[Ord. 2011-O-2, 5/25/2011, § 212]
For any of the activities regulated by this Part, the preliminary
or final approval of subdivision and/or land development plans, the
issuance of any building or occupancy permit, or the commencement
of any earth disturbance activity may not proceed until the property
owner or applicant or his/her agent has received written approval
of a stormwater management site plan from Newtown Township and an
adequate erosion and sediment control plan review by the Township
and/or by the Conservation District and NPDES permit for stormwater
discharges associated with construction activities if the proposed
land disturbance is greater than one acre.
[Ord. 2011-O-2, 5/25/2011, § 213]
1.
The stormwater management site plan shall consist of a general description
of the project including calculations, maps and plans. A note on the
maps shall refer to the associated computations and erosion and sediment
control plan by title and date. The cover sheet of the computations
and erosion and sediment control plan shall refer to the associated
maps by title and date. All stormwater management site plan materials
shall be submitted to Newtown Township in a format that is clear,
concise, legible, neat, and well organized; otherwise, the stormwater
management site plan shall not be accepted for review and shall be
returned to the applicant. The following items shall be included with
the SWM site plan:
A.
General.
(1)
General description of the project including plan contents.
(2)
General description of proposed SWM techniques to be used for
SWM facilities.
(3)
Complete hydrologic and hydraulic computations for all SWM facilities.
(4)
All reviews and letters of adequacy from the Conservation District
for the erosion and sedimentation plan as required by Township, County
or State regulations.
(5)
A general description of proposed non-point source pollution
controls.
(6)
The SWM site plan application and associated fee for all regulated activities not already paying pay fees by under the SALDO [Chapter 22] regulations.
(7)
The SWM site plan checklist (Appendix C).
B.
Plans. SWM site plan shall provide the following information:
(1)
The overall stormwater management concept for the project.
(2)
A determination of natural site conditions and stormwater management
needs. This shall include, but not be limited to:
(a)
Site Features.
1)
The location of the project relative to highways, municipal
boundaries or other identifiable landmarks.
2)
The locations of all existing and proposed utilities, sanitary
sewers, on-site septic systems, wells, stormwater BMPs and water lines
on site and within 100 feet of property lines.
3)
Proposed structures, roads, paved areas, buildings and other
impervious areas; and the listing of the total amount of impervious
surfaces and total land disturbance.
4)
The total tract boundary and size with distances marked to the
nearest foot and bearings to the nearest degree.
5)
Plan, profile and cross-section drawings of all SWM BMP's, including drainage structures, pipes, open channels, and swales. At a minimum this should include pre- and post-drainage area maps, including drainage areas to each inlet or structure, stormwater details sheets, and landscape plans (if proposing a rain garden, bioretention facilities, low impact development, or vegetative basins) or as required in the SALDO [Chapter 22].
6)
The location of all erosion and sediment control facilities.
7)
Alterations to the land surface and vegetative cover.
8)
Locations and details of retaining walls.
(b)
Natural Site Conditions.
1)
Natural features within the subject site and within 100 feet
of any boundary of the site, including, but not limited to the following:
a)
Steep slopes.
b)
Ponds.
c)
Lakes.
d)
Streams.
e)
Wetlands.
f)
Hydric soils.
g)
Hydrologic soil groups A and B.
h)
Vernal pools.
i)
Stream buffers.
j)
Open channels.
k)
Existing recharge areas.
l)
Floodplains.
m)
Prominent land forms, underlying geologic formations
and sinkholes.
n)
Woodlands and natural vegetation areas.
2)
A detailed site evaluation for projects proposed in areas of
frequent flooding, karst topography, and other environmentally sensitive
areas, brownfield areas and source water protection areas.
3)
Existing and proposed contour lines at two foot intervals.
4)
The total extent of the drainage area upstream from the site
and all down gradient receiving channels, swales and waters to which
stormwater runoff or drainage will be discharged.
(c)
The effect of the project (in terms of runoff volumes, water
quality, and peak flows) on surrounding properties and aquatic features
and on any existing stormwater conveyance system that may be affected
by the project.
(3)
The format of the plan shall include the following:
(a)
The expected project time schedule.
(b)
The name of the development, the name and address of the owner
and/or equitable owner of the property.
(c)
The tax map parcel number and the address of the site.
(d)
The date of submission.
(e)
A graphic and written scale of one inch equals no more than
50 feet.
(f)
A north arrow.
(g)
The size of the plan shall be 11 inches by 17 inches for only
plans that are not a part of a subdivision or land development submission,
or 24 inches by 36 inches or 30 inches by 42 inches.
