Appropriate sections from the municipality's Subdivision and
Land Development Ordinance, and other applicable local ordinances,
shall be followed in preparing the SWM site plans. The municipality
shall not approve any SWM site plan that is deficient in meeting the
requirements of this chapter. At its sole discretion and in accordance
with this article, when a SWM site plan is found to be deficient,
the municipality may either disapprove the submission and require
a resubmission, or in the case of minor deficiencies, the municipality
may accept submission of modifications. The following items shall
be included in the SWM site plan:
A. Provisions for permanent access or maintenance easements for all physical SWM BMPs, such as ponds and infiltration structures, as necessary to implement the Operation and Maintenance (O&M) plan discussed in Subsection
C(9) below.
B. The following signature block for the municipality:
"(Municipal official or Designated Plan Reviewer (Section 403.A)),
on this date (Signature date), has reviewed and hereby certifies that
the SWM Site Plan meets all design standards and criteria of the Municipal
Ordinance No. _____, except where waivers have been granted as noted
on the Plan. The review is based on a survey and plan prepared by
others and assumes that all information is correct and valid as submitted."
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C. The SWM site plan shall provide the following information:
(1) The overall stormwater management concept for the project.
(2) A determination of site conditions in accordance with the BMP Manual3. A detailed site evaluation shall be completed for projects
proposed in environmentally sensitive areas, such as brownfields.
(3) A key map showing the development site's location within the municipality's
stormwater management districts, watersheds and subareas. On all site
drawings, show the boundaries of the district(s), watershed(s) and
subarea(s) as they are located on the development site and identify
their district and watershed names and applicable subarea numbers.
(4) Location of the 100-year floodplain on the development site based
on the current municipal Flood Insurance Rate Maps.
(5) Stormwater runoff design computations and documentation as specified in this chapter, or as otherwise necessary to demonstrate that the maximum practicable measures have been taken to meet the requirements of this chapter, including the recommendations and general requirements in §
280-14.
(6) Expected project time schedule.
(7) A soil erosion and sediment control plan, where applicable, as prepared
for and submitted to the approval authority.
(8) 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 stormwater conveyance system that may be affected
by the project.
(9) Plan and profile drawings and details of all SWM BMPs, including
drainage structures, pipes, open channels, and swales.
(10)
SWM site plan shall show the property lines, dimensions of the
site and the locations of existing and proposed on-lot wastewater
facilities and water supply wells, property boundaries, existing and
proposed topography, point(s) of interest, utilities, and potential
utility conflicts.
(11)
The SWM site plan shall include an O&M plan for all existing
and proposed physical stormwater management facilities. This plan
shall address long-term ownership and responsibilities for O&M
including type and schedule/frequency of maintenance activities, personnel
and equipment requirements, estimated annual maintenance costs, and
method of financing continuing O&M.
(12)
A justification, acceptable to the designated plan reviewer,
must be included in the SWM site plan if BMPs other than green infrastructure
methods and LID practices are proposed to achieve the volume, rate
and water quality controls under this chapter.
(13)
Certification and seal of the qualified professional responsible
for the preparation of the plans and report.
(14)
Watershed maps delineating pre-development and postdevelopment
watershed boundaries and land cover conditions, as well as the flow
path and segments used to determine time of concentrations for each
watershed.
(15)
Storm sewer calculations and watershed maps delineating all
subareas used to size and compute flow for storm sewer system.
(16)
Existing contours at intervals of two feet except in areas with
slopes greater than 15%, in which case five-foot contour intervals
may be used.
(17)
Contours of the finished project site at intervals of two feet,
except in areas with slopes greater than 15%, in which case, five-foot
contour intervals may be used.
Up to five copies of the SWM site plan shall be submitted as
follows:
A. Two copies to the municipality.
B. One copy to the municipal engineer (when applicable).
C. One copy to the Allegheny County Conservation District (when requested
by the District).
A modification to a submitted SWM site plan that involves a
change in SWM BMPs or techniques, or that involves the relocation
or redesign of SWM BMPs, or that is necessary because soil or other
conditions are not as stated on the SWM site plan, as determined by
the designated plan reviewer, shall require a resubmission of the
modified SWM site plan in accordance with this article.
A disapproved SWM site plan may be resubmitted, with the revisions addressing the municipality's concerns, to the municipality in accordance with this article. The applicable review fee, in accord with Article
VI, must accompany a resubmission of a disapproved SWM site plan.
The municipality's approval of an SWM site plan authorizes the regulated activities contained in the SWM site plan for a maximum term of validity of five years following the date of approval. The municipality may specify a term of validity shorter than five years in the approval for any specific SWM site plan. Terms of validity shall commence on the date the municipality signs the approval for an SWM site plan. If an approved SWM site plan is not completed according to §
280-15 within the term of validity, then the municipality may consider the SWM site plan disapproved and may revoke any and all permits. SWM site plans that are considered disapproved by the municipality shall be resubmitted in accordance with §
280-23 of this chapter.