For any of the activities regulated by this chapter, the preliminary
or final approval of subdivision and/or land development plans, the
issuance of any building or occupancy permit, or the commencement
of any earth disturbance activity may not proceed until the property
owner or applicant or his/her agent has received written approval
of a drainage plan from the municipality, obtained an NPDES permit
for stormwater discharges associated with construction activities,
if greater than one acre of land disturbance, from the Montgomery
County Conservation District and/or DEP, and an adequate erosion and
sediment control plan review by the Conservation District. The Borough
shall be provided with a copy of all outside agency permit applications
and final approval or permit.
The drainage plan shall consist of a general description of the project, including sequencing items described in § 101-19, 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, erosion and sediment control plan, and post-construction stormwater management (PCSM) plan shall refer to the associated maps by title and date. All drainage plan materials shall be submitted to the municipality in a format that is clear, concise, legible, neat, and well organized. If not, the drainage plan shall not be accepted for review and shall be returned to the applicant. The following items shall be included in the drainage plan:
A.
General.
(2)
General description of proposed 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.
(4)
An erosion and sediment control plan, including all reviews and letters
of adequacy from the Conservation District, as applicable.
(5)
A general description of proposed nonpoint source pollution controls.
(7)
The development or construction schedule.
B.
Maps. Map(s) of the project area shall be submitted on twenty-four-inch-by-thirty-six-inch
sheets and/or shall be prepared in a form that meets the requirements
for recording at the offices of the Recorder of Deeds of Montgomery
County. If the SALDO has more stringent criteria than this chapter,
then the more stringent criteria shall apply.[2] The contents of the map(s) shall include, but not be limited
to:
(1)
The location of the project relative to highways, municipal boundaries,
or other identifiable landmarks.
(2)
Existing contours at intervals of two feet. In areas of slopes greater
than 25%, five-foot contour intervals may be used.
(3)
Existing streams, lakes, ponds, or other waters of the commonwealth
within the project area.
(4)
Other physical features, including flood hazard boundaries, stream
buffers, existing drainage courses, 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 waterlines within 50 feet of property lines.
(6)
An overlay showing soil names, boundaries and limitations (in tabular
format).
(7)
Limits of earth disturbance, including the type and amount of impervious
area that would be added.
(8)
Proposed structures, roads, paved areas, and buildings.
(9)
Final contours at intervals of two feet. In areas of steep slopes
(greater than 25%), five-foot contour intervals may be used.
(10)
The name of the development, the name and address of the owner
of the property, and the name of the individual or firm preparing
the plan.
(11)
The date of submission.
(12)
A graphic and written scale of one inch equals no more than
50 feet; for tracts of 20 acres or more, the scale shall be one inch
equals no more than 100 feet.
(13)
A North arrow.
(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 would be affected by the project.
(17)
The location of all open channels, as well as indicating where
they are draining after they leave the site (storm sewer, defined
drainage swale, stream channel, waters of the commonwealth, etc.).
(18)
Overland drainage patterns and swales.
(19)
A fifteen-foot-wide access easement to all stormwater management
facilities that would provide ingress to and egress from a public
right-of-way.
(20)
The location of all erosion and sediment control facilities,
both temporary and permanent, and all post-construction stormwater
management facilities, BMPs, systems, etc.
(21)
A statement, signed by the applicant, acknowledging that any
revision to the approved plan must be approved by the municipality.
If more than one acre of land is disturbed, the Conservation District
and/or DEP must approve the plan. Any revision to the erosion and
sediment control plan must be submitted to the approving agency for
a determination of adequacy.
(22)
The following signature block for the design engineer: "I, (Design
Engineer), on (date of signature), hereby certify that the drainage
plan meets all design standards and criteria of the West Conshohocken
Borough Stormwater Management Ordinance."
C.
Supplemental information to be submitted to the municipality.
(1)
A written description of the following information shall be submitted
by the applicant and shall include:
(2)
An erosion and sediment control plan.
(3)
A description of 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.
(4)
A declaration of adequacy and a highway occupancy permit from the
Pennsylvania Department of Transportation (PennDOT) district office
when utilization of a PennDOT storm drainage system is proposed.
D.
Stormwater management facilities.
(1)
All PCSM BMP facilities must be located on a plan and described in
detail. The PCSM plan package should include, at a minimum, pre- and
post-drainage area plans, an overall PCSM plan, PCSM details sheets,
landscaping or conservation plans, etc.
(2)
When infiltration measures, such as seepage pits, beds, or trenches,
are used, the locations of existing and proposed septic tanks, infiltration
areas and wells must be shown. Minimum setback distances should be
identified from water supply wells, septic areas, and any adjacent
or downgradient buildings and/or structures with below-grade floors
or inhabitable space. This shall be done on the proposed development
site and/or downgradient of the site.
(3)
All calculations, assumptions, and criteria used in the design of
the stormwater management facilities must be shown.
The municipality shall require a complete drainage plan, as
specified in this chapter.
A.
Proof of application or documentation of required permit(s) or approvals
for the permits listed below shall be part of the plan:
C.
For projects that require SALDO approval, the drainage plan shall
be submitted by the applicant as part of the preliminary plan submission
where applicable for the regulated activity.
