This Part 2 shall be known and cited as the "Wissahickon Creek
Stormwater Management Ordinance."
The Board of Supervisors of Whitpain Township finds 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.
Inadequate planning and management of stormwater runoff resulting
from land development throughout a watershed can also harm surface
water resources by changing the natural hydrologic patterns, accelerating
stream flows (which increase scour and erosion of streambeds and streambanks,
thereby increasing sedimentation), destroying aquatic habitat, and
increasing aquatic pollutant concentrations and loadings such as sediments,
nutrients, heavy metals, and pathogens. Groundwater resources are
also impacted through loss of recharge.
C.
A comprehensive program of stormwater management, including minimization
of impacts of development, redevelopment, and activities causing accelerated
erosion and loss of natural infiltration, is fundamental to the public
health, safety, welfare, and the protection of the people of the Municipality
and all of the people of the commonwealth, their resources, and the
environment.
D.
Stormwater is an important resource by providing groundwater recharge
for water supplies and baseflow of streams, which also helps to protect
and maintain surface water quality.
E.
Impacts from stormwater runoff can be minimized by using project
designs that maintain the natural hydrologic regime and sustain high
water quality, groundwater recharge, stream baseflow, and aquatic
ecosystems.
F.
Federal and state regulations require certain municipalities to implement
a program of stormwater controls. These municipalities are required
to obtain a permit for stormwater discharges from their separate storm
sewer systems under the National Pollutant Discharge Elimination System
(NPDES).
G.
Nonstormwater discharges to municipal separate storm sewer systems
can contribute to pollution of waters of the commonwealth.
The purpose of this Part 2 is to promote the public health, safety, and welfare within the Wissahickon Creek Watershed by maintaining the natural hydrologic regime and by minimizing the harms and maximizing the benefits described in § 125-49 of this Part 2, through provisions designed to:
A.
Meet legal water quality requirements under state law, including regulations of 25 Pa. Code, Chapter 93, to protect, maintain, reclaim, and restore the existing and designated uses of the waters of the commonwealth.
B.
Preserve the natural drainage systems as much as possible.
C.
Manage stormwater close to the source.
D.
Provide procedures and performance standards for stormwater planning
and management.
E.
Maintain groundwater recharge to prevent degradation of surface and
groundwater quality and to otherwise protect water resources.
F.
Prevent scour and erosion of streambanks and streambeds.
G.
Provide proper operation and maintenance of all stormwater best management
practices (BMPs) that are implemented within the Municipality.
H.
Provide standards to meet National Pollutant Discharge Elimination
System (NPDES) requirements.
I.
Meet legal water quality requirements under state law, including
regulations at 25 Pa. Code § 93.4.a requiring protection
and maintenance of "existing uses" and maintenance of the level of
water quality to support those uses in all streams, and the protection
and maintenance of water quality in "special protection" streams.
J.
Address the quality and quantity of stormwater discharges.
K.
Provide standards necessary to meet NPDES permit requirements.
L.
Implement an illegal discharge detection and elimination program
that addresses nonstormwater discharges into the Municipality's separate
storm sewer system.
M.
Preserve and restore the flood-carrying capacity of streams.
N.
Prevent scour and erosion of streambanks and streambeds.
The Municipality is empowered to regulate land use and activities
that may affect runoff and surface and groundwater quality and quantity
by the authority of:
A.
Primary authority. The Municipality is empowered to regulate land
use activities that affect runoff and surface and groundwater quality
and quantity by the authority of the Act of October 4, 1978, P.L.
864 (Act 167), 32 P.S. § 680.1 et seq., as amended, the
"Storm Water Management Act," and the appropriate municipal code.
A.
All regulated activities and all activities that may affect stormwater runoff, including land development and earth disturbance activities, are subject to regulation by this Part 2. This Part 2 shall apply to those portions of the Municipality that lie within the Wissahickon Creek Watershed, in accordance with the Stormwater Management Districts established in § 125-71.
B.
Regulated activities include the following:
(1)
Land development.
(2)
Subdivisions.
(3)
Alteration of the natural hydrologic regime.
