No development plan, subdivision plat or land development plan
shall be approved; no permit authorizing construction or development
issued; nor any earth disturbance activity subject to this chapter
shall be initiated or undertaken unless and until a stormwater management
plan for such activity is reviewed and approved in accord with the
provisions of this chapter.
A.
No regulated development activities within the City shall commence until approval by the City of a stormwater management plan which demonstrates compliance with state water quality requirements after construction is complete. Refer to the Regulated Development Activity Table located in Article III of this chapter.
B.
The stormwater management plan must be designed, implemented and
maintained to meet state water quality requirements, and any other
more stringent requirements as determined by the City.
C.
To control post-construction stormwater impacts from regulated development
activities, state water quality requirements can be met by BMPs, including
site design and green infrastructure, which provide for replication
of pre-construction stormwater infiltration and runoff conditions,
so that post-construction stormwater discharges do not degrade the
physical, chemical or biological characteristics of the receiving
waters. As described in the DEP Comprehensive Stormwater Management
Policy (#392-0300-002, September 28, 2002), this may be achieved by
the following:
(1)
By maximizing the use of the site's natural characteristics.
(2)
Infiltration. Replication of pre-construction stormwater infiltration
conditions.
(3)
Treatment. Use of water quality treatment BMPs to ensure filtering
out of the chemical and physical pollutants from the stormwater runoff.
(4)
Streambank and streambed protection. Management of volume and rate
of post-construction stormwater discharges, using detention/retention
and other means, to prevent physical degradation of receiving waters
(e.g., from scouring).
D.
In the absence of an existing stormwater conveyance or easement whether
natural or man-made for release of stormwater flow from a development
site, an easement must be provided. Information shall be presented
as to the ownership, responsible party, and agreement for said easement.
E.
The stormwater management plan must meet DEP regulations that require
municipalities to ensure design, implementation, and maintenance of
best management practices (BMPs) that control runoff from new development
and redevelopment after regulated development activities are complete.
These requirements include the need to implement post-construction
stormwater facilities and BMPs with assurance of long-term operations
and maintenance of those BMPs.
F.
Evidence of any necessary permit(s), such as Chapter 102 erosion and sedimentation control or Chapter 105 stream encroachment, for regulated development activities from WCD or the appropriate DEP regional office must be provided to the municipality. The issuance of an NPDES construction permit (or permit coverage under the Statewide General Permit (PAG-2) may satisfy the requirements of Subsection A above, after review and approval by the municipality.
G.
Appropriate sections from the City's Subdivision and Land Development
Ordinance (SALDO), and other applicable local ordinances, shall be
followed in preparing the SWM plans.
H.
The City of Monessen shall not approve any SWM plan that is deficient
in meeting the requirements of this chapter. At its sole discretion
and in accordance with this article, when a SWM plan is found to be
deficient, the City may either disapprove the submission and require
a resubmission, or in the case of minor deficiencies, the City may
accept submission of modifications.
I.
Professional certification. The stormwater management plan (including
all calculations) must be prepared and sealed by a qualified professional
with training and expertise in hydrology and hydraulics. Documentation
of qualifications may be required by the City.
General format. The stormwater management plan shall include
a narrative and a set of plan drawings. Refer to checklist Appendix
E.[1]
A.
A narrative describing the overall stormwater management concept
for the project.
(1)
A determination of site conditions in accordance with the PA DEP
Stormwater BMP Manual. A detailed site evaluation shall be completed
for projects proposed in environmentally sensitive areas, such as
brownfields.
(2)
Runoff calculations. Stormwater runoff design calculations for determining pre-and post-development discharge rates, for designing proposed stormwater control facilities and to demonstrate that the maximum practicable measures have been taken to meet the requirements of this chapter, must be submitted with the stormwater management plan. All calculations shall be prepared using the methods and data prescribed by general requirements in § 338-15 of this chapter. Refer to the Acceptable Computation Methodologies table in Article III § 338-20 of this chapter.
(3)
Expected project time schedule for the installation of all temporary
and permanent stormwater control measures and devices. If the development
is to be constructed in stages, the applicant must describe how stormwater
facilities and BMPs will be sequentially installed to manage stormwater
runoff safely during each stage of development.
(4)
The effect of the project (in terms of runoff rate, volumes, and
water quality) on surrounding properties and aquatic features and
on any existing stormwater conveyance system that may be affected
by the project.
(5)
If appropriate, the narrative should provide justification as to
why any preferred stormwater management techniques, such as LID and
green infrastructure, as listed in this chapter, are not proposed
for use. Refer to the PA DEP Stormwater BMP Manual 2006 or most recent
edition for list of acceptable management techniques.
B.
