The following items shall be included in the stormwater management
site plan:
A. Appropriate sections from the Township's Subdivision and Land
Development Ordinance, and other applicable local ordinances, shall
be followed in preparing the stormwater management site plans.
B. The Township shall not approve any stormwater management site plan
that is deficient in meeting the requirements of this chapter. At
its sole discretion and in accordance with this article, when a stormwater
management site plan is found to be deficient, the Township may either
disapprove the submission and require a resubmission, or in the case
of minor deficiencies, the Township may accept submission of modifications.
C. Provisions for permanent access or maintenance easements for all physical stormwater BMPs, such as ponds and infiltration structures, as necessary to implement the operation and maintenance (O&M) plan discussed in §
247-401D(35) below.
D. The stormwater management site plan shall provide the following information:
(1)
The overall stormwater management concept for the project.
(2)
A determination of site conditions in accordance with the BMP
Manual by a qualified professional. A detailed site evaluation shall
be completed for projects proposed in areas of carbonate geology or
karst topography, and other environmentally sensitive areas, such
as brownfields or hotspots.
(3)
Stormwater runoff design computations and documentation as specified in this chapter, or as otherwise necessary to demonstrate that the maximum practicable measures have been taken to meet the requirements of this chapter, including the recommendations and general requirements in §
247-301.
(4)
Expected project time schedule.
(5)
An erosion and sediment pollution control plan.
(6)
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.
(7)
Plan and profile drawings of all stormwater BMPs, including
drainage structures, pipes, open channels, and swales.
(8)
The stormwater management site plan shall show the locations
of existing and proposed on-lot wastewater facilities and water supply
wells.
(9)
A general description of project.
(10)
An erosion and sediment pollution control plan.
(11)
The location of the project relative to highways, municipalities
or other identifiable landmarks.
(12)
Existing and proposed contours at intervals of no more than
two feet.
(13)
Steep slopes, as defined by the Township's Zoning Ordinance,
shall be highlighted or hatched on the plans. A steep slopes summary
shall be provided in tabular format which identifies all steep slope
area in square feet.
(14)
Existing streams, lakes, ponds or other bodies of water within
the project area.
(15)
Other physical features, including flood hazard boundaries,
sinkholes, streams, existing drainage courses, areas of natural vegetation
to be preserved, and the total extent of the upstream area draining
through the site.
(16)
The locations of all existing and proposed utilities, sanitary
sewers and waterlines within 50 feet of property lines, including
existing and proposed on-lot wastewater facilities and water supply
wells.
(17)
An overlay showing soil names and boundaries.
(18)
Proposed changes to the land surface and vegetative cover, including
limits of earth disturbance and the type and amount of impervious
area that would be added. An impervious summary shall be provided
in a tabular format identifying various types of impervious area in
square feet (i.e., building, pavement, miscellaneous, etc.).
(19)
Existing and proposed structures, roads, paved areas and buildings.
(20)
The name of the development which is consistent with the application
submitted (i.e., land development; subdivision and land development;
minor subdivision plan, building permit plan, sketch plan, etc.).
(21)
The name, address, phone number and email address of the owner
of the property, and of the individual or firm preparing the plan.
(22)
The date of the initial submission and date of any plan revisions
or iterations. Plan revision dates shall be consistent on every sheet
of a plan set.
(23)
A graphic and 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.
(25)
The total tract boundary and size with distances marked to the
nearest foot and bearings to the nearest degree. Metes and bounds
for all property lines shall be provided.
(26)
Existing and proposed land use(s).
(27)
A key map showing all existing man-made features beyond the
property boundary that would be affected by the project.
(28)
Overland drainage paths, including time-of-concentration (TC)
paths.
(29)
A pre- and post-construction drainage area plan and inlet drainage
area plan.
(30)
Stormwater management site plans shall contain a PA One Call
serial number and reference any utilities who have responded with
contact information (i.e., phone and email). If stormwater management
site plans are part of a greater project plan set such as land development
plans, the required information does not need to be specifically on
the stormwater management site plans but should be included within
the greater plan set. The plans shall further note: "The contractor
must submit a PA One Call a minimum of 10 days prior to the start
of work. Proof that a PA One Call was made shall be provided to the
Township."