E.
Six copies of the drainage plan may be submitted to the Borough and
distributed as follows:
F.
Any submissions to the agencies listed above that are found to be
incomplete shall not be accepted for review and shall be returned
to the applicant with a notification in writing of the specific manner
in which the submission is incomplete.
A.
The Municipal Engineer shall review the drainage plan for consistency
with this chapter, the West Conshohocken Borough Stormwater Management
Ordinance. Any plans found incomplete shall not be accepted for review
and shall be returned to the applicant.
C.
The Conservation District, in accordance with established criteria
and procedures, shall review the drainage plan for consistency with
stormwater management and erosion and sediment pollution control requirements
and provide comments to the municipality. Such comments shall be considered
by the municipality prior to final approval of the drainage plan.
D.
For activities regulated by this chapter, the Municipal Engineer
shall notify the applicant and the municipality in writing, within
30 calendar days, whether the drainage plan is consistent with this
chapter.
(1)
If the Municipal Engineer determines that the drainage plan is consistent
with this chapter, the Municipal Engineer shall forward a letter of
consistency to the applicant.
(2)
If the Municipal Engineer determines that the drainage plan is inconsistent
or noncompliant with this chapter, the Municipal Engineer shall forward
a letter to the applicant citing the reason(s) and specific ordinance
sections for the inconsistency or noncompliance. Inconsistency or
noncompliance may be due to inadequate information to make a reasonable
judgment as to compliance with this chapter. Any drainage plans that
are inconsistent or noncompliant may be revised by the applicant and
resubmitted. The applicant shall be notified of the Municipal Engineer's
findings.
E.
For regulated activities specified in § 101-5 of this chapter that require a building permit, the Municipal Engineer shall notify the Municipal Building Code Official in writing, within a time frame consistent with the Municipal Building Code and/or Municipal SALDO, whether the drainage plan is consistent with the Stormwater Management Ordinance. The Municipal Building Code Official shall forward a copy of the consistency/inconsistency letter to the applicant. Any drainage plan deemed inconsistent may be revised by the applicant and resubmitted.
F.
For regulated activities under this chapter that require an NPDES
permit, the applicant shall forward a copy of the Municipal Engineer's
letter stating that the drainage plan is consistent with this chapter
to the Conservation District and/or DEP. In addition, a short summary
of the proposed post-construction stormwater management design and
proposed BMPs should also be forwarded to the Conservation District
and/or DEP. DEP and the Conservation District may consider the Municipal
Engineer's review comments in determining whether to issue a
permit.
G.
The municipality shall not grant preliminary or final approval to any subdivision or land development for regulated activities specified in § 101-5 of this chapter if the drainage plan has been found by the Municipal Engineer to be inconsistent with this chapter. All required permits from DEP must be obtained prior to approval of any subdivision or land development.
H.
No building permits for any regulated activity specified in § 101-5 of this chapter shall be approved by the municipality if the drainage plan has been found to be inconsistent with this chapter, as determined by the Municipal Engineer and/or the Conservation District, or without considering the comments of the Municipal Engineer and/or the Conservation District. All required permits from DEP must be obtained prior to issuance of a building permit.
I.
The applicant shall be responsible for completing record drawings
of all stormwater management facilities included in the approved drainage
plan at the end of the project. The record drawings and an explanation
of any discrepancies with the design plans shall be submitted to the
Municipal Engineer for final approval. In no case shall the municipality
approve the record drawings until the municipality receives a copy
of an approved declaration of adequacy and/or highway occupancy permit
from the PennDOT District Office, NPDES permit, and any other applicable
permits or approvals from DEP or the Conservation District. The above
permits and approvals must be based on the record drawings.
J.
The municipality's approval of a drainage plan shall be valid for a period not to exceed five years commencing on the date that the municipality signs the approved drainage plan. If stormwater management facilities included in the approved drainage plan have not been constructed or, if constructed, record drawings of these facilities have not been approved within this five-year time period, then the municipality may consider the drainage plan inconsistent or noncompliant and may revoke any and all permits. Drainage plans that are determined to be inconsistent or noncompliant by the municipality shall be resubmitted in accordance with § 101-15 of this chapter.
A.
A modification to a submitted drainage plan under review by the municipality for a development site that involves the following shall require a resubmission to the municipality of a modified drainage plan consistent with § 101-12 of this chapter and be subject to review as specified in § 101-13 of this chapter:
B.
A modification to an already approved or inconsistent or noncompliant
drainage plan shall be submitted to the municipality, accompanied
by the applicable municipal review and inspection fee. A modification
to a drainage plan for which a formal action has not been taken by
the municipality shall be submitted to the municipality accompanied
by the applicable municipal review and inspection fee.
An inconsistent or noncompliant drainage plan may be resubmitted with the revisions addressing the Municipal Engineer's concerns documented in writing. It must be addressed to the Borough in accordance with § 101-12 of this chapter, distributed accordingly, and be subject to review as specified in § 101-13 of this chapter. The applicable municipal review and inspection fee must accompany a resubmission of an inconsistent or noncompliant drainage plan.
