The following principles, standards, and design requirements shall be used in the evaluation of all subdivision and land development proposals. Other design requirements as established in Chapter 155, Zoning, or other chapters shall be used in addition to the following:
A.
All portions of a tract shall be designated as to its use, such as
lots, roads, open space, parking areas, etc.
(1)
Developers shall include the following in the subdivision or
land development design:
(a)
Provision of adequate rights-of-way and improvements.
(b)
Easements for storm and sanitary sewer facilities in those areas
that cannot be immediately joined to the existing storm and sanitary
sewer systems of the Township.
(c)
When required by the Board of Commissioners, reservation of
areas and easements for pedestrian access, bikeways and/or bridle
trails appropriate to the proposed subdivision or land development.
(2)
Community facilities shall be considered in the approval of
subdivision and land development plans. Areas reserved for such facilities
should be adequate to serve the additional dwellings or other buildings
contemplated by the subdivision or land development.
B.
Developments shall preserve scenic areas and historic viewsheds,
open spaces, historic sites and structures, natural features of the
land and other community assets.
(1)
Preservation of natural features. Every subdivision or land
development plan shall be designed to preserve and protect the natural
features of the land, including existing grades and contours, bodies
of water and watercourses, large trees standing alone or in groves,
shade trees and specimen trees, scenic and historic points, pedestrian
walks and bridle trails that have been in public use and other community
assets.
(b)
Development and disturbance of floodplain land areas shall be governed by additional standards contained in this chapter, Chapter 155, Zoning, and the applicable building codes.
(c)
The burden shall be on the developer to justify any material
changes in the natural features of the land by satisfactory proofs
that subdivision or land development would not be feasible without
such changes and that there are no practical alternatives. The fact
that subdivision or land development would involve greater expense
or less density because of the maintenance of certain natural features
will not in and of itself be considered a justification for changes
in such features.
(2)
Preservation of historic resources. Every subdivision or land
development plan shall be designed to preserve and protect historic
sites, viewsheds, and structures. The burden shall be on the developer
to justify any material changes in historic sites and structures by
satisfactory proof that subdivision or land development would not
be feasible without such changes and that there are no practical alternatives
which would permit the preservation of the historical nature of the
property. The fact that subdivision or land development would involve
greater expense or less density because of the maintenance of historic
sites and structures will not in and of itself be considered a justification
for material changes or alterations to such historic sites or structures.
(3)
Preservation of the community. To protect and maintain noise
level quality, open space, aesthetic quality and the social and economic
stability of all parts of the Township and to coordinate subdivision
and land development with existing nearby neighborhoods, the Board
of Commissioners may impose reasonable buffer requirements beyond
that what is otherwise required in order to accomplish the following
with respect to the proposed subdivision or land development:
C.
The improvements shall be constructed, installed, and guaranteed,
at no expense to the Township, as part of plan approval, including,
but not limited to, traffic controls, streets, curbs, sidewalks, water
and sewage facilities, stormwater management facilities, streetlights,
fire hydrants, road signs, monuments, lot pins, utilities, and shade
trees.
D.
The standards contained within this article are the minimum standards
and requirements for the protection of the health, safety, and welfare
of the residents of the Township and are to be used in all subdivisions
and land developments. In addition, the Township reserves the right
to require standards in excess of the minimum requirements if warranted
to protect the health, safety, and general welfare of the community.
A.
All subdivisions and land developments shall conform to the Official
Highway Map, the design standards set forth in this article and all
other pertinent sections of this Code.
(1)
The construction specifications for all improvements shall be
those contained in the Lower Merion Standards and Specifications for
Improvement Construction.
(2)
Where literal compliance with the standards herein specified
is impractical, the Board of Commissioners may modify or adjust the
standards to permit reasonable utilization of property while at the
same time securing substantial conformance with the objectives of
this article.
B.
Comprehensive Plans. Proposals for land development or subdivision
shall be generally consistent with the Township's Comprehensive Plan,
especially as to the use of land, intensity of development, transportation,
community facilities, and resource protection. Residential development
should also be consistent with the housing element of the plan. All
proposals should be located in areas designated for development in
the future land use plan element and be serviced by currently available
infrastructure or infrastructure that will be developed concurrent
with the development.
C.
Other plans. Proposals shall be generally consistent with the appropriate
state, regional, county, and the adopted Comprehensive Plan and other
plans. Where regional facilities are proposed in the plan, such as
highways, efforts shall be made to preserve needed rights-of-way for
future infrastructure projects in the proposed land development or
subdivision.
D.
Public service improvements. Proposals shall be consistent with the
location and timing of public service improvements, such as water
and sewage facilities, in accordance with the appropriate infrastructure
plans governing those facilities. In addition, the location of public
service facilities as outlined in a capital improvement program or
official map should be considered.
Proposed land developments and subdivisions shall be designed
to address the opportunities and limitations present on a site and
its adjacent surroundings. The plan shall use site opportunities to
enhance the overall quality of the development and lessen potential
negative impacts upon a site and the surrounding community. The physical,
social, and psychological needs of the users of the site should be
evaluated and appropriately incorporated into the final subdivision
layout or site design. The impacts of the proposed development on
the natural environment and surrounding land uses shall be given a
high priority and made an integral part of the overall design for
the land development and subdivision. The following site organization
guidelines shall be used:
A.
Site improvement layout. The buildings shall be placed in consideration
with the site's topography, existing vegetation, and surrounding land
uses, taking into account energy conservation, solar access, and pertinent
natural features.
B.
Existing natural features. Existing natural features should be recognized
and integrated into the site layout. Natural features, such as streams,
hillsides, wetlands, unique habitats, woodlands, and similar natural
resources should be considered strong design determinants and be incorporated
into the overall site plan to strengthen the unique quality of the
land.
C.
Open space and scenic views. The placement of open space and preservation
of scenic views should be a fundamental design decision. Open space
lands should provide for a variety of benefits, including recreation,
natural resource protection, scenic views and vistas, and buffers
for site elements and land uses.
D.
Circulation. Movement within a site and access to the site should
be designed for the safety and convenience of various types of users.
Cross access between properties and joint access are encouraged to
improve circulation and improve access safety.
E.
Relationship to surrounding uses. The proposed design should complement
appropriate surrounding uses through building setbacks, buffers, and
separation of uses. Various potential negative impacts upon surrounding
land uses including noise, light, and loss of privacy should be mitigated.
F.
Sustainable development. The development of a site should use methods
that reduce energy, water, and greenhouse gas emissions of the property.
Opportunities to utilize renewable energy sources, conserve and reuse
water resources, and reduce greenhouse gas emissions fuel consumption
should be considered. In addition, the development should use materials
that reduce embodied carbon and use life-cycle assessments and make
use of renewable energy sources for electricity.
G.
Health hazards. The configuration of a subdivision or land development
should reduce risk or hazards to health, safety and well-being of
future users of the subdivision or land development and to the community
as a whole.
H.
Concept development plan. Where an applicant seeks approval for the
development of a portion of a tract with the intent that the remainder
would be developed at a future date, the applicant shall submit with
the initial application a concept development plan showing with specificity
the portion of the tract intended for current development, and showing
in concept form the manner in which the balance of the tract might
be fully developed in conformance with Township regulations.
(1)
The intent of such a submittal is to enable the Township to
review the basic site design concept, to advise the applicant as to
potential problems and concerns that full development of the site
would entail, and to assure that the current development of the property
properly anticipates the future development with respect to land use,
traffic movement, parking, building placement, required infrastructure,
and impact on abutting properties, when proper planning techniques
are applied.
(2)
The concept development plan must present a comprehensive overview
of potential uses to which the property can be put in conformance
with current Township codes. The failure to present such a plan, unless
waived by the Board of Commissioners, shall constitute a separate
and distinct basis for denying a subdivision and/or land development
plan application.
A.
Lot size and width. Each lot shall comply with the minimum area and width requirements of Chapter 155, Zoning, and be generally sufficient in size and shape to adequately accommodate the development or use proposed for it.
(1)
Lots that contain natural features, such as wetlands, water
bodies, steep slopes, or other features, shall be made large enough
to provide suitable area for the intended use of the lot without requiring
encroachment upon natural features.
(2)
Lots with existing or planned public improvements such as fuel
pipelines, underground utility easements, stormwater detention basins,
high voltage power lines, or other facilities should be sized to allow
suitable room for the intended use of the lot without requiring encroachment
on the public facilities or easements.
B.
Lot depth, side lines and irregular configuration.
(1)
A lot may not be created whose depth is greater than 2.5 times
its width.
(2)
A lot may not be created which is excessively irregular unless
reasonably dictated by the topography of the land, other natural feature,
or the existing configuration of an adjacent lot. An excessively irregular
lot is one which is not four-sided or which has a boundary line the
length of which is more than 2.5 times the length of the opposite
or adjacent boundary line.
(3)
The side lines of a lot shall be at right angles or radial to
the right-of-way lines.
C.
Narrow lots may be created only when authorized by the Board of Commissioners as a conditional use under the provisions of § 155-3.13A of the Code of the Township of Lower Merion.
D.
No lot shall be approved for a subdivision where any of the following
conditions apply:
E.
All lots must conform to the zoning district requirements applicable
to the parcel being subdivided.
F.
Survey monuments. All subdivisions and land development shall be
monumented as directed by the Township Engineer. Permanent survey
monuments shall be of stone or concrete and located on the right-of-way
lines at corners, at angle points and as otherwise required. Monuments
shall be indicated on all plans. They shall be placed after a new
street has been completed. The center line of all new streets shall
be marked with spikes and referenced to permanent monuments or structures.
G.
Bench marks. The Township has established a system of 150 bench marks
giving elevation throughout the area based on the National Geodetic
Vertical Datum of 1929 (NGVD29). Information as to location and elevations
of these bench marks is available upon request made to the Lower Merion
Department of Public Works. All contours and elevations shown on plans
must be based on this system.
H.
Adjacent lots owned by the same person may be consolidated by recording
a deed describing the lots as a single parcel, without subdivision
plan approval, where the only change being made to a lot line is the
elimination of one or more of them, subject to administrative review
by the Building and Planning Department. This exemption from the approval
procedures set forth in this chapter shall be subject to the following:
(1)
A statement must be placed in the deed acknowledging that it
is a deed of consolidation intended to merge the lots and that any
future independent use of the lots would require subdivision approval.
(2)
The application to register the deed shall constitute an application
to amend the Township's plan of properties to show the consolidation.
(3)
Prior to registering such deed, the Director of Building and
Planning shall notify the Zoning Officer of the consolidation.
