For any of the regulated activities of this chapter, 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 (SWM) plan from the Township and an adequate erosion and sediment control plan review by the Conservation District. Activities which are exempted from stormwater management plan requirements of this chapter by § 166-5B must meet the simplified drainage plan requirements of § 166-12A.
A.
A simplified drainage plan shall consist of general property information,
a clear description of the proposed improvements, pertinent calculations
and plans. All simplified drainage plan materials shall be submitted
to the Township in a format that is clear, concise, legible, neat,
and well organized; otherwise, the simplified drainage plan shall
not be accepted for review and shall be returned to the applicant.
A simplified drainage plan shall include all of the following information:
(1)
General property information, including the property street address,
property area (in acres or square feet), the name of the current property
owner along with his/her street address, and current property zoning
information.
(2)
Approximate property lines and roads within 100 feet of the project
area.
(3)
A North arrow.
(4)
Existing streams, lakes, ponds or other waters of the commonwealth.
(5)
Location of existing and proposed structures, driveways and any other
impervious areas on the property. The plan must indicate the approximate
dimensions and areas (in square feet) of each of these features.
(6)
Location of any existing or proposed on-site septic systems and/or
potable water wells. The plan must indicate the approximate distance
between these features and any proposed infiltration BMPs.
(7)
Separate calculations of the total existing pervious area and of
the total proposed impervious area on the property.
(8)
Calculation of the total earth disturbance area for the project.
(9)
Show the location and construction of permanent stormwater BMPs.
The simplified drainage plan must describe the materials, dimensions
and construction of each permanent stormwater BMP.
(10)
Proposed grading, including overland drainage patterns and swales.
(11)
Erosion and sediment controls.
B.
A stormwater management plan shall consist of a general description
of the project, including sequencing items, 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
plan materials shall be submitted to the Township in a format that
is clear, concise, legible, neat, and well organized; otherwise, the
stormwater management plan shall not be accepted for review and shall
be returned to the applicant. The following items shall be included
in the stormwater management plan:
(1)
General.
(a)
A general description of the project.
(b)
A general description of the proposed stormwater techniques,
including construction specifications of the materials to be used
for stormwater management facilities.
(c)
Complete hydrologic, hydraulic, and structural computations
for all stormwater management facilities.
(d)
An erosion and sediment control plan, including all reviews
and letters of adequacy from the Conservation District.
(e)
A general description of proposed non-point-source pollution
controls.
(2)
Map(s). Map(s) of the project area shall be submitted on twenty-four-inch
by thirty-six-inch sheets and/or prepared in a form that meets the
requirements for recording at the office of the Montgomery County
Recorder of Deeds. If the East Norriton Township Subdivision and Land
Development Ordinance (SALDO)[1] has more-stringent criteria than this chapter, than the
more-stringent criteria shall apply. The contents of the map(s) shall
include, but not be limited to:
(a)
Plans of the proposed stormwater drainage systems, including
all storm drain pipes, manholes and inlets, runoff control devices
and open drainage channels.
(b)
Clear identification of the location and nature of permanent
stormwater BMPs.
(c)
The location of the project relative to highways, municipalities
or other identifiable landmarks.
(d)
Mapping of the watershed area or areas in which the proposed
subdivision or land development is located (United States Coast and
Geodetic Survey quadrangle map or similar).
(e)
Existing and final contours at intervals of two feet. In areas
of steep slopes (greater than 15%), five-foot contour intervals may
be used.
(f)
Existing streams, lakes, ponds or other waters of the commonwealth
within the project area.
(g)
Other physical features, including flood hazard boundaries,
stream buffers, existing drainagecourses, areas of natural vegetation
to be preserved and the total extent of the upstream area draining
through the site.
(h)
The locations of all existing and proposed utilities, sewers
and water lines within 50 feet of property lines.
(i)
Soil type names and boundaries.
(j)
Limits of earth disturbance, including the type and amount of
impervious area that would be added.
(k)
Proposed changes to the land surface and vegetative cover.
(l)
Proposed structures, roads, paved areas and buildings.
(m)
The name of the development, the name and address of the owner
of the property, and the name of the individual or firm preparing
the plan.
(n)
The date of submission.
(o)
A graphic written scale of one inch equals no more than 50 feet;
for tracts of 20 acres or more, the scale shall be one inch equals
no more than 100 feet.
(p)
A North arrow.
(q)
The total tract boundary and size, with distances marked to
the nearest foot and bearings to the nearest degree.
(r)
Existing and proposed land use(s).
(s)
A key map showing all existing man-made features beyond the
property boundary that would be affected by the project.
(t)
Location of all open channels.
