floodplain and the base flood elevation as defined in Chapter
176, Zoning.
The length, width, and shape of blocks shall
be guided by the following:
A. Minimum dimensional requirements of the zoning ordinance;
B. Respect for existing natural features which may constrain
subdivision or land development;
C. Need to provide efficient, convenient and safe pedestrian
and vehicular circulation;
D. Suitability of lotting pattern and building sites
created by the blocks.
A. Lots shall meet or exceed the minimum area and width requirements of Chapter
176, Zoning.
B. Deep, narrow lots are to be avoided, except that lots
for attached dwelling units may receive special consideration.
C. Wide, shallow lots are to be avoided.
D. Every lot shall contain a building envelope suitable
for the type(s) of development proposed.
E. Every lot shall have frontage along the right-of-way
of a public street.
F. Lot lines shall be drawn parallel, concentric, at
right angles, or radial to the right-of-way line whenever feasible
and not otherwise justifiable by existing, permanent, natural or man-made
features.
A. No proposal will be approved with a property line extending through any portion of an existing building, except where that property line follows a party wall separating semidetached or attached units, in accordance with Chapter
176, Zoning.
B. When existing buildings are retained:
(1) Minimum building setbacks shall be met or exceeded,
in respect to all new lot lines created, for the district in which
the buildings are located, even if this results in a lot area or dimensions
in excess of the otherwise applicable minimums;
(2) Building setbacks in excess of the applicable minimums
are encouraged, in respect to all new lot lines created, when the
height and/or bulk of the existing building significantly exceeds
that of proposed, abutting development. For tall buildings, a setback
equal to the height of the building is suggested as a minimum. For
proportionally wide or deep buildings, a setback equal to 1/2
of the width or depth of the building is suggested as a minimum;
(3) Run-down buildings shall be rehabilitated on the exterior
to conform in quality with surrounding new development;
(4) Structurally deficient buildings shall be rehabilitated
in conformance with the Borough Building Code and BOCA Property Maintenance Code;
(5) Additions to retained buildings shall conform in all
respects to the requirements of the zoning ordinance applicable to
the district in which the building is located and shall be in harmony
with the character, design, building materials, and other architectural
features of the building;
(6) Historical or culturally significant buildings shall
retain their respective characters, to the greatest extent practical;
(7) New buildings abutting the retained building should
reflect the character and architectural features of the retained building
to the greatest extent practical;
(8) In nonresidential districts retained buildings shall be provided with adequate parking, service, and landscaped areas in accordance with the provisions of Chapter
176, Zoning, for the intended use. If the applicant cannot specify the intended use, then the most land consumptive provisions shall be applied, to ensure sufficient land area for uses permitted in that district;
(9) The building setback lines, existing and proposed
buildings, driveways, parking areas, walks, and other similar information
shall be shown on the plan, with a note added describing the buildings,
and their intended purposes;
(10)
No plan approval will be granted to a subdivision
or a land development unless and until the above requirements are
complied with to the satisfaction of the Borough Council upon recommendation
of the Borough Planning Commission and Engineer.
C. When existing buildings will be removed:
(1) The plan must show the location and include a brief
description of the building(s) to be removed;
(2) Plan approval will be granted upon written agreement to the expeditious removal of buildings intended for removal, in conformance with applicable Borough requirements and procedures regarding demolition of buildings and disposition of the reusable parts and/or disposal of the rubble. If the building will not be removed immediately, a financial guarantee must be posted for its removal, in compliance with §
147-49 herein.
[Amended 3-8-2007 by Ord. No. 340]
A. Applicability. All subdivisions and land developments
shall comply with the standards of this article.
(1) A landscape plan shall be submitted as part of the
preliminary plan submission. The landscape plan shall be prepared
by a landscape architect licensed in the State of Pennsylvania.
(2) The landscape plan shall depict a planting design
that mitigates the impacts of the proposed site activity, is coordinated
with the proposed development and the surrounding community character
and complies with at least the minimum planting requirements of this
article.
B. Preservation and protection of existing vegetation.
(1) Preservation of existing vegetation.
(a)
All subdivisions and land developments shall
be laid out in such a manner as to minimize the removal and/or disturbance
of healthy trees, shrubs and other vegetation on the site. Special
consideration shall be given to mature specimen trees and ecologically
significant woodlands.
(b)
Removal or disturbance of vegetation in environmentally sensitive areas, including wetlands, floodplains, steep slopes, riparian corridors, Pennsylvania Natural Diversity Inventory (PNDI) wildlife habitats, and ecologically significant woodlands, shall be undertaken only as permitted in §
147-39B(4)(a)[1] to minimize the adverse effects of such actions.
(c)
The applicant shall prove to the satisfaction
of Borough Council that vegetation removal is minimized. If challenged
by the municipality, the applicant shall produce evidence such as
written documents or plans certified by a registered landscape architect
or other qualified professional showing that no more desirable layouts
are possible and no alternative clearing or grading plan would reduce
the loss of mature trees, tree masses, and woodlands.
(d)
Each freestanding mature tree, tree mass, or
woodland on the site shall be designated "to remain" or "to be removed"
in accordance with the following criteria:
[1]
A mature tree, tree mass, or woodland shall
be designated "to remain" only if it meets all of the following criteria:
[a]
The outermost branches of the tree(s) are at
least five feet or the trunk of the tree at least 20 feet, whichever
is greater, from any limit of disturbance.
[b]
The outermost branches of the tree(s) are at
least five feet or the trunk of the tree is at least 20 feet, whichever
is greater, from any proposed changes in grade or drainage such as
excavations, mounding, or impoundments.
[c]
The tree(s) are clear of any proposed sight
triangles, do not, by their location or apparent health, pose any
undue threat to the health, safety, and welfare of the community.
[d]
Existing drainage patterns and water supply
for the protected vegetation shall be maintained to the greatest degree
feasible.
[2]
Mature trees, tree masses, or woodlands that
do not fit the above criteria shall be designated "to be removed."
(2) Protection of existing vegetation. Existing vegetation designated "to remain," in accordance with §
147-39B(1)(d) above, as part of the landscaping of a subdivision or land development shall be identified in the field prior to any clearing and shall be physically protected throughout the construction process. A temporary, sturdy physical barrier, such as a snow fence, shall be erected a minimum of one foot outside the dripline or a minimum of 20 feet from the tree's trunk, whichever is greater, on all sides of mature trees, tree masses, or woodlands prior to major clearing or construction. The barrier shall be placed to prevent disturbance to or compaction of soil inside the barrier and shall remain until construction is complete. The barrier shall be shown on the erosion and sedimentation control plan and the landscape plan. Reference to the installation of tree protection should be included in the sequence of construction notes to insure incorporation of tree protection before the earliest stages of site disturbance.
(3) Credit for preserved trees.
(a)
Requirements for street trees and buffer plantings could be met, whenever possible, by preserving existing trees. Credit for existing trees which are "to remain," as determined in §
147-39B(1)(d)[1] to offset either the street tree or buffer planting requirements are to be calculated as follows:
|
Preserved Tree
(dbh in inches)
|
Number of Trees Credited
(2 1/2-inch caliper)
|
---|
|
36 or greater
|
8
|
|
18 to 35
|
6
|
|
12 to 17
|
4
|
|
8 to 11
|
2
|
(4) Tree replacement planting requirements.
(a)
Size requirements.
[1]
Any permitted removals (those listed "to be
removed") of mature trees with six up to eight inches diameter at
breast height (dbh) must be replaced with one or more trees whose
total trunk diameter (measured by caliper as nursery stock) equals
the total inches in dbh of the tree(s) removed.
[2]
Each mature tree of eight up to 18 inches dbh
which is designated "to be removed," as outlined above, shall be replaced
with one tree of not less than 2 1/2 inches in caliper at the
time of planting. 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 inches
or greater dbh) per square foot area. Calculated woodland tree removals
and individual mature tree removals shall be listed on the plan.
[3]
Each mature tree of 18 inches or greater dbh
designated "to be removed" shall be replaced with one or more 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 in the form of a table. Replacement plantings shall be
in addition to other required plantings.
(c)
If the site does not reasonably contain enough
room for the required replacement trees, Borough Council may allow
the developer to locate some or all of the replacement trees on public
lands or accept an equivalent fee in lieu of plantings, at its discretion.
(d)
Calculation and estimation of existing trees
shall be performed by the applicant and approved by the Borough before
any clearing commences and shall be documented on the plan.
(e)
Calculation and estimation of the existing trees
remaining after construction shall be performed and compared with
the calculations of the approved plan and trees shall be replaced
as required by this section prior to the issuing of any occupancy
permits.
C. Street trees.
(1) Street trees shall be required:
(a)
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.
(b)
Along all proposed streets.
(c)
Along access driveways that serve five or more
residential dwelling units.
(d)
Along access driveways that serve nonresidential
properties.
(e)
Along walkways through parking lots and between
nonresidential buildings.
(2) The street tree requirement may be waived by Borough
Council to maintain scenic views of open space, natural features,
or other valued features.
(3) Street trees shall be located between the ultimate
right-of-way line and the building setback line and shall meet the
following standards:
(a)
Trees shall be planted a minimum distance of
five feet and a maximum distance of 15 feet outside the ultimate right-of-way
line. However, in certain cases, as follows, Borough Council may permit
trees to be planted within the ultimate right-of-way:
[1]
In areas, such as Main Street, where planting
areas may be located within the ultimate right-of-way.
[2]
In cases where closely spaced rows of street
trees may be desirable and future street widening is considered unlikely.
(b)
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.
(c)
Trees shall be located so as not to interfere
with the installation and maintenance of sidewalks and utilities.
Trees shall be planted such that their trunks are a minimum distance
of three feet from curbs and sidewalks, 12 feet measured horizontal
distance from overhead utilities, and six feet from underground utilities.