(4)
Each deed submitted for registration and recording shall have
attached thereto a plan prepared, signed and sealed by a registered
surveyor showing the metes and bounds, gross and net (after deducting
the rights-of-way of any public or private street) areas and error
of closure of the consolidated lot. The error of closure shall not
be greater than one part in 5,000.
(5)
Upon merger by deed, use or subdivision approval, adjacent lots
shall lose their separate identity for all purposes relating to their
development.
B.
Public gathering space (PGS). When used as an incentive in Chapter 155 Zoning, the following standards apply:
(1)
Dimensions and placement.
(a)
Location.
[1]
The PGS shall be integral to the development and designed as
a focal point.
[2]
The PGS shall be generally regular in shape, be oriented towards
the street line or pedestrianway, and easily and directly accessible
from adjoining buildings and pedestrianways.
[3]
The PGS shall be entirely open to the air, and no portion of
a building, other than a balcony, shall project over the PGS.
[4]
The PGS shall not be used for parking, loading, or motor vehicle
access.
[5]
If the development includes commercial uses, such uses shall
be directly connected to the PGS.
[6]
The PGS shall not contain areas set aside for stormwater/sanitary
facilities and other aboveground utilities.
(b)
All contiguous PGS areas on a property shall be considered as
one PGS.
(c)
The maximum number of separate PGSs on any lot is three.
(2)
Access.
(a)
Public easement. The PGS, when approved, shall be permanently
set aside as such by a recorded covenant in a form acceptable to the
Township Solicitor to guarantee public access to the PGS.
(b)
Sidewalk frontage zone. To facilitate pedestrian access to a
PGS the following shall apply to the area of the PGS located within
15 feet of a street line or pedestrianway, as illustrated in Figure
4.6.2, Sidewalk Frontage Zone.
|
Figure 4.6.2
Sidewalk Frontage Zone
 |
[1]
At least 50% of such area shall be free of obstructions.
[2]
Only the following obstructions shall be allowed in the remaining
50% of such area: public space signage, railings for steps, trash
receptacles, trees and fixed or movable seating and tables, bicycle
racks planting walls or trellises, knee walls, water features and
artwork. Shade structures or trellises may be roofed with solar panels.
(c)
Grade. The PGS shall be located at the same level of adjoining
sidewalks, pedestrianways and streets. Minor changes in elevation
shall be permitted where a PGS fronts on streets with slopes greater
than 2.5% along the frontage.
(d)
Obstructions.
[1]
No exhaust vents or mechanical equipment is permitted on any
PGS or on any building wall fronting upon the PGS, unless separated
from it by a barrier sufficient to substantially, visually and audibly,
conceal the audio and visual effects of its presence and operation.
[2]
Air intake vents or shafts shall be permitted within a PGS,
provided that such vents are concealed from public view by planting
or other design features and that such vents do not impair visibility
within the PGS area.
(e)
The PGS shall be open to the public whenever the development
is open to the public. An hours of access plaque or sign shall be
visible from a public way indicating the hours of public access to
the PGS.
(3)
Amenities.
(a)
Seating.
[1]
Standards for seating within the PGS are intended to facilitate
the provision of abundant, comfortable and accessible seating throughout
the PGS, including, more specifically, as follows:
[a]
To provide a broad variety of seating types and
configurations;
[b]
To accommodate individual users engaged in solitary
activities, as well as groups engaged in social activities;
[c]
To provide a comfortable and safe seating surface
by providing smooth, even and level surfaces with rounded edges;
[d]
To incorporate, to the maximum extent possible,
a combination of fixed benches, movable chairs, seating with backs,
seat walls and ledges, and seating steps; and
[e]
To provide ample opportunity for social seating
as a basic seating type that consists of seats that are placed in
close proximity and at angles to one another or in facing configurations
that facilitate social interaction.
(b)
Shade. The PGS shall provide shade where seating is provided
by using one or more of the following elements: canopies, trellises,
plantings, and umbrellas.
(c)
Trees and plantings. The provisions of this section are intended
to facilitate a combination of landscaping elements in order to provide
comfort, shade and textural variety.
[1]
A maximum of 30% of the PGS shall be landscaped with trees,
shrubs, and plantings with year-round interest.
[2]
A minimum of one large canopy tree per 250 square feet of PGS shall be provided for all PGSs. The size and species selection of the large canopy tree shall comply with Article V.
[3]
A minimum of 50% of required trees shall be planted at grade
within planting beds with no raised curbs or railings. Trees planted
at grade shall be surrounded by a porous surface (such as grating
or open-joint paving) that allows water to penetrate into the soil.
(d)
Lighting and electrical power.
[1]
Pedestrian-scaled lighting shall be provided within the PGS
and along sidewalks or internal pedestrian pathways connecting to
the PGS. Special attention should be provided in lighting steps and
other changes in elevation and areas under tree canopies and permitted
canopies within the PGS.
[2]
A lighting schedule, including luminaries, wattage and their locations and designs, shall be provided and comply with the Lighting Code, Chapter 105.
[3]
Electrical power shall be supplied to the PGS.
(e)
Litter receptacle. Trash and recycling containers shall be distributed
throughout the PGS.
(f)
Bicycle parking. A minimum of six of the required bike parking
spaces shall be provided within the PGS. For PGSs greater than 3,500
square feet in size, one bike parking space shall be provided per
500 square feet of PGS area, or portion thereof.
(4)
Maintenance. The developer shall be responsible for the maintenance
of the PGS, including, but not limited to, the location of permitted
obstructions, litter control, maintenance of required lighting levels,
and the care and replacement of furnishings and vegetation within
the PGS. The developer shall record a covenant on the property in
a form acceptable to the Township Solicitor to guarantee this requirement.
C.
Recreation land dedication criteria and standards.
(1)
Purpose.
(a)
In order to meet the recreational needs of future inhabitants
of developments and subdivisions in the Township, recreational land
shall be dedicated for the use of the residents by a permanent means
acceptable to the Township Solicitor.
(b)
The land or fees, or combination thereof, are to be used only
for the purpose of providing, acquiring, operating or maintaining
park or recreational facilities reasonably accessible to the development.
(2)
Applicability. This chapter shall apply under the following
circumstances for subdivision and land development which involves
residential or mixed-use development:
(3)
Minimum recreation land dedication; in-lieu options.
(a)
Residential and mixed-use development. Fifteen percent of the
tract area shall be set aside as a recreational area.
(4)
Park and recreational land or facilities standards. Any park
or recreational land or facilities shall be subject to the following,
which provisions shall apply as well to all fees heretofore paid and
currently held pursuant to this section:
(a)
The land to be used for park and recreational facilities shall
be in accordance with the principles and standards contained in the
Township's Recreation Plan and/or Open Space Plan and meet the following
criteria.
[1]
The land shall be well-drained and suitable for physically active
recreational purposes.
[2]
The average slope of the land shall be less than 6%.
[3]
The area set aside cannot have displaced a wetland.
[4]
If an existing park or trail is contiguous, the land dedicated
shall connect to the existing park or trail.
[5]
The land shall have appropriate and adequate access for maintenance
purposes and for use by pedestrians.
[6]
Whenever possible, the area set aside shall be along the outer
boundaries of the tract to allow for connections to future open space
on adjacent land.
[7]
The land shall not be used as stormwater management facilities
or stormwater basins.
(b)
Where a developer requests the Township's agreement to permit
the construction of recreational facilities in lieu of the dedication
of land for recreational purposes as required by this section, such
facilities shall meet the following minimum criteria in addition to
those others imposed by the Township:
[1]
The recreational facilities must be in addition to those otherwise
required to be constructed.
[2]
The recreational facilities must be outdoors and not under a
roof.
[3]
The primary use of the facilities must be for active recreational
activities.
[4]
The area of the proposed recreational facilities will be used
to measure the degree to which the required 10% or 15% of the tract
area to be set aside has been satisfied.
(5)
Administration of fees.
(a)
A fee authorized under this section shall, upon its receipt
by the Township, be deposited in an interest-bearing account, clearly
identified as reserved for providing, acquiring, operating or maintaining
park or recreation facilities. Interest earned on such accounts shall
become funds of that account.
(b)
Upon request of any person who paid any fee under this section,
the Township shall refund such fee, plus interest accumulated thereon
from the date of payment, if the Township has used the fee paid for
a purpose other than the purposes set forth in this section.
(c)
Fees due hereunder are payable at the time of application for
a building permit for the development.
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
vegetation.
A.
Every effort shall be made to avoid removal of trees having a dbh
of six inches or greater from the property in the process of subdividing,
land developing, grading or installing improvements. Where, in the
judgment of the Board of Commissioners, such removal is unavoidable,
the applicant shall install required replacement trees in such locations
and of such required size, variety and quantity as the Board of Commissioners
shall direct having the goal of ensuring their viability.
(1)
The applicant shall prove to the satisfaction of the Township
that vegetation removal for the desired development is minimized.
A written document or plan may be requested to be provided by a registered
landscape architect or other qualified professional showing that no
more functional layouts are possible and no alternative clearing or
grading plan would reduce the loss of mature trees, tree masses, and
woodlands, as determined by the Director of Building and Planning.
B.
Notwithstanding the six-inch dbh limitation, no substantial area
of smaller trees or shrub cover shall be removed without comparable
replacement as approved by the Board of Commissioners. A plan and
a statement of material to be removed and/or demolished shall be submitted
for approval.
C.
Removal or disturbance of vegetation in environmentally sensitive areas, including wetlands, floodplains, steep slopes, riparian corridors, wildlife habitats, and ecologically significant woodlands as identified in the Montgomery County Natural Areas Inventory shall be undertaken only as permitted under Chapter 155, Zoning, § 155-7.5.
D.
Wetland protection. The presence of hydric soils may indicate wetlands.
When hydric soils are indicated on the site, a wetland study jurisdictional
determination shall be conducted in accordance with the U.S. Army
Corps of Engineers Wetlands Delineation Manual (1987 Manual).
(1)
The area of wetlands as defined by the U.S. Army Corps of Engineers
and the Commonwealth of Pennsylvania in accordance with Section 404
of the Federal Clean Water Act of 1977 and the Pennsylvania Clean
Streams Act shall be preserved in subdivisions and land developments.
(2)
A twenty-five-foot setback shall be maintained around the perimeter
of all wetlands. This area will be known as the "wetland buffer."
No removal of vegetation, except the selective removal of dead trees
and/or noxious vegetation in the wetland area or buffer, shall take
place without the specific permission of the Township.
E.