(u)
Overland drainage patterns and swales.
(v)
A fifteen-foot-wide access easement around all stormwater management
facilities that would provide ingress and egress from a public right-of-way.
(w)
The location of all existing and proposed drainage facilities
and stormwater controls affecting the subject property.
(x)
The location of all erosion and sediment control facilities.
(y)
The location of the stormwater management district boundaries, as described in § 166-24 of this chapter, which are applicable to the site.
(z)
A plan showing the berm embankment and outlet structure. The
plan shall indicate the top of the berm elevation, the top width of
the berm, side slopes, the emergency spillway elevation, elevations
of the outlet structure, including riser, and the dimensions and spacing
of anti-seep collars.
(aa)
A cross-section diagram through the outlet structure, emergency
spillway and berm embankment.
(bb)
A detailed plan of the trash rack and anti-vortex device.
(cc)
An overall plan of the basin area, at a scale of one inch equals
40 feet or less, showing all grading and landscaping.
(dd)
A note on the plan indicating a proposed maintenance program
for all stormwater management control facilities. This program must
include the proposed ownership of the control facilities, the maintenance
requirements for the facilities and the detail of the financial responsibility
for the required maintenance period.
(ee)
A note on the plan indicating the location and responsibility
for maintenance of stormwater management facilities that would be
located off site. All off-site facilities shall meet the performance
standards and design criteria specified in this chapter.
(ff)
A statement, signed by the applicant, acknowledging that any
revision to the approved stormwater management plan must be approved
by the Township, and that a revised erosion and sediment control plan
must be submitted to the Conservation District for a determination
of adequacy.
(gg)
The following signature block for the design engineer:
"I, (design engineer), on this date (date of signature), hereby
certify that the stormwater management plan meets all design standards
and criteria of the East Norriton Township Stormwater Management Ordinance."
C.
Supplemental information to be submitted to the Township.
(1)
A written description of the following information shall be submitted
by the applicant and shall include:
(a)
The overall stormwater management concept for the project designed
in accordance with this chapter. All existing drainage features which
are to be incorporated in the design shall be so identified with an
explanation of the operations of the facilities.
(b)
Stormwater runoff computations for all points of runoff concentration
before, during and after the development, including all supporting
data, as specified in this chapter.
(c)
Design computations for sizing each outlet device.
(d)
A stage-storage curve for each detention or retention basin.
(e)
Flood routing and storage requirement calculations.
(f)
Stormwater management techniques to be applied both during and
after development.
(g)
Expected project time schedule.
(h)
Development stages or project phases, if so proposed. If the
project is to be developed in stages, the entire project stormwater
management plan shall be presented with the first stage, and appropriate
stages for the drainage system shall be indicated, in accordance with
DEP rules and regulations.
(2)
An erosion and sediment control plan.
(3)
A description of the effect of the project (in terms of runoff volumes
and peak flows) on adjacent properties and on any existing Township
stormwater collection system that may receive runoff from the project
site.
(4)
A declaration of adequacy and highway occupancy permit from the Pennsylvania
Department of Transportation (PennDOT) district office when utilization
of a PennDOT storm drainage system is proposed.
D.
Stormwater management facilities.
(1)
All stormwater management facilities must be located on a plan and
described in detail.
(2)
When infiltration measures such as seepage pits, beds, or trenches
are used, the locations of existing and proposed septic tank infiltration
areas and wells must be shown.
(3)
All calculations, assumptions, and criteria used in the design of
the stormwater management facilities must be shown.
Unless exempted by § 166-5 of this chapter, the Township shall require receipt of a complete stormwater management plan. For activities exempted by § 166-5B of this chapter, the Township shall require receipt of a simplified drainage plan.
A.
Proof of application or documentation of required permit(s) or approvals
for the programs listed below shall be part of the complete stormwater
management plan:
B.
The plan shall be coordinated with the state and federal permit process
and the Township's subdivision and land development process.
C.
For projects that require subdivision and land development approval,
the stormwater management plan shall be submitted by the applicant
as part of the preliminary plan submission, where applicable for the
regulated activity.
D.
For projects that do not require subdivision and land development approval, see § 166-12 of this chapter.
E.
Submission of a stormwater management plan. The application shall
be received by the Zoning Officer. The date of receipt shall be stamped
and the filing fee received in full. A cursory examination of the
application and stormwater management plan will be conducted.
(1)
Five copies of the stormwater management plan shall be submitted,
unless otherwise required by the Zoning Officer.
F.
Submission of a simplified drainage plan. The application shall be
received by the Zoning Officer. The date of receipt shall be stamped
and the filing fee received in full. A cursory examination of the
application and simplified drainage plan will be conducted.
