For any of the activities regulated by this chapter, 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 stormwater management
plan from the municipality.
The stormwater management plan shall consist of all applicable
calculations, maps, and plans. A note on the maps shall refer to the
associated computations and erosion and sedimentation control plan
by title and date. The cover sheet of the computations and erosion
and sedimentation control plan shall refer to the associated maps
by title and date. All stormwater management plan materials shall
be submitted to the municipality in a format that is clear, concise,
legible, neat, and well organized; otherwise, the stormwater management
plan shall be disapproved and returned to the applicant. The following
items shall be included in the stormwater management plan:
A. Feasibility analysis.
(1)
A feasibility analysis that evaluates the potential application of infiltration, flow attenuation, bioretention, wetland, or wet pond BMPs must be submitted with the stormwater management plans required in Article
IV, including those developments not intending the use of such facilities. This analysis shall provide:
(a)
A general assessment of the anticipated additional runoff based on the design storm and post-development condition and utilizing the calculation procedures required in §
190-305;
(b)
Indication of drainage areas on the development site resulting
in impervious, pervious, and rooftop runoff;
(c)
Indication of type of land use (residential, nonresidential)
generating the impervious surface runoff;
(d)
Delineation of soils on the site from the USDA, NRCS Web Soil
Survey and on-site soil study. A soil study shall be conducted by
a soil scientist and shall include sufficient probes/deep holes to
evaluate application of BMPs;
(e)
Indication of soils generally suitable for infiltration and/or
wet pond/artificial wetland BMPs as shown in the table entitled: "General
Soil Suitability for Infiltration, Wet Pond and Artificial Wetland
Best Management Practices with Consideration to Runoff Point of Origin
and Land Use Type," including specification of those soils requiring
modifications;
(f)
Calculated acreage of suitable soils for infiltration BMPs and
wet pond or artificial wetland BMPs and percentage of suitable soils
based on total site acreage;
(g)
Calculated acreage of suitable soils for infiltration BMPs and
wet pond or artificial wetland BMPs made unavailable due to proposed
development layout and justification that alternative development
layout which would reduce impact on suitable soil availability is
unfeasible;
(h)
Analysis of potential infiltration or wet pond or artificial wetland BMPs which could be implemented to manage the projected post-development runoff with consideration of suitable soil availability runoff point of and type of land use [Subsection
A(1)(b) and
(c) above] and the general design standards and maintenance issues included in this chapter, including an indication of how most post-development runoff can be managed by these BMPs (e.g., the entire post-development runoff or partial amount of runoff expressed as a percentage); and
(i)
Rationale for the decision to not proceed with implementation
of infiltration BMPs or wet pond or artificial wetland BMPs such as
excessive cost of implementation, insufficient soil suitability, and
development constraints.
(2)
The feasibility analysis must allow the municipality to review
the general soil characteristics of a site and the proposed development
for that site and determine if infiltration BMPs or wet pond or artificial
wetland BMPs could have been more thoroughly pursued for use by the
developer. The information required in the analysis is detailed enough
to determine the potential applicability of these BMPs for a proposed
development, but general enough not to force a developer into incurring
excessive cost associated with conducting laborious field and/or laboratory
soil testing for a site which ultimately may not be suitable for infiltration
or wet pond or artificial wetland BMP implementation. However, with
the requirements for conducting a feasibility analysis, developers
will be aware that they are expected to use these BMPs wherever possible
and are required to provide adequate justification if these BMPs are
not to be implemented. Essentially, all developers will be conducting
feasibility analysis since such analysis would become the preliminary
step in evaluating the potential for implementation of these mandatory
BMPs where possible. Developers for those sites that are determined
to be generally suitable from these analyses (taking into consideration
the areal extent of suitable soils necessary to accommodate an infiltration
or wet pond or wetland BMP for the type and size of development proposed)
are required to conduct the detailed soil testing and other feasibility
testing required in other sections of this chapter which contain the
description and additional design criteria of these BMPs.
B. A detailed geologic evaluation of the project site shall be performed
to determine the suitability of recharge facilities. The evaluation
shall be performed by a qualified geologist and/or soil scientist,
and at a minimum, address soil permeability, depth to bedrock, susceptibility
to sinkhole formation, and subgrade stability.
C. General.
(1)
General description of project.
(2)
General description of permanent stormwater management techniques,
including construction specifications of the materials to be used
for stormwater management facilities.
(3)
Complete hydrologic, hydraulic, and structural computations
for all stormwater management facilities.
D. Map(s) of the project area shall be 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 Bucks County.
The contents of the map(s) shall include, but not be limited to:
(1)
The location of the project relative to highways, municipalities,
or other identifiable landmarks.
(2)
Existing contours at intervals of two feet. In areas of steep
slopes (greater than 25%), five-foot contours may be used.
(3)
Existing streams, lakes, ponds, or other bodies of water within
the project area.
(4)
Other physical features, including flood hazard boundaries,
sinkholes, streams, existing drainage courses, wetlands, areas of
natural vegetation to be preserved, and the total extent of the upstream
area draining through the site.
