[Amended 9-14-1987 by Ord. No. 136]
Unless specified otherwise by the Board of Supervisors,
all new streets or widened portions of all existing public rights-of-way
intended for public use shall be dedicated to the township. However,
where a development abuts a state-owned right-of-way, the applicant
shall request the appropriate state agency to accept dedication. In
the absence of a specific legal record to the contrary, the center
line of any existing right-of-way for a street is to be determined
by a licensed professional surveyor and the Township Engineer.
A. Street system.
(1) Conformance with adopted plans. The proposed street
pattern shall conform to existing streets, to the township plan of
streets and to such county and state road and highway plans as have
been duly adopted.
(2) Arrangement. Streets shall be arranged in a manner
to meet with the approval of the Board of Supervisors considered in
relation to both existing and planned streets and located so as to
allow proper development of surrounding properties. Secondary and
through highways shall be connected with such existing streets and
highways so as to form continuations thereof. Residential streets
shall be laid out so as to discourage their use as secondary streets
or through highways.
(3) Conformity with topography. Streets shall be adjusted
to the contour of the land so as to produce usable lots and streets
of reasonable grade, alignment and drainage.
(4) Grading. Streets shall be graded to the full width
of the ultimate right-of-way and provision made for slopes beyond
the ultimate right-of-way in conformance with township specifications.
(5) Provisions of streets for future development. Access
shall be given to all lots and portions of the tract in the subdivision
and to adjacent unsubdivided territory. Streets giving such access
shall be improved to the limits of the subdivision. Remnants, reserve
strips and landlocked areas shall not be created.
(6) New streets. New streets shall be designed to continue
existing streets at equal or greater right-of-way and cartway width,
where practical.
(7) Dead-end streets. Dead-end streets are prohibited unless designed as culs-de-sac or designed for future access to neighboring tracts. In the case of the latter, the requirements of Subsection
C of this section shall be met.
(8) Street names. Continuations of existing streets shall
be known by the same name. Names for new streets shall not duplicate
or closely resemble names of existing streets. All street names are
subject to the approval of the Township Planning Commission and the
Board of Supervisors.
(9) Half streets. The dedication of half streets at the
edges of a new subdivision is prohibited. If circumstances render
this impracticable, adequate provision for the concurrent dedication
of the remaining half of the street must be furnished by the subdivider,
developer or builder. When there exists a half street in an adjoining
subdivision, the remaining half shall be provided by the proposed
development.
B. Street alignment.
(1) Sight distance on horizontal and vertical curves.
Proper sight distance should generally be provided with respect to
both horizontal and vertical alignments. Measured along the center
line, this should be 800 feet for primary roads; 400 feet for secondary
roads; and 200 feet for local residential streets as related to posted
speed limits and measured at the center line and at a driver's eye
height of 3.75 feet.
(2) Horizontal curves shall generally be used at all changes
in excess of 2º and shall consider distance, change in grade,
alignment and friction. Long radius curves shall be used rather than
a series of curves connected by short tangents; minimum radius curves
at the end of long tangents.
(a)
Curvature. The minimum radius at the center
line for horizontal curves on primary streets shall be 300 feet; for
secondary streets, 200 feet; and for all other streets, 150 feet.
(b)
Tangents between curves. Except for local streets
there shall be a tangent of at least 100 feet measured at the center
line between reverse curves.
(3) Vertical curves. Vertical curves shall be used at
changes in grade of more than 1%. The length of the curve shall approximate
50 feet on secondary streets and 25 feet on all other streets for
each 1% of change in grade. Over summits or in sumps, vertical curves
shall not produce excessive flatness in grade. The high or low point
on a vertical curve must be definitely and clearly shown. All vertical
curves shall comply with American Association of State Highway Officials
standards.
(4) Street grades.
(a)
There shall be a minimum grade of at least 1%
on all streets.
(b)
Maximum grade. There shall be a grade of 7%
on primary and secondary streets, and 10% on all other streets for
distances of not more than 1,500 feet. However, grades in excess of
5% shall be avoided wherever possible. The grade shall be measured
along the center line.
(c)
Curve-grade combinations. A combination of minimum
radius horizontal curves and maximum grades will not be approved.
(d)
Street intersections. The grade within 50 feet
of any side of an intersection or the outer perimeter of a cul-de-sac
shall not exceed 4%. The grade shall be measured along the curbline
of the street.
(e)
Street grading. All streets shall be graded
to the grades shown on the street profile and cross-section plan submitted
and approved with the preliminary plan of subdivision and land development.
They shall be inspected and checked for accuracy by the Township Engineer.
C. Right-of-way width, paving width and curbing.
(1) Classification. All streets will be classified as
"marginal access," "rural," "residential," "cul-de-sac," "secondary"
or "primary" and shall be governed as follows.
(2) The minimum widths of the right-of-way and the paving
and the requirements for curbing shall not be less than those of an
existing street of which the new street is to be a continuation, nor
less than the following:
(a)
Marginal access streets. Marginal access streets
serve as minor streets for access to adjacent properties on only one
side of the street. This type of street runs parallel and adjacent
to a primary or secondary street and serves to reduce the number of
access points which intersect the larger streets, thereby increasing
the efficiency and safety of traffic flow along the major street while
providing adequate access to abutting development. All marginal access
streets shall consist of an additional right-of-way abutting and measured
from the ultimate right-of-way line of the major street as defined
by the Township Official Map Summary.