Riparian corridor management. Whenever a pond, watercourse, stream,
or intermittent stream, as identified by the USGS, is located within
a development site, it shall remain open in its natural state and
location.
(1)
Unless otherwise described in Chapter 155, Zoning, or separate code, a twenty-five-foot-wide buffer from each bank of the water body shall be maintained along all intermittent or perennial watercourses and ponds. This buffer area will be known as the "riparian corridor." No removal of vegetation, except for dead trees and shrubs or periodic mowing of existing lawns or fields, shall take place within this buffer area without the specific permission of the Township.
(2)
No stormwater detention basins shall be allowed within the riparian
corridor.
(4)
Within any riparian corridor, no construction, development,
use, activity, or encroachment shall be permitted, except flood retention
dams, culverts and bridges, approved by the Township Engineer and
approved by the Pennsylvania Department of Environmental Protection
for those watercourses which drain an area of more than 1/2 square
mile. In all other cases, a corridor management plan shall be submitted
and approved by the Township, and the impacts of such development
shall be mitigated by the implementation of the corridor management
plan.
(a)
The developer shall submit to the Township Engineer a corridor
management plan prepared by a qualified design professional which
fully evaluates the effects of any proposed uses on the riparian corridor.
(b)
The corridor management plan shall identify the existing conditions
(vegetation, floodplain, soils, slopes, etc.), all proposed activities,
and all proposed management techniques, including any measures necessary
to offset disturbances to the riparian corridor.
(c)
The plan shall be approved as part of the subdivision and land
development process.
F.
Grading. Lots shall be laid out and graded to provide positive drainage
away from buildings. Wherever practicable, water shall be drained
to the street rather than to cross lots contained within the proposed
subdivision or land development.
(1)
Additional water caused by subdivision or land development may not be drained directly onto an adjoining property without the express written consent of the adjoining property owner. Whenever any person, firm or corporation paves, fills, strips, grades or regrades any land or disturbs, modifies, blocks, diverts or affects the natural land or subsurface flow of stormwater or constructs, erects or installs any drainage dam, ditch, culvert, drainpipe or bridge on any premises in the Township of Lower Merion, plans must be submitted to and approved by the Township Engineer. The requirements of Chapter 121, Stormwater Management and Erosion Control, must be met.
A.
Existing buildings. The following regulations shall apply as they
affect parcels upon which buildings exist at the time of the subdivision
or land development:
(1)
The subdivision of a lot that creates nonconforming setbacks for existing buildings according to the requirements of Chapter 155, Zoning, will not be approved.
A.
General design standards for new streets and additions to existing
streets. All new streets and additions to existing streets shall:
(1)
Be designed in accordance with the Township of Lower Merion
standards as provided in this chapter. The Township of Lower Merion
may accept or refuse dedication of any street.
(2)
Be generally consistent with the circulation element of the
Township of Lower Merion Comprehensive Plan and county or state highway
plans, and be designed to conform to the existing street system and
Official Highway Map.
(3)
Provide appropriate access between abutting tracts of land for
immediate or future use.
(4)
Conform to existing topography to assure reasonable grades,
alignment and drainage, appropriate access to lots, limits on the
depth of public infrastructure, and minimization of regrading and
removal of vegetation.
(5)
Be designed to continue existing streets at equal or greater
cartway width; however, additional right-of-way shall be provided
to meet current standards.
(6)
Include curbs and sidewalks installed along all existing and
proposed public and private streets and common parking areas.
(7)
Have shoulders that are graded to the full width of the right-of-way
and provision made for slopes beyond the right-of-way.
B.
Private streets.
(1)
Private streets shall be designed and constructed in conformance
with all design and engineering regulations of the Township Code and
this chapter that apply to public streets, unless otherwise provided
herein.
(2)
Whenever dedication of a street is not accepted by the Board
of Commissioners, the applicant shall submit, and record with the
plan, a covenant addressing the ownership, access rights, and maintenance
responsibilities for that street.
C.
Street classification based on functional classification of roads
map. Every street, road, or highway within the Township of Lower Merion
shall be classified by its function as shown on the Functional Classification
Map in the Township Comprehensive Plan, and shall be subject to the
requirements for its classification as contained in this article.
The classifications are as follows:
(1)
General. The design standards for each road classification are
contained in Table 4.9.1, Road Design Standards, and standard street
cross-section diagrams corresponding to each functional class.
|
Table 4.9.1
Road Design Standards
| ||||
|---|---|---|---|---|
|
Functional Classification of Road
|
Minimum Right-of-Way Width
(feet)
|
Minimum Cartway Width
(feet)
|
Verge
(feet minimum)
|
Pedestrian Amenities1, 2
|
|
Primary arterial street
|
80
|
46
|
4
|
Sidewalk; 8 feet minimum
|
|
Secondary arterial street
|
60
|
38
|
5
|
Sidewalk; 5 feet minimum
|
|
Tertiary arterial street
|
60
|
27 to 38
|
4
|
Sidewalk; 5 feet minimum
|
|
Local (minor) street
|
50
|
27 to 30
|
3
|
Sidewalk; 5 feet minimum
|
|
Local (minor) street in Open Space Overlay District
|
34 (45 required for public dedication)
|
20
|
3
|
Sidewalk; 5 feet minimum
|
|
Alley
|
333
|
163
|
N/A
|
N/A
|
|
NOTES:
| |
|
1.
|
Additional sidewalk width may be required in areas where higher
volumes of pedestrian traffic are anticipated.
|
|
2.
|
A sidewalk and/or verge of the minimum width specified shall be provided unless otherwise required by Chapter 155, Zoning.
|
|
3.
|
Greater widths may be required if necessitated by the proposed
use in the opinion of the Township Engineer.
|
(2)
Freeways. A freeway is a multilane, divided highway with fully
controlled access provided only at grade-separated interchanges. Freeways
serve the largest volumes of high-speed vehicular traffic through
the region.
(3)
Primary arterial streets. Primary arterial streets move traffic
across the community and accommodate higher-intensity commercial,
residential, and institutional land uses. Cartways are for the exclusive
use by motorized vehicles. To improve efficiency and safety of vehicular
travel, curb cuts from adjacent land uses should be consolidated.
Bicycles and pedestrians should be accommodated on wide, multi-use
side paths separated from traffic by a landscaped verge. Intersections
with secondary and tertiary arterial streets should receive additional
design features, including bumpouts, ADA compliant curb ramps, crosswalks
and signage, to improve traffic safety. On-street parking on primary
arterial streets should only be permitted in commercial districts.
Transit riders should be accommodated at highly visible, dedicated
locations. Transit stops should incorporate SEPTA's design guidelines.
|
Figure 4.9.1
Section: Primary Arterial Streets
 |
(4)
Secondary arterial streets. Secondary arterial streets move
traffic across the community and may include concentrations of higher-intensity
commercial, residential and institutional land uses in addition to
low-density residential uses. To improve efficiency and safety of
vehicular travel, curb cuts from adjacent land uses should be consolidated,
particularly through commercial districts. Dedicated left-turn lanes
may be considered on secondary arterial streets through commercial
districts to create pedestrian-scaled/neighborhood-oriented shopping
environments. Bicycles and pedestrians should be accommodated on sidewalks
measuring a minimum of five feet in width separated from traffic by
a landscaped verge. Intersections with primary and tertiary arterial
streets should receive additional design features, including bumpouts,
crosswalks, accessible ramps, and signage, to improve traffic safety.
On-street parking should be considered in commercial districts, where
feasible. Transit riders should be accommodated at highly visible,
dedicated locations. Transit stops should incorporate SEPTA's design
guidelines.
|
Figure 4.9.2
Section: Secondary Arterial Streets
 |
(5)
Tertiary arterial streets. Tertiary arterial streets connect
vehicular traffic from low-density residential neighborhoods with
primary and secondary arterial streets. Tertiary arterial streets
should support low-density residential and neighborhood-oriented land
uses, including libraries, parks, community centers and locally scaled
institutional uses. Tertiary arterial streets function as crucial
segments in the Township's bicycle network. Pedestrians should be
accommodated on five-foot wide sidewalks, preferably separated from
the cartway by a landscaped verge. Intersections with primary arterial
streets, secondary arterial streets and higher-volume local roads
should receive additional design features, including bumpouts, crosswalks,
and signage, to improve traffic safety. On-street parking should be
permitted where practical.
|
Figure 4.9.3
Section: Tertiary Arterial Streets
 |
(6)
Local (minor) streets. Local (minor) streets accommodate vehicles,
bicycles, and pedestrians through residential neighborhoods. Local
streets primarily accommodate low-density residential and neighborhood-oriented
land uses. Local (minor) streets function as the core of the Township's
bike network. Pedestrians should be accommodated on five-foot wide
sidewalks, preferably separated from the cartway by a landscaped verge.
Intersections with primary arterial, secondary arterial, and tertiary
arterial streets should receive additional design features, including
bumpouts, crosswalks, and signage, in order to calm traffic and enhance
pedestrian safety. On-street parking should be permitted where practical.
|
Figure 4.9.4
Section: Local (Minor) Streets
 |
(7)
Alleys. Alleys are undedicated small service roads which provide
a secondary access to lots, buildings, and/or off-street parking and
loading and unloading facilities. Alleys greater than 600 feet in
length are discouraged.
(a)
An adequate turning area shall be provided at any end of an
alley which is not an intersection with a street or another alley.
(b)
No fences, hedges, shrubbery, walls, planting, or other obstructions
shall be located within the right-of-way.
(c)
Intersections of right-of-way lines shall be rounded by a tangential
arc, the minimum radius of which shall be 25 feet, and the edge of
the paving at intersections shall be rounded by a tangential arc,
the minimum radius of which shall be 25 feet.
(d)
Reasonable sight distance shall be provided at intersections
with streets.
D.
Context sensitive street design for main street focus areas. (Reserved)
E.
Curbing. Curbing shall be installed along all existing and proposed
public and private streets, common commercial driveways, and common
parking areas, and shall be constructed in accordance with the Township
Design Standards Manual.
(1)
The Board of Commissioners may waive or defer the curbing requirements,
in full or partially, in the following situations:
(a)
When utilizing an approved stormwater management technique.
Grass swales and infiltration trenches along streets are encouraged
in appropriate locations in the Township, provided that pedestrian
safety and traffic circulation are addressed.
(b)
When adjoining sections of a road do not have curbing and in
the opinion of the Township Engineer it would be preferable to install
the curbing at the same time that curbing is installed along the adjoining
sections of the roadway.
(c)
When adjoining sections of the road do not have curbing and
in the opinion of the Director of Building and Planning the installation
of curbing would detract from the street's established character.