The stormwater management plan drawings shall be drawn to a scale
of not less than one inch equals 50 feet. All sheets shall contain
a title block with name and address of applicant and designer, scale,
north arrow, legend and date of preparation.
(1)
Existing and proposed features. The plan shall show the following:
(a)
Watershed location. The City of Monessen is within the Monongahela
River Watershed. Provide a key map (using USGS Topo maps) showing
the location of the development site within the watershed, and watershed
subarea(s). On all site drawings, show the boundaries of the watershedand
subarea(s) as they are located on the development site and identify
watershed name, name Refer to Appendix A Monongahela River Watershed
and Appendix B Monessen Watershed Subareas Map.[3]
[3]
Editor's Note: Said appendixes are included as attachments to this chapter.
(b)
Floodplain boundaries. Identify 100-year floodplains on the
development site (as appropriate) based on the municipality Flood
Insurance Study maps.
(c)
Natural features. Show all bodies of water (natural or artificial),
watercourses (permanent and intermittent), swales, wetlands, and other
natural drainage courses on the development site, or which will be
affected by runoff from the development.
(d)
Soils. Provide an overlay showing soil types and boundaries
within the development site (consult WCD, SCS and U.S. Geological
Survey for information).
(e)
Contours. Show existing and final contours at intervals of two
feet; in areas with slopes greater than 15%, five-foot contour intervals
may be used.
(f)
Land cover. Show existing and final land cover classifications,
including existing and proposed improvements, as necessary to support
and illustrate the runoff calculations performed.
(g)
Drainage area delineations. Show the boundaries of the drainage
areas and points of interest employed in the runoff calculations performed.
(h)
Utilities and easements. Show the locations and easements of
existing utilities, stormwater management or drainage controls and/or
structures, such as sanitary sewers, water, gas, electric, telecommunications,
storm sewers, swales, culverts, and any easements, which are located
on the development site, or which are off site but may be affected
by runoff from the development.
(i)
Identify if the development site is within the municipal separate
sanitary sewer system (MS4) or within the combination sanitary storm
sewer system (CS4). Refer to Appendix A.
(j)
For a listing of streets with a separate storm sewer system
refer to Appendix G. Streets not listed in Appendix G have combination
sanitary and storm sewers and are within the CS4 District. Refer to
Appendix G.[4]
[4]
Editor's Note: Said appendix is included as an attachment to this chapter.
(2)
Proposed stormwater facilities and BMPs. All proposed stormwater
runoff control measures must be shown on the plan including methods
for collecting, conveying and storing stormwater runoff on site, which
are to be used both during and after construction. Erosion and sedimentation
controls shall be shown in accordance with applicable City and WCD
requirements. The plan shall provide information on the exact type,
location, sizing, design and construction of all proposed facilities
and relationship to the existing watershed drainage system.
(a)
If the development is to be constructed in stages, the applicant
must demonstrate that stormwater facilities will be installed to manage
stormwater runoff safely during each stage of development.
(b)
A schedule for the installation of all temporary and permanent
stormwater control measures and devices shall be included in the narrative
and shown on the site plan.
(3)
Easements, rights-of-way, deed restrictions. BMPs and stormwater
management facilities that provide control for more than one lot shall
be located on a separate dedicated lot or in an easement. All existing
and proposed easements for any BMPs and stormwater management facilities
and controls for access, inspections, maintenance, repair, preservation,
and use shall be shown on the plan and, if required, dedicated to
the entity, association or person required. The easement and the purpose
for the same shall be set forth on the plan and in the agreement required
by this chapter.
[1]
Editor's Note: Said appendix is included as an attachment to this chapter.
A list of any approvals/permits relative to stormwater management
that will be required from other governmental agencies (e.g., Chapter
102 Erosion and Sedimentation Control, PennDOT HOP, Chapter 105 Water
Obstruction and Encroachment Permit from PA DEP) and anticipated dates
of submission/receipt should be included with the stormwater plan
submission. Copies of permit applications may be requested by the
City where they may be helpful for the plan review.
The application shall contain a proposed operation and maintenance plan (O&M) for all stormwater control facilities in accordance with the following and as described in Article VI of this chapter:
C.
Submit any legal agreements required to implement the maintenance program and an executed O&M agreement as required by this chapter. Refer to Article VI, § 338-38 and Appendix C.[1]
[1]
Editor's Note: Said appendix is included as an attachment to this chapter.
D.
A record of inspections and repairs performed shall be provided to
the City and WCD in accordance with the approved O&M plan.
Submit fees and financial guarantees in accordance with the provisions of this chapter. Refer to the Article VI, § 338-39 and Appendix F.[1]
[1]
Editor's Note: Said appendix is included as an attachment to this chapter.