(d)
Tree species shall be selected based on appropriate
growth rates and mature heights for use beneath and adjacent to overhead
utility lines.
(e)
Trees shall be planted at a rate of at least
one tree per 40 linear of street frontage or fraction thereof. Trees
shall be distributed along the entire frontage of the property, although
they need not be evenly spaced.
(f)
Trees shall comply with the requirements of Subsection
J herein. The use of tree species selected from the List of Recommended Plant Materials is encouraged; however, it is important to note that not all trees are applicable in all situations. Alternative species could be permitted subject to the recommendation of the Borough Engineer/Landscape Architect as directed by Borough Council (§
147-40).
D. Buffering plantings.
(1) Use requirements. Buffer plantings shall be installed
in subdivisions and land developments to integrate new development
with its surroundings, to separate incompatible land uses by providing
screening and to minimize or eliminate views to certain site elements
in compliance with the following regulations:
(a)
Buffer plantings shall be required for the following
types of development and as otherwise specified in the Schwenksville
Borough Zoning Ordinance:
[1]
All nonresidential development.
[2]
All single-family detached development over
three units.
[3]
All multifamily, single-family attached and
semiattached development.
[4]
Active recreational facilities.
[5]
Construction of any of the following items:
[a]
Public utility facilities or structures;
[b]
Waste collection, storage and/or treatment facilities;
[d]
Any other structure of similar character or
impact.
(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 existing zoning 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. The Borough Zoning Officer shall have final approval of interpretation
of land uses or Zoning Map.
(2) Buffer area location and dimensions.
(a)
A buffer planting area of not less than 15 feet
in width measured from the property or right-of-way line shall be
established along all property lines and external street boundaries
of the tract proposed for subdivision or land development, unless
otherwise specified in the Zoning Ordinance. Where zoning regulations allow building setbacks less
than 15 feet, the buffer area may be reduced to equal the width of
the minimum building setback.
(b)
The buffer area may be included within the front,
side, or rear yard setback.
(c)
The buffer area shall be a continuous pervious
planting area consisting of canopy trees, small understory trees and
shrubs, with grass or ground cover. No paving shall be permitted within
the buffer areas except for driveway crossing and/or walkways.
(d)
Parking is not permitted in the buffer area.
(e)
Stormwater basins are permitted in the buffer
area, provided that the visual screening requirements of the buffer
are met.
(3) Minimum buffer planting requirements. 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 Table 1.
(4) Minimum plant material requirements. The following
requirements are minimum standards; additional plant material, grading
treatments, or architectural elements may be included in the plan,
at the applicant's discretion. In accordance with Table 1, for every
100 linear feet of property line and external street boundaries of
the tract proposed for subdivision or land development to be buffered,
the following minimum quantities, types and sizes of plant material
shall be required. (Size of plant material when planted. Height at
maturity must provide a sufficient screen.)
(a)
Softening buffer:
[1]
One canopy trees (two to 2 1/2 inches caliper).
[2]
Two understory trees (1 1/2 inches minimum
caliper).
[3]
Two evergreen trees (eight feet minimum height).
(b)
Filtering buffer:
[1]
Two canopy tree (two to 2 1/2 inches minimum
caliper).
[2]
Two understory trees (1 1/2 inches minimum
caliper).
[3]
Five evergreen trees (eight feet minimum height).
[4]
Five (mixture of deciduous/coniferous) shrubs
(24 inches minimum height).
(c)
Screening buffer. (A screening buffer 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 Borough Council.)
[1]
Eight evergreen trees (eight feet minimum height),
two understory trees (1 1/2 inches minimum caliper), two tall
canopy trees (two to 2 1/2 inches minimum caliper), 10 (mixture
of deciduous/coniferous) shrubs (24 inches minimum height); or
[2]
Thirty upright evergreen shrubs (six feet minimum
height); or
[3]
Fifteen upright evergreen shrubs (four feet
minimum height), four ornamental trees (1 1/2 inches minimum
caliper, or three canopy trees (two to 2 1/2 inches minimum caliper);
or
[4]
An alternative planting design that will result
in at least an equivalent degree of visual screening to one of the
above screening buffers.
(d)
Limited area/buffer. (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 municipality. The sufficiency
of the buffer shall be determined by Borough Council.)
[1]
One upright evergreen shrub per three feet (four
feet minimum height).
[2]
Four- to six-foot solid fence or wall with landscaping.
(5) Mitigation of visual impacts.
(a)
The use of a screening buffer planting shall
be required to mitigate the adverse visual impacts that the proposed
land uses or site elements have on the subject tract, adjoining properties
and the community in general. In addition to the requirements for
buffer plantings as listed in Table 1, the following proposed land
uses and site elements shall be screened from off site with a screening
buffer planting:
[1]
Dumpsters, trash disposal, recycling areas,
and mechanical equipment.
[2]
Service and loading docks.
[4]
Sewage treatment plants and pump stations.
(b)
Existing topographic conditions, such as embankments
or berms, in conjunction with existing vegetation may be substituted
for part or all of the required property line buffers at the discretion
of Borough Council. The minimum visual effect shall be equal to or
exceed that the of the required buffer or screen.
Table 1
Property Line Buffers
[See 147-39D(4) for the description
of softening, filtering and screening buffers]
|
---|
|
|
Adjacent Uses
|
---|
Proposed use
|
Office/
Industrial and Public Recreation
|
Commercial/
Industrial
|
Multifamily, Single-family Attached,
Mobile Home Park
|
Two-Family Single-family Detached
|
---|
Office/IndustrialA
|
Softening
|
Softening
|
Filtering
|
Screening
|
Commercial/Industrial
|
Filtering
|
Softening
|
Screening
|
Screening
|
ResidentialB
|
SofteningC
|
Filtering
|
Softening
|
Softening
|
Active Recreation (playing fields,
golf courses, swim clubs, etc.)
|
Softening
|
Filtering
|
Softening
|
Softening
|
A
|
All uses in office/limited industrial
parks shall be considered Office/Institutional Uses.
|
B
|
All mixed uses that have a residential
component shall be considered Residential.
|
C
|
All residential infill development
adjacent to other residents shall be screened pursuant to this category.
|
E. Parking lot landscaping.
(1) Parking lots should be effectively landscaped with
trees and shrubs to reduce the visual impact of glare, headlights,
and parking lot lights; to delineate driving lanes and 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.
(2) Planting regulations. All parking lots shall be landscaped
according to the following regulations:
(a)
Parking stall rows.
[1]
One planting island shall be provided for every
15 stalls. There shall be no more than 15 contiguous parking stalls
in row without a planting island.
[2]
As an alternative to the previous planting island
requirement (planting islands located every 15 contiguous parking
spaces), the applicant must provide one canopy tree for every 10 parking
spaces in other planting island areas and in perimeter parking planting
areas, at the discretion of Borough Council.
(b)
The ends of all parking rows shall be divided
from drives by planting islands equivalent to at least the width of
one parking space.
(c)
In residential developments, large parking lots
shall be divided by planting strips into smaller parking areas of
no more than 40 stalls.
(d)
In nonresidential developments, large parking
lots shall be divided by planting strips into smaller parking areas
of no more than 80 stalls.
(e)
Planting islands shall be a minimum of one parking
stall or nine feet by 18 feet in area, whichever is greater, underlain
by soil (not base course material) and shall be protected by curbing,
wheel stops, or bollards. Each planting island shall contain one shade
tree plus low-growing shrubs and/or non-lawn ground cover to cover
the entire area.
(f)
All planting strips shall be a minimum of 10
feet wide. Strips shall run the length of the parking row, underlain
by soil, and shall be protected by curbs, wheelstops, or bollards.
Planting strips shall contain plantings of one canopy tree every 25
feet, plus shrubs and/or non-lawn ground cover to cover the entire
area at maturity.
(g)
The placement of light standards shall be coordinated
with the landscape plan to avoid a conflict with the effectiveness
of light fixtures.
(h)
Plant materials shall comply with the requirements of Subsection
J herein. The use of tree species selected from the List of Recommended Plant Materials is encouraged; however it is important to note that not all plant materials are applicable in all situations. Alternative species could be permitted subject to the recommendation of the Borough Engineer/Landscape Architect as directed by Borough Council (§
147-40).
(3) Screening requirement. All parking lots shall be screened
from public roads and from adjacent properties according to the following:
(a)
The perimeter of all parking lots shall be planted with a filtering buffer as per §
147-39D(4).
(b)
The perimeter planting area around all parking
lots shall be a minimum of 10 feet in width.
F. Additional plantings.
(1) All proposed nonresidential structures shall incorporate
the following minimum plant materials in the landscaping areas adjacent
to the proposed structure:
(a)
One canopy tree (two to 2 1/2 inches minimum
caliper) or two understory (eight feet minimum height) shall be planted
for every 50 feet of proposed building facade facing a public street.
(b)
Five deciduous or evergreen shrubs (18 inches
minimum height) shall be planted for every 20 feet of proposed building
facade facing a public street.
(c)
Planting areas shall be minimum 150 square feet
with a minimum ten-foot width.
(d)
A minimum of 25% of the area between the building
facade and the property frontage shall consist of pervious planting
areas.
(2) All proposed residential lots shall plant at least
one canopy tree per 10,000 square feet, or a portion thereof, of lot
area. Existing trees to remain may satisfy part of this entire planting
requirement.
(3) All proposed attached residential units shall plant
a minimum of one canopy tree for every two dwelling units.
(a)
At the discretion of Borough 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.
G. Stormwater basins and associated facilities. Landscaping
shall be required in and around all stormwater management basins according
to the following:
(1) 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 or lawn grass specifically suited for stormwater basins. (See §
147-40 for recommended plants for stormwater basins; however it is important to note that not all plant materials are applicable in all situations. Alternative species could be permitted subject to the recommendation of the Borough Engineer/Landscape Architect as directed by Borough Council.