(h)
An access easement around all stormwater management facilities
is required that would provide ingress to and egress from a public
right-of-way. The size of the easement shall commensurate with the
maintenance and access requirements determined in the design of the
BMP and as approved by the Township Engineer.
(i)
A location map showing the relation of the project site to adjoining
properties, streets, township boundaries or other identifiable land
marks.
(j)
A key map showing all existing man-made features beyond the
property boundary that would be affected by the project.
(k)
All proposed landscape and vegetative BMP measures, including
a planting schedule indicating the locations, species and sizes of
plantings and seeding as may be required, including seeding mixes
and rates.
(l)
A note on the plan indicating the location and a description
of how each stormwater management facility will be operated and maintained
and the identity and contact information with the persons responsible
for the operation and maintenance. All facilities shall meet the performance
standards and design criteria specified in this Part.
(m)
The name and address of the individual or firm preparing the
plan and if required, the name, address and seal of the registered,
professional engineer, responsible for the preparation of the plan.
(n)
The following signature block for the design Engineer: "I, (Design
Engineer), on this date (date of signature), hereby certify that the
SWM Site Plan meets all design standards and criteria of the Newtown
Township Stormwater Management Ordinance."
(o)
A statement, signed by the applicant or site owner, acknowledging
that any revision to the approved SWM site plan must be approved by
the Township and that a revised E&S plan may be required to be
submitted to the Conservation District. The statement should also
include a note acknowledging that the stormwater BMPs are fixtures
that cannot be altered or removed unless approved by the Township.
(p)
A detailed plan of all required off-site improvements.
(4)
A soil erosion and sediment control plan, where applicable,
as prepared for and submitted to Newtown Township and the Bucks County
Conservation District.
(5)
The SWM site plan shall include an operations and maintenance
(O&M) plan for all existing and proposed stormwater management
facilities.
C.
Calculations. The following information should be included in the
stormwater report and calculations:
(1)
A general description of the proposed development.
(2)
A general description of temporary and permanent accelerated
erosion control.
(3)
A general description of temporary and permanent sediment control.
(4)
A general description of stormwater management both during and
after development.
(5)
A study of the watershed, including plans, in which the site
is located to assess the impact the proposal will have on downstream
conditions.
(6)
Computations of the stormwater runoff for all points of runoff
concentration before and after development, including:
(a)
The design computations for the stormwater drainage systems,
erosion and sedimentation controls, drain pipes and inlets, runoff
control measures, volume control measures, BMPs, culverts and drainage
channels.
(b)
Computations of the stormwater runoff before, during and after
construction, including all supporting material.
(c)
The flood routing and/or storage requirement calculations.
(d)
A stage-storage curve for the detention/retention/wet basin.
(7)
The estimate development schedule for the site, including:
(a)
Stripping and/or clearing.
(b)
Rough grading and installation of erosion and sediment control
facilities and practices.
(c)
Installation of improvements, including streets, underground
utilities, buildings, driveways, parking areas, stormwater BMPs, and
other structures and facilities.
(d)
Final grading and vegetative establishment, including program
of operations for conversion of erosion and sediment controls to permanent
stormwater management facilities.
(8)
A statement describing temporary control measures and facilities
to be used during earthmoving.
(9)
A permanent stormwater management program.
(a)
A statement regarding conformance with requirements of this
Part, including BMPs.
(b)
Types, locations, dimensioned details and specifications of
stormwater management facilities and BMPs, including detailed plans
of all required off-site improvements.
(c)
Design considerations and calculations supporting the stormwater
management program.
(e)
The location and legal descriptions of rights-of-way, easements
or land offered for dedication related to the management of stormwater.
(10)
Maintenance procedures and ownership arrangements for temporary
and permanent stormwater management facilities, including BMPs.
(11)
For detention basins, the following information shall be submitted:
(a)
General description of proposed facilities and the operation
of the runoff control measures.
(b)
A sketch of the berm embankment and outlet structure, indicating
the embankment top elevation, embankment side slopes, top width of
embankment, slope of basin floor, emergency spillway elevation, outlet
structure dimensions and elevations, outlet pipe size and length,
cut-off trench location and dimensions, dimensions and spacing of
anti-seep collars and if required, temporary riser location and dimensions.
(c)
Design computations of the outlet pipe and outlet structure.
(d)
A plot of the stage/storage (acre/feet versus elevation) and
all supporting computations.
(e)
Flood routing computations and hydrographs for all required
storms.
(f)
Time of concentration and curve number computations.
(g)
A detailed plan of the trash rack and anti-vortex device, if
required.
(h)
An overflow system shall be provided to carry runoff to the
detention basins, when the capacity of the storm drain pipe system
is exceeded. The overflow system shall have sufficient capacity to
carry the run-off difference between the one-hundred-year storm peak
flow rate and the capacity of the storm drain pipe system. The one-hundred-year
storm peak shall be calculated by the soil cover complex method.
