For any of the regulated activities by this Chapter and not eligible for the exemptions provided in §
22-611, the final approval of subdivision and/or land development plans, the issuance of any building or occupancy permit, or the commencement of any land disturbance activity may not proceed until the property owner or developer or his/her agent has received written approval of a Drainage Plan from the Township.
The Drainage Plan shall consist of all applicable 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 plans by title and date. All Drainage
Plan materials shall be submitted to the Township in a format that
is clear, concise, legible, neat and well organized; otherwise, the
Drainage Plan shall be disapproved. The following items shall be included
in the plan submission:
A. General.
(1)
General statement of the scope of the project.
(2)
General description of permanent stormwater management techniques,
including: construction specifications of the materials to be used
for stormwater management facilities, how each permanent stormwater
BMP will be operated and maintained, and the identity of the person(s)
responsible for operations and maintenance.
(3)
Project location on a 7 1/2 minute USGS topographic map.
(4)
Discussion of ownership and maintenance of all drainage and
stormwater management facilities.
(5)
Complete hydrologic, hydraulic and structural computations for
all stormwater management facilities.
B. The contents of the plans shall include, but not be limited to:
(1)
The location of the project relative to highways, municipalities
or other identifiable landmarks.
(2)
The mapping of the watershed area or areas in which the proposed
subdivision or land development is located.
(3)
Existing and proposed contours as per the requirements for preliminary
or final plans.
(4)
Existing water bodies within the project area including streams,
lakes, ponds, field delineated wetlands or other bodies of water.
(5)
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.
(6)
The locations of all existing and proposed utilities, sanitary
sewers, and water lines within 50 feet of property lines.
(7)
Soil names and boundaries. Additionally, the Hydrologic Soil
Group of the soils should be identified.
(8)
Proposed changes to the land surface and vegetative cover including
the type and amount of impervious area to be added.
(9)
Proposed structures, roads, paved areas, and buildings.
(10)
Final contours at intervals of two feet. In areas of steep slopes
(greater than 15%), five-foot contour intervals may be used.
(12)
A key map showing all existing man-made features beyond the
property boundary that may be affected by the project.
(13)
Horizontal alignment and vertical profiles of all open channels.
(15)
Appropriate access easements in accordance with this Chapter
around all stormwater management and conveyance facilities, located
outside the Township right-of-way, that would provide ingress to and
egress from a public right-of-way.
(16)
Design details for stormwater infiltration, water quality, and
detention/retention facilities including operation and maintenance
requirements.
(17)
A statement, signed by the landowner, acknowledging that the
stormwater BMPs are fixtures that cannot be altered or removed without
prior approval by the Township.
(18)
The location and clear identification of the nature of permanent
stormwater BMPs.
(19)
The complete drainage system for the subdivision or land development
including the identification of drainage features which will be incorporated
into the design.
(20)
An overall stormwater management plan for the entire site. If
the subdivision or land development is to be developed in phases,
the plan shall be submitted with the first phase and appropriate future
development phases for the drainage system shall be indicated. The
advice of the Township Engineer shall be sought in designing the stormwater
management plan.
(21)
The location of all erosion and sedimentation control facilities.
(22)
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.
(23)
A highway occupancy permit from the PennDOT district office
when utilization of a PennDOT storm drainage system is proposed.
C. Stormwater Management Facilities.
(1)
All stormwater management facilities must be located on a plan
and described in detail.
(2)
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.
(3)
All calculations, assumptions, and criteria used in the design
of the stormwater management facilities must be shown.
(4)
A schedule for the installation of all stormwater control facilities
must be included in the plan.
A disapproved Drainage Plan may be resubmitted, with the revisions addressing the Township's concerns documented in writing, to the Township in accordance with §
22-702 of this Chapter and be subject to review as specified in §
22-703 of this Chapter. The applicable review fee must accompany a resubmission of a disapproved Drainage Plan.