(a)
Trees and shrubs shall be planted in and around
stormwater basins given they do not interfere in the proper function
of the basin and no trees are planted within 30 feet of an outlet/drain
structure, emergency spillway or dam. A minimum of two trees and 10
shrubs per 100 linear feet of basin perimeter shall be planted in
and around the basin.
(b)
Naturalized ground cover plant species, such
as wildflowers 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:
[1]
The plantings provide a satisfactory continuous
cover to all areas of the basin.
[2]
The plantings do not interfere in the safe and
efficient function of the basin as determined by the Municipal Engineer.
(c)
Lawn grass areas may be sodded or hydroseeded
to minimize erosion during the establishment period. Once established,
these turfgrass areas shall be maintained at a height of not more
than six inches.
(2) Basin shape shall incorporate curvilinear features
to blend with the surrounding topography.
(3) Minimum grades inside stormwater basins shall be 2%
and maximum side slopes of the basin shall be 33% (3:1 slope).
(4) Stormwater basins shall be screened from adjacent properties using the buffer plantings standards according to §
147-39D.
H. Riparian corridor planting requirements.
(1) Purpose and application. In areas within Schwenksville,
the edge of water features and stream corridors should be in forest
cover to further the ecological and environmental benefits. To promote
reestablishment of forest cover and woodland habitat, new tree plantings
shall be implemented within 25 feet from the top of the stream bank
wherever existing trees do not meet the minimum tree planting requirements.
(2) Existing trees within 25 feet from the top of the stream bank shall be preserved and retained. Existing tree cover should be surveyed and inventoried to assess the need for any new plantings. Existing tree species included on the noxious/invasive plant species list, §
147-40K, should be removed and the disturbed area shall be immediately stabilized.
(3) Planting requirements.
(a)
New trees shall be planted at a minimum rate
of 15 feet on center or one tree per 225 square feet in staggered
rows or an equivalent informal arrangement within 25 feet from the
top of the stream bank.
(b)
New trees shall be a variety of sizes ranging
from a minimum four- to five-foot branched whip to an approximate
one-and-one-half-inch balled and burlapped planting stock.
(c)
New tree plantings shall be composed of native
riparian tree species.
(d)
Tree plantings shall be located along the stream
bank to provide shade for the stream, soil erosion control and stormwater
benefits, according to accepted stream bank restoration practices.
I. Landscape design criteria.
(1) 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 habit, erosion control, stormwater management,
and aesthetic value.
[3]
Maintenance and replacement considerations such
as hardiness, resistance to insects and disease, longevity, availability
and costs of plant materials.
[4]
A minimum variety of tree species is required
as follows:
|
Number of Trees
|
Minimum Number of Tree Species
|
Maximum % of Any One Species
|
---|
|
0-5
|
1
|
100%
|
|
6-15
|
2
|
50%
|
|
16-30
|
3
|
40%
|
|
31-50
|
4
|
30%
|
|
51+
|
6
|
20%
|
(d)
Existing native noninvasive healthy trees, shrubs,
or woodlands may be substituted for part or all of the required plant
material at the discretion of Borough 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.
(e)
Plant materials shall meet the specifications of Subsection
J herein.
J. Plant materials specifications, maintenance and guarantee.
The following standards shall apply to all plant materials or transplanted
trees as required under this article.
(1) Plant specifications.
(a)
All plants shall meet the minimum standards
for health, form, and root condition as outlined in the American Nursery
and Landscape Association (ANLA) Standards.
(b)
All plant material shall be hardy and within
the USDA Hardiness Zone 6 applicable to Montgomery County, Pennsylvania.
(c)
Proposed plant materials shall meet or exceed the minimum planting size requirement for the intended landscape use. Use of plantings selected from the List of Recommended Plant Material (§
147-40) is encouraged; however it is important to note that not all plant materials are applicable in all situations. Alternative species could be permitted subject to the recommendation of the Borough Engineer/Landscape Architect as directed by Borough Council.
(2) Maintenance.
(a)
Required plant material shall be maintained
for the life of the project to achieve the required visual effect
of the buffer or screen. It shall be the ultimate responsibility of
successive property owners to insure that the required plantings are
properly maintained. Dead or diseased plant material shall be removed
or treated promptly by the property owner and replaced at the next
planting season.
(b)
Safety. All sight triangles shall remain clear,
and any plant material that could endanger safety, such as unstable
limbs, shall be removed and the plant material replaced if necessary.
It shall be the responsibility of the property owner to maintain all
plantings and architectural elements to insure a safe environment.
(c)
Maintenance guidelines for the plantings are
encouraged to be published by the planting plan designer to be used
by ground maintenance personnel to insure that the design's buffering
and screening concepts are continued.
(3) Landscape bond.
(a)
Any tree or shrub area that dies within 18 months
of planting shall be replaced by the current landowner or developer.
Any tree or shrub that within 18 months of planting or replanting
is deemed, in the opinion of the municipality, not to have survived
or not to have grown in a manner characteristic of its type shall
be replaced. Substitutions for certain species of plants may be made
only when approved by the municipality.
(b)
The developer or landowner shall deposit with
the municipality a sum of money equal to the amount necessary to cover
the cost of purchasing, planting, maintaining, and replacing all vegetative
materials for a period of 18 months.
K. Plan requirements.
(1) Preliminary landscape plan at scale shall show the
following:
(a)
Existing features. The location and character
of existing buildings, mature trees standing alone; outer limits of
tree masses and other existing vegetation; the location of floodplains,
wetlands, and other natural features that may affect the location
of proposed streets, buildings, and landscape plantings. These features
should be differentiated by different line weights on the plan or
be on a separate sheet.
(b)
Proposed landscaping:
[1]
Approximate location of all proposed landscaping
required under this article.
[2]
Demarcation of existing vegetation "to remain"
or "to be removed" and the means of protecting existing vegetation
during construction.
[3]
Approximate location of proposed buildings,
paving, utilities, or other improvements.
(2) Final landscape plan.
(a)
Drafting standards. The same standards shall
be required as for a preliminary plan.
(b)
Information to be shown:
[1]
Plan scale, date, North arrow, and location
map with zoning district designations for the site and adjacent properties.
[2]
Location of all existing and proposed buildings
and structures.
[3]
Location of all existing and proposed roads,
parking, service areas, and other paved areas.
[4]
Location of all outside storage and trash receptacle
areas.
[5]
Sidewalks, berms, fences, walls, freestanding
signs, and site lighting.
[6]
Existing and proposed underground and aboveground
utilities such as site lighting, transformers, hydrants, manholes,
valve boxes, etc. (Reference may be made to other submission drawings.)
[7]
All existing and proposed contours at two-foot
intervals to determine the relationship of planting and grading areas
with slopes in excess of 3:1 shall be highlighted on the plan.
[8]
Existing mature trees, woodland, and tree masses
to remain.
[9]
Existing mature trees, woodland, and tree masses
to be removed.
[10]
Location of all proposed landscape improvements
and species at scale, including required street trees, stormwater
basin landscaping, parking lot landscaping, property line buffer,
and site element screen landscaping.
[11]
A planting schedule listing the scientific and
common name, size, quantity, and root condition of all proposed plant
material.
[12]
A schedule showing all landscape requirements
and plantings proposed for each category.
[13]
Planting details, including method of protecting
existing vegetation, and landscape planting methods. Supporting calculations
shall be included in the schedule.
[14]
Information in the form of notes or specifications
concerning seed mix, seeding methods, sodding, ground cover, mulching,
and the like, etc.
[15]
A detailed cost estimate shall be submitted
with the public improvement escrow, showing the value of all proposed
landscaping, including all labor, materials, and guarantee.
(c)
This condition may be satisfied through a land
development agreement with sufficient and appropriate financial guarantees.
(d)
Certificates. When approved, the landscape plan
must show:
[1]
The signature and seal of the registered landscape
architect responsible for preparing the landscape plan and details.
[2]
The signature of the subdivider, developer,
or builder.
[3]
The signatures of the elected municipal officials,
Engineer or Landscape Architect, and Planning Commission.
[Amended 3-8-2007 by Ord. No. 340]
The following lists shall be used for all planting
required by this chapter. Alternative plant materials may be used
only with the approval of Borough Council, after sufficient evidence
is submitted regarding their suitability for their purposes and locations.
A. Shade or canopy trees.
(1) Suitable for street trees, parking lots, buffers and
screens. (Minimum mature height, 30 feet or more.)
|
Scientific Name
|
Common Name
|
---|
|
Acer rubrum
|
Red Maple (native)
|
|
Celtis occidentalis
|
Hackberry (native)
|
|
Cladastris lutea
|
Yellowood (native)
|
|
Fraxinus americana "Rosehill"
|
Rosehill White Ash
|
|
Fraxinus Pennsylvania
|
Marshall's Seedless Green Ash cv Marshall's
Seedless
|
|
Ginkgo biloba "Princeton Sentry"
|
Ginkgo (male only)
|
|
Gleditsia triacanthos inermis
|
Thornless Honeylocust
|
|
Koelreuteria paniculata
|
Golden Rain Tree
|
|
Liquidamber styraciflua
|
Sweet Gum (native)
|
|
Platanus occidentalis
|
Sycamore (native)
|
|
Platanus x acerifolia "Bloodgood"
|
London Planetree
|
|
Quercus bicolor
|
Swamp White Oak (native)
|
|
Quercus borealis
|
North Red Oak (native)
|
|
Quercus coccinea
|
Scarlet Oak (native)
|
|
Quercus imbricaria
|
Shingle Oak (native)
|
|
Quercus phellos
|
Willow Oak (native)
|
|
Quercus rubra
|
Red Oak (native)
|
|
Quercus shumardii
|
Shumard Oak
|
|
Sophora japonica
|
Japanese Pagodatree
|
|
Tilia americana
|
American Linden (native)
|
|
Tilia cordata
|
Little Leaf Linden
|
|
Tilia tomentosa
|
Silver Linden
|
|
Ulmus parvifolia
|
Chinese Lacebark Elm
|
|
Zelkova serrata
|
Japanese Zelkova
|
(2) Suitable for property line buffers and nonvehicular
use areas only. (Minimum mature height, 30 feet or more.)