(e)
When the installation of curbing is deemed to be unnecessary
by the Director of Public Works.
(2)
Handicap accessible curb cuts that meet the requirements of
the American Disabilities Act (ADA) shall be installed at all intersections
where sidewalks or trails are provided or proposed.
F.
Sidewalks and verges. Sidewalks, and other pedestrian amenities,
shall be installed along all existing and proposed public and private
streets, common driveways, and common parking areas according to the
following standards:
(1)
Sidewalks shall be provided along all existing and proposed
public and private streets according to the dimensions in Table 4.9.1,
Road Design Standards, based on the functional classification of the
road, or Table 4.9.3, Single-Access Street Design Standards.[1] Any sidewalk not described in Table 4.9.1 or Table 4.9.3
shall be a minimum of five feet wide.
[1]
Editor's Note: Table 4.9.1 is included in § 135-4.6C(1), and Table 4.9.3 is included in § 135-4.9N(3).
(2)
All sidewalks shall be constructed in accordance with Township
Design Standards as well as the following:
(a)
The grade and paving of the sidewalk shall be continuous across
driveways, except in certain cases where heavy traffic volume dictates
special treatment.
(b)
The grade and alignment of all sidewalks shall be approved by
the Township Engineer.
(c)
Where proposed sidewalks meet existing sidewalks which have
a different width, a tapered transition shall be constructed.
(3)
The Board of Commissioners may defer the sidewalk requirements,
in full or partially, in the following situations:
(a)
When the subject property is not generally consistent with the
sidewalk implementation criteria established in the township Comprehensive
Plan.
(b)
When an off-road pedestrian pathway can be shown to be more
desirable, such as when steep slopes or other natural features or
physical constraints make the installation of sidewalk impracticable,
or when using open space areas, provided that the following standards
are met:
[1]
Appropriate connections are provided between the off-road pedestrian
pathways and the surrounding pedestrian origins and destinations and
existing sidewalk on abutting properties, if applicable.
[2]
The off-road pedestrian pathway shall be constructed to meet
the following standards:
[a]
The path shall be paved with asphalt having a minimum
thickness of 2.5 inches and a minimum aggregate subbase of four inches.
[b]
An alternative material that provides an adequate
walking surface, such as concrete, porous pavement, or other similar
paver systems, may be approved by the Township Engineer.
[3]
The off-road pedestrian pathway shall be maintained by the property
owner.
[4]
An easement guaranteeing public access to the off-road pedestrian
pathway shall be provided.
(d)
When adjoining sections of the road do not have sidewalks and
in the opinion of the Township Engineer it would be preferable to
install the sidewalks at the same time sidewalks are installed on
adjoining sections of the road.
(e)
When the installation of sidewalks is deemed to be unnecessary
by the Director of Building and Planning; however, alternative methods
of providing for pedestrian circulation through the property should
be provided, as appropriate.
(4)
In addition to the required sidewalk, a verge shall be provided
along all existing and proposed public and private streets according
to the dimensions in Table 4.9.1, Road Design Standards, based on
the functional classification of the road, or Table 4.9.3, Single-Access
Street Design Standards.
(a)
The verge shall be provided between the curbline, or edge of
the cartway, and the sidewalk.
(b)
Verges shall be maintained by the adjacent property owner as
a land-scaped strip between the sidewalk and the curb. If landscaping
is impractical at the site, porous pavers, brick pavers or similar
surface may be used at the discretion of the Board of Commissioners.
Alternating landscape and hardscape is encouraged, especially if on-street
parking is present adjacent to the verge, in order to provide pedestrian
access between the sidewalks and the on-street parking.
(c)
Verges may contain shade trees and large canopy trees and other
landscaping. Verges can also be used for stormwater management features,
such as rain gardens, provided that a maintenance agreement is signed
between the property owner and the Township.
(d)
Verges may contain street furniture including but not limited
to streetlights, trash receptacles, mailboxes, or newspaper boxes.
No obstacle in the verge may reduce the required sidewalk width for
use by pedestrians.
(e)
If benches are provided within the verge, they must be placed
a minimum of three feet from the back of curb. Otherwise, benches
must be placed at the back of the sidewalk.
G.
Crosswalks.
(1)
Crosswalks shall be clearly delineated at all intersections
where there is a sidewalk or trail connection and marked to the width
of the largest contributing sidewalk or trail. In no case shall a
crosswalk be less than five feet wide.
(2)
Crosswalks and their transition to adjacent sidewalks or trails
shall be designed to facilitate access and use by persons who are
physically disabled, in compliance with the Americans with Disabilities
Act (ADA).
(3)
Crosswalk patterns, materials, and colors shall be consistent
with applicable Township and PennDOT standards.
(4)
Pedestrian signalization shall be provided at intersections
where traffic signals exist.
(5)
Where a crosswalk is located on an arterial street or at a mid-block
location, the Board of Commissioners may require one or more of the
following measures as described in the Pennsylvania Traffic Calming
Handbook giving consideration to the recommendation of the Township
Engineer, the Public Works Director, and the Traffic Safety Unit:
(a)
High-visibility or decorative crosswalks.
[1]
High-visibility crosswalks shall comply with PennDOT Publication
111 standards for Type C - Perpendicular crosswalks.
[2]
Decorative crosswalks shall comply with PennDOT Publication
111 standards for decorative crosswalks as well as the following standards:
[a]
All decorative crosswalks shall consist of stamped
asphalt with an eight-inch cross section from top to bottom with seven
inches of twenty-five-millimeter Superpave base course and 1.5 inches
of nine-millimeter wearing course.
[b]
Final details for any decorative crosswalk proposed
in any Township right-of-way shall be subject to the approval of the
Public Works Department prior to installation.
(b)
Curb extensions, bulb-outs, or raised medians.
(c)
Raised speed table crosswalks.
(d)
Other pedestrian safety method deemed to be appropriate by the
Board of Commissioners as recommended by the Township Engineer.
(6)
The responsibility of maintaining crosswalks shall be contained
in a covenant filed against the abutting property.
H.
Trails and pathways.
(1)
Trails and pathways shall have adequate access for use by all
residents/occupants of the development or, preferably, the general
public.
(2)
The Board of Commissioners may request, as a condition of final
plan approval, public easements or rights-of-way for the use of pedestrians,
bicyclists and/or equestrians in the following situations:
(a)
When a subdivision or land development lies adjacent to a park,
school, commercial/business district, other subdivision, or other
pedestrian destination;
(b)
When a trail is shown in the Township's adopted open space or
recreation plans;
(c)
Where the right-of-way continues an existing trail or bridle
path;
(d)
Where the right-of-way will connect with an existing right-of-way
on an adjoining property; or
(e)
Where the right-of-way will extend to another street or alley,
or to the boundary line of a property capable of further subdivision
and there is no convenient alternate access route.
(3)
When a subdivision or land development includes or abuts an
existing or a proposed trail, the applicant shall make provision for
the continued use of the trail subject to alterations of the course
of the trail within the boundaries of the development under the following
conditions:
(a)
Such rights-of-way may, at the option of the developer, be located
adjacent to existing or proposed lot lines or in such a manner as
to minimize any obstruction to the development.
(b)
Existing rights-of-way may be relocated reasonably if a connection
with a right-of-way on an adjoining property is maintained.
(c)
The proposed alteration will not diminish the trail design and
function.
(d)
Where an existing trail runs coincidentally with the paved road
intended for use by motorized vehicles, landscaping and other physical
structures shall be used to increase the separation between the trail
and the road.
(4)
Trails shall be a minimum of six feet wide with an additional
cleared area of two feet on either side. Where multiple types of users
are anticipated, such as pedestrians and bicyclists, additional trail
width should be provided so that the trail is a minimum of 12 feet
wide with an additional cleared area of four feet on either side.
(5)
For phased developments, a development timeline shall be provided
as part of the final plan submission, subject to the approval of the
Director of Building and Planning, describing when the trail or pathway
will be provided relative to other site improvements and occupancy
of the site.
(6)
When trails are intended for public use, they shall be protected by a permanent access easement or right-of-way on the properties on which they are located. Unless otherwise provided for in Chapter 155, Zoning, the width of the easement or right-of-way in which the trail is located shall be a minimum of 20 feet. The language of the easement shall be to the satisfaction of the Township Solicitor.
(7)
No trail shall be designed with the intent to accommodate motorized
vehicles except for micromobility devices, emergency or maintenance
access.
I.
Bicycle amenities.
(1)
Bicycle amenities, including bicycle lanes, sharrows, and multipurpose
pathways shall be located as consistent with the Township Comprehensive
Plan and any official map adopted by the Board of Commissioners. Amenities
proposed within the public right-of-way shall be subject to the approval
of the Director of Public Works and the Traffic Safety Unit.
(2)
General standards. All bicycle amenities shall comply with the
following general standards:
(a)
Bicycle lanes and sharrows shall be designed and dimensioned to comply with all applicable PennDOT and FHWA Manual on Uniform Traffic Control Devices standards. Multipurpose pathways shall be designed and dimensioned to comply with the design standards contained in Chapter 155, Zoning.
(b)
Bicycle amenities shall be marked with appropriate pavement
markings, reflectors, and signage in accordance with all applicable
FHWA Manual on Uniform Traffic Control Devices and PennDOT standards.
(c)
Where the roadway narrows, signage and pavement markings shall
be added to warn drivers and bicyclists to help them avoid bicycle-automobile
conflicts.
J.
On-street loading and unloading zones. On-street zones for designated short-term loading and unloading are encouraged for all developments with 100 feet or more of street frontage on an arterial street, unless otherwise required by Chapter 155, Zoning. All on-street loading and unloading zones shall comply with the following standards:
(1)
An on-street loading and unloading zone shall be equal in size
to three on-street parking spaces.
(2)
Where on-street parking is either existing or proposed, the
on-street loading and unloading zone shall be provided by designating
on-street parking spaces.
(3)
Where on-street parking is not either existing or proposed,
the on-street loading and unloading zone may be provided by creating
an inset space along the curbline, provided that the minimum required
sidewalk width is maintained.
(4)
On-street loading and unloading zones shall be clearly identified
with signage and/or pavement markings.
(5)
All locations within the public right-of-way shall be subject
to the approval of the Director of Public Works.
K.
Bus stop and shelters design guidelines for fixed route public transit
service.
(1)
The applicant shall notify and coordinate with SEPTA and the
Township Director of Building and Planning to determine if a bus stop
is appropriate when the proposed subdivision or land development meets
any one of the following criteria:
(a)
Located along an existing or planned fixed route public transit
service.