(i)
Detention basins shall not be located within floodplains; nor
within areas of floodplain soils with the exception that areas of
alluvial soils may be utilized if proof is accepted that the area
is not subject to flooding.
(j)
Detention basins shall be designed to facilitate regular maintenance,
mowing and periodic de-silting and reseeding.
(k)
The maximum slope of the earthen detention basin embankments
shall be four to one. The top or toe of any slope shall be located
a minimum of five feet from any property line. Whenever possible the
side slopes and basin shape shall conform to the natural topography.
(l)
The minimum top width of the detention basin berm shall be 10
feet.
(m)
In order to insure proper drainage on the basin bottom, a minimum
grade of 2% shall be maintained for areas of sheet flow.
(n)
Whenever possible, the emergency spillway for detention basins
shall be constructed on undisturbed ground. Emergency spillways shall
be constructed of reinforced concrete or, in lieu thereof, concrete
grass pavers. All emergency spillways shall be constructed so that
the detention basin berm is protected against erosion. The minimum
capacity of all emergency spillways shall be the peak flow rate from
the one-hundred-year design storm after development The construction
material of the emergency spillway shall extend along the upstream
and downstream berm embankment slopes. The downstream slope of the
spillway shall as a minimum extend to the toe of the berm embankment.
The emergency spillway shall not discharge over earthen fill and/or
easily erodible material.
(o)
The minimum freeboard shall be one foot. Freeboard is the difference
between the design flow elevations in the emergency spillway and the
top of the settled detention basin embankment.
(p)
Anti-seep collars shall be poured-in-place and installed around
the pipe barrel within the normal saturation zone of the detention
basin berms. The anti-seep collars and their connections to the pipe
barrel shall be watertight. The anti-seep collars shall extend a minimum
of two feet beyond the outside of the principal pipe barrel. The maximum
spacing between collars shall be 14 times the minimum projection of
the collar measured perpendicular to the pipe. A minimum of two anti-seep
collars shall be installed on each outlet pipe.
(q)
All outlet pipes through the basin berm shall be reinforced
concrete pipe with watertight joints.
(r)
Energy dissipating devices (rip-rap, end sills, etc.) shall
be placed at all basin and pipe outlets.
[Ord. 2011-O-2, 5/25/2011, § 214]
1.
Newtown Township shall require receipt of a complete stormwater management
site plan, as specified in this Part.
A.
Proof of application or documentation of required permit(s) or approvals
for the programs listed below shall be part of the plan:
(1)
NPDES permit for stormwater discharges from construction activities.
(2)
DEP joint permit application.
(3)
PennDOT highway occupancy permit.
(4)
Chapter 105, "Dam Safety and Waterway Management."
(5)
Chapter 106, "Floodplain Management."
(6)
Any other permit under applicable State or Federal regulations.
B.
The plan shall be coordinated with the State and Federal permit.
For regulated activities requiring permits from Pennsylvania DEP or
the U.S. Army Corps of Engineers, the applicant shall make all submittals
directly to the agency with all required submittal documents and fees.
Proof of application or documentation of required permit(s) and approvals
must be submitted as part of the plan.
C.
For regulated activities the stormwater management site plan shall
be submitted by the developer to the Zoning/Code Enforcement Officer
either as part of the preliminary plan submission for the subdivision
or land development or as a SWM site plan application for any other
regulated activity.
D.
Five copies of the stormwater management site plan shall be submitted.
Distribution of the stormwater management site plan shall be made
by the Zoning/Code Enforcement Officer, as follows:
E.
Additional copies shall be submitted as requested by the Township, County or DEP. All stormwater management site plans submitted as part of a subdivision or land development shall follow the submission requirements of the SALDO [Chapter 22].
F.
The applicant shall make submissions to the Bucks County Planning
Commission and/or the Bucks County Conservation District, as required.
G.
The stormwater management site plan shall be accompanied by the requisite
fee and escrow.
H.
Any submissions to the agencies listed above that are found to be
incomplete shall not be accepted for review and shall be returned
to the applicant with a notification in writing of the specific manner
in which the submission is incomplete.
I.
Additional copies shall be submitted as requested by the Township,
PADEP or County Conservation District.
[Ord. 2011-O-2, 5/25/2011, § 215]
1.
The Township Engineer shall review the stormwater management site
plan for consistency with this Part. Any plans found incomplete shall
not be accepted for review and shall be returned to the applicant.
2.
The Township Engineer shall review the stormwater management site plan for any SALDO [Chapter 22] provisions not otherwise superseded by this Part.