(4)
Construction or reconstruction (see definition in § 125-58) of or addition of new impervious or semi-pervious surfaces (i.e., driveways, parking lots, roads, etc.).
(5)
Construction of new buildings or additions to existing buildings.
(6)
Redevelopment.
(7)
Diversion piping or encroachments in any natural or man-made channel.
(8)
Stormwater BMPs or appurtenances thereto.
(9)
Earth disturbance activities of equal to or greater than 5,000 square
feet.
(10)
Any of the above regulated activities which were approved more
than five years prior to the effective date of this Part 2 and resubmitted
for municipal approval.
A.
Table 125A summarizes the exemptions from certain requirements in this Part 2. "Proposed Impervious Surface" in Table 125A includes new, additional, or replacement impervious surface/cover. "Repaving" existing surfaces without reconstruction (see § 125-58) does not constitute replacement.
|
Table 125A
| ||||||||
|---|---|---|---|---|---|---|---|---|
|
|
|
Proposed New Impervious Cover
| ||||||
|
|
|
<1,000 sq. ft.
|
>1,000 to <5,000 sq.
ft.
|
>5,000 sq. ft.
| ||||
|
Article or Section
|
Type of Project
|
Earth Disturb- ance <5,000 sq. ft.
|
Earth Disturb- ance >5,000 sq. ft. - 1 acre
|
Earth Disturb- ance > 1 acre
|
Earth Disturb- ance <5,000 sq. ft.
|
Earth Disturb- ance >5,000 sq. ft. - 1 acre
|
Earth Disturb- ance > 1 acre
|
All Earth Disturb- ance Categories
|
|
Article III SWM Site Plan Require- ments
|
Develop- ment and redevelop- ment
|
Exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
|
§ 125-67 Non- structural Project Design
|
Develop- ment and redevelop- ment
|
Exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
|
§ 125-68 Ground- water Recharge
|
Develop- ment and redevelop- ment
|
Exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
|
§ 125-69 Water Volume Control Require- ments
|
Develop- ment and redevelop- ment
|
Exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
|
|
Develop- ment
|
Exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
|
§ 125-70 Stream Bank Erosion Require- ments
|
Redevelop- ment
|
|
Exempt
|
|
Exempt
|
Exempt
|
|
|
|
§ 125-71 Stormwater Peak Rate Control and Manage- ment Districts
|
Develop- ment and redevelop- ment
|
Exempt
|
Exempt
|
Not exempt
|
Exempt
|
Exempt
|
Not exempt
|
Not exempt
|
|
Erosion and Sediment Pollution Control Plan
|
Earth disturb- ance
|
See earth disturb- ance require- ments
|
See earth disturb- ance require- ments
|
See earth disturb- ance require- ments
|
See earth disturb- ance require- ments
|
See earth disturb- ance require- ments
|
See earth disturb- ance require- ments
|
See earth disturb- ance require- ments
|
|
| ||||||||
|
|
|
(Refer to municipal earth disturbance requirements,
as applicable)
| ||||||
|
Notes:
|
|---|
|
Exempt: Exempt unless a determination is made by the Municipality that the project is subject to § 125-53C.
|
|
Not Exempt: Not exempt. All provisions apply.
|
B.
Exemptions for land use activities.
(1)
Disconnected regulated activities (regulated activities that create disconnected impervious areas) smaller in area than 1,000 square feet are exempt from the SWM site plan (§ 125-59) preparation requirements of this Part 2, except when the associated earth disturbance area is equal to or greater than 5,000 square feet.
(2)
Disconnected regulated activities (regulated activities that create disconnected impervious areas), having an area equal to or greater than 1,000 square feet and less than 5,000 square feet, and with an associated earth disturbance area of less than 5,000 square feet, are exempt only from the peak rate control (§ 125-71) requirements of this Part 2 in the case of new development, and are exempt from peak rate control (§ 125-71) and streambank erosion (§ 125-71) requirements in the case of re-development.
C.
Infiltration exemptions.
(1)
Depth to limiting zone. A minimum of two feet of soil suitable for
infiltration must exist between the invert of the infiltration BMP
and the top of the nearest limiting zone. Otherwise, the Rev requirement
shall not be applied to the development site, and the entire WQv must
be treated.
