The drainage plan shall consist of two parts,
a plan showing the stormwater facilities construction and a design
narrative including the design calculations.
The drainage plan submission shall contain the
following:
A. Plans shall be submitted on sheet sizes of 18 inches
by 24 inches or 24 inches by 36 inches, blueprints or black line prints
or photo copies. Reproducible Mylars may be submitted for Township
approval and signature upon final plan approval.
B. Project name, sheet titles and drawing numbers and
index.
C. Names and addresses of landowner, land developer/subdivider,
existing topographic surveyor and the plan designer.
D. Names of landowners adjacent to the property.
E. Plan date and date of the latest plan revision.
F. Certificate signature blocks for:
(1) The Township Engineer; and
(2) A certification of design signed and sealed by a registered
professional engineer, a registered landscape architect or a registered
professional land surveyor. The certification shall state:
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"I, _________________________, a registered
professional engineer/landscape architect/professional land surveyor,
hereby certify that the drainage plan meets all the requirements of
the Greene Township Stormwater Management Ordinance."
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G. Project location map at a minimum of one inch equals
2,000 feet showing the project site property line, limits of development,
streets, street names and bodies of water within 1,000 feet of the
project boundary and the downstream drainage path from the proposed
site to the nearest stream or the Greene Township boundary (whichever
occurs first).
H. North arrow, graphic scale and written scale. Plans
shall be to a scale of one inch equal to 10, 20, 30, 40 or 50 feet.
General site layout plans which will not be used for construction
detail may be at one inch equal to 100 feet.
I. The total tract boundary and size with distances marked
to the nearest foot and bearings to the nearest degree.
J. 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.
K. The locations of all existing and proposed utilities,
sanitary sewers, and waterlines within 50 feet of property lines.
L. Proposed changes to the land surface and vegetative
cover, including the type and amount of impervious area that would
be added.
M. Proposed structures, roads, paved areas, and buildings.
N. Clearly show existing and proposed drainage patterns,
overland drainage paths, outlines of existing and proposed drainage
areas and subareas and the paths for calculating the times of concentration
(as an alternative, information regarding existing and proposed drainage
areas, subareas and paths may be included in the design narrative),
existing and proposed elevation contours at intervals of at least
one foot for plans at scale of one inch equal to 10 or 20 feet, at
least two feet for all other scales. Where land is sloped more than
15%, contour intervals may be every five feet. Show spot elevations
at high points and low points and critical areas which cannot be interpolated
between contours. Indicate the location and elevation of the benchmark.
Provide the date the existing topography was surveyed and the method
of survey (aerial or field).
O. Existing and proposed land use(s).
P. A key map showing all existing man-made features beyond
the property boundary that would be affected by the project.
Q. Horizontal and vertical profiles of all open channels,
including hydraulic capacity.
R. A fifteen-foot-wide access easement around all stormwater
management facilities that would provide ingress to and egress from
a public right-of-way.
S. 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.
T. A construction detail of any improvements made to
sinkholes and the location of all notes to be posted, as specified
in this chapter.
U. A statement, signed by the landowner, acknowledging
the stormwater management system to be a permanent fixture that can
be altered or removed only after approval of a revised plan by the
Greene Township Board of Supervisors.
V. Provide an outline of soil type limits and list soil
types as shown in the Soil Survey of Franklin County. Provide a table
listing the soil map symbol and soil name abbreviations for applicable
on-site soil types.
W. Existing features and proposed improvements, existing
and final land covers, existing and proposed storm drainage facilities.
Provide a drawing legend of the unidentified or undesignated existing
and proposed features.
X. Profiles of stormwater piping systems using a horizontal
scale the same scale as the plan and a vertical scale 1/10th of the
horizontal scale. Identify pipe sizes, types, lengths, slopes and
inverts. Identify pertinent elevations for inlets, manholes and all
other profiled facilities.
Y. Construction details, sections and specifications
of facilities with sufficient information and dimensions for construction
interpretation which will provide the constructor with sufficient
information to meet the requirements of this chapter. Provide a note
which states the materials and details specified shall not be altered
during construction without written approval by the Township Board
of Supervisors.
Z. 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.
AA. All stormwater management facilities must be located
on a plan and described in detail.
BB. Describe maintenance responsibilities and the responsible
party(ies). Provide a note prohibiting drainage easement areas from
being obstructed with trees, shrubbery and structures. Provide a plan
note allowing Township officials access to easement areas for inspection
or correction of stormwater facilities.
CC. Existing and proposed one-hundred-year stormwater
elevation and finished floor elevations for lots adjacent to the one-hundred-year
stormwater elevation in areas with streams, intermittent channels,
water impounding areas and low or slow drainage areas. Show FEMA information
where applicable.
DD. The location of all erosion and sedimentation control
facilities required by PaDEP Chapter 102.
EE. Limits of construction phases and a narrative describing
the construction sequence.