The Potter Township Supervisors find that:
A.
Inadequate management of accelerated stormwater runoff resulting
from development throughout a watershed increases flood flows and
velocities; contributes to erosion and sedimentation; overtaxes the
carrying capacity of existing streams and storm sewers; greatly increases
the cost of public facilities to convey and manage stormwater; undermines
floodplain management and flood reduction efforts in upstream and
downstream communities; reduces groundwater recharge; and threatens
public health and safety.
B.
This stormwater management chapter has been developed considering
the actual hydrologic processes that occur within the Spring Creek
Watershed and how these processes can best be represented in hydrologic
models that are used in engineering practice to model developing areas
for stormwater management purposes. Process driven stormwater management
planning is critical in the Spring Creek Watershed due to the underlying
geology. The Spring Creek Watershed is mainly underlain by carbonate
formations. As a result, significant areas within the watershed do
not produce over-land or surface runoff, but rather contribute to
the storm flow component of runoff in larger tributary areas via a
greater than normal interflow component.
C.
A comprehensive program of stormwater management, including reasonable
regulation of development and activities causing accelerated erosion,
is fundamental to the public health, safety, welfare, and the protection
of the people of the municipality and all the people of the commonwealth,
their resources, and the environment.
The purpose of this chapter is to promote health, safety, and welfare within the Spring Creek Watershed by minimizing the damages described in § 173-101A of this chapter through provisions designed to:
A.
Manage accelerated runoff and erosion and sedimentation problems
at their source by regulating activities that cause these problems.
B.
Utilize and preserve the existing natural drainage systems.
C.
Encourage the use of low-impact development techniques to promote
infiltration and groundwater recharge where appropriate.
D.
Maintain existing flows and quality of streams and watercourses in
the Township and the commonwealth.
E.
Preserve and restore the flood-carrying capacity of streams.
F.
Provide proper maintenance of all permanent stormwater management
facilities that are constructed in the basin.
G.
Provide performance standards and design criteria for watershed-wide
stormwater management and planning.
H.
Protect groundwater and surface water quality.
The Township is empowered to regulate land use activities that
affect runoff by the authority by the Act of October 4, 1978 32 P.S.,
P.L. 864 (Act 167), § 680.1 et seq., as amended, the "Stormwater
Management Act."
B.
This chapter shall only apply to permanent stormwater management
facilities constructed as part of any of the regulated activities
listed in this section. Stormwater management and erosion and sediment
pollution control during construction activities are specifically
not regulated by this chapter, but shall continue to be regulated
under existing laws and ordinances.
C.
This chapter contains only the stormwater management performance
standards and design criteria that are necessary or desirable from
a watershed-wide perspective. Local stormwater management design criteria
(e.g., inlet spacing, inlet type, collection system design and details,
outlet structure design, etc.) shall continue to be regulated by the
applicable Township ordinances or at the Township Engineer's
discretion. However, these design criteria have also been provided
within this chapter and may be adopted in full by municipalities.
D.
The following activities are defined as "regulated activities" and
shall be regulated by this chapter:
(1)
Land development;
(2)
Subdivision;
(3)
Construction of new or additional impervious or semi-pervious
surfaces (roadways, driveways, parking lots, etc.);
(4)
Construction of new buildings or additions to existing buildings;
(5)
Diversion or piping of any natural or man-made stream channel;
(6)
Installation of stormwater management facilities or appurtenances
thereto.
Any ordinance or ordinance provision of the Township inconsistent
with any of the provisions of this chapter is hereby repealed to the
extent of the inconsistency only.
Should any section or provision of this chapter be declared
invalid by a court of competent jurisdiction, such decision shall
not affect the validity of any of the remaining provisions of this
chapter.
Approvals issued pursuant to this chapter do not relieve the
applicant of the responsibility to comply with or to secure required
permits or approvals for activities regulated by any other applicable
codes, rules, statutes, or ordinances.
The granting of any exemption, permit, or approval by the Township
does not relieve the applicant from assuring that stormwater runoff
from the development site will not cause injury or damage to other
persons or property.
Specific methods and publications indicated in this chapter
shall, in all cases, refer to the latest available edition and include
revisions or amendments thereto.
A.
Activities identified below are exempt from the requirement to submit a stormwater management plan to the governing municipality for review. Exemption shall not relieve the applicant from implementing such measures as are necessary to protect health, safety, and property. These measures include adequate and safe conveyance of stormwater on the site and as it leaves the site. This exemption shall not relieve the applicant from meeting the special requirements for water quality and groundwater recharge for high quality (HQ) and exceptional value (EV) watersheds (DEP Chapter 93 and anti-degradation requirement), and § 173-304C and E of this chapter relative recharge and water quality volume requirements.
(1)
All development activities having impervious coverage of less
than 10% of the total site area up to a maximum impervious area of
5,000 square feet. However, adequate and safe conveyance of stormwater
from the site must be provided. For developments that are to be constructed
in phases, the sum of all final phases must be considered in establishing
exemption eligibility. Impervious cover shall include, but not be
limited to, any roof, parking or driveway areas, and any new streets
and sidewalks, or bikeways.
(2)
Land disturbance associated with the construction or alteration
of one- and two-family dwellings, provided that the disturbance does
not alter any stormwater condition beyond the boundaries of the lot
or alter provisions of a previously approved stormwater management
plan for the lot or encompassing subdivision. Multiple (greater than
two) lot subdivisions cannot be exempted.
(3)
Any site less than one acre in size that decreases the total
site impervious area following development, and:
(a)
Is not located within a recognized sensitive area (as defined in Article II, Definitions, of this chapter);
(c)
Is not located in an area where existing downstream stormwater
problems are known to occur (the Township Engineer shall make the
final determination as to preexisting problems, but the Township must
have supporting documentation of past problems).
(4)
In addition, the Township Engineer may waive the requirement
to prepare a stormwater management plan for sites larger than 1.0
acre for which the overall site impervious area is being decreased,
and which meets the other conditions identified above.
B.
The diversion or piping of any natural or man-made stream channel and/or for the installation of stormwater management facilities or modifications thereto cannot be exempted. These activities always require the submission of a stormwater management plan. Exemptions A and B, above in § 173-110 cannot be combined for use with small residential subdivisions.