(2)
Hotspots.
(a)
Stormwater hotspot. Below is a list of types of hotspots that
may be recognized by the Municipality. If a site is a potential hotspot,
it has important implications for how stormwater is managed. First
and foremost, untreated stormwater runoff from hotspots concentrated
into a collection system shall not be recharged into groundwater where
it may contaminate water supplies. Therefore, the Rev requirement
shall not be applied to development sites that lie within a hotspot
(the entire WQv must still be treated). Second, a greater level of
stormwater treatment shall be applied at hotspot sites to prevent
pollutant washoff after construction. The Environmental Protection
Agency's (EPA) National Pollutant Discharge Elimination System (NPDES)
stormwater program requires some industrial sites to prepare and implement
a stormwater pollution prevention plan.
(b)
List of potential hotspots:
[1]
Vehicle salvage yards and recycling facilities.
[2]
Vehicle fueling stations.
[3]
Vehicle service and maintenance facilities.
[4]
Vehicle and equipment cleaning facilities.
[5]
Fleet storage areas (bus, truck, etc.).
[6]
Industrial sites based on Standard Industrial Codes.
[7]
Marinas (service and maintenance).
[8]
Outdoor liquid container storage.
[9]
Commercial/industrial facilities.
[10]
Public works storage areas.
[11]
Facilities that generate, transfer, store, or
dispose hazardous materials.
[12]
Commercial container nursery.
(c)
The following land uses and activities are not normally considered
hotspots:
(3)
Rate of infiltration: When infiltration is not feasible due to poor
infiltration rates or hotspot, the water quality volume must be treated
by an approved SMP.
D.
Additional exemption criteria:
(1)
Exemption responsibilities. An exemption shall not relieve the applicant
from implementing such measures as are necessary to protect public
health, safety, property, water quality, and the environment.
(2)
Drainage problems.Ehere drainage problems exist downstream of the
proposed activity, then the Municipality may deny exemptions.
(3)
Exemptions are limited to specific portions of this Part 2.
(4)
HQ and EV streams. The Municipality shall deny exemptions in high
quality (HQ) or exceptional value (EV) waters and source water protection
areas (SWPA).
(5)
For a development taking place in stages, the entire development
plan must be used in determining compliance with these exemption criteria.
The starting point from which to consider tracts as "parent tracts"
in which future subdivisions and respective impervious area computations
are cumulatively considered shall be the date of the municipal ordinance
adoption of the original Wissahickon Creek Watershed Stormwater Management
Plan Ordinance (dated January 4, 2016).
For example: If a property owner in Montgomery County proposes
a three-hundred-square-foot shed after adoption of the municipal stormwater
management ordinance, that property owner would be exempt from site
plan and peak rate control requirements. If, at a later date, the
property owner proposes to construct a garage and driveway adding
an additional 1,300 square feet of impervious surface, the applicant
would be required to submit a SWM site plan or small project SWM site
plan demonstrating the stormwater control requirements for the total
impervious surface of 1,600 square feet.
E.
The Municipality may deny or revoke any exemption pursuant to this
section at any time for any project that the Municipality believes
may pose a threat to public health, safety, property or the environment.
Approvals issued pursuant to this Part 2 do not relieve the applicant of the responsibility to secure required permits or approvals for activities regulated by any other applicable code, rule, act, or ordinance, including 25 Pa. Code, Chapters 92, 102 and 105.
Notwithstanding any provision(s) of this Part 2, including exemptions,
any landowner or any person engaged in the alteration or development
of land that may affect stormwater runoff characteristics shall implement
such measures as are reasonably necessary to prevent injury to health,
safety, or other property. Such measures also shall include actions
as are required to manage the rate, volume, direction, and quality
of resulting stormwater runoff in a manner that otherwise adequately
protects health, safety, property, and water quality.
Any permit or authorization issued or approved based on false,
misleading, or erroneous information provided by an applicant is void
without the necessity of any proceedings for revocation. Any work
undertaken or use established pursuant to such permit or other authorization
is unlawful. No action may be taken by a board, agency, or employee
of the Municipality purporting to validate such a violation.