A.
The Township Engineer shall review the stormwater management plan
or simplified drainage plan for consistency with this chapter and
the Stony Creek/Saw Mill Run Act 167 Stormwater Management Plan. Any
found incomplete shall not be accepted for review and shall be returned
to the applicant.
B.
The Township Engineer shall review the stormwater management plan
for any subdivision or land development against the East Norriton
Township Subdivision and Land Development Ordinance (SALDO) provisions
not otherwise superseded by this chapter.[1]
C.
The Conservation District, in accordance with established criteria
and procedures, shall review the stormwater management plan for consistency
with stormwater management and erosion and sediment pollution control
requirements and provide comments to the Township. Such comments shall
be considered by the Township prior to final approval of the stormwater
management plan.
D.
For activities regulated by this chapter, the Township Engineer shall
notify the applicant and the Township, in writing, within 30 calendar
days, whether the stormwater management plan is consistent with the
requirements of this chapter.
(1)
If the Township Engineer determines that the stormwater management
plan is consistent with the requirements of this chapter, the Township
Engineer shall forward a letter of consistency to the Township, which
will then forward a copy to the applicant.
(2)
If the Township Engineer determines that the stormwater management
plan is inconsistent or noncompliant with the requirements of this
chapter, the Township Engineer shall forward a letter to the Township
citing the reason(s) and specific chapter sections for inconsistency
or noncompliance. The Township shall then forward a copy of the Township
Engineer's letter to the applicant. Inconsistency or noncompliance
may be due to inadequate information to make a reasonable judgment
as to compliance with the requirements of this chapter. Any stormwater
management plans that are inconsistent or noncompliant may be revised
by the applicant and resubmitted when consistent with this chapter.
The Township shall then notify the applicant of the Township Engineer's
findings. Any inconsistent or noncompliant stormwater management plans
may be revised by the applicant and resubmitted consistent with this
chapter.
E.
For regulated activities under this chapter that require an NPDES
permit application, the applicant shall forward a copy of the Township
Engineer's letter stating that the stormwater management plan
is consistent with the requirements of the East Norriton Township
Stormwater Management Ordinance to the Conservation District. DEP
and the Conservation District may consider the Township Engineer's
review comments in determining whether to issue a permit.
F.
The Township shall not grant preliminary or final approval to any
subdivision or land development for regulated activities if the stormwater
management plan has been found by the Township Engineer to be inconsistent
with the requirements of this chapter. All required permits from DEP
must be obtained prior to approval of any subdivision or land development.
G.
No building permits for any regulated activities shall be approved
by the Township if the stormwater management plan has been found to
be inconsistent with the requirements of this chapter, 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.
H.
The applicant shall be responsible for completing record drawings
of all stormwater management facilities included in the approved stormwater
management plan. The record drawings and an explanation of any discrepancies
with the design plans shall be submitted to the Township Engineer
for final approval. In no case shall the Township approve the record
drawings until the Township receives a copy of an approved declaration
of adequacy and/or highway occupancy permit from the PennDOT district
office, NPDES permit, and any other applicable permits or approvals
from DEP or the Conservation District. The above permits and approvals
must be based on the record drawings.
I.
The Township's approval of a stormwater management plan shall
be valid for a period not to exceed five years commencing on the date
that the Township signs the approved stormwater management plan. If
stormwater management facilities included in the approved stormwater
management plan have not been constructed or, if constructed, record
drawings of these facilities have not been approved within this five-year
time period, then the Township may consider the stormwater management
plan inconsistent or noncompliant and may revoke any and all permits.
Stormwater management plans that are determined to be inconsistent
or noncompliant by the Township shall be resubmitted in accordance
with this chapter.
A.
A modification to a submitted stormwater management plan under review by the Township for a development site that involves the following shall require the resubmission to the Township of a modified stormwater management plan consistent with § 166-13 of this chapter and be subject to review as specified in § 166-14 of this chapter:
B.
A modification to an already approved or inconsistent or noncompliant
stormwater management plan shall be submitted to the Township, accompanied
by the applicable Township review and inspection fee. A modification
to a stormwater management plan for which formal action has not been
taken by the Township shall be submitted to the Township accompanied
by the applicable Township review and inspection fee.
An inconsistent or noncompliant stormwater management plan may be resubmitted with the revisions addressing the Township Engineer's concerns documented in writing. It must be addressed to the Township in accordance with § 166-13 of this chapter, distributed accordingly, and be subject to review as specified in § 166-14 of this chapter. The applicable Township review and inspection fee must accompany a resubmission of an inconsistent or noncompliant stormwater management plan.