[1]
The Township Engineer shall stipulate curbing
type, grass strip size and cartway width.
[2]
In addition to the above regulations, marginal
access streets shall meet the following standards:
[a] Marginal culs-de-sac will meet
marginal street regulations with a standard cul-de-sac turnaround
at the closed end.
[b] Where marginal access streets form
a necessary leg of another classification of street, they shall be
governed by the regulations of the other street classification.
[c] Where sidewalks do not exist or
should be replaced, they shall be installed in the outermost portion
of the right-of-way of the marginal street.
(b)
Residential streets. Residential streets shall
be those which are used strictly to serve residential areas and do
not serve as through streets in a development. They shall have a minimum
right-of-way width of 50 feet and shall have a minimum paved width
of 30 feet. Construction of the street, curbing and sidewalk shall
be in accordance with specifications hereinafter included in these
standards.
(c)
Cul-de-sac streets. Cul-de-sac streets shall
be those streets with one end open for vehicular access and the other
terminating in a vehicular turnaround or a "P" loop road, further
defined as follows:
[Amended 6-17-2008 by Ord. No. 348]
[1]
Permanent cul-de-sac streets with vehicular
turnaround:
[a] Shall be constructed to the specifications
of street curbing and sidewalks hereinafter included in these standards.
No parking shall be permitted in the bulb of the cul-de-sac (with
and without landscaped islands).
[b] Shall not be less than 250 feet
nor more than 750 feet in length, as measured from the center line
of the through street to the center of the cul-de-sac turnaround.
[c] A maximum of five curb depressions
are permitted on the bulb of the cul-de-sac, with the bulb beginning
at such points as the street right-of-way exceeds the standard parallel
width.
[d] Culs-de-sac in all residential
zoning districts shall contain a landscaped island in the turnaround
that shall meet the following design standards:
[i] For turnarounds, the cul-de-sac
shall be provided with a circular vehicular turnaround at the closed
end comprised of a twenty-six-foot-wide curbed and paved cartway with
an inside radius of 60 feet and an outside radius of 86 feet, within
a right-of-way with an inside radius of 50 feet and outside radius
of 96 feet.
[ii] At the closed end of the cul-de-sac,
there shall be a landscaped island with a radius of 50 feet which
meets the following requirements:
[A] The landscaped island shall be
owned and maintained by a homeowners' association. The bylaws of the
homeowners' association, and all documents governing ownership, maintenance
and use restrictions for common facilities, shall be submitted to
and approved by the Township Board of Supervisors, in consultation
with the Township Solicitor.
[B] Provisions for snow storage shall
be provided in all turnaround islands. A snow storage easement shall
be shown on the plans.
[C] The landscaping of the island is
to be designed by a landscape architect and the islands are to be
designed for stormwater management and infiltration in accordance
with the Stormwater Ordinance, where feasible.
[e] Culs-de-sac in nonresidential zoning
districts shall be provided with a circular vehicular turnaround at
the closed end with a minimum outer paved radius of 60 feet within
a minimum right-of-way radius of 70 feet. Additional cartway and/or
right-of-way radius may be required. A snow storage easement shall
be provided at the rear of the cul-de-sac bulb. The easement shall
be centered on the projection of the cartway center line into the
bulb right-of-way and adjoining lot for a minimum depth of 15 feet
from the right-of-way and a minimum arc length width of 50 feet, or
as may be modified at the discretion of the Township Board of Supervisors
upon advice of the Public Works Director and Township Engineer.
[f] The Fire Marshal shall review all
proposals for culs-de-sac to determine the need for an emergency vehicular
access. The requirement for, location of and design of the emergency
vehicular access shall be subject to the Fire Marshal's approval.
[2]
Temporary cul-de-sac streets with vehicular
turnaround:
[a] May be temporarily closed at one
end, with the intent to extend the street onto the abutting tract
upon its development.
[b] Shall be built to the tract boundary
line at a location and grade that are logical for extension onto the
abutting tract, but shall not exceed 750 feet in length.
[c] Shall not be extended as a cul-de-sac
street, but shall be connected to another through street.
[d] Shall form a logical step in the
circulation pattern of the area in which it is located.
[e] Shall be provided with a vehicular
turnaround at the closed end, abutting the tract boundary, with a
paving radius of at least 42 feet.
[i] Construction shall meet the same
requirements as for a permanent cul-de-sac turnaround with the exception
of the dimensional requirements.
[ii] Those portions of the turnaround
extending beyond the standard street right-of-way shall be located
on temporary access easements, valid only until the road is extended.
[iii] Upon extension of the street,
the full rights and responsibilities for the area of the temporary
easements shall revert to the owners of the lots on which they were
located.
[f] The developer responsible for extension
of the street shall also be responsible for the following:
[i] Removal of all curbing and paving
of the temporary turnaround beyond the width of the street's cartway.
[ii] Installation of new sidewalk,
curbing and cartway paving to complete the street connection.
[iii] Extension of utilities as necessary.
[iv] Repair of any improvements damaged
in the process.
[v] Grading, installation and/or restoration
of lawn areas where affected by this removal and construction process.
[3]
Permanent "P" loop roads:
[a] Shall be constructed to the specifications
of street curbing and sidewalks hereinafter included in these standards.