(b)
Has a character, magnitude, or location that will have substantial
effect upon the health, safety, or welfare of citizens in more than
one municipality and could be considered a development of regional
significance and impact, such as regional shopping centers, industrial
or commercial parks, warehouses, residential developments, regional
entertainment or recreation centers, hospitals or medical care facilities,
and educational institutions.
(c)
The proposed land development that meets any one of the following
characteristics, which are consistent with transportation impact study
warrants included in PennDOT's Transportation Impact Study Guidelines:
[1]
The site is expected to generate 3,000 or more average daily
trips or 1,500 vehicles per day.
[2]
During any one-hour time period of any day of the week, the
development is expected to generate 100 or more vehicle trips entering
the development or 100 or more vehicle trips exiting the development.
[3]
For existing sites being redeveloped, the site is expected to
generate 100 or more additional trips entering or exiting the development
during any one-hour time period of any day of the week.
[4]
In the opinion of the Director of Building and Planning, the
development or redevelopment is expected to have a significant impact
on the transportation system, even if the above warrants are not met.
(2)
The location and design of a bus stop shall be reviewed and
approved by SEPTA. SEPTA shall provide written documentation certifying
that a location is an existing or potential future bus stop.
(3)
The location and design of a bus stop, including conformance
with other chapters of the Township Code and construction standards,
shall be reviewed and approved by the Director of Building and Planning.
Improvements shown in the right-of-way shall be approved by the Director
of Public Works and the Traffic Safety Unit.
(4)
On-street parking and loading zones shall be prohibited or limited
at the bus stop to avoid obstructing the curbside in the area of the
bus stop and provide sufficient space for the bus to pull to the ADA
loading pad, curb ramp, and/or curb.
(5)
Bus stop infrastructure for fixed route bus stops shall be designed
and constructed in accordance with ADA requirements.
(7)
ADA loading pads. An accessible loading pad shall be provided
adjacent to the curb or roadway edge where the front doors of a fixed
route bus service open to receive and discharge passengers at a designated
bus stop. A second loading pad located at the rear door of the bus
may be required.
(a)
All ADA loading pads shall be provided at curb-height to accommodate
bus wheelchair lifts and/or ramps. A street-level ADA loading pad
may be provided as an alternative with approval from the Director
of Building and Planning and SEPTA.
(b)
All ADA loading pads shall be connected via an ADA accessible
route to adjacent pedestrian infrastructure, such as a sidewalk, path,
or multi-use trail. ADA loading pads may be integrated with the sidewalk
or other pedestrian infrastructure. A stand-alone ADA loading pad
with an ADA accessible route to the nearest roadway or public right-of-way
may be provided as an alternative with approval from the Director
of Building and Planning and SEPTA.
(c)
A minimum clear area of the ADA pad for boarding and alighting,
which is five feet measured parallel to the roadway and eight feet
measured perpendicular to the roadway, shall be provided and shall
not be obstructed by utility poles, fire hydrants, street furniture,
overhangs, trees, shrubs, and similar obstacles.
(d)
Parallel to the roadway, the slope of the loading pad shall
be the same as the roadway, to the maximum extent practicable. Perpendicular
to the roadway, the slope of the loading pad shall not be steeper
than 2%.
(e)
Minimum construction standards. The ADA loading pad shall have a firm, stable, and slip-resistant surface, preferably concrete built consistent with the minimum construction standards for sidewalks as specified in Chapter 133, Streets and Sidewalk, of the Township Code or asphalt consistent with the minimum construction standards for paths and multi-use trails.
(8)
Bus shelters.
(a)
All aspects of the bus shelter shall comply with ADA requirements,
including but not limited to access points, clearance and circulation
within the shelter, and seating. Any benches or seating may not obstruct
the required 30 inches by 48 inches clear floor space in the shelter.
(b)
The bus shelter shall be integrated with the ADA loading pad
or connected to the ADA loading pad via an ADA accessible route.
(c)
A bus shelter includes a roof or canopy and may be enclosed
on up to three sides with partial enclosure of a fourth side permitted
for protection against wind or other weather elements. A bus shelter
may be integrated with the structure of an adjacent building or externally
attached.
(d)
For security and safety purposes, the side and rear panels of
the shelter shall be constructed of a clear, shatter-resistant material.
(e)
Bus stop passenger information signs may be provided within
or on a bus shelter and shall be considered exempt from municipal
sign ordinance requirements.
(f)
Any lighting for a bus shelter shall be installed in such a
manner to provide adequate visibility during darkness for patrons
of the transportation system. The lighting shall be installed in such
a way so that the source of light shall be shielded from all abutting
residential properties and traffic along the roadway where the shelters
are located. The lighting shall not conflict with any traffic control
devices.
(g)
Bus shelters shall be installed and maintained according to
the manufacturer's design specifications.
(h)
Location.
[1]
The shelter shall be located near the front end of the bus stop
zone so as to minimize the distance to access and board the bus.
[2]
Concrete bus stopping/loading pad within the cartway shall be
required at the discretion of Public Works.
[3]
The shelter shall not obstruct the required minimum clear area
of the ADA loading pad for boarding and alighting.
[4]
The shelter shall be within 50 feet of the ADA loading pad.
[5]
The location of a bus shelter shall not interfere with horizontal
clearance for access and maintenance, including pedestrian traffic
along a sidewalk or curb ramps. A minimum clearance of five feet shall
be maintained around the shelter.
[6]
The shelter, including roof or panels, shall be located a minimum
of five feet from the curb or roadway edge.
[7]
On-street parking shall be restricted within a minimum 10 feet
from any bus shelter.
[8]
The location of the bus shelter shall conform to clear sight
triangles and other minimum sight distance requirements for driveways
and intersections. The shelter shall provide a clear view of the roadway
and approaching bus.
(j)
Foundation.
[1]
The bus shelter shall be anchored and attached to a concrete
foundation with a slope that is not greater than 1:50.
[2]
Specifications for the bus shelter and foundation shall be consistent
with the manufacturer's specifications (if applicable) and approved
by the transit agency and municipality.
(9)
Bus stop street furniture.
(a)
Bus stop street furniture may include, but is not limited to,
bus passenger benches, leaning rails, waste receptacles, and bicycle
racks.
(b)
Bus stop street furniture shall not obstruct the required minimum
clear area of the ADA loading pad for boarding and alighting.
(c)
The location of bus stop street furniture shall not interfere
with horizontal clearance for access and maintenance, including pedestrian
traffic along a sidewalk.
(d)
The location of street furniture shall conform to clear sight
triangles and other minimum sight distance requirements for driveways
and intersections.
(e)
Furniture shall be anchored securely to prevent unauthorized
movement and shall be able to be relocated or replaced by those authorized
to maintain the furniture.
(f)
Bus stop passenger benches.
[1]
Benches shall be ADA compliant in terms of dimensions and construction.
[2]
Benches shall be placed facing the roadway and outside of boarding
and alighting areas and pedestrian routes.
[3]
Benches shall be installed on a firm, stable, and slip-resistant
surface.
[4]
Benches shall be located a minimum of four feet from the curb
or roadway edge.
(10)
Bus stop signs. Bus stop signs, including bus stop location
signs and bus stop passenger information signs, installed and maintained
by the transit agency shall be permitted within the public right-of-way
and on private property and shall be considered governmental signs.
(11)
Bus stop passenger information signs.
(a)
Bus stop information signs shall not obstruct pedestrian access
routes or the required minimum clear area of the ADA loading pad for
boarding and alighting.
(b)
Bus stop information signs shall be either mounted on the same
post or pole as the bus stop signs or shall be integrated with the
bus shelters.
L.
Street alignment. Streets shall be adjusted to the contour of the
land so as to produce usable lots and streets of reasonable grade,
reasonable utility depth, alignment, and drainage. Sight distance,
horizontal, and vertical curvature, super-elevation, and maximum and
minimum street grades shall be determined by the Township 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 (AASHTO), most recent edition,
or PennDOT standards, whichever is more suitable to site conditions.
In addition, the following standards and guidelines shall be complied
with:
(1)
Minimum horizontal and vertical curvature for all streets shall
conform to the standards in the AASHTO Manual for the Design of Highways
and Streets, as well as the following general standards:
(a)
Horizontal curves shall be used at all changes in alignment
in excess of 2°.
(b)
Reverse curves shall be separated by tangents of 50 feet or
more.
(c)
Vertical curves shall be used at changes in grade of more than
1%. The length of the curve shall approximate 50 feet on arterial
streets and 25 feet for local (minor) streets for each 1% of change
in grade. Over summits or in sumps, vertical curves shall not produce
excessive flatness of grade.
(d)
Long radius, gentle curves shall be used rather than shorter
radius curves connected by tangents, particularly where truck traffic
is anticipated.
(e)
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.
(f)
Minimum radii of the center line on horizontal curves shall
be 350 feet on arterial streets and 150 feet on local (minor) streets.
(g)
Super-elevation and additional width shall be used for curves
of less than 600-foot radii on arterial streets and of less than 300-foot
radii on local (minor) streets.
(2)
Street grades shall comply with the following and shall be measured
along the center line of the street, unless noted otherwise below:
(a)
The minimum grade for all streets shall be 1%.
(b)
Grades in excess of 5% are to be avoided on all streets wherever
practicable.
(c)
The maximum grade shall be 7% for arterial streets and 10% for
local (minor) streets.
(d)
Curve-grade combinations shall follow accepted engineering guidelines
for safety and efficiency. For example, a combination of minimum radius
horizontal curves and maximum grades will not be approved.
(e)
The grade within 50 feet of any side of an intersection, or
the outer perimeter of a turnaround, shall not exceed 3%. The grade
shall be measured along the curb or flow lines of the street.
|
Table 4.9.2
Street Alignment and Intersection Standards
| |||
|---|---|---|---|
|
Functional Classification of Road
|
Maximum Intersection Spacing
(feet)
|
Minimum Clear Sight Triangle
(feet)
|
Corner Radius1
(feet)
|
|
Primary arterial street
|
600
|
100
|
35
|
|
Secondary arterial street
|
600
|
100
|
30
|
|
Tertiary arterial street
|
300
|
75
|
25
|
|
Local (minor) street
|
300
|
75
|
20
|
|
NOTE:
| |
|
1.
|
All radii specified herein must be increased if large trucks,
fire trucks, or other emergency vehicles would have difficulty with
ingress or egress as determined by the Township Fire Marshal.
|
M.
Street intersection design. All street intersections shall be governed
by the standards of this section and the appropriate PennDOT and AASHTO
standards.