|
Scientific Name
|
Common Name
|
---|
|
Acer saccharinum
|
Silver Maple (native)
|
|
Acer saccharum
|
Sugar Maple (native)
|
|
Betula nigra
|
River Birch (native)
|
|
Fagus grandifolia
|
American Beech (native)
|
|
Fagus sylvatica
|
European Beech
|
|
Fraxinus americana
|
White Ash (native)
|
|
Liriodendron tulipifera
|
Tuliptree (native)
|
|
Metasequoia glypostroboides
|
Dawn Redwood
|
|
Ostrya virginiana
|
Hop Hornbeam (native)
|
|
Phellodendron amurense
|
Amur Cork Tree
|
|
Plantanus acerifolia
|
London Plane
|
|
Quercus alba
|
White Oak (native)
|
|
Quercus coccinea
|
Scarlet Oak (native)
|
|
Quercus palustris
|
Pin Oak (native)
|
|
Quercus vellutina
|
Black Oak (native)
|
|
Sassafras albidum
|
Sassafras (native)
|
B. Understory trees. Suitable as street trees beneath
overhead utility lines. (Mature height, 15 to 35 feet.)
|
Scientific Name
|
Common Name
|
---|
|
Amelanchier canadensis
|
Shadblow Serviceberry (native)
|
|
Amelanchier laevis
|
Allegheny Serviceberry (native)
|
|
Amelanchier X grandiflora
|
Hybrid Serviceberry (native)
|
|
Carpinus carolinia
|
Ironwood (native)
|
|
Cercis candensis
|
Redbud (native)
|
|
Chionanthus virginicus
|
Fringetree (native)
|
|
Cornus florida
|
Flowering Dogwood (native)
|
|
Cornus kousa chinensis
|
Chinese Kousa Dogwood
|
|
Cornus mas
|
Corneliancherry Dogwood
|
|
Crataegus cv. Toba
|
Toba Hawthorn
|
|
Crataegus phaenopyrum
|
Washington Hawthorn
|
|
Crataegus viridis "Winter King"
|
Winter King Hawthorn
|
|
Halesia carolinia
|
Silverbells (native)
|
|
Hammamelis virginiana
|
Witch Hazel (native)
|
|
Koelreuteria paniculata
|
Golden Raintree
|
|
Magnolia soulangeana
|
Saucer Magnolia
|
|
Magnolia virginiana
|
Sweetbay Magnolia (native)
|
|
Malus (cultivars)
|
Crabapple (disease resistant varieties)
|
|
Oxydendrum arboreum
|
Sourwood (native)
|
|
Prunus sargentii
|
Sargent Cherry
|
|
Prunus serrulata cv. Kwanzan
|
Kwanzan Cherry
|
|
Prunus yedoensis
|
Yoshino Cherry
|
|
Pyrus calleryana cv. Redspire
|
Redspire Pear
|
|
Styrax japonica
|
Japanese Snowbell
|
|
Syringa amurensis var. japonica
|
Japanese Tree Lilac
|
C. Large deciduous shrubs. Suitable for use in property
line buffers or site element screen (not clipped hedges). (Minimum
mature height, 15 feet or more.)
|
Scientific Name
|
Common Name
|
---|
|
Aronia arbutifolia
|
Black Chokeberry (native)
|
|
Calycanthus floridus
|
Sweetshrub (native)
|
|
Cephalanthus occidentalis
|
Buttonbush (native)
|
|
Clethra alnifolia
|
Summersweet (native)
|
|
Cornus sericea
|
Redosier Dogwood (native)
|
|
Enkianthus campanulatus
|
Redvien Enkianthus
|
|
Euonymus alatus
|
Burning Bush
|
|
Forsythia sp.
|
Forsythia
|
|
Fothergilla major
|
Large Fothergilla (native)
|
|
Ilex verticilata
|
Winterberry (native)
|
|
Lindera benzoin
|
Spicebush (native)
|
|
Lonicera fragrantissima
|
Winter Honeysuckle
|
|
Myrica pennsylvanica
|
Bayberry (native)
|
|
Philadelphus coronaris
|
Mockorange
|
|
Physocarpus opulifolius
|
Common Ninebark
|
|
Rhus glabra
|
Smooth Sumac (native)
|
|
Rhus typhina
|
Staghorn Sumac (native)
|
|
Sambucus canadensis
|
Elderberry (native)
|
|
Spirea nipponica
|
Snow Mound Spirea
|
|
Vaccinium corymbosum
|
Blueberry (native)
|
|
Viburnum dentatum
|
Arrow Wood (native)
|
|
Viburnum lentago
|
Nannyberry (native)
|
|
Viburnum prunifolium
|
Black Haw (native)
|
|
Viburnum opulus
|
European Cranberrybush Viburnum
|
|
Viburnum trilobum
|
American Cranberry (native)
|
D. Deciduous or evergreen shrubs. Suitable for clipped
hedges in property line buffers or site element screens. (Minimum
mature height, four feet or more.)
|
Scientific Name
|
Common Name
|
---|
|
Aronia arbutifolia
|
Black Chokeberry (native)
|
|
Cornus mas
|
Corneliancherry Dogwood
|
|
Cotoneaster salicifolia
|
Willowleaf Cotoneaster
|
|
Euonymus alatus
|
Winged Euonymus
|
|
Euonymus alatus campactus
|
Dwarf Winged Euonymus
|
|
Euonymus fortuneii vegetus sarcoxie
|
Big Leaf Wintercreeper
|
|
Ilex crenata
|
Japanese Holly
|
|
Ilex glabra
|
Inkberry (native)
|
|
Juniperus chinensis cv. glauca hetzi
|
Hetz Blue Juniper
|
|
Juniperus chinensis cv. pfitzeriana compacta
|
Compact Pfitzer Juniper
|
|
Ligustrum ibolium
|
Ibolium Privet
|
|
Lonicera fragrantissima
|
Winter Honeysuckle
|
|
Philadelphus lemoinei
|
Mockorange
|
|
Ribes alpinum
|
Currant
|
|
Taxus baccata
|
English Yew
|
|
Taxus x media
|
Hybrid Yew
|
|
Viburnum dentatum
|
Arrow Wood (native)
|
|
Viburnum lentago
|
Nannyberry (native)
|
|
Viburnum opulus
|
European Cranberry Bush
|
|
Viburnum prunifolium
|
Black Haw (native)
|
|
Thuja occidentalis
|
American Arborvitae (native)
|
E. Evergreen shrubs. Suitable for site element screens.
(Minimum mature height, four feet.)
|
Scientific Name
|
Common Name
|
---|
|
Azalea, evergreen varieties, must reach three-foot
height
|
Azalea
|
|
Ilex crenata
|
Japanese Holly
|
|
Ilex glabra
|
Inkberry (native)
|
|
Ilex meserveae (varieties)
|
Blue Holly(s)
|
|
Juniperus chinensis "Hetzi Glauca"
|
Hetz Blue Juniper
|
|
Juniperus virginiana
|
Eastern Red Cedar (native)
|
|
Kalmia latifolia and cultivars
|
Mountain Laurel (native)
|
|
Leucothoe fontanessiana
|
Leucothoe
|
|
Pieris floribunda
|
Mountain Andromeda (native)
|
|
Pieris japonica
|
Japanese Andromeda
|
|
Rhododendron sp.
|
Various large Rhododendrums
|
|
Taxus sp.
|
Yew
|
|
Thuja sp.
|
Arborvitae
|
|
Viburnum rhytidophyllum
|
Leatherleaf Viburum
|
F. Evergreen trees. Suitable for property line buffers
or site element screens. (Minimum mature height, 20 feet.)
|
Scientific Name
|
Common Name
|
---|
|
Abies concolor
|
White Fir
|
|
Chamaecyparis obtusa
|
Hinoki Falsecypress
|
|
Chamaecyparis pisifera
|
Japanese Falsecypress
|
|
Ilex opaca
|
American Holly (native)
|
|
Picea abies
|
Norway Spruce
|
|
Picea glauca
|
White Spruce
|
|
Picea omorika
|
Siberian Spruce
|
|
Picea pungens
|
Colorado Spruce
|
|
Pinus strobus
|
White Pine (native)
|
|
Pinus thunbergii
|
Japanese Black Pine
|
|
Pseudotsuga menziesii
|
Douglas Fir
|
G. Canopy trees. Suitable for stormwater detention basins.
|
|
Scientific Name
|
Common Name
|
---|
|
+
|
Acer rubrum
|
Red Maple
|
|
*
|
Acer saccharinum
|
Silver Maple
|
|
*
|
Betula nigra
|
River Birch
|
|
|
Celtis occidentalis
|
Common Hackberry
|
|
*
|
Fraxinus americana
|
White Ash
|
|
|
Fraxinus pennsylvanica
|
Green Ash
|
|
+
|
Liquidamber styraciflua
|
Sweet Gum
|
|
|
Liriodendron tulipifera
|
Tulip Poplar
|
|
*
|
Nyssa sylvatica
|
Black Gum
|
|
|
Platanus occidentalis
|
Sycamore
|
|
|
Platanus x acerifolia
|
London Planetree
|
|
|
Prunus serrotina
|
Black Cherry
|
|
|
Quercus alba
|
White Oak
|
|
*
|
Quercus phellos
|
Willow Oak
|
|
+
|
Quercus bicolor
|
Swamp White Oak
|
|
*
|
Quercus palustris
|
Pin Oak
|
|
|
Quercus shumardi
|
Shumard Oak
|
|
|
Sassafras albidum
|
Sassafras
|
|
+
|
Taxodium distichum
|
Bald Cypress
|
H. Deciduous/evergreen ornamental trees. Suitable for
stormwater detention basins.