[b] Shall not be less than 250 feet
nor more than 800 feet in length, as measured from the center line
of the through street to the center line of the intersecting streets
that form the loop.
[c] Shall only be accessed by a boulevard
entrance with a minimum right-of-way of 60 feet. A landscaped island
in the boulevard entrance shall be provided that meets the following
design standards:
[i] At the center of the boulevard
there shall be a ten-foot-wide island which meets the following requirements:
[A] The landscaped island shall be
owned and maintained by a homeowners' association. The bylaws of the
homeowners' association and all documents governing ownership, maintenance
and use restrictions for common facilities shall be submitted to and
approved by the Township Board of Supervisors, in consultation with
the Township Solicitor.
[B] The landscaping of the island is
to be designed by a landscape architect.
[d] A minimum of six full-frontage
lots and a maximum of 15 lots will be permitted on the "P" loop portion
of the roadway. This includes all lots on the outside and within the
"P" loop.
(d)
Secondary streets. Secondary streets shall be
defined in two ways:
[1]
A secondary feeder street shall be those which
are used as connecting and through streets to serve residential areas
and to connect residential streets to collector roads and community
facilities, with light traffic volumes. They shall have a minimum
right-of-way of 60 feet and shall have a minimum paved width of 36
feet. Construction of the street, curbing and sidewalk shall be in
accordance with specifications hereinafter included in the standards;
[2]
A secondary collector street will serve to connect
feeder streets and residential streets to other feeder roads, community
facilities, and major highways, with medium traffic volume. Additionally,
collector streets may also serve business or industrial areas. They
shall have a minimum right-of-way width of 80 feet and shall have
a minimum paved width of 40 feet.
(e)
Primary streets. Primary streets connect population
centers or communities serving large volumes of fast-moving through
traffic and shall be defined in three ways:
[1]
Limited access highways that deny access to
adjacent property owners and provide access at only a limited number
of grade-separated interchanges. They shall have a minimum right-of-way
of 150 feet, widened appropriately at interchanges, containing:
[a] Four twelve-foot travel lanes (minimum).
[c] Median (four-foot minimum).
[d] Acceleration and deceleration lanes.
[e] Entrance and exit roadways.
[2]
Controlled access highways which provide for
access at a few grade-level intersections (e.g., with other major
streets, large shopping centers, etc.). They shall have a minimum
right-of-way of 100 feet, appropriately widened at intersections for
turning lanes, channelization, etc., and containing:
[a] Four twelve-foot travel lanes.
[c] Four-foot median (minimum).
[3]
Semicontrolled access highways which place lesser
restrictions on the access of adjacent property owners by providing
more frequent access points at grade-level intersections (e.g. with
secondary streets, marginal access streets etc.). They shall have
a minimum right-of-way of 100 feet, appropriately widened at intersections
for turning lanes, channelization, etc., and containing:
[a] Four twelve-foot travel lanes.
[b] Two eight-foot shoulders.
D. Street width. The following general standards shall
apply to street width.
(1) The minimum width of the right-of-way and paving and the requirements for curbing shall not be less than those of an existing street of which the new street is to be a continuation, nor less than as required above in Subsection
C.
(2) Minimum right-of-way width for development along existing
streets shall correspond with ultimate right-of-way for these streets,
as defined on the Township Official Map Summary.
(3) The area between an existing right-of-way line and
the ultimate right-of-way line should be offered for dedication to
the authority having jurisdiction over the road when land is subdivided
or developed along an existing right-of-way.
(4) Islands, medial strips and channelization may be required
in any area where traffic volumes warrant their use for safety and
efficiency, and may be permitted in any area at the discretion of
the Board of Supervisors. Such devices on state roads must meet or
exceed the requirements of the Pennsylvania Department of Transportation.
(5) Additional widths may be required by the township:
(a)
Where necessary for public safety and convenience.
(b)
For parking in commercial or industrial areas.
(c)
Where old roads do not provide the proper width
and additional dedication is necessary.
(6) No fences, hedges, trees, shrubbery, walls, plantings
or other obstructions shall be located or be permitted within the
right-of-way except for ground covers such as grass, ivy, crown-vetch
or horizontally spreading shrubs less than one foot high, or retaining
walls necessitated by road widening and constructed by the authority
having jurisdiction over the road.
E. Alleys. Alleys are prohibited in residential developments.
In commercial or industrial districts without expressly designed loading
areas, alleys with a minimum width of 25 feet shall be required. Where
such alleys dead-end, they shall be provided with a turnaround having
a radius of not less than 25 feet. The cartway shall be a minimum
of 20 feet. Exceptions may be made when an alley from an adjacent
borough is extended into the township.
(1) The paving requirements shall be the same as for street
paving.
(2) Intersections of right-of-way lines shall be rounded
by a tangential arc, the minimum radius of which shall be 10 feet,
and the edge of the paving at intersections shall be rounded by a
tangential arc the minimum radius of which shall be 15 feet.
(3) No fences, hedges, trees, shrubbery walls, plantings
or other obstructions shall be located within the right-of-way. Reasonable
sight distance shall be provided at intersections with streets.
F. Paving. The minimum pavement for all residential streets
and all commercial, industrial and multifamily parking areas and driveways
shall be installed as shown on the final plan and in accordance with
the following standards. The Township Engineer may establish more
stringent requirements for higher class highways and special industrial
and commercial uses.