(1)
Primary and secondary arterial streets. Wherever practicable,
the number of intersections with primary and secondary arterial streets
shall be kept to a minimum and shall have a minimum spacing according
to Table 4.9.2, Street Alignment and Intersection Standards, above.
(2)
Number of streets. No more than two streets shall intersect
at the same point.
(3)
Three-way/four-way intersections. Three-way or T-intersections
should be used instead of four-way intersections involving local (minor)
streets intersecting arterial streets unless the four-way intersection
would promote necessary and desirable traffic movements or where traffic
signals or four-way stop signs are proposed.
(4)
Angle of intersections.
(a)
All intersection approaches shall be designed at ninety-degree
angles for a minimum of 50 feet from the edge of the cartway.
(b)
Where angled intersections are used, they should be no less
than 65° and designed so that the heavier traffic flow will make
the obliquely angled turn rather than the acutely angled turn.
(5)
Grading. The shoulders shall be graded to the full width of
the right-of-way and provision made for slopes beyond the right-of-way.
(6)
Improvements to existing intersections. When existing streets
intersect at odd angles or have more than four approaches, the applicant
shall improve the intersection to bring it into compliance with this
chapter, to the maximum extent feasible, as determined by the Township
Engineer. For state and county highways, improvements shall comply
with the requirements of the appropriate agency having jurisdiction
over the road.
(7)
Radii of pavement and right-of-way at intersections. Wherever
practicable, right-of-way lines shall intersect at right angles and
shall be rounded by a tangential arc having a minimum radius of 10
feet.
(8)
Curbs. Wherever practicable, curblines shall be rounded by a
tangential arc, the minimum radius of which shall be as indicated
in Table 4.9.2, Street Alignment and Intersection Standards. The grade
lines of the curb at intersections shall intersect if the tangents
are extended.
(9)
Sight distance and clear sight triangle. All intersections shall
provide clear sight distance in compliance with the standards within
Chapter 441 (Access to and Occupancy of Highways by Driveways and
Local Roads), Title 67 of the Pennsylvania Code, and AASHTO standards.
(a)
The calculated minimum sight distance shall be measured along
the center line of the street from a point 10 feet back of the pavement
edge of the intersecting road and four feet above the road surface.
(b)
If the minimum required sight distance cannot be achieved, the
Township may exercise one or more of the following options:
[1]
Prohibit left turns by exiting vehicles.
[2]
Restrict turning movements to right turns in and out of a driveway.
[3]
Require installation of a right turn acceleration lane or deceleration
lane.
[4]
Require installation of a separate left turn standby lane.
[5]
Alter the horizontal or vertical geometry of the roadway.
[6]
Deny access to the road.
[7]
Provide intersection controls as determined by the Township
Engineer.
(c)
Proper sight lines shall be maintained at intersections of streets.
There shall be measured along the center line a minimum clear sight
triangle of 75 feet from the point of intersection, or as determined
by the Township Engineer. No building or other obstruction will be
permitted in this area. Any obstruction to sight shall be removed
at the time the street is permitted in this area. Any obstruction
to sight shall be removed at the time the street is graded, or at
the time a building or structure is erected on the adjacent lot, whichever
occurs first.
|
Figure 4.9.5
Clear Sight Triangle Distances
 |
(10)
The Board of Commissioners may waive the street intersection
requirements, in full or partially, under one or more of the following
conditions:
(a)
When changes made on the applicant's land will not improve the
intersection's deficiencies.
(b)
When other road improvements are already planned which would
correct the problem without changes required of the applicant.
(c)
When not required by PennDOT where the intersections are under
their jurisdiction.
(11)
Street intersection spacing shall be in compliance with the
regulations contained in this section, measured from center line to
center line.
(a)
The applicant shall prepare a vehicular access and maneuverability
analysis for all street intersections proposed along arterial streets.
(b)
The spacings listed in Table 4.9.2, Street Alignment and Intersection
Standards, shall be considered minimum spacing. Where greater spacing
is required in compliance with AASHTO or PennDOT standards, the greater
spacing distances shall be applied, as determined by the Township
Engineer.
(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.
N.
Single-access street standards. Any street which is served by only
one intersection with a through street shall be considered a single-access
street, regardless of the street's configuration within the proposed
subdivision or land development. No dead-end streets are permitted
to be created.
(1)
Single-access streets shall be classified as single-access loop
streets and shall not include culs-de-sac.
(2)
Single-access street intersections with through streets:
(a)
Single access streets shall be established beginning at a three-way
intersection perpendicular to a through street.
(b)
Four-way intersections may be created using two permanent single
access streets intersecting directly opposite one another along a
through street, when the through street is a local street.
(3)
The minimum right-of-way and paving widths for single-access
streets shall be as specified in Table 4.9.3, Single-Access Street
Design Standards, below, unless otherwise approved by the Board of
Commissioners upon recommendation of the Township Engineer and Public
Works. The two corner lots at the intersection of a proposed single-access
street with an existing street are counted, whether or not they utilize
the single-access street for access.
|
Table 4.9.3
Single-Access Street Design Standards
| ||
|---|---|---|
|
Zoning District
|
Minimum Right-of-Way Width
(feet)
|
Minimum Cartway Width
(feet)
|
|
Any Zoning District, Except OSOD
|
50
|
271
|
|
Open Space Overlay District (OSOD)
|
45
|
20
|
|
NOTE:
| |
|
1.
|
The Township Engineer may require additional width of paving
in commercial center and light industrial zoning districts in accordance
with AASHTO standards.
|
(4)
Single-access loop streets: shall not exceed 2,000 feet in length,
measured from the intersection with the through street, along the
entire center line around to its intersection with itself.
O.
Street signs and names.
(1)
Street signs. The developer shall erect a street sign or street
signs at every intersection. At intersections where streets cross,
there shall be at least two such street signs and at the intersections
where one street ends or joins another street, there shall be at least
one sign. They shall be four-way signs of such material, size, height,
and location as specified by the Township Engineer and in conformity
with the existing signs already established in the Township. Street
signs for existing and new streets shall be approved by the Lower
Merion Department of Public Works and shall be erected at the developer's
expense.
P.
Driveway access.
(1)
Any new driveway proposed to be installed, or change of use/driveway
classification, or any driveway proposed to be widened or enlarged,
must comply with the requirements for driveways in this section and
must be constructed in accordance with Township standards.
(2)
Final approval of any driveway location, classification, or
design shall be considered by the Township unless highway occupancy,
right-of-way permits, or access permits have been granted by the state,
county, and/or Township and preliminary plan approval has been granted
by the Board of Commissioners for the subdivision and/or land development
which the driveway(s) will serve.
(3)
No more than five dwelling units may share a common driveway.
(4)
Driveway intersections with streets:
(a)
When a lot adjoins streets of different classes as shown on
the Functional Classification of Roads Map, the driveway shall provide
access to the street of lesser classification unless this requirement
is waived by the Board of Commissioners for reasons of sight distance,
incompatibility of traffic, grading, drainage, or other major reasons.
(b)
Driveways shall provide adequate sight distance in compliance
with the standards established by PennDOT and AASHTO.
(d)
Driveways shall be designed and constructed in compliance with
Chapter 441 (Access to and Occupancy of Highways by Driveways and
Local Roads) of Title 67 of the Pennsylvania Code, unless Township
standards are more restrictive.
(e)
Driveways serving individual parcels of land may be prohibited
where such intersections would create congestion, interference, and/or
hazards to traffic flow and safety by reason of street grades, vegetation,
frequency of driveway intersections, limited sight distances, and/or
high-speed traffic flow, or any other reason as determined by the
Traffic Safety Unit or Department of Public Works. In such cases,
the Board of Commissioners may permit reasonable alternative forms
of vehicular access to the parcel of land on Township roadways by
other means which are legally and technically suitable in the opinions
of the Township Solicitor and Engineer, and Director of Public Works.
(5)
Number and spacing of driveways. 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.
(a)
Shared access between adjoining lots should be considered prior
to constructing any new driveway. Crossover easements are required
and must be noted on the plan and included in all affected deeds.
(b)
Where feasible, a driveway shall be aligned with access points
on the opposite side of the street.
(6)
Distance from street intersections. Driveways shall be located
as far from street intersections as is reasonably possible, but no
less than the following distance from the point of the intersection
between two street center lines:
(7)
Stopping areas. Regardless of the driveway classification, all
driveways shall be provided with a stopping area 20 feet in length
as measured behind the right-of-way line.
(8)
Maximum grade for driveways. Excessive driveway grades that
may create a hazard at either street or interior terminus will not
be permitted. The driveway slope within the right-of-way may not exceed
2%. Outside the right-of-way, the following standards shall apply:
(9)
Sight distance determinations. Sight distances at intersections of new driveways with existing roads shall be determined in accordance with the standards in § 135-4.9M(9).
(10)
Driveways longer than 200 feet. Driveways which exceed 200 feet
in length frequently present difficulties in and impediments to the
delivery of municipal and emergency services and present difficulties
in vehicular passage. Therefore, the Board of Commissioners may impose
one or more of the following additional construction requirements
to alleviate such difficulties and impediments as it determines necessary
for proposed driveways which exceed 200 feet in length:
(a)
Driveways which exceed 200 feet in length shall be constructed
to Township road standards and shall have a minimum width of 10 feet.
(b)
Pull-outs shall be installed at intervals of no more than 200
feet and shall have dimensions of no less than nine feet by 19 feet.
(c)
Driveways which exceed 400 feet in length shall be constructed
with a turnaround using a Y or a T or a circular configuration with
a twenty-five-foot radius at the terminus.
(d)
Driveways which exceed 600 feet in length shall have private
hydrants installed at such intervals as shall be mandated by the Fire
Marshal for local (minor) streets.
(e)
If literal compliance with any of the foregoing requirements
would be impractical, the Board of Commissioners, with the advice
of the Township Engineer, may modify or adjust such requirements to
permit reasonable utilization of property while at the same time securing
substantial conformance with the objectives of this section.
Q.
Parking and related internal drive aisles. Parking and related internal
drive aisles shall be governed by the following regulations:
(1)
Purpose. The specific purposes to be served by these requirements
are:
(a)
To add visual character and improve the appearance of parking
areas by reducing their massiveness into smaller units.
(b)
To integrate parking areas into the pedestrian circulation system.
(c)
To provide shade for parked cars and reduce heat islands, stormwater
runoff, and air pollution.
(d)
To reduce random vehicular flow across parking areas.
(e)
To permit a high level of visibility for those uses for which
visibility is an important factor.