|
|
Scientific Name
|
Common Name
|
---|
|
*
|
Amelanchir canadensis
|
Shadblow Serviceberry
|
|
*
|
Carpinus carolinia
|
Ironwood
|
|
|
Chamaecyparis thyoides
|
Atlantic Whitecedar
|
|
*
|
Chionanthus virginicus
|
Fringetree
|
|
*
|
Magnolia virginiana
|
Sweetbay
|
|
|
Ostrya virginiana
|
Hophornbeam
|
|
+
|
Salix caprea
|
Willow sp.
|
|
+
|
Salix discolor
|
Pussy Willow sp.
|
|
*
|
Thuja occidentalis cv. nigra
|
Arborvitae
|
I. Deciduous or evergreen shrubs. Suitable for stormwater
detention basins.
|
|
Scientific Name
|
Common Name
|
---|
|
|
Alnus serrulata
|
Smooth Alder
|
|
+
|
Aronia arbutifolia
|
Red Chokeberry
|
|
|
Aronia melanocarpa
|
Black Chokeberry
|
|
*
|
Caly canthus florida
|
Sweetshrub
|
|
+
|
Cephalanthus occidentalis
|
Buttonbush
|
|
+
|
Clethra alnifolia
|
Summersweet
|
|
+
|
Cornus amonum
|
Silky Dogwood
|
|
|
Cornus racemosa
|
Gray Dogwood
|
|
+
|
Cornus sericea
|
Redosier Dogwood
|
|
|
Ilex decidua
|
Possumhaw
|
|
+
|
Ilex glabra
|
Inkberry
|
|
+
|
Ilex verticilata
|
Winterberry
|
|
|
Itea virginiana
|
Virginia Sweetspire
|
|
|
Juniperus virginiana
|
Eastern Redcedar
|
|
*
|
Lindera benzoin
|
Spicebush
|
|
*
|
Myrica cerifera
|
Southern Bayberry
|
|
+
|
Myrica pennsylvanica
|
Northern Bayberry
|
|
|
Rhododendron atlanticum
|
Coast Azalea
|
|
+
|
Rhododendron nudiflorum
|
Pinxterbloom Azalea
|
|
+
|
Rhododendron viscosum
|
Swamp Azalea
|
|
*
|
Sambucus Canadensis
|
Elderberry
|
|
|
Sambucus racemosa
|
Red Elder
|
|
|
Spirea latifolia
|
Meadowsweet
|
|
*
|
Viburnum cassanoides
|
Witherod
|
|
*
|
Viburnum dentatum
|
Arrowwood
|
|
*
|
Viburnum lentago
|
Nannyberry
|
|
|
Viburnum prunifolium
|
Blackhaw
|
|
*
|
Viburnum tribolum
|
American Cranberrybush
|
J. Herbaceous perennials. Suitable for stormwater detention
basins.
|
|
Scientific Name
|
Common Name
|
---|
|
|
Acorus calamus
|
Sweetflag
|
|
|
Andropogon virginicus
|
Broomsedge
|
|
|
Aquilegia canadensis
|
Wild Columbine
|
|
|
Asclepias incarnata
|
Swamp Milkweed
|
|
|
Asclepias tuberosa
|
Butterflyweed
|
|
*
|
Aster novae angliae
|
New England Aster
|
|
|
Aster novae-belgii
|
New York Aster
|
|
|
Caltha palustris
|
Marsh Marigold
|
|
|
Chelone glabra
|
White Turtlehead
|
|
|
Chelone lyonii
|
Pink Turtlehead
|
|
*
|
Chrysanthemum lencanthemum
|
Ox-Eye Daisy
|
|
*
|
Echinacea purpurea
|
Purple Cornflower
|
|
+*
|
Eupatorium dubium
|
Joe Pye Weed
|
|
+*
|
Eupatorium fistulosum
|
Hollow Joe Pye Weed
|
|
|
Filipendula rubra
|
Queen of the Prairie
|
|
*
|
Hemerocallis sp.
|
Day Lily
|
|
*
|
Hesperis matronalis
|
Dames Rocket
|
|
+
|
Hibiscus moshentos
|
Rose Mallow
|
|
+*
|
Iris pseudocaris
|
Yellow Iris
|
|
+
|
Iris vericolor
|
Blue Flag
|
|
|
Lilium superbum
|
Meadow Lily
|
|
|
Liatris spicata
|
Blazing Star
|
|
+*
|
Lobelia cardinalis
|
Cardinal Flower
|
|
+*
|
Lobelia siphilitica
|
Blue Lobelia
|
|
*
|
Monarda didyma
|
Bee Balm
|
|
+*
|
Panicum virgatum
|
Switchgrass
|
|
*
|
Phalaris arundinacae
|
Canary Reed Grass
|
|
*
|
Rudbeckia sp.
|
Black-Eyed Susan
|
|
+
|
Scirpus acustus
|
Hard Stem Bullrush
|
|
+
|
Spartina alternifolia
|
Cordgrass
|
|
|
Tradescantia ohiensis
|
Spiderwort
|
|
+
|
Typha angustifolia
|
Narrowleaf Cattail
|
|
+
|
Typha latifolia
|
Common Cattail
|
|
+*
|
Vernonia noveboracensis
|
New York Iron Weed
|
|
NOTES: Applicable to tree lists in Subsections G through J:
|
---|
|
* Suitable for usually well-drained areas that
may be subject to occasional flooding.
|
---|
|
+ Suitable for permanently wet areas.
|
K. Noxious/invasive tree species list. The following tree species may be considered as noxious, invasive exotic or undesirable in sensitive plant communities. Their removal may be warranted for ecological restoration purposes. Removals of these species should not require mitigation, as set forth in §
147-39B.
|
Scientific Name
|
Common Name
|
---|
|
Acer platanoides
|
Norway maple
|
|
Acer pseudoplatanus
|
Sycamore maple
|
|
Ailanthus altissima
|
Tree of Heaven
|
|
Eleagnus angustifolia
|
Russian olive
|
|
Eleagnus umbellata
|
Autumn olive
|
|
Evodia daniellii
|
Korean evodia
|
|
Morus alba
|
Mulberry
|
|
Paulownia tomentosa
|
Empress tree
|
|
Phellodenron amurense
|
Amur cork tree (female)
|
|
Prunus avium
|
Sweet cherry
|
|
Robinia pseudoacacia
|
Black locust
|
|
Ulmus pumila
|
Siberian elm
|
The design of subdivisions and land developments
should be done in a manner which would preserve desirable natural
and/or historic features of a site wherever reasonably possible. Included
in such features would be the following:
B. Historic structures or sites;
C. Trees six inches or more in caliper at chest height;
D. Woodlands, tree masses, hedgerows, or other significant
plant materials.
No topsoil shall be removed from the site or
used as spoil. Topsoil must be removed from the areas of construction
and stored separately. Upon completion of the construction, the topsoil
must be redistributed on the site uniformly. All areas of the site
shall be stabilized by seeding or planting on slopes of less than
10% and shall be stabilized by sodding on slopes 10% or more and planted
in ground cover on slopes 20% or more.
Items preserved under §§
147-41 and
147-42 above shall be protected during all phases of construction by fencing or other means from the effects of construction equipment operation, grading, and any other activity which could endanger the preserved items.
Applicants are encouraged to provide open space
for parks, playgrounds, recreational facilities, and other community
spaces. In commercial areas, space for walkways, malls, sitting areas,
or other community spaces are encouraged. Preservation of existing
natural amenities as part of these spaces should be considered by
the applicant.
The items listed below shall be designed, constructed,
developed, installed, inspected, and/or maintained in compliance with
the Borough's Engineering Standards, which standards are incorporated
by reference as a part of this chapter.
A. Street, driveway, and parking area paving;
B. Radii of pavement and right-of-way at intersections;
C. Driveways and parking areas on a lot serving a single
dwelling unit;
F. Stormwater runoff and other drainage facilities;
G. Utility locations, easements, and rights-of-way;
H. Sanitary sewers and on-site disposals;
J. Erosion and sediment control;
M. All other items related to subdivision and/or land
development for which it is reasonable and prudent to be included.
Applicants shall provide a reliable, safe, and
adequate water supply to support the intended uses approved as part
of a development plan.
A. If water is to be provided by means other than private
wells owned and maintained by the individual owners of lots within
the subdivision or development, applicants shall present evidence
to the Borough Council that the subdivision or development is to be
supplied by a certificated public utility, a bona fide cooperative
association of lot owners, or by a municipal corporation, authority,
or utility. A copy of a certificate of public convenience from the
Pennsylvania Public Utility Commission or an application for such
certificate, a cooperative agreement, or a commitment or agreement
to serve the area in question, whichever is appropriate, shall be
acceptable evidence.
B. If private wells, owned and maintained by the individual
owners of lots within the subdivision or development will be used,
applicants shall certify their adequacy, in writing, to the Borough
Council.
[Added 1-9-2003 by Ord. No. 316]
A. Purposes. In order to protect the health, safety,
and general welfare of the Schwenksville Borough residents by protecting
the surface and groundwater of Schwenksville Borough, the developer
shall construct and install drainage and stormwater management practices,
or shall modify the design of proposed improvements, to achieve the
following purposes:
(1)
Maintain the existing predevelopment water balance
in watersheds and subwatersheds containing first-order streams and
other sensitive streams in Schwenksville Borough, and to work to restore
natural hydrologic functions and habitat wherever possible throughout
the stream system.
(2)
Maintain the predevelopment volume of groundwater
recharge.