(31)
A note on the plans indicating that the Township shall be notified
72 hours prior to construction of any stormwater management facilities.
(32)
The effect of the project (in terms of runoff volumes and peak
flows) on adjacent properties and on any existing municipal stormwater
collection system that may receive runoff from the project site.
(33)
When groundwater recharge methods, such as seepage pits, beds
or trenches, are used, the locations of existing and proposed septic
tank infiltration areas and wells must be shown.
(34)
A zoning compliance table summarizing the requirements of the site, the existing site compliance information, and the proposed zoning compliance information in accordance with the Township's Zoning Ordinance, Chapter
310.
(35)
The stormwater management site plan shall include a stormwater
management operation and maintenance (O&M) plan for all existing
and proposed physical stormwater management facilities. This plan
shall address long-term ownership and responsibilities for O&M
as well as schedules and costs for O&M activities. The plan shall
contain the following information at a minimum:
(a)
The following notes:
[1] The landowner hereby grants and conveys to the
Township a blanket easement over the entire property for access at
such limited times as the Township reasonably deems necessary to inspect,
operate, maintain, or repair the stormwater management facilities,
BMPs, erosion and sedimentation management facilities, and other improvements.
The purpose of such easement is to ensure safe and proper function
of the facilities and the condition of adjacent areas, all pursuant
to the provisions of the Stormwater Management Ordinance. The Township
shall have the right, but not the obligation, to conduct such inspections,
operations, maintenance, or repairs. When such inspections are conducted,
the Township shall give the landowner copies of the inspection report
with findings and evaluations.
[2] The landowner acknowledges that the stormwater
management facilities and BMPs are permanent fixtures that cannot
be altered or removed. The landowner shall not place any structure,
fill, landscaping or vegetation into any stormwater management facility
or BMP which would limit or alter the function of the facility, structure,
or BMP, unless a revised plan is submitted and approved by the Township.
Such revised plan shall be recorded with a new stormwater operation
and maintenance agreement, prior to any alteration being implemented.
[3] Before proceeding with any of the improvements,
the landowner shall give at least 72 hours' notice to the Township
Engineer so that arrangements can be made for the inspection of the
work as it progresses.
[4] Before the Township issues a use and occupancy
permit, the landowner shall submit an as-built plan prepared and signed
by a registered professional land surveyor and/or professional engineer.
The as-built plan shall show the location of the building(s), the
property corner monuments with elevations, rain leaders, utility line
locations, building envelope, walkways, driveways, decks, patios,
easements, steep slopes, floodplain, riparian corridor, the stormwater
management facilities and associated construction details with elevations,
the final grade elevations, landscape features (e.g., including walls),
and any other information that may be deemed necessary by the Township
which shall be consistent with what is shown on the approved plan.
The plan shall also contain a chart for each lot listing how much
impervious area each stormwater management facility was designed to
handle and how much impervious area has been installed to date.
[5] The landowner agrees to provide a copy of any required
stormwater operation and maintenance agreements to its successors
and/or assigns, and agrees to incorporate a reference to the terms
of this agreement in any future deed of conveyance. The failure of
the landowner to perform any act required by this subsection shall
not impair the validity of the agreement, limit its enforceability
in any way, or impair any portion of the stormwater facilities maintenance
requirements or responsibilities. The term "landowner" shall include
the above-named landowner and the heirs, administrators, executors,
successors, and/or assigns of the landowner, whether or not such future
owners have signed this agreement.
[6] The following signature block for the design engineer
who is licensed in the Commonwealth of Pennsylvania: "___, (Design
Engineer) on this date ___, (date of signature) has reviewed and hereby
certifies that the stormwater management site plan meets all design
standards and criteria of the Perkiomen Township Stormwater Management
Ordinance of 2022."
[7] The landowner or the owner's designee (i.e.,
privately hired engineers or qualified professional) shall inspect
stormwater management facilities and BMPs installed under the Stormwater
Management Ordinance according to the following frequencies, at a
minimum, to ensure the BMPs, facilities and/or structures continue
to function as intended:
(Select based on criteria: (Criteria 1) - Development by an
individual homeowner, on a single lot, with stormwater management
facilities and BMPs which are located entirely within their property
boundaries and which only serve their individual property; (Criteria
2) Any other type of development)
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(Criteria 1)
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•
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Within 30 days of receiving a written request from the Township
for an inspection, unless the Township agrees to a longer period of
time.