(f)
To facilitate snow removal and storm drainage, and to conserve
energy in construction and resurfacing operations, by laying out the
paving surface with minimal obstructions.
(2)
General.
(a)
Off-street parking facilities shall be provided in compliance with the parking requirements of Chapter 155, Zoning, of the Township Code, as well as the regulations contained herein.
(b)
Parking spaces designed for the exclusive use by disabled persons
shall be installed in all parking lots as close and convenient to
building entrances as is reasonable. The specific number and locations
of handicapped stalls shall be in conformance with the Americans with
Disabilities Act (ADA).
(c)
Construction materials for off-street parking areas, including
driveways used as required parking, shall only consist of concrete,
pervious concrete, concrete wheel-strips with grass, asphalt, or pavers.
Materials which reduce embodied carbon, use life-cycle analysis or
are pervious are acceptable if approved by the Township Engineer.
(d)
Provisions for pedestrian safety within a parking lot shall
be required by providing sidewalks, delineated crosswalks, traffic
calming devices, signage, and/or other measures.
(e)
Innovative stormwater management controls that encourage infiltration of stormwater runoff on-site, such as rain gardens and porous pavement, shall be incorporated into parking lot design, as required in Article V herein.
(f)
The allowance and configuration of on-street parking on Township
roads shall be as permitted by the Board of Commissioners as recommended
by Director of Public Works.
(3)
All parking lots.
(a)
Parking shall not be permitted along driveways which serve as
the entrance(s) or exit(s) to parking areas with a capacity of 50
vehicles or more. A minimum driveway length of 50 feet shall be provided
between the road ultimate right-of-way line and the first parking
space or internal driveway intersection in parking lots with 50 vehicles
or more.
(b)
Parking areas shall be set back from tract boundary lines and ultimate right-of-way lines in compliance with the requirements of Chapter 155, Zoning, of the Township Code. In any case not regulated by Chapter 155, Zoning, of the Township Code, parking areas shall be in compliance with Article V, Landscape Standards.
(c)
Dead-end parking areas are discouraged and shall not be used
when the required parking capacity can be accommodated in a layout
that permits more convenient vehicular movements. Up to 30 parking
spaces may only be located in a dead-ended parking area, only if a
suitable turnaround area is provided at the closed end.
(d)
Emergency access shall be reviewed by the Township Fire Marshal
subject to compliance with the International Fire Code.
(4)
Parking lot dimensions. The minimum size of all parking stalls and aisles shall be consistent with requirements of Chapter 155, Zoning, of the Township Code and Americans with Disabilities Act (ADA) provisions, where applicable.
(5)
Shared access. When required by the Board of Commissioners,
agreements between applicants for shared vehicular access shall be
the preferred means of reducing the total number of curb cuts for
traffic safety and congestion reasons.
(a)
When two or more abutting lots share an access driveway, the
driveway should be designed as the main access to those lots, and
one or more existing access driveways shall be closed.
(b)
Where development of three or more adjoining parcels consolidates
vehicular access into one shared driveway, that driveway may be upgraded
into a medium volume driveway according to PennDOT standards.
(c)
Shared access driveways may be located entirely on one lot or
split along a common lot line.
(6)
Drive aisles within sites proposed for nonresidential development.
The following requirements apply to all drive aisles within all sites
proposed for nonresidential land development.
(a)
Interior storefront drive aisles within shopping center developments
shall be a minimum paved width of 28 feet to allow one lane in each
direction and a dropoff/pickup lane along the sidewalks. The following
additional standards shall apply to interior storefront drive aisles:
(b)
Drive aisles along other nonresidential buildings shall be a
minimum paved width of 22 feet, except where a dropoff/pickup lane
is proposed.
(7)
Pedestrian pathways and crosswalks. The following requirements
shall apply to all surface parking lots where 10 or more new parking
spaces are proposed.
(a)
Pedestrian access to each building on-site from adjacent public
sidewalks, the street, and all areas of the parking lot shall be physically
delineated and provided through the installation of sidewalks and
defined crosswalks.
(b)
Pedestrian pathways.
[1]
Pedestrian pathways shall be clearly separated from vehicular
use areas with sidewalks, landscaping, a change in grade, or a change
in paving material.
[2]
Pedestrian pathways in parking areas shall be barrier-free,
and a minimum of five feet wide. Additional width may be required
in some areas with heavy pedestrian traffic.
[3]
To facilitate pedestrian movement, at least one pedestrian route
shall be provided that enables access from the far end of the parking
lot to the main entry of a building.
(c)
Crosswalks. Where a pedestrian circulation route within the
parking area crosses a vehicular drive aisle, a crosswalk with a differing
paving material, continental-style crosswalk markings, or a speed
table shall be provided.
R.
Electric vehicle charging stations (EVCS).
(1)
Electric vehicle readiness standards.
(a)
For any new development or redevelopment requiring more than
25 additional parking spaces, sufficient space and capacity shall
be provided to support the operation of Level 2 EVCS for at least
20% of the additional parking spaces, with a dedicated branch circuit
and overcurrent protection for each Level 2 EVCS.
(b)
For any new development or redevelopment of a parking structure,
all parking spaces located within the parking structure shall be made
EVCS capable with conduit installed throughout the structure and electrical
subpanels sized to accommodate a Level 2 EVCS for each parking space
capable of delivering a minimum of 32 amps/7.7 kWh.
(c)
All new single-family and multifamily dwellings with garages
shall be constructed to include a dedicated 40 amp branch circuit
capable of powering a 32 amp Level 2 EVCS within the garage, and installation
of a 220-240 volt/40 amp outlet in a location within the garage that
would be conducive to EVCS use.
(d)
It is strongly encouraged, but not required, that all new, expanded
and reconstructed single-family dwelling garages provide a 220-240-volt/40
amp outlet or support either a dual port 30-amp system or a fast AC
80-amp single port system on a dedicated circuit and in close proximity
to designated vehicle parking to accommodate the potential future
hardwire installation of a Level 2 EVCS.
(e)
A maintenance and operation plan shall be submitted for the
review and approval of the Township Engineer.
(2)
EV parking capacity and minimum required parking requirements.
(a)
For any new development or redevelopment with at least 10 parking
spaces serving residential uses, at least 10% shall be electric vehicle
parking spaces (EVPS) served by a Level 1 or Level 2 EVCS connection.
(b)
For any new development or redevelopment requiring 25 additional
parking spaces, at least 5% shall be EVPSs served by a Level 2 EVCS
connection. At least one EVPS, or 10% of the EVPSs generated to meet
this requirement, whichever is greater, shall be available for public
use.
(c)
For any new development or redevelopment requiring 250 parking
spaces or more, at least 1% shall be an EVPS connected to a Level
3 EVCS port having minimum output of 150 kWh.
(d)
For developments with both residential and nonresidential uses
(mixed-use), EV parking capacity and minimum parking requirements
shall be calculated based on the proportional number of parking spaces
allocated to each use.
(e)
EV parking capacity and minimum parking requirements are calculated
on the parking spaces required for the development.
(3)
Electric vehicle charging station standards.
(a)
Installation of EVCS shall meet the requirements of all applicable
electrical codes and building codes.
(b)
EVCS cords shall be retractable or have a place to hang the
cord and connector above the pedestrian surface. Any cords connecting
the charger to a vehicle shall be configured so that they do not cross
a driveway, sidewalk, or passenger unloading area.
(c)
EVCS outlets and connectors shall be mounted to comply with
all relevant Americans with Disabilities Act (ADA) requirements.
(d)
Where EVCS equipment is provided within an adjacent pedestrian
circulation area, such as a sidewalk or accessible route to the building
entrance, the charging equipment must be located so as not to interfere
with accessibility requirements.
(e)
EVCS pedestals shall be designed to minimize their potential
damage by accidents and vandalism and to be safe for use in inclement
weather. Pedestal location shall be a minimum four feet back from
curb or edge of cartway.
(f)
EVCS shall be protected from vehicle impacts by curbs, wheel
stops, bollards or other physical barriers. The EVCS shall be offset
a minimum of 24 inches clear from the physical barrier.
(4)
Electric vehicle parking space (EVPS) design and location.
(a)
The minimum dimensions for any EVPS shall be in accordance with parking spaces as outlined in Chapter 155, Zoning.
(b)
EVPSs shall be located in parking spaces which are desirable
and convenient to incentivize the use of electric vehicles.
(c)
Any EVPS available for public use shall be marked with a sign
indicating that its use is either reserved for EVs or preferred for
use by EVs.
(e)
Site lighting shall be provided in the area where an EVCS is
installed, unless the parking area is limited to daytime use only.
All new electric, telephone and communication service facilities,
both main and service lines, shall be provided by underground cables,
installed in accordance with the prevailing standards and practices
of the utility or other companies providing such services, except
where it is demonstrated to the satisfaction of the Board of Commissioners
that the underground installation herein required is not feasible
because of the physical condition of the lands involved. All proposed
underground cables which are within the right-of-way of a street shall
be located as specified by the Board of Commissioners as directed
by the Director of Public Works.
A.
Water service and fire hydrants.
(1)
An adequate public water supply shall be provided by the developer
for the proposed use and for fire control.
(2)
The design for public water supply facilities shall be in accordance
with PADEP Water Supply Manual, and the specifications of the utility
providing water service.
(3)
Fire hydrants shall be provided by the developer and installed
subject to approval of locations by the Township.
(a)
Furthermore, in the event that a fire hydrant or hydrants are
installed to service public or private streets in a subdivision or
land development, the developer shall deposit funds or securities
in escrow sufficient to cover the cost of the annual fire hydrant
rental charge imposed by the water utility provider for a prospective
period of 10 years of hydrant rental.
(b)
The developer shall be responsible for the continued payment
imposed by the water utility provider.
B.
Sanitary sewers. All sanitary sewer systems and privately owned sewage
and industrial waste treatment works shall comply with the rules and
regulations established by the Department of Environmental Protection
of the Commonwealth of Pennsylvania, as amended and revised.
(1)
Wherever practicable, sanitary sewers shall be installed and
connected to the Township sanitary sewer system. If outfall sewers
are not available but are planned and have been shown in the most
current ten-year growth area as set forth in the 537 Sewage Facilities
Plan of the Township, a system of sewers, together with all necessary
laterals extending from the main sewer to the street right-of-way
line, shall be installed and capped as determined by the Township
Engineer. The Board of Commissioners may waive the above requirements
for lots of one acre or larger or in open space preservation developments
if the following criteria can be met.