(3)
Maintain predevelopment runoff volumes, and
prevent a significant increase in surface runoff volumes, predevelopment
to postdevelopment, which could worsen flooding downstream in the
watershed, enlarge floodplains, erode streambanks, and create other
flood-related health-welfare-property losses.
(4)
Maintain or reduce predevelopment peak rates
of discharge, site by site, for specified reference storms, so flooding
at adjacent downstream sites does not worsen, and to work to reduce
peak runoff rates to natural level.
(5)
Manage stormwater impacts close to the source
of runoff, requiring a minimum of structures and maximizing the use
of natural processes.
(6)
Minimize non-point source pollutant loadings
to ground and surface waters throughout Schwenksville Borough.
(7)
Minimize impacts on stream temperatures.
B. Stormwater management plan.
(1)
All major and minor subdivisions and land developments
that disturb greater than 1,000 square feet shall submit a stormwater
management plan and report. The stormwater management plan and report
shall contain, but not be limited to, the following:
(a)
A suitable map of the total watershed (a united
States Geological Survey quadrangle map is sufficient) with predevelopment
(existing) and postdevelopment (proposed) areas outlined.
(b)
Suitable maps and drawings showing all existing
drainage facilities affecting the subject property.
(c)
A plan of the proposed stormwater drainage system
attributable to the subdivision or land development.
(d)
The design computations for the stormwater drainage
systems, including storm drainpipes, inlets, runoff-control measures
and culverts, drainage channels, and other best management practices.
(e)
A grading plan, including all areas of disturbance,
of the subject subdivision or land development.
(f)
A plan of the erosion and sedimentation procedures
to be utilized.
(g)
A plan of the storm-water drainage system, showing
all pipes, swales, channels, structures, detention basins, and other
best management practices shall be submitted as part of the stormwater
management plan. The drainage areas into each inlet or structure must
be delineated on the plan of the storm drainage system.
(h)
A maintenance plan consistent with the requirements of Subsection
G.
(i)
Delineate the pathways of all concentrated flow
(i.e., flow other than overland sheet flow).
C. Permanent stormwater management standards. All minor
and major subdivisions and land developments shall provide stormwater
controls designed and constructed to provide groundwater recharge,
water-quality treatment, and peak-flow attenuation in conformance
with the following:
(1)
Recharge requirement. In order to preserve predevelopment
levels of groundwater recharge and minimize the increased volumes
of stormwater discharging into local streams, structural best management
practices shall be implemented on site consistent with the following:
(a)
Structural best management practices, including
but not limited to permeable pavement, infiltration trenches, and
seepage beds shall be used to mitigate for the decreased levels of
groundwater recharge and the increased volumes of stormwater caused
by land disturbance and the creation of impervious surface.
(b)
Based upon the proposed area of land disturbance,
including impervious areas, and the underlying hydrologic soil grouping,
the following formula shall be used to determine the minimum volume
of water (acre-feet) to be intercepted and retained to infiltrate
on site:
|
Recharge Volume (acre-feet)=[(A*0.38)+(B*0.25)+C*0.13)+(D*0.06)]/12
|
|
Where:
|
|
A = disturbed acreage underlain by hydrologic
soil group "A"
|
|
B = disturbed acreage underlain by hydrologic
soil group "B"
|
|
C = disturbed acreage underlain by hydrologic
soil group "C"
|
|
D = disturbed acreage underlain by hydrologic
soil group "D"
|
|
Example: Existing 15 acre parcel with 6 acres
of disturbance on "B" soils and 3 acres of disturbance on "C" soils.
|
|
Recharge Volume =
[(0*0.38)+(6*0.25)+(3*0.13)+(0*0.06)]/12=0.158
acre feet
|
|
Therefore structural best management practices
need to be designed and constructed on site to intercept and retain
a minimum of 0.158 acre-feet of stormwater.
|
(2)
Recharge alternatives.
(a)
The Borough Council may determine, upon recommendation
of the Borough Engineer, that use of best management practices to
satisfy the recharge requirement is not possible due to site configuration,
existing soil, bedrock, water table, or other site conditions, or
may result in groundwater contamination due to existing or proposed
site activities.
(b)
In place of the recharge requirement, the peak rate standards of Subsection
C(4), below, shall be modified so that the postdevelopment peak rate of discharge from the site must be equal to or less than 75% of the predevelopment peak rate for all storms up to and including the ten-year storm.
(3)
Water quality requirement. In order to reduce
the water quality impacts of stormwater on receiving streams, nonstructural
(vegetative) best management practices and dry basin discharge controls
shall be utilized on site consistent with both of the following:
(a)
Nonstructural (vegetated) best management practices,
including but not limited to bioretention areas, filter strips, grass
swales, and riparian buffers, shall be used to mitigate the impacts
of stormwater from impervious areas on water quality. Based upon the
total site area and the underlying hydrologic soil grouping, the following
formula shall be used to determine the minimum percentage of impervious
area to be directed to and/or drained by nonstructural best management
practices:
|
Percent Area = (A * 38) + (B * 25) + (C * 13)
+ (D * 6)
|
|
Where:
|
|
A = percentage of site underlain by hydrologic
soil group "A"
|
|
B = percentage of site underlain by hydrologic
soil group "B"
|
|
C = percentage of site underlain by hydrologic
soil group "C"
|
|
D = percentage of site underlain by hydrologic
soil group "D"
|
|
Example: Existing 15-acre parcel with 40% of
the site underlain by "B" soils, 20% underlain by "C" soils, and 20%
of the site underlain by "D" soils.
|
|
Percent Area = (0 * 38)+(0.40 * 25)+(0.20 *
13)+(0.40 * 6) = 15%
|
|
Therefore a minimum of 15% of the site's proposed
impervious area shall be directed to and/or drained by nonstructural
best management practices.
|
(b)
The volume of stormwater for the one-year, twenty-four-hour
design storm (rainfall depth equals 2.7 inches), generated by areas
of impervious surface not directed to structural or nonstructural
best management practices, shall be controlled so that the one-year
storm takes 24 hours to drain from the facility from a point where
the maximum volume of water captured by the facility for the one-year
storm is achieved (i.e., the maximum water surface elevation achieved
in the facility).
(4)
Peak flow attenuation. Following compliance
with the recharge and water quality requirements, peak flow from the
proposed development shall be attenuated consistent with the following
requirements:
(a)
The peak rate of stormwater discharge from the
site for the following design storms shall not exceed the peak discharge
from the site of the same storm before proposed development:
|
Design Storm
|
Inches of Precipitation
|
---|
|
2-year, 24-hour storm
|
3.3
|
|
5-year, 24-hour storm
|
4.2
|
|
10-year, 24-hour storm
|
5.0
|
|
25-year, 24-hour storm
|
5.8
|
|
50-year, 24-hour storm
|
6.4
|
|
100-year, 24-hour storm
|
7.2
|
(b)
To reduce the need for large wet and/or dry ponds to satisfy the peak-flow attenuation requirements, the impact of structural and nonstructural best management practices implemented to meet the requirements of Subsection
C(1),
(2) and
(3) and is may be considered when designing the facility(s) to satisfy the peak flow attenuation requirement to reflect the volume of runoff being infiltrated and/or increased times of concentration.
D. Stormwater management calculation methods.
(1)
The following assumptions shall apply for runoff
calculations:
(a)
Average antecedent moisture conditions.
(b)
A Type II distribution storm.
(c)
Meadow in good condition shall be used in predevelopment
runoff calculations for all areas, including areas of existing cultivation
and/or impervious surface, except woodlands. Woodland in good condition
may be used for all wooded areas.
(d)
In performing the stormwater calculations, all
those areas to be disturbed during construction and subsequently returned
to open space will be assumed to be reduced one hydrologic soil group
category level for postdevelopment runoff calculations (i.e., Hydrologic
Soil Group B is reduced to Hydrologic Soil Group C and so forth).
(e)
Where applicable, postdevelopment time of concentration
to a dry basin shall be the time of concentration to the point of
discharge into the basin. Overland flow from the discharge point to
the outlet structure shall not be included in the time of concentration.
(f)
The postdevelopment sheet flow length shall
be 150 feet, unless a shorter length is required. The maximum postdevelopment
sheet flow length for unpaved surfaces shall be 100 feet for most
situations (150 feet for areas which will remain undisturbed). Use
of maximum flow lengths shall be justified and all flow lengths are
subject to approval by the Borough.
(2)
In all plans and designs for stormwater management
systems and facilities submitted to the Borough Engineer for approval,
stormwater peak discharge and runoff shall be determined through the
use of the Soil Cover Complex Method as set forth in Urban Hydrology
for Small Watersheds, Technical Release No. 55, with specific attention
given to antecedent moisture conditions, flood routing, time of concentration,
and peak discharge specifications included therein and in Hydrology
National Engineering Handbook, Section 4, both by the United States
Department of Agriculture, Natural Resources Conservation Service.
Note that use of TR-55 with many of the natural system-based approaches
and practices encouraged herein requires that calculations be performed
on a detailed small subarea basis. The Borough Engineer may permit
the use of the Rational Method for calculation of runoff on land developments
of 10 acres or less and for the design of stormwater conveyance structures.
E. Design standards for best management practices. The
Pennsylvania Handbook of Best Management Practices for Developing
Areas (1998) shall serve as a design guide for structural and nonstructural
best management practices. Additional design guidance may also be
obtained from other related references prepared by the U.S. Environmental
Protection Agency, the Washington Metropolitan Council of Governments,
the Natural Resource Conservation Service, and the Pennsylvania Department
of Environmental Protection. In addition to the design requirements
included in the above documents, the following minimum design standards
shall be required for the following best management practices:
(1)
Infiltration trenches and dry wells shall meet
the following minimum design standards:
(a)
The lowest elevation of the infiltration area
shall be at least two feet above the seasonal high water table and
bedrock.