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Or (Criteria 2)
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•
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Annually for the first five years after the construction of
the stormwater facilities.
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•
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Once every three years thereafter.
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•
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During or immediately after the cessation of a ten-year or greater
storm.
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•
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Within 30 days of receiving a Township request for inspection
(made in writing), unless a greater period of time is accepted by
the Township.
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A written inspection report with photos shall be created to
document each inspection. The inspection report shall contain the
date and time of the inspection, the individual(s) who completed the
inspection, the location of all stormwater management facilities and
BMPs, or structure inspected, observations on performance, and recommendations
for improving performance, if applicable. Inspection reports shall
be submitted to Perkiomen Township within 30 days following completion
of the inspection. The Township shall have the right, but not the
obligation, to track the required written inspection reports.
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(b)
For each stormwater management facility or BMP, a list of applicable
maintenances items to be performed should be provided, and said maintenance
items should be accompanied with a required time-related frequency
(i.e., annually, quarterly, after large rain events, etc.). The required
maintenance items shall be generally consistent with the requirements
of the PA BMP Manual, or as required by the Township Engineer.
(c)
The plan shall identify the location of each BMP and note the
latitude and longitude of its centroid in tabular format on the plans.
(d)
The plan shall identify the location of all stormwater management
facilities and BMPs. The technical specifications of all stormwater
aspects shall be included on the plans, which includes, but is not
limited to, construction details, profiles, and specifications.
(e)
The plans shall include an overall site plan showing the entire
property boundary.
E. Supplemental information.
(1)
A stormwater management report which includes:
(a)
The overall stormwater management concept for the project designed in accordance with Article
III of this chapter.
(b)
Stormwater runoff computations as specified in this chapter.
Complete hydrologic, hydraulic and structural computations for all
stormwater management facilities.
(c)
Stormwater management techniques to be applied both during and
after development.
(d)
Development stages (project phases) if so proposed.
(e)
A geologic assessment of the effects of runoff on sinkholes
as specified in this chapter.
(f)
An infiltration/geological testing report which includes documented
infiltration rates and provides a summary of the soil horizons associated
with each test pit.
(g)
An operation and maintenance plan in accordance with §
247-407 of this chapter.
(h)
In the event an existing stormwater management facility has
unknown characteristics, it must be studied, and documentation of
the findings shall be provided to the Township. Stormwater credit
for existing facilities may only be utilized if determined through
documented evidence as to be adequate by the Township Engineer.
(2)
All plan submissions and supporting documents submitted to and
received from the Montgomery County Conservation District (MCCD),
the PA DEP, PennDOT, and third-party agencies which are involved with
the project shall be provided to the Township.
(3)
A stormwater management permit application, as provided in Appendix
D.
A modification to a submitted stormwater management site plan
that involves a change in stormwater BMPs or techniques, or that involves
the relocation or redesign of stormwater BMPs, or that is necessary
because soil or other conditions are not as stated on the stormwater
management site plan as determined by the Township shall require a
resubmission of the modified stormwater management site plan in accordance
with this article.
A disapproved stormwater management site plan may be resubmitted
to the Township, with the revisions addressing the Township's
concerns, to the Township in accordance with this article. The applicable
review fee must accompany a resubmission of a disapproved stormwater
management site plan.
The Township's approval of a stormwater management site plan authorizes the regulated activities contained in the stormwater management site plan for a maximum term of validity of five years following the date of approval. The Township may specify a term of validity shorter than five years in the approval for any specific stormwater management site plan. Terms of validity shall commence on the date of approval when the Township signs the approval for a stormwater management site plan. If an approved stormwater management site plan is not completed according to §
247-407 within the term of validity, then the Township may consider the stormwater management site plan disapproved and may revoke any and all permits. Stormwater management site plans that are considered disapproved by the Township shall be resubmitted in accordance with §
247-405 of this chapter.