(1) General. All paving shall be constructed, both as
to materials and methods, generally in conformance with applicable
portions of the Pennsylvania Department of Transportation Specifications
Form 408, current edition. Size and dimensions shall be set forth
in these regulations.
(2) Pavement design. The pavement shall have a minimum
total compacted depth of 14 1/2 inches consisting of one-inch screenings
under 10 inches of crushed aggregate base course and 3 1/2 inches
of bituminous surface course ID-2A [two inches binder and 1 1/2 inches
wearing in separate application] conforming to the Pennsylvania Department
of Transportation Specifications Form 408.
(3) Paving cross section. All pavements, except where
superelevated for curbs, shall have a minimum slope from the center
of the road to the gutter line of 1/4 inch per foot and a maximum
slope of 3/8 inch per foot.
G. Street intersections.
(1) Number of intersections. No more than two streets
shall cross at the same point. Four-way intersections are to be avoided
in the layout when three-way or T-intersections can be utilized. When
existing streets intersect at odd angles, or have more than four approaches,
the subdivider, developer or builder shall be required to make corrective
changes to eliminate the odd angle or reduce the number of approaches
to the intersection by curving the lesser street.
(2) Minimum angle of intersection. Right angle of intersections
shall be used whenever practicable, especially when local streets
empty into major or secondary streets. There shall be no intersection
angle, measured at the center line, of less than 90º minimum.
(3) Center line. Where center lines of residential or
secondary streets open into opposite sides of a major street within
100 feet of each other they shall be made to coincide by curving the
minor street or streets.
(4) Primary thoroughfare. Wherever practicable, intersections
with through highways shall be kept to a minimum and shall be located
at least 800 feet apart.
(5) Sight distance. Proper sight lines shall be maintained
at all intersections of streets. There shall be measured along the
center line a minimum clear sight triangle of 75 feet from the point
of intersection. No building, trees, hedge, shrubbery or other obstruction
whatsoever will be permitted in this area. Any obstruction to sight
shall be removed at the time a building or structure is erected, whichever
shall first occur.
(6) Maximum grade. Maximum grade within any intersection
shall not exceed 1%, and approaches to an intersection shall follow
a straight horizontal course for 100 feet.
(7) Approach grades. All approaches to an intersection
shall not exceed 4% for a distance of 50 feet measured from the nearest
right-of-way line of the intersecting street.
(8) Radii of pavement and right-of-way at intersections.
Street intersections shall be rounded with tangential arcs at pavement
edge (curbline) and right-of-way lines as listed below. Where two
streets of different right-of-way widths intersect, the radii of curvature
for the widest street shall apply.
|
Type of Street
|
Minimum Radius of Arc at Intersection
of Pavement Edge or Curbline
(feet)
|
Minimum Radius of Arc at Intersection
of Right-of-Way Line
(feet)
|
---|
|
Primary
|
35 (or more as may be required)
|
20 (or more as may be required)
|
|
Secondary
|
35
|
20
|
|
Residential
|
25
|
15
|
|
Cul-de-sac
|
25
|
15
|
H. Ownership and maintenance of streets. New roads designed to Township
specifications shall be offererd to the Township for dedication for
ownership and maintenance via a note on the record plan and through
deeds of dedication. Private roads to be owned and maintained by a
homeowners' association shall be designed to meet the minimum Township
specifications. An easement shall be provided over private roads and
associated sidewalk to benefit the Township and memorialized by an
easement agreement.
[Added 1-20-2020 by Ord.
No. 409]
I. Street signs.
[Added 1-20-2020 by Ord.
No. 409]
(1) All streets, both public and private, shall be properly marked with
street signs in a manner and form acceptable to the Township. Existing
street signs are grandfathered until such time as they need to be
replaced. New street signs shall comply with the following specifications:
(a) The sign and pole on which the sign is mounted shall meet the approved
current Township and/or Pennsylvania Department of Transportation
standards and specifications for street signs as set forth within
the current edition of the Manual on Uniform Traffic Control Devices,
as amended (MUTCD).
(b) The text shall be in reflective white letters and/or numbers in accordance
with the minimum retro-reflectivity requirements of the MUTCD.
(c) The sign shall be located on a pole at least seven feet tall.
[Amended 9-14-1987 by Ord. No. 136]
Plain cement concrete curb shall be constructed
along all existing streets and roads and along both sides of a new
interior street unless the Board of Supervisors shall otherwise direct
that this construction shall be postponed or eliminated. All commercial,
industrial and multifamily parking areas and driveways shall have
curbs where pavement edge and grass meet. The size and type shall
be as specified by the Township Engineer according to a design detail
as furnished by said Engineer. All curbing shall be constructed, both
as to materials and methods, generally in conformance with applicable
portions of Pennsylvania Department of Transportation Specifications
Form 408, current edition. Intersections where sidewalks are provided
shall be provided with depressions for wheelchair use.
Except where a structure was obviously built
to house more than one family, but where heretofore that structure
and the surrounding property was held in single and separate ownership,
and further where such a subdivision is proposed for the purpose of
separating such a structure into two or more ownership parcels, no
subdivision or land development will be approved with the property
line extending through any portion of any existing structure.