(b)
The infiltration system shall have positive
overflow controls to prevent storage within one foot of the finished
surface or grade.
(c)
The infiltration system shall be set back at
least 15 feet from all structures with subgrade elements (i.e., basements).
(d)
Infiltration systems shall be designed to infiltrate
the stored volume in 24 hours or less.
(e)
Infiltration rates shall not be used in computing
the storage volume of the infiltration system.
(f)
Surface inflows shall be designed to prevent
direct discharge of sediment into the infiltration system.
(2)
Dry basins shall be naturalized consistent with
the following minimum design standards:
(a)
Minimum grades inside the basin shall be 2%,
and the maximum side slopes shall be 25% (four units horizontal to
one unit vertical).
(b)
Inlet structures and outlet structures shall
be separated to the greatest extent possible in order to maximize
the flow path through the basin. The minimum flow path length for
at least half (50%) the volume of water directed through the basin
shall be calculated using the following formula:
|
|
|
where:
|
|
L = Minimum flow path length
|
|
a = Surface area of the basin in square feet
at the lowest orifice
|
(c)
To create a more free-form and curvilinear basin
so that from most edges of the basin the whole basin will not be in
view, the total perimeter length of the basin shall be increased so
that it is greater than or equal to the length derived by the following
formula:
|
|
|
where:
|
|
P = Minimum basin perimeter length required
|
|
a = Surface area of the basin in square feet
at the lowest orifice
|
|
The Borough Council, upon recommendation of
the Borough Engineer, may permit a more traditionally shaped (oval
or rectangular) basin(s) when conditions, such as topography, parcel
size, or other site conditions warrant. When permitted, the basin(s)
shall be designed in consultation with the Borough Engineer to include
a landscaped island or peninsula large enough and appropriately placed
to reduce the perceived size of the basin.
|
(d)
Basins shall be landscaped in accordance with the requirements of §
147-39.
(e)
Inlet structures. The invert of the inlet pipe
into a basin shall be six inches above the basin floor or lining so
that the pipe can adequately drain after rain storms. Inlets shall
discharge into areas of the basin that slope toward the outlet structure.
(f)
Outlet structures. To minimize clogging and
to facilitate cleaning, outlet pipes shall have an internal diameter
of at least 18 inches and a minimum grade of 1%. Anti-seep collars
shall be located on all outlet pipes. All principal outlet structures
shall be built with reinforced concrete with watertight construction
joints. The use of architecturally treated concrete, stucco, painted
surface or stone facade treatment for enhancing the outlet structure
shall be required. Outlet pipes shall be constructed of reinforced
concrete with rubber gaskets in conformance with AASHTO M170, M198
and M207. Childproof trash racks or antivortex devices should be constructed
at all outlets and designed to facilitate cleaning and avoid clogging
caused by debris.
(g)
Emergency spillways shall be sized and located
to permit the safe passage of the postdevelopment peak discharge from
the one-hundred-year-frequency storm flowing into the basin. The maximum
velocities in vegetated spillways excavated in undisturbed soil shall
be checked, based upon the velocity of peak flow in the emergency
spillway during an assumed clogged primary outlet condition. Where
maximum velocities exceed design standards contained in the Engineering
Field Manual for Conservation Practices, (U.S. Natural Resource Conservation
Service) suitable lining shall be provided. All emergency spillways
placed on fill materials shall be lined. Lining for emergency spillways
shall incorporate native colors and materials where possible, including
mono-slab revetments, grass pavers and native stone.
(h)
Freeboard. Freeboard is the difference between
the design flow elevations in the emergency spillway and the top of
the settled basin embankment. The minimum, freeboard shall be two
feet.
(i)
A key trench shall be provided for the basin
berm which extends two feet into undisturbed soil, has top width of
six feet and side slopes of one to one.
(j)
A clay core shall be provided for the basin
berm which has a top elevation at the twenty-five-year water surface
elevation, a minimum of four feet wide with one-to-one side slopes.
(k)
Energy dissipators and level spreaders. Energy
dissipators and/or level spreaders shall be installed to prevent erosion
and/or initiate sheet flow at points where pipes or drainageways discharge
to or from basins. Energy dissipators shall comply with criteria in
Hydraulic Engineering Circular No. 15-Design for Stable Channels with
Flexible Linings, published by the Federal Highway Administration
of the U.S. Department of Transportation, or the Engineering Field
Manual for Conservation Practices, Natural Resource Conservation Service.
Native rock should be used in constructing dissipators where practical.
(l)
Stabilization. Proper stabilization structures,
including stilling basins, energy dissipators, and channel lining,
shall be constructed at the outlets of all basins and emergency spillways.
The stabilization structures should control water to avoid erosion,
reduce velocities of released water and direct water so that it does
not interfere with downstream activities.
(m)
Basin setback. All basins shall be constructed
in conformance with the setback requirements of the underlying zoning
district for principal structures, as measured from the top of the
berm elevation, provided the basin is set back a minimum of 20 feet
from all existing and proposed structures, including porches, stairs,
and decks. The setback distance may be adjusted at the discretion
of the Borough Engineer based upon factors such as topography, soil
conditions, and the location of structures.
(3)
Wet basins. Existing ponds or permanent pool
basins can be used, provided they meet the following requirements:
(a)
A report, prepared by a biologist, ecologist,
or similarly qualified professional, shall be submitted to the Borough
for review that evaluates the design of the proposed wet basin's ability
to meet the following criteria:
[1]
The minimum permanent pool level to be maintained
shall allow sufficient depth throughout the year to reduce the growth
of unwanted vegetation and mosquitoes.
[2]
The pond is of sufficient size to allow the
appropriate aquatic community needed to maintain a healthy pond ecology.
[3]
The design of a wet basin shall include the
determination of the proposed site's ability to support a viable permanent
pool. The design should take into account such factors as the required
rate and quality of dry weather inflow, the quality of stormwater
inflow, seasonal and longer-term variations in groundwater table,
and effects of suspected pollutant loadings. The Pennsylvania Fish
Commission and Natural Resource Conservation Service should be consulted
during the design of these facilities.
(b)
Emergency spillways shall be sized and located
to permit the safe passage of stormwater flows from a one-hundred-year
storm. The maximum velocities in vegetated spillways excavated in
undisturbed soil shall be checked based upon the velocity of peak
flow in the emergency spillway during an assumed clogged primary outlet
condition. Where maximum velocities exceed design standards contained
in the Engineering Field Manual for Conservation Practices (U.S. Natural
Resource Conservation Service), suitable lining shall be provided.
All emergency spillways placed on fill materials shall be lined. Lining
for emergency spillways shall incorporate native colors and materials
where possible, including mono-slab revetments, grass pavers and native
stone.
(c)
An outlet structure shall be designed to allow
complete drainage of the pond for maintenance.
(4)
Underground detention facilities shall meet
the following minimum design standards:
(a)
Underground detention facilities shall only
be placed below traffic and parking areas and designed to be heavy
duty and structurally capable of withstanding highway H-20 loading
or the heaviest Fire Department vehicle, whichever is greater.
(b)
Underground chambers or pipes shall be aligned
parallel to the contours.
(c)
The water quality requirements of Subsection
C(3) shall apply to underground detention facilities.
(d)
Access to the underground detention facilities
shall be provided for maintenance personnel.
(e)
The underground detention facilities shall be
designed to include overflow controls that either divert runoff via
a flow splitter placed at the facility entrance or an overflow weir/orifice
system designed in conjunction with the outlet of the facility.
(5)
Grass swales shall meet the following minimum
design standards:
(a)
Swales shall be designed in accordance with the requirements of Subsection
F(4)(a).
(b)
The bottom of the grass swale shall be two feet
minimum and six feet maximum with side slopes of three to one or flatter.
(c)
Swales within and outside street rights-of-way
shall be designed to carry the design storm with three inches of freeboard.
(d)
Swales to be used to convey runoff outside of
the street right-of-way shall be the trapezoidal type.
(e)
Swales shall not be used in street rights-of-way
where curbing is to be installed. Stormwater conveyance shall be via
storm sewer in these cases.
(f)
Swages shall not be used to convey stormwater
within a street right-of-way on slopes exceeding 8%. In these cases,
storm sewer shall be used.
(g)
Grass swages proposed to satisfy the water quality requirements of Subsection
C(3) shall be designed consistent with the following:
[1]
The maximum flow velocity in the grass swale
for runoff from the water quality design storm (one-year, twenty-four-hour)
shall not exceed 1.5 feet per second (fps).
[2]
The average slope of the grass swale shall not
exceed 4%.
F. Storm sewers and drainageways.
(1)
General provisions. All storm drains and drainage
facilities, such as gutters, catch basins, bridges, inlets, and culverts,
shall be installed and the land graded for adequate drainage as shown
on the grading plan submitted and approved with the final plan. Construction
of these facilities shall generally conform with PennDOT Specifications
Publication 408, latest version.
(2)
When required. Storm drains and appurtenances
shall be required to be constructed by the subdivider to take surface
water from the bottom of vertical grades to lead water away from springs,
and to avoid excessive use of cross gutters at street intersections
and elsewhere.
(a)
Natural watercourses shall not be disturbed.
(b)
Surface water shall be conveyed to the nearest
adequate storm drain, detention basin, natural watercourse, or drainage
facility.
(c)
Stormwater runoff shall discharge to an existing
watercourse with defined bed and bank or an existing storm drain system.
It shall not be concentrated onto adjacent properties nor shall the
velocity of flow be increased beyond that existing prior to subdivision,
land development or the commencement of land disturbance activities
unless written approval is given by the adjacent property owners to
the proposed discharge of surface runoff and the written agreements
are approved by the Borough.