3.
The Conservation District, in accordance with established criteria
and procedures, shall review the stormwater management site plan for
consistency with stormwater management and erosion and sediment pollution
control requirements and provide comments to Newtown Township. Such
comments shall be considered by the Township prior to final approval
of the stormwater management site plan.
4.
For activities regulated by this Part, the Township Engineer shall
notify Newtown Township in writing, within 45 calendar days of the
application being accepted by the Township, whether the stormwater
management site plan is consistent with the provisions of this Part.
A.
If the Township Engineer determines that the stormwater management
site plan is consistent with the provisions of this Part, the Township
Engineer shall forward two copies of the plan stamped, "approved"
along with a letter of consistency to the Township Zoning/Code Enforcement
Officer who will then forward a copy to the applicant.
B.
If the Township Engineer determines that the stormwater management
site plan is inconsistent or noncompliant with the stormwater management
plan, the Township Engineer shall forward a letter to the Township
Zoning Officer with a copy to the applicant citing the reason(s) and
specific sections of this Part for the inconsistency or noncompliance.
Inconsistency or noncompliance may be due to inadequate information
to make a reasonable judgment as to compliance with the stormwater
management plan. Any stormwater management site plans that are inconsistent
or noncompliant may be revised by the applicant and resubmitted when
consistent with this Part. Any inconsistent or noncompliant stormwater
management site plans may be revised by the applicant and resubmitted
consistent with this Part.
5.
For regulated activities specified in § 205 of this Part which require a building permit, the Township Engineer shall notify the Township Zoning/Code Enforcement Officer in writing, within a time frame consistent with the Township Building Code and/or Township SALDO [Chapter 22], whether the stormwater management site plan is consistent with this Part. The Township Zoning/Code Enforcement Officer shall forward a copy of the consistency/inconsistency letter to the applicant. Any stormwater management site plan deemed inconsistent may be revised by the applicant and resubmitted consistent with this Part.
6.
For regulated activities under this Part that require an NPDES permit
application, the applicant shall forward a copy of the Township Engineer's
letter to the Conservation District stating that the stormwater management
site plan is consistent with this Part. DEP and the Conservation District
may consider the Township Engineer's review comments in determining
whether to issue a permit.
7.
No building permits for any regulated activity specified in § 205
of this Part shall be approved by Newtown Township if the stormwater
management site plan has been found to be inconsistent with this Part,
as determined by the Township Engineer and Conservation District,
or without considering the comments of the Township Engineer and Conservation
District. All required permits from DEP must be obtained prior to
issuance of a building permit.
8.
The applicant shall be responsible for completing as-built drawings
of all stormwater management facilities included in the approved stormwater
management site plan. The as-built drawings and an explanation of
any discrepancies with the design plans shall be submitted to the
Township Engineer for final approval.
9.
Newtown Township's approval of a stormwater management site plan
shall be valid for a period not to exceed three years commencing on
the date that Newtown Township approves the approved stormwater management
site plan. Newtown Township may specify a term of validity shorter
than three years for the approval for any specific stormwater management
site plan. If stormwater management facilities included in the approved
stormwater management site plan have not been constructed, or if constructed,
and as-built drawings of these facilities have not been approved within
this three year time period, then Newtown Township may consider the
stormwater management site plan inconsistent or noncompliant and may
revoke any and all permits. Stormwater management site plans that
are determined to be inconsistent or noncompliant by Newtown Township
shall be resubmitted in accordance with § 226 of this Part.
[Ord. 2011-O-2, 5/25/2011, § 216]
1.
A modification to a submitted stormwater management site plan under
review by Newtown Township for a development site that involves the
following shall require a resubmission to Newtown Township of a modified
stormwater management site plan consistent with § 222 of
this Part and be subject to review as specified in § 224
of this Part:
2.
A modification to an already approved or inconsistent or noncompliant
stormwater management site plan shall be submitted to Newtown Township,
accompanied by the applicable Township review and inspection fee and
escrow. A modification to a stormwater management site plan for which
a formal action has not been taken by Newtown Township shall be submitted
to Newtown Township, accompanied by the applicable Township review
and inspection fee and escrow.
[Ord. 2011-O-2, 5/25/2011, § 217]
An inconsistent or noncompliant stormwater management site plan
may be resubmitted, with the revisions addressing the Township Engineer's
concerns documented in writing and addressed to the Township Zoning/Code
Enforcement Officer in accordance with § 223 of this Part
and distributed accordingly and be subject to review as specified
in § 224 of this Part. The applicable Township review and
inspection fee and escrow must accompany a resubmission of an inconsistent
or noncompliant stormwater management site plan.