A. If structure(s) is to remain.
(1) In residential zoning districts of the township, the
lot size and the lot dimensions of the newly created lot containing
the structure(s) must be in scale with the height and bulk of the
structure even if this requires a lot area and/or dimensions exceeding
the minimum zoning requirement for that district. Structures proposed
on the vacant portions of lands being subdivided shall conform, to
the extent possible, to the height, bulk, building material and architectural
character of the existing structures in the immediate vicinity and
the subdivision plans shall show building plans at suitable detail.
(2) In other zoning districts of the township (especially
commercial and industrial districts), the subdivision of the land
must provide adequate service and parking facilities, etc., in keeping
with the minimum requirements of the Zoning Ordinance for each lot and cumulatively for all lots in the subdivision.
No subdivision will be approved in such instances if the servicing
and/or parking facilities, etc., attendant to the existing structure
are deemed inadequate or would be considered to become inadequate
with the development of the now vacant lands. Any new structures contemplated
on the newly subdivided parcels shall be in conformity with the existing
structures in the immediate vicinity to the extent possible in regards
to height, bulk, building material and architectural character and
the subdivision plans shall show building plans at suitable detail.
(3) Alterations and replacements will be permitted within
the existing structure, but exterior extensions of the building must
conform to the requirements of the Franconia Township Zoning Ordinance.
B. If an existing structure(s) is to be removed, subdivision
approval will be issued conditional upon the expeditious removal of
existing structures in complete conformity with all other pertinent
township procedural requirements. The subdivision plans shall furthermore
show in detail the proposed development of each parcel of ground,
and the proposed development shall not provide less service and parking
facilities, etc., than now exist. In commercial and industrial areas,
plots of land that have been cleared, as well as the existing vacant
portions of such lands, should be developed in conformity with the
long-range needs of the area to the extent possible, and all developmental
requirements embodied in the Township Subdivision Regulations and
Zoning Ordinance shall be adhered to. If roadway realignments and other
similar requirements are deemed necessary in the immediate vicinity
of the plot being subdivided, they shall be corrected as part of the
subdivision design to the utmost of the subdivider's ability.
C. If an existing structure is to be partly replaced
or is to be added on to. Demolition plans and/or construction plans
must be detailed as part of the subdivision plan review, and subsequent
subdivision approval will be conditional upon compliance with said
proposed details. Additions to existing structures shall be in harmony
with existing structures in the immediate vicinity, especially in
respect to height, bulk, building material and architectural characteristics.
In the case of partial demolition of existing structures, the remaining
structure must be in keeping with the existent buildings in the immediate
vicinity in relation to type, bulk, building materials and architectural
characteristics. Renovation work to the remaining portion of a structure
following partial demolition must be completed promptly and expeditiously.
[Amended 8-18-2014 by Ord. No. 377]
A. Site excavation and fill. No permanent excavation or fill shall be
made with a face steeper in slope than two to one except under one
or more of the following conditions:
(1) The excavation or fill is located so that a line having a slope of
1 1/2 horizontal to one vertical and passing through any portion
of the face will be entirely inside of the property lines of the property
on which the excavation or fill is made.
(2) The material in which the excavation or fill is made is sufficiently
stable to sustain a slope of steeper than two to one, and a written
statement of a civil engineer, licensed by the Commonwealth of Pennsylvania
and experienced in soil engineering, to that effect is submitted to
the Township Engineer and approved by him. The statement shall state
that the site has been inspected and the deviation from the slope
specified hereinbefore will not result in injury to persons or damage
to property.
(3) A concrete or stone-masonry wall constructed according to present
or future designs of the Township of Franconia is provided to support
the face of the excavation or fill.
B. Slopes and fences. The top or bottom edge of slopes shall be a minimum
of three feet from property or right-of-way lines of streets or alleys
in order to permit the normal rounding of the edge without encroaching
on the abutting property. All property lines (where walls or slopes
are steeper than one horizontal to one vertical and five feet or more
in height) shall be protected by a chain-link fence four feet in height
approved by the Township. The fence shall be an integral part of the
wall.
C. Site grading plan. The Township Engineer shall require a grading
plan in conjunction with the plan of subdivision, land development
or regulated earthmoving activity in order to ensure compliance with
the above standards and the provisions of a separately enacted Grading
Ordinance.
D. A stormwater and watershed management plan shall be provided in accordance with the requirements of Article
X for all regulated activities over 5,000 square feet (1,000 square feet in the Neshaminy Watershed), including post-construction stormwater management facilities, each of which shall include an operations and management plan.
Amended 9-14-1987 by Ord. No. 136; 5-16-2005 by Ord. No.
331; 8-18-2014 by Ord. No. 377]
A. Design requirements.
(1) Storm drains, storm and surface drainage. All storm drains and drainage
facilities, such as gutters, catch basins, bridges and culverts, shall
be installed and the land graded for adequate drainage as shown on
the grading plan submitted and approved with the preliminary plan.
Surface grading of nonpaved surfaces shall be of a minimum grade of
2% (0.02 foot per foot), except where underdrain is provided within
designed channels such minimal surface grade shall be 1% (0.01 foot
per foot).