(2)
If sanitary sewers are not to be installed initially, easements shall be provided on the preliminary, final and minor plan and land development waiver plans and shall show the dedication of appropriate easements across private property for later construction and maintenance of sewers, except where such requirements are waived under Subsection B(1) above. A deed of easement shall be recorded for each such easement.
(3)
Sanitary sewer pipe shall be sized for full flow from the tract.
Larger pipe size may be required to accommodate future extensions
as required by the Township Engineer. Pipe material must be designed
in accordance with Township standards.
(4)
Minimum grades shall be 0.8% except at terminal runs, which
shall be 1%.
(5)
Manholes shall be placed at every point where the sanitary sewer
line changes direction in line or grade. Where drops are proposed,
an outside drop is required, and the proper channeling is required
by Township standards. In no instance shall the spacing exceed 300
feet. Manhole frames, covers, buckets and steps may be purchased from
the Township. Township standard lid and frame are required.
(6)
Materials. Lateral connections to each lot shown on the preliminary
plan shall be installed to the right-of-way line of the street prior
to road paving. Each building shall have a separate connection to
the Township sewer on the lot or in the abutting street, except that
garages accessory to dwellings may be connected to the dwelling line.
Laterals must be designed in accordance with Township standards.
(7)
On-site sewage disposal facilities. Whenever it is impracticable to connect with Township sewers, on-site sewage disposal facilities may be permitted upon application and approval by Montgomery County and the Pennsylvania Department of Environmental Protection. Such facilities shall be so located as to permit easy and economical connection to the sewer system of the Township when sewers are installed, except where this requirement is waived under Subsection B(1) above.
A.
Stormwater management. Whenever an increase in volume and/or rate of runoff will occur as the result of subdivision or land development, the developer will be required to provide adequate stormwater management facilities in accordance with Chapter 121 of this Code and provide financial security for the completion of those facilities as set forth in this Chapter. The design of all stormwater management facilities shall be in accordance with Chapter 121 of this Code and submitted to the Township Engineer for review and, when required, to the Pennsylvania Department of Environmental Protection or the United States Department of Agriculture, Soil Conservation Service. Where retention basins and/or other facilities are required, the responsibility for the continued maintenance and operation of the retention basins and/or other facilities shall be the obligation of the property owner or the homeowners' association, as applicable. Any deed given for the transfer of a lot where stormwater piping and/or a retention facility is provided on a recorded lot shall refer to such structures and facilities and state that the maintenance and operation shall be the continued responsibility of the property owner or the homeowners' association, as applicable. A fence four feet in height with a self-closing gate surrounding the retention basin may be required as directed by the Township Engineer.
B.
Special drainage problems.
(1)
Unnatural drainage. Whenever construction stops or concentrates
the natural flow of storm drainage in such a way as to affect adjoining
properties, approval of the adjoining property owners must be obtained
in writing. Approval of plans by the Township does not authorize drainage
onto adjoining properties.
(2)
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 or connected
to the storm drainage system of the Township. Connections to the storm
drainage system may require easements from the Township or adjacent
neighbors and will require the approval of the Director of Public
Works and the approval of a right-of-way permit. These facilities
may not be used for toxic drainage.
C.
Runoff computations. Computation of the rate of flow at any given
location shall be based on the rational formula:
|
Q = CIA
|
|
Where:
| ||
|
Q
|
=
|
Volume in cubic feet per second.
|
|
C
|
=
|
Runoff coefficient.
|
|
I
|
=
|
Intensity of rainfall in inches per hour.
|
|
A
|
=
|
Watershed area in acres.
|
|
In setting the value of the runoff coefficient "C," consideration
will be given to the physical features of the drainage basin and the
best available data on the future density of development of the drainage
basin. In no case shall it be less than 0.40 in a developed area.
|
D.
E.
Standard headwalls shall be installed on all pipes and, additionally,
trash bars shall be installed on all pipes equal to or greater than
24 inches diameter.
F.
Pipeline design. Storm sewer pipelines shall be designed by either of the two methods described in Subsection F(1) and (2) below. Both shall be based on the Manning equation and shall utilize the friction factors:
n = 0.012 smooth-lined corrugated plastic pipe.
n = 0.015 concrete pipe.
n = 0.021 corrugated metal pipe.
The minimum allowable pipe size is 15 inches.
(1)
Pipeline submerged.
(a)
This method is based on the assumption that when the storm sewer
system is under maximum load, the hydraulic gradient will be at or
above the crown of the pipe and that flow in the lines will be controlled
by head differentials between structures or other locations where
the system is open to the ground surface, such as inlets or outlets,
manholes and stream inlets and outlets. The head of water above the
crown of any pipe can range from zero feet to a point which will not
cause surface flooding.
(b)
The slope of the hydraulic gradient in any section of storm
sewer between opening to the surface shall be calculated on the assumption
that the pipe is flowing full at a constant velocity and at the required
capacity.
(c)
The elevation of the hydraulic gradient at any point in the
pipe shall be no lower than the crown of the pipe and no higher than
the surface of the ground.
(d)
The elevation of the hydraulic gradient at any point where the
system opens to the surface, such as an inlet or manhole, shall be
no higher than one foot below the surface of the ground.
(e)
Head losses at inlet structures, manholes, cleanouts, etc. shall
be based on formulas provided by the Federal Highway Administration's
HEC-22 - Urban Drainage Design Manual; Energy Losses. Where the inlet
and outlet pipe sizes are not the same, the elevation of the hydraulic
gradient shall be dropped an amount based on the following formula:
|
H = 0.2 inches + 0.8 (D2-D1)
|
|
Where:
| ||
|
D1
|
=
|
The diameter of inlet pipe.
|
|
D2
|
=
|
The diameter of outlet pipe.
|
|
If D1 is larger than D2, head loss = 0.2 feet
| ||
(f)
The minimum slope of any pipe shall be such that a minimum velocity
of 2.5 feet per second shall be maintained when the pipe is flowing
1/4 full.
(2)
Pipeline flowing full.
(a)
This method is based on the assumption that the hydraulic gradient
will match the inside top of the pipe when the system is under maximum
hydraulic load.
(b)
For this method, head losses through manholes, inlets, etc.,
shall be ignored.
(c)
The minimum slope of any pipe shall be such that a minimum velocity
of 2.5 feet per second shall be maintained when the pipe is flowing
1/4 full. When the pipe sizes change, the inside tops of the pipes
shall be matched.
G.
Continuous profiles for each reach of pipe shall be plotted along
with the location of the hydraulic gradient and the hydraulic information
pertinent to each reach within the system. This information shall
include the pipe size and type, the "n" factor, the slope of the hydraulic
gradient, slope of the pipe, the design capacity and the velocity
at the design capacity.
H.
Inlets.
(1)
Single or PennDOT Type C (single/double) No. 1 open-mouth inlets
shall be used on streets with grades of 4% or less. Double No. 1 open
mouth inlets shall be used on streets of more than 4%.
(2)
Sufficient inlets shall be located and constructed so as to
collect all of the stormwater flow in the drainage area tributary
to the inlet for the twenty-five-year frequency storm.
(3)
The gutter of all inlets shall be set not less than two inches
nor more than four inches below the gutter grade. The surface of the
paving adjacent to the inlets shall be constructed to blend into the
lowered gutter grade at the inlet in such a manner that a sudden dropoff
or dip at the inlet will not be created. The spread of runoff in the
gutter is to be no more than half the width of one through traffic
lane, when calculated for the twenty-five-year frequency storm.
(4)
Where surface water is collected from two directions at one
street corner, inlets shall be placed at, or near, the tangent points
of both ends of the radius. The use of an inlet in the radius shall
not be allowed.
(5)
Bicycle safe grates shall be utilized, where applicable.
I.
Manholes shall be located at intervals of approximately 300 feet
where pipe sizes of 24 inches or less are used and 400 feet apart
for larger sizes. Inlets should be substituted for manholes where
they will serve a useful purpose. Manhole and inlet castings may be
purchased from the Lower Merion Department of Public Works. The Township
standard frame and lid shall be used when in the public right-of-way.
J.
Open channel design: as referenced in PA DEP's Erosion and Sediment
Pollution Control Program Manual, as amended.
(1)
Open channel design should be based on the following hydraulic
considerations:
(a)
Manning's equation.
n = 0.015 for best concrete lined ditch.
n = 0.025 for best unlined ditch.
n = 0.03 to 0.15 for fair to poor natural streams and watercourses.
(b)
Velocity.
|
Excavation Material
|
Velocity
(feet per second)
|
|---|---|
|
Fine sand and firm loam
|
2.50 to 3.5
|
|
Stiff clay and hardpan
|
3.75 to 6.0
|
|
Concrete-lined ditch
|
15
|
(2)
Ample freeboard should be provided on all channels.
(3)
The channel should be designed to conform, wherever possible,
to the adjacent ground conditions. This means that it should not be
projecting excessively above the surrounding ground or placed excessively
below the surrounding ground.
(4)
Continuous profiles for each reach of open channel shall be
plotted along with the adjacent average ground and the hydraulic information
pertinent to each reach within the system. This information shall
include the type of channel lining, the "n" factor, the width of the
channel bottom, the side slopes, the water depth, the design capacity
and the velocity at the design capacity.
K.
Bridges and culverts. Single-opening culverts are desirable. The
design of culverts shall be such as to minimize the probability of
debris accumulation. Bridges and culverts shall be designed to meet
current Pennsylvania Department of Transportation standards to support
expected loads and to carry expected flows. They shall be constructed
for the full width of the right-of-way.
L.
The Pennsylvania Department of Environmental Protection, Bureau of
Water Quality Management, Division of Dams and Encroachments, requires
a permit for construction or changes in a watercourse which drains
an area of more than 1/2 square mile. No open watercourses shall be
permitted within the right-of-way of any street.
M.
Location. Wherever practicable, storm drains shall be located behind
the curb and within the right-of-way of the street. They shall be
protected by a cover of at least 18 inches. The plan shall note that
the continued maintenance of storm drains outside the street right-of-way
shall be the responsibility of the property owner. Storm drains located
within a private right-of-way are the responsibility of the property
owner.
N.
Stormwater roof drains shall connect to stormwater infiltration BMPs,
where practicable. Stormwater roof drains immediately adjacent to
a sidewalk shall not discharge water over a sidewalk but shall extend
under the sidewalk to the gutter. Where accessible, the roof drains
shall be connected with the storm drainage system of the Township,
upon the approval of the Director of Public Works.
O.
All sump pump discharges must either discharge on-site or make an
underground connection to the Township storm collection system. No
discharges are allowed at the curbline.
(Reserved)
(Reserved)