(d)
Open watercourses will be permitted where they
exist naturally and where, in the opinion of the Borough Engineer,
they will not interfere with public convenience or safety but in fact
will provide comparable or superior drainage capabilities of piped
drainage. Where necessary, stream corridor improvements, including
rock stabilization and gabions, shall be performed.
(e)
When submitting a plan for approval involving
the construction of storm drainage facilities, the designer's computations
shall be submitted in duplicate to facilitate the checking of design.
(f)
Design of storm drainage facilities shall be
completed in accordance with accepted engineering practices, subject
to approval by the Borough Engineer.
(g)
where practical, inlets shall be situated in
grassed swales or depressions.
(h)
Inlets in road curbs shall incorporate grit
chambers.
(3)
Location. Wherever practicable, storm sewers
shall be located within the right-of-way of the street. They shall
be protected by a cover of at least 18 inches.
(4)
Size and grade.
(a)
Storm sewer system shall be designed to carry
the one-hundred-year stormwater runoff, which shall be determined
using the Rational Method. The following coefficients are to be used
for design.
|
Ground Cover
|
Coefficient (C)
|
---|
|
Impervious
|
0.95
|
|
Lawn/Grass/Open Space
|
0.35*
|
|
* This coefficient may be reduced to 0.25 for
a ground cover of woods located off site or within reserved open space
only.
|
|
All other design criteria shall be in accordance with the Pennsylvania Department of Transportation Design Manual 2, Chapter 10.
|
(b)
Storm sewers shall have a minimum internal diameter
of 15 inches and a minimum grade of 0.5% (1/2 of 1%) unless otherwise
approved by the Borough Engineer. Maximum internal pipe diameter shall
be 60 inches. Special box culverts or open channels shall be used
when a sixty-inch pipe is not capable of carrying the design storm.
Open channels will not be permitted where a conduit equal to or less
than 60 inches in diameter can be constructed.
(5)
Storm drainage pipe materials. All storm drainage
pipes up to but not including 42 inches in equivalent diameter shall
be constructed of the following materials:
(a)
Reinforced concrete, rubber gasketed, conforming
to AASHTO M170, M198 and M207.
(b)
Reinforced concrete, tongue and groove, conforming
to AASHTO M170 and M207.
(c)
Corrugated polyethylene (PE) N12, smooth interior
only, conforming to ASTM D1248, ASTM D2412, AASHTO M252 and 294. A
PE pipe shall be placed on a minimum of six inches of AASHTO #57 stone
and backfilled with same to a foot above the crown of the pipe.
(d)
Corrugated polyethylene (PE) perforated underdrain
shall conform to AASHTO M252.
(6)
All storm drainage pipe and/or culverts 42 inches
in equivalent diameter and above shall be constructed of any of the
following materials:
(a)
Reinforced concrete, tongue and groove, conforming
to AASHTO M170 and M207.
(b)
Reinforced concrete piping, rubber gasketed,
shall conform to AASHTO M170, M198 and M207.
(c)
Precasted reinforced concrete box sections in
accordance with AASHTO M259.
(d)
Cement concrete, cast in place, mix design strength
of 4,000 psi
(7)
All storm sewer is to be installed in straight
alignments. Curved storm sewer sections are not acceptable.
(8)
Roof drainage from all multifamily and nonresidential
buildings shall be conveyed from roof downspouts through an underground
roof drain, which shall outlet into a storm sewer system, stormwater
management basin or natural watercourse.
(9)
Underdrains shall be used at all areas as directed
by the Borough Engineer for the purpose of eliminating soft spots
and springs within the roadway.
(10)
Manholes. Manholes shall be constructed at all
changes in horizontal or vertical alignment; shall be spaced not more
than 300 feet apart on pipe of 24 inches internal diameter or less,
and not more than 450 feet apart where larger sizes are installed.
Inlets may be substituted for manholes where they will serve a useful
purpose. Manhole frames and covers shall be good quality cast iron;
covers shall be marked "STORM" and have a minimum weight of 220 pounds.
(11)
Inlets. Inlet spacing shall be so arranged that
95% of the gutter flow associated with the ten-year, twenty-four-hour
storm will be captured. No inlet smaller than PennDOT Type 4 Foot
Special Inlet shall be used. Double four-foot or six-foot inlets separated
by 20 linear feet of pipe shall be required if adequate efficiency
is not realized with the PennDOT Type 4 Foot Special Inlet. Inlets
at street intersections shall be placed on the tangent and not on
the curved portions. The gutter adjacent to and immediately upgrade
from the inlet shall be so warped as to direct the water into the
inlet.
(12)
Headwalls, endwalls, flared endsections and
similar structures.
(a)
Such structures shall conform to PennDOT standards.
(b)
A11 stormwater pipe discharge locations shall
be fitted with one of the structures.
(13)
Castings. Manhole and inlet castings, together
with their covers or gratings, shall conform to PennDOT or Borough
standards as may be in effect at the time the design of the sewer
is submitted.
(14)
Unnatural drainage. Wherever construction stops
or concentrates the natural flow of storm drainage in such a way to
adjoining properties, approval of the owners shall be obtained in
writing and a copy filed with the Borough. Approval of plans by the
Borough Council does not authorize or sanction drainage affecting
adjoining properties.
(15)
Drainage from non-natural sources. Water originating
from other than natural sources, such as air-conditioning units, sump
pumps, or other dry weather flow, wherever practicable, shall be discharged
into natural watercourses on the property. The discharge of water
under the sidewalk through the curb into the gutter is prohibited.
(16)
Design criteria:
(a)
Minimum internal pipe diameter shall be 15 inches.
(b)
Permissible channel velocities, slopes, and
cover shall be in accordance with the Natural Resource Conservation
Service Engineering Field Manual, Chapter 7, "Grassed Waterways and
Outlets."
(c)
Existing stream channels shall be maintained
in their natural state. Only under unusual circumstances will it be
permitted to line, straighten, or relocate an existing stream, with
approval of the Department of Environmental Protection (DEP) and the
Montgomery County Conservation District.
(d)
Acceptable energy-dissipation devices shall
be installed to bring discharge velocities down to limits specified
in the Natural Resource Conservation Service Engineering Field Manual,
Chapter 7. Rip-rapping and/or gabions may be required by the Borough
Engineer where erosion potential is great.
(e)
Where open-ended influent pipes cannot be avoided,
safety facilities shall be constructed, acceptable to the Borough
Engineer, such as a debris structure utilizing a six-inch-by-six-inch
rebar grid.
G. Maintenance responsibilities.
(1)
General responsibilities:
(a)
The owner of stormwater management facilities
shall be responsible for their proper maintenance during and after
development. A maintenance plan shall be prepared for review and approval
by the Borough Engineer and shall be executed and signed by the Borough
Engineer and applicant.
(b)
On or before completion of subdivision or land
development improvements, the permanent stormwater management system
for a tract shall be fully installed and functional in accordance
with the approved stormwater management plan. Temporary sediment-trapping
facilities in detention basins upon inspection and approval by the
Borough Engineer shall be converted into permanent stormwater management
basins; additional facilities designed to serve more than an individual
lot shall begin operation. All such work shall be specified in the
approved stormwater management plan.
(2)
Stormwater management facilities ownership and
maintenance. All stormwater management facilities identified within
an approved stormwater management plan shall be owned and maintained
by one, or a combination, of the following entities:
(a)
Individual lot stormwater facilities. Stormwater
management facilities and systems that are located on an individual
lot are the responsibility of that landowner to maintain. All deeds
shall incorporate the maintenance responsibilities specified in the
approved maintenance plan, making explicit individual owners' responsibilities
for stormwater management measures and for the common property.
(b)
Homeowners' or condominium association ownership
(other than stormwater facilities located on individually owned lots).
A single entity taking the form of a private corporation, partnership
firm, estate or other legal entity empowered to own real estate exclusive
of individual lot owners shall be set up to manage stormwater management
facilities that are suitable for such management and perform other
functions defined in this section. Maintenance responsibilities specified
in the approved maintenance plan should be referenced on the plan
and recorded into lot deeds, homeowners' or condominium association
articles of incorporation, or some other permanent legal document.
(c)
Municipal ownership. Where Schwenksville Borough
has accepted an offer of dedication of the permanent stormwater management
facilities, the Borough shall be responsible for maintenance. Borough
ownership notwithstanding, the applicant is required to prepare a
stormwater management plan including a maintenance component, as defined
above. Upon approval of the stormwater management facilities by the
Borough Council, the applicant shall provide a financial security,
in a form approved by the Borough Solicitor, for maintenance guarantees,
as follows:
[1]
Long-term maintenance bond. The long-term maintenance
bond shall be in any amount equal to the present worth of maintenance
cost for the facilities for a ten-year period. The estimated annual
maintenance cost for the facilities shall be based on a reasonable
fee schedule provided by the Borough Engineer and adopted by the Borough
Council.
[2]
Documentation. The terms of the maintenance
guarantees shall be documented as part of the stormwater management
plan and the maintenance plan subpart.
(3)
Maintenance plan. A maintenance plan shall be
prepared to identify the ownership and maintenance responsibilities
for all stormwater management facilities. At a minimum the maintenance
plan shall include the following:
(a)
Any obligations concerning perpetuation and/or
maintenance of natural drainage or infiltration facilities, and other
facilities identified within the stormwater management plan.
(b)
A description of the facilities and systems
on the lot, as called for above, setting forth in deed restrictions
binding on the landowner's successors in interest.
(c)
Assurances that no action will be taken by any
lot owner to disrupt or in any way impair the effectiveness of any
stormwater management system, setting forth in deed restrictions the
ability of the Borough to take corrective measures if it is determined
at any time that stipulated permanent stormwater management facilities
have been eliminated, altered, or improperly maintained, including
the ability of the Borough to cause the work to be done and lien all
costs against the property should the required corrective measures
not be taken by the lot owner within a period of time set by the Borough
Engineer.