(2) When required:
(a)
Storm drains and appurtenances shall be required to be constructed
by the subdivider to take surface water from the bottom of vertical
grades, where gutter flows exceed one half the lane width of a highway,
in channels where flow velocity exceeds the ability of the channel
lining to resist erosion or degradation, where underdrain is necessary
to lead water away from springs and to avoid excessive use of cross
gutters at street intersections and elsewhere. All surface waters
shall be enclosed in storm drainage structures except where the stormwater
management and watershed plan encourages designed infiltration in
surface water channels or natural channels are maintainable.
[1]
Open watercourses are to be preserved where they exist naturally
and where, in the opinion of the departments affected, they will not
interfere with public convenience or safety, but in fact will provide
comparable or superior drainage capabilities of piped drainage. Stabilization
design of eroding natural waterways shall be incorporated with the
stormwater and watershed management plan.
[2]
When submitting a plan for approval involving the construction
of storm drainage facilities, the designer's computations shall be
submitted in duplicate to facilitate the checking of design.
[3]
Design of storm drainage facilities shall be completed in accordance
with accepted engineering practices in conjunction with standards
and approval to be given by the Township Engineer.
(b)
Storm drainage facilities, including PCSWM, shall be designed so that the peak discharge of runoff after development for the design storm shall be no more than the peak flow before the development was undertaken or the less under Article
X, Stormwater and Watershed Management. For development and redevelopment sites, the ground cover used to determine the existing conditions runoff volume and flow rate for the developed portion of the site shall be based upon actual land cover conditions. If the developed site contains impervious surfaces, 20% of the impervious surface area shall be considered meadow in the model for existing conditions.
(3) 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.
(4) Size, grade and type. Storm drains shall be adequate for the anticipated
runoff when the area is fully developed as permitted by zoning. They
shall have a minimum internal diameter of 18 inches and a minimum
grade of 1/2 of 1% unless otherwise approved by the Township Engineer.
Storm drainage piping beneath paved surfaces, adjacent and/or within
paved surfaces and/or highway right-of-ways, or as may be directed
by the Township Engineer, shall be reinforced concrete pipe of the
appropriate design class.
(5) Change in direction. Special curved storm drain sections may be used
where abrupt changes are made in alignment in lieu of constructing
manholes only for pipe sizes over 30 inches in diameter and with permission
of the Township Engineer.
(6) Manholes. Manholes shall be constructed at all changes in horizontal
or vertical alignment, shall be spaced not more than 300 feet apart
on pipe of 24 inches' internal diameter or less, and not more than
400 feet apart where larger sizes are installed. Inlets may be substituted
for manholes where they will serve a useful purpose.
(7) Inlets. Inlet spacing shall be so arranged that 95% of the gutter
flow will be captured. Inlets should be spaced to intercept sufficient
flow to handle at least 1/2 of the traveled cartway lane. No inlet
smaller than Franconia Standard Type 4 Foot Special Inlet shall be
used on streets with grades of 4% or less. Franconia Standard Type
6 Foot Special Inlets shall be used on streets with grades of more
than 4%. Inlets at street intersections shall be placed on the tangent
and not on the curved portions. The gutter adjacent to and immediately
upgrade from the inlet shall be so warped as to direct the water into
the inlet.
(8) Castings. Manhole and inlet castings, together with their covers
or gratings, shall conform to Pennsylvania Department of Transportation
or Township standards, as may be in effect at the time the design
of the sewer is submitted.
(9) Stormwater roof drains. Stormwater roof drains and pipes shall not
discharge water over a sidewalk but shall be either infiltrated into
a designed infiltration system or extended under the sidewalk into
the storm sewer collection system.
(10)
Unnatural drainage. Wherever construction stops or concentrates
the natural flow of storm drainage in such a way as to affect adjoining
properties, approval of the owners should be obtained in writing and
a copy filed with the Township Manager. Approval of plans by the Township
does not authorize or sanction drainage affecting adjoining properties.
(11)
Drainage from nonnatural sources. Water originating from other than natural sources, such as air conditioning, dwelling units, sump pumps or other dry-weather flow, shall be treated in accordance with DEP NPDES requirements and Article
X. It is desirable that the engineer seek to avoid the discharge of water under the sidewalk through the curb into the gutter except as may be allowed under Article
X.
(12)
Stormwater facility setbacks. Separation distances between stormwater
facilities and buildings shall be in accordance with the guidelines
of the PA BMP Manual, latest revision, and site layout shall consider
the effect of infiltration facilities on nearby basements. The site
layout and construction of new aboveground stormwater facilities shall
be controlled by the following regulations:
[Added 1-20-2020 by Ord.
No. 409]
(a)
Single-family residential uses. For all single-family residential
uses, no part of any aboveground stormwater facility shall occupy
more than 25% of the required yard area, measured as to linear dimension
or surface area. Aboveground stormwater facilities shall be located
on the perimeter of the lot, shall be entirely within the lot lines,
and shall be located as far from the dwelling as possible in order
to provide a reasonable amount of usable yard space. No aboveground
stormwater facilities shall be located closer than a distance equal
to the minimum required rear yard setback for the zoning district
in which they are located from a building, whether on the same lot
or any adjacent lot as measured from the 100-year high water surface
elevation on the inside of the emergency spillway.