(5)
The locations of all existing and proposed utilities, sanitary
sewers, and water lines located on the site and/or within 50 feet
of property lines.
(6)
An overlay showing soil names and boundaries. This overlay shall
include a table on the map showing the recharge capabilities of each
soil represented on site in inches per hour and describe their recharge
or infiltration capabilities.
(7)
Proposed changes to the land surface and vegetative cover, including
the type and amount of impervious area that would be added.
(8)
Proposed structures, roads, paved areas, and buildings. Where
pervious pavement is proposed for parking lots, recreational facilities,
nondedicated streets, or other areas, pavement construction specifications
shall be noted on the plan.
(9)
Final contours at intervals at two feet. In areas of steep slopes
(greater than 25%), five-foot contour intervals may be used.
(10)
The name of the development, tax parcel number(s), the name
and address of the owner of the property, and the name of the individual
or firm preparing the plan.
(12)
A graphic and written scale of one inch equals no more than
50 feet. For tracts of 20 acres or more, the scale may be one inch
equals no more than 100 feet.
(14)
The total tract boundary and size with distances marked to the
nearest foot and bearings to the nearest degree.
(15)
Existing and proposed land use(s).
(16)
A key map showing all existing man-made features beyond the
property boundary that may be affected by the project.
(17)
Horizontal and vertical profiles of all open channels, including
hydraulic capacity.
(18)
Overland drainage paths and path utilized to determine time
of concentration.
(19)
A twenty-foot-wide access easement around all stormwater management
facilities that would provide ingress to and egress from a public
right-of-way.
(20)
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.
(21)
A construction detail of any improvements made to sinkholes
and the location of all notes to be posted, as specified in this chapter.
(22)
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 Township, which
shall be recorded with the record plan and which shall be applicable
to all future landowners.
(23)
The location of all erosion and sedimentation control facilities.
(24)
The following signature block for the design engineer:
(Design engineer), on this date (date of signature), has reviewed
and hereby certifies that the stormwater management plan meets all
design standards and criteria of Nockamixon Township Watershed Act
167 Stormwater Management Ordinance.
E. Supplemental information.
(1)
A written description of the following information shall be
submitted:
(a)
The overall stormwater management concept for the project.
(b)
Stormwater runoff computations as specified in this chapter.
(c)
Stormwater management techniques to be applied both during and
after development.
(d)
Expected project time schedule.
(2)
A soil erosion and sedimentation control plan, where applicable,
including all reviews and approvals, as required by PADEP and/or Bucks
Conservation District.
(3)
A geologic assessment of the effects of runoff on sinkholes
as specified in this chapter.
(4)
The effect of the project (in terms of runoff volume and peak
flow) on adjacent properties and on any existing municipal stormwater
collection system that may receive runoff from the project site.
(5)
A declaration of adequacy and highway occupancy permit from
the PADOT district office when utilization of a PADOT storm drainage
system is proposed.
F. 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 proposed, the locations of existing and proposed septic
tank infiltration areas and wells must be shown. A separation distance
of no less than 20 feet shall be provided between any septic system
and any facility used for stormwater management.
(3)
All calculations, assumptions, and criteria used in the design
of the stormwater management facilities must be shown. If multiple
facilities are proposed in conjunction with each other, such as infiltration
best management practices with vegetation-based management practices,
a summary narrative, shall be included describing any sequence and
how the facilities are meant to function with each other to manage
stormwater runoff.
For all activities regulated by this chapter, the steps below
shall be followed for submission. For any activities that require
a PADEP joint permit application and regulated under Chapter 105 (Dam
Safety and Waterway Management) or Chapter 106 (Floodplain Management)
of PADEP's Rules and Regulations, require a PADOT highway occupancy
permit, or require any other permit under applicable local, state,
or federal regulations, the permit(s) shall be part of the plan.
A. The stormwater management plan shall be submitted by the developer
as part of the preliminary plan submission for the regulated activity.
B. A minimum of three copies of the stormwater management plan shall
be submitted.
C. Distribution of the stormwater management plan will be as follows:
(1)
Two copies to the municipality accompanied by the requisite
municipal review fee, as specified in this chapter.
(2)
One copy to the Municipal Engineer.
A disapproved stormwater management plan may be resubmitted, with the revisions addressing the Municipal Engineer's concerns documented, in writing, to the Municipal Engineer in accordance with §
190-404 of this chapter and be subject to review as specified in §
190-405 of this chapter. The applicable municipal review fee must accompany a resubmission of a disapproved stormwater management plan.
A set of design plans approved by the Township shall be on file
at the site throughout the duration of the development activity. Periodic
inspections may be made by the Township or designee during development
activities.
At the completion of the project, and as a prerequisite for the release of the performance guarantee under §
190-801, the owner or his representatives shall:
A. Contact the Township Engineer to request inspection of the site for
completion of stormwater management facilities and compliance with
the approved plans and specifications.
B. Provide a set of as-built drawings as required pursuant to the Township
Building Code and/or Subdivision and Land Development Ordinance.
No occupancy permit for any new structure on the site shall
be issued unless the stormwater management facilities approved for
the lot have been installed and found satisfactory to the Township
Engineer.