For any of the activities regulated by this chapter and not eligible for the exemptions provided in §
174-12, 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 applicant has received written approval of a SWM site plan from the Township.
The SWM site plan and SWM site report shall consist of all applicable
calculations, maps, and plans. All SWM site plan materials shall be
submitted to the Township in a format that is clear, concise, legible,
neat, and well organized; otherwise, the SWM site plan shall be rejected.
Appropriate sections from the Township Subdivision and Land Development
Ordinance, and other applicable local ordinances, shall be followed
in preparing the SWM site plan.
A. SWM site plan shall include (but not be limited to):
(1) Plans no larger than twenty-two-inch-by-thirty-six-inch sheets and
in a form that meets the requirements for recording in the Office
of the Recorder of Deeds of Dauphin County.
(2) The name of the development; name and location and/or address of
the property site; name, address, telephone number, and e-mail address
of the applicant/owner of the property; and name, address, telephone
number, e-mail address, and engineering seal and signature of the
individual preparing the SWM site plan.
(3) The date of submission and dates of all revisions.
(4) A graphical and written scale on all drawings and maps.
(5) A North arrow on all drawings and maps.
(6) A location map at a minimum scale of one inch equals 1,000 feet.
(7) Metes and bounds description of the entire tract perimeter, existing
and proposed easements, and rights-of-way.
(8) Existing and proposed contours at intervals of two feet.
(9) Existing water bodies within the project area including streams,
lakes, ponds, field-delineated wetlands or other bodies of water,
sinkholes, flood hazard boundaries (FEMA-delineated floodplains and
floodways), all sensitive environmental features, areas of natural
vegetation to be preserved, the total extent of the upstream area
draining through the site, and overland drainage paths.
(10)
All existing and proposed utilities, on-lot wastewater facilities,
water supply wells, sanitary sewers, and water lines on and within
50 feet of property lines.
(11)
A key map showing all existing man-made features beyond the
property boundary that may be affected by the project.
(12)
Soil names and boundaries with identification of the hydraulic
soil group classification.
(13)
The proposed limit of disturbance line and associated proposed
disturbed acres.
(14)
Proposed structures, roads, paved areas, buildings, and other
improvements including plans and profiles of roads and paved areas
and floor elevations of buildings.
(15)
Horizontal alignment, vertical profiles, and cross sections
of all open channels, pipes, swales, and other BMPs.
(16)
The location and clear identification of the nature of permanent
stormwater BMPs. This information shall include the limits of design
impervious area and, where applicable, modification of design for
impervious area in excess of that specified.
(17)
The location of all erosion and sedimentation control facilities.
(18)
A minimum twenty-foot-wide access easement around all stormwater
management facilities that would provide ingress to and egress from
a public right-of-way. In lieu of providing an easement to the public
right-of-way, a note may be added to the plan granting the Township
or its designees access to all easements via the nearest public right-of-way.
(19)
Construction details for all drainage and stormwater BMPs. Where
possible, guidance for modification of the design for additional impervious
area shall be provided.
(20)
Construction details of any improvements made to sinkholes.
(21)
Identification of short-term and long-term ownership, operations,
and maintenance responsibilities.
(22)
Notes and statements:
(a)
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.
(b)
A statement referencing the operation and maintenance (O&M)
agreement and stating that the O&M agreement is part of the SWM
site plan.
(c)
A note indicating that as-built survey plans will be provided
for all stormwater management facilities prior to occupancy of land
or structures, or the release of financial security for said facilities.
(d)
The following signature block for the qualified professional
preparing the SWM site plan:
|
"I, __________, hereby certify that the Stormwater Management
Site Plan meets all design standards and criteria of the Township
of Derry Stormwater Management Ordinance, Chapter 174."
|
B. SWM site report shall include (but not be limited to):
(1) The name of the development; name and location and/or address of
the property site; name, address, telephone number, and e-mail address
of the applicant/owner of the property; and name, address, telephone
number, e-mail address, and engineering seal and signature of the
individual preparing the SWM site report.
(2) Project description narrative including expected project time schedule.
(3) Location map showing the project site and its location relative to
release rate districts.
(4) Drainage area maps for all watersheds and inlets depicting the time
of concentration paths.
(5) A detailed description of the existing site conditions. 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.
(6) Complete hydrologic, hydraulic and structural computations, calculations,
assumptions, and criteria for the design of all stormwater BMPs.
(7) Description of, justification, and actual field results for infiltration
testing with respect to the type of test and test location for the
design of infiltration BMPs.
(8) Calculations showing the total drainage area and impervious area
loading rates to each BMP.
(9) 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 municipal stormwater collection system that may receive
runoff from the project site.
(10)
Description of the proposed changes to the land surface and
vegetative cover, including the type and amount of impervious area
to be added.
(11)
All applicable worksheets from Chapter 8 of the BMP Manual when
establishing volume controls.
(12)
Identification of short-term and long-term ownership, operation,
and maintenance responsibilities as well as schedules and costs for
inspection and maintenance activities for each permanent stormwater
or drainage BMP, including provisions for permanent access or maintenance
easements.
C. Supplemental information to be provided prior to recording of the
SWM site plan, as applicable:
(1) Signed and executed operation and maintenance agreement (
Appendix A).
(2) Signed and executed easements, as required for all on-site and off-site
work.
(3) An erosion and sedimentation control plan and approval letter from
DCCD.
(5) Permits from PADEP and ACOE.
(7) A wetland delineation report.
(8) A highway occupancy permit from PennDOT when utilization of a PennDOT
storm drainage system is proposed or when proposed facilities would
encroach onto a PennDOT right-of-way.
A modification to a submitted SWM site plan and report for a
development site that involves a change in stormwater management facilities
or techniques, or that involves the relocation or redesign of stormwater
management facilities, or that is necessary because soil or other
conditions are not as stated on the SWM site plan as determined by
the Township, shall require a resubmission of the modified SWM site
plan in accordance with this chapter.
A disapproved SWM site plan and report may be resubmitted, with
the revisions addressing the Township's concerns documented in
writing, to the Township in accordance with this chapter. The applicable
Township review fee must accompany a resubmission of a disapproved
SWM site plan and report.