(b)
Multifamily residential uses. For all multifamily residential
uses where the lot is used for residential purposes, no part of any
aboveground stormwater facility shall be located in the required yard
area of any individual dwelling unit. No part of any aboveground stormwater
facility shall occupy more than 35% of the required yard area, measured
as to linear dimension or surface area, of any required yard. No aboveground
stormwater facilities shall be located closer than a distance equal
to the minimum required rear yard setback for the zoning district
in which they are located from a building, whether on the same lot
or any adjacent lot as measured from the 100-year high water surface
elevation on the inside of the emergency spillway.
(c)
Nonresidential uses. For all nonresidential uses, no part of
any aboveground stormwater facility shall occupy more than 15% of
the required yard area, measured as to linear dimension or surface
area. No aboveground stormwater facilities shall be located closer
than a distance equal to the minimum required rear yard setback for
the zoning district in which they are located from a building, whether
on the same lot or any adjacent lot as measured from the 100-year
high water surface elevation on the inside of the emergency spillway.
B. Design submission and supporting computations.
(1) Stormwater runoff calculations shall use a generally accepted calculation
technique that is based on the NRCS soil cover complex method. Design
parameters shall be those in SCS TR-55. Table 122-26.1 summarizes
other computation methods that the design engineer may select as the
appropriate technique in consultation with the Township Engineer based
on the individual limitations and suitability of each method for a
particular site.
The Rational Method is an alternate technique that may be used
for drainage areas under 200 acres in consultation with the Township
Engineer. Runoff coefficients (c) for both existing and proposed conditions
shall utilize PennDOT Design Manual for this method unless otherwise
directed by the Township Engineer.
(2) All calculations consistent with the Franconia Code using the soil
cover complex method shall use the appropriate design rainfall depths
for the various return period storms according to the National Oceanic
and Atmospheric Administration (NOAA) Atlas 14, Volume 2, Version
3.0, rain data corresponding to the Perkasie, Pennsylvania, rain gauge,
as presented in Table A-1 of Appendix A of this chapter. The design storm rainfall amount chosen for design can
be obtained from the National Oceanic and Atmospheric Administration
Atlas 14 interactive website: http://hdsc.nws.noaa.gov/.
[Amended 1-20-2020 by Ord. No. 409]
(3) Runoff curve numbers (CN) for existing to be used in the soil cover
complex method, Rational Method or other selected hydrologic methodology
shall assume the existing conditions flow rate determination, undeveloped
land shall be considered as "meadow" in good condition, unless the
natural ground cover generates a lower curve number or Rational "C"
value (i.e., forest).
(4) All calculations using the Rational Method shall use rainfall intensities
consistent with appropriate times of concentration for overland flow,
with sheet flow limited to return periods from the design storm curves
from PA Department of Transportation Design Rainfall Curves (1986).
Times of concentration for overland flow shall be calculated using
the methodology presented in Chapter 3 of Urban Hydrology for Small
Watersheds, NRCS, TR-55 (as amended or replaced from time to time
by NRCS - 100 Foot Maximum Length).
(5) The designer shall consider that the runoff from proposed sites graded
to the subsoil will not have the same runoff conditions as the site
under existing conditions even if topsoiled and seeded. The designer
shall increase their proposed condition CN or C value to reflect proposed
soil conditions.
(6) The design of any stormwater detention facilities intended to meet
the performance standards of this chapter shall be verified by routing
the design storm hydrograph through these facilities using the Storage-Indication
Method. For drainage areas greater than 0.5 acre in size, the design
storm hydrograph shall be computed using a calculation method that
produces a full hydrograph. The municipality may approve the use of
any generally accepted full hydrograph approximation technique that
shall use a total runoff volume that is consistent with the volume
from a method that produces a full hydrograph.
|
Table 122-26.1
Acceptable Computation Hydrologic Methodologies For Stormwater
Management Plans
|
---|
|
Method
|
Method Developed By
|
Applicability
|
---|
|
TR-20 (or commercial computer package based on TR-20)
|
USDA NRCS
|
Applicable where use of full hydrology computer model is desirable
or necessary
|
|
TR-55 (or commercial computer package)
|
|
Applicable for development USDA NRCS plans within limitations
described
|
|
HEC-1, HEC-HMS
|
U.S. Army C.O.E
|
Applicable where use of full hydrologic computer models
|
|
PSRM
|
Penn State University
|
Applicable where use of a hydrologic computer model is desirable
or necessary; simpler than TR-20 or HEC-1
|
|
Rational Method PennDOT Design Manual (or commercial computer
package based on Rational Method)
|
|
For sites less than 200 acres, or approved by Township Engineer
|
|
Other methods
|
|
As approved by the Township Engineer
|
(7) All plans showing the proposed storm sewer construction must be accompanied
by a complete design submitted by the PA registered engineer or land
surveyor. Such design shall include hydraulic grade line, pipe full
capacity, full and partial full velocity, inlet interception efficiency
with bypass channel flow width, outfall flow spread and apron stability
sizing computations.
(8) When subdivisions or land developments are submitted to the Township
for approval in sections, a complete storm sewer design for the proposed
subdivision and land development shall be submitted. The proposed
design must include the entire tract, including all contributing upstream
drainage area(s) and projected land use.
(9) If only a section of a subdivision or land development is contemplated
for construction, the engineer shall show how he proposes to handle
stormwater from this section in order to prevent damage to adjacent
properties. If temporary construction is required, the engineer shall
include such structures in the plan submitted.
