For any of the regulated activities of this chapter, prior to
the final approval of subdivision and/or land development plans, or
the issuance of any permit, or the commencement of any regulated earth-disturbance
activity, the owner, subdivider, developer or his agent shall submit
a drainage plan and receive municipal approval of the plan.
Exemptions from the drainage plan requirements are as specified in §
415-6.
The following items shall be included in and/or on the drainage
plan:
A. General.
(1) A map(s) prepared in a clear, concise, legible, neat and well-organized
manner that shall be:
(a)
Submitted on twenty-four-inch-by-thirty-six-inch sheets and
shall be prepared in a form that meets the requirements for recording
at the offices of the Recorder of Deeds of Montgomery County; and
(b)
At a scale of one inch equals no more than 50 feet except that
a scale of one inch equals 100 feet may be used for tracts of 20 acres
or more.
(c)
Signed and sealed by a qualified design professional.
(2) A report including a general narrative description of the project
and proposed stormwater controls and calculations signed and sealed
by a qualified design professional; and
(3) Supplemental information as necessary.
B. Map(s) of the project area showing the:
(1) Name and address of the project site, the name and address of the
owner of the property and the name of the individual or firm preparing
the drainage plan;
(3) Written and graphic scale;
(5) Tract boundary described to the nearest foot and degree;
(7) Existing and proposed land use(s);
(8) Location map showing the project relative to highways, municipalities
or other identifiable landmarks preferably at a scale of one inch
equal to 1,000 feet;
(9) Existing contours at intervals of two feet. In areas of steep slopes
(greater than 15%), five-foot contour intervals may be used;
(10)
Off-site drainage areas/boundaries impacting the project including
topographic detail;
(11)
Streams, lakes, ponds or other bodies of water within the project
area;
(12)
Other features including:
(c)
Existing drainage swales/courses;
(e)
Overland drainage patterns;
(i)
Areas of natural vegetation to be preserved;
(13)
Locations of all existing and proposed utilities (whether aboveground
or underground), sanitary sewers and water lines within 50 feet of
property lines of the project site;
(14)
Locations of on-lot sewage disposal systems;
(15)
Location of all public water supply wells within 400 feet of
the project and all private water supply wells within 100 feet of
the project;
(16)
Soil types and boundaries based on the county soil survey, as
applicable, latest edition. Any hydric soils present on the site should
be identified as such;
(17)
Geologic types, boundaries and any special geologic features
present on the site;
(18)
Proposed changes to land surface and vegetative cover;
(19)
Proposed structures, roads, paved areas and buildings;
(20)
Final contours at intervals of two feet. In areas of steep slopes
(greater than 15%), five-foot contour intervals may be used;
(21)
Stormwater management district boundaries applicable to the
site;
(22)
Clear identification of the location and nature of all stormwater
management controls and BMPs including:
(a)
Groundwater recharge methods such as seepage pits, beds or trenches;
(b)
Other control devices or methods such as rooftop storage, semipervious
paving materials, grass swales, parking lot ponding, vegetated strips,
detention, retention or wet basins, storm sewers, etc.;
(23)
Adequate access easement (a minimum of 20 feet) around all stormwater
BMPs that would provide municipal ingress to and egress from a public
right-of-way;
(24)
Limits of earth disturbance, including the type and amount of
impervious area that would be added;
(25)
A note referencing the associated calculations and, if separate,
the erosion and sediment control plan by title and date;
(26)
A note indicating the ownership and maintenance responsibilities
for each proposed stormwater management facility;
(27)
A statement, signed by the landowner, acknowledging that any
revision to the approved drainage plan must be approved by the Township
and, if applicable, the Conservation District;
(28)
A statement, signed by the design engineer as follows:
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"I, (name of design engineer), on this date (date of signature),
hereby certify that the drainage plan meets all design standards and
criteria of the Upper Hanover Township Stormwater Ordinance."
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(29)
Construction details including cross sections where appropriate
of the proposed stormwater management facilities;
(30)
When requested by the Township Engineer, construction specifications
of the materials to be used for stormwater management facilities;
and
(31)
When requested by the Township Engineer, profiles of proposed
stormwater facilities or other proposed improvements.
C. A narrative report including:
(1) The overall stormwater management concept for the project;
(2) A schematic showing all tributaries contributing flow to the site
and all existing man-made features beyond the property boundary that
would be affected by the project;
(3) All calculations, assumptions and criteria used in the design of
the BMPs shall be provided;
(4) All site testing data used to determine the feasibility of infiltration
on a site; and
(5) 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.
D. Supplemental information including:
(1) For regulated earth-disturbance activities, a BMP operations and maintenance plan prepared in accordance with §
415-24A(1) above, including:
(a)
A description of how each permanent stormwater BMP will be operated
and maintained and the identity of the person(s) responsible for operations
and maintenance;
(b)
A statement, signed by the landowner, acknowledging that the
stormwater BMPs are fixtures that cannot be altered or removed without
approval by the municipality;
(c)
The name of the project, the name and address of the owner of
the property, and the name of the individual or firm preparing the
plan.
(2) An erosion control plan if separate from the drainage plan maps set.
(3) Any additional information deemed necessary by the Township in order
to determine compliance with the provisions of this chapter.
(4) For activities that require an NPDES Permit for Stormwater Discharges
from Construction Activities, a PaDEP Joint Permit Application, a
PennDOT Highway Occupancy Permit, or any other permit under applicable
state or federal regulations or are regulated under Chapter 105 (Dam
Safety and Waterway Management) or Chapter 106 (Floodplain Management)
of PaDEP's Rules and Regulations, proof of application for said permit(s)
or approvals shall be part of the plan.
A modification to a drainage plan for a proposed development site which involves a change in control methods or techniques, or which involves the relocation or redesign of control measures, or which is necessary because soil or other conditions are not as stated on the drainage plan (as determined by the municipality) shall require a resubmission of the modified drainage plan consistent with §
415-25 subject to review per §
415-26 of this chapter.