(10)
In the event that such temporary measures cannot ensure protection
to adjacent properties, then the main outfall line of the storm sewer
shall be included as part of the construction for the proposed section.
[Amended 9-14-1987 by Ord. No. 136]
In addition to the township review, for areas
greater than 25 acres a separate Department of Conservation and Natural
Resources review will be required, and for areas over five acres approval
from the Montgomery County Soil Conservation Service will be required.
A. General.
(1) For qualifying tracts, no changes shall be made in
the contour of the land; no grading, excavating, removal or destruction
of the topsoil, trees or other vegetative cover of the land shall
be commenced until such time that a plan for minimizing erosion and
sedimentation has been approved.
(2) No subdivision or land development plan shall be approved
unless there has been a plan approved by the Board of Supervisors
that provided for minimizing erosion and sedimentation consistent
with this section, and an improvement bond or other acceptable securities
are deposited with the township in the form of an escrow guaranty
which will insure installation and completion of the required improvements;
or unless there has been a determination by the Board of Supervisors
that a plan for minimizing erosion and sedimentation is not necessary.
(3) The Board of Supervisors, in its consideration of
any preliminary plan of subdivision and land development, shall condition
its approval upon the execution of measures designed to prevent accelerated
soil erosion and resulting sedimentation, as required by the Pennsylvania
Department of Conservation and Natural Resources or Franconia Township.
All applicable regulations and permit requirements of said Department
as stipulated in its Soil Erosion and Sedimentation Control Manual
shall be followed by all parties engaged in earthmoving activities.
The manual is available at the office of the Montgomery County Conservation
District, Norristown, Pennsylvania. The Township Engineer shall assure
compliance with the appropriate specifications and requirements.
B. Performance principles.
(1) Any effective method of minimizing erosion and sedimentation
can be included in the plan. Any questionable method should be discussed
with the Township Engineer prior to submission.
(2) No unfiltered stormwater coming from an area which
has been distributed shall be permitted onto an adjacent tract.
C. Responsibility.
(1) Whenever sedimentation is caused by stripping vegetation,
regrading or other development activity, it shall be the responsibility
of the person, corporation or other entity causing such sedimentation
to remove it from all adjoining surfaces, drainage systems and watercourses
and to repair any damage at his expense as quickly as possible.
(2) It is the responsibility of any person, corporation,
or other entity doing any act on or across a stream, watercourse or
swale or upon the floodplain or right-of-way thereof, to maintain,
as nearly as possible, in its present state the stream, watercourse,
swale, floodplain or right-of-way during the activity and to return
it to its original or equal condition after such activity is completed.
(3) No person, corporation or other entity shall block,
impede the flow of, alter, construct any structure or deposit any
material or thing or commit any act which will affect normal or flood
flow in any stream or watercourse without having obtained prior approval
from the township or Pennsylvania Department of Conservation and Natural
Resources, whichever is applicable.
D. Compliance with regulations and procedures.
(1) The Board of Supervisors in its consideration of all preliminary plans of subdivision and land development shall condition its approval upon the execution of erosion and sediment control measures as contained in Subsections
B,
C and
D of this section.
(2) The installation and design of the required erosion
and sediment control measures shall be in accordance with the standards
and specifications on file with the Township Engineer.
(3) Final plans for minimizing erosion and sedimentation as approved will be incorporated into the agreement and bond requirements as required under Article
IV of this chapter.
(4) The approval of plans and specifications for the control
of erosion and sedimentation shall be concurrent with the approval
of the final plans of subdivision or land development, and become
a part thereof.
(5) At such time as a building permit is applied for,
a plan of the site, including foundation outline, first floor and
garage elevations, sump pump or other surface drain locations, building
placement from lot lines, lot grading, surface water control and lot-specific
erosion and sediment control, shall be supplied with the required
building plans.
(6) Permission for clearing and grading prior to recording
of plans may be obtained under temporary easements or other conditions
satisfactory to the township.
(7) In the event that the developer proceeds to clear and grade prior to recording plans, without satisfying conditions specified under Subsection
D(6), the Board may revoke the approval of the preliminary plan.
[Added 9-16-2019 by Ord. No. 405]
The siting and construction of detention basins shall be controlled
by the following regulations.
A. Single-family residential districts. In all single-family residential districts, where the lot is used for single-family residential purposes, no part of any detention basin shall occupy more than 25% of the required yard area, measured as to linear dimension or surface area. The detention basins shall be located on the perimeter of the lot, shall be entirely within the lot lines, and shall be located as far from the dwelling as possible. If a property in a single-family residential district is used for other than a single-family residential dwelling, detention basins shall be located in accordance with Subsection
C hereof. No detention basin shall be located within 75 feet of any building, whether on the same lot or any adjacent lot.
B. Multifamily residential districts. In all multifamily residential
districts where the lot is used for residential purposes, no part
of any detention basin shall be located in the required yard area
of any individual dwelling unit. No part of any detention basin shall
occupy more than 35% of the required yard area, measured as to linear
dimension or surface area, of any district yard. No detention basin
shall be located within 75 feet of any building, whether such building
is on the same lot or any adjacent lot.
C. Nonresidential districts. In all nonresidential districts, no part
of any detention basin shall occupy more than 15% of the required
yard area, measured as to linear dimension or surface area. No detention
basin shall be located within 100 feet of any building, whether such
building is on the same lot or any adjacent lot.