For the purposes of this chapter, certain terms and words used
herein shall be interpreted as follows:
A.
Words used in the present tense include the future tense; the singular
number includes the plural, and the plural number includes the singular;
words of masculine gender include feminine gender; and words of feminine
gender include masculine gender.
B.
The word "includes" or "including" shall not limit the term to the
specific example but is intended to extend its meaning to all other
instances of like kind and character.
C.
The words "shall" and "must" are mandatory; the words "may" and "should"
are permissive.
As used in this chapter, the following terms shall have the
meanings indicated:
The Storm Water Management Act (Act of October 4, 1978, P.L.
864 No. 167; 32 P.S. § 680.1 et seq., as amended).
The Plan for managing stormwater runoff throughout a designated
watershed, adopted by Allegheny County as required by the Pennsylvania
Storm Water Management Act (Act 167). Activities in Wilkins Township
are governed under the provisions of the 2018 Allegheny County Act
167 Stormwater Management Plan.
Activities associated with agriculture such as agricultural
cultivation, agricultural operation, and animal heavy use areas. This
includes the work of producing crops including tillage, land clearing,
plowing, disking, harrowing, planting, harvesting crops or pasturing
and raising of livestock and installation of conservation measures.
Construction of new buildings or impervious area is not considered
an agricultural activity.
A landowner, developer, or other person who has filed an
application to the Township for approval to engage in any regulated
activity at a project site in the Township.
Activities, facilities, designs, measures, or procedures
used to manage stormwater impacts from regulated activities, to meet
state water quality requirements, to promote groundwater recharge,
and to otherwise meet the purposes of this chapter. Stormwater BMPs
are commonly grouped into one of two broad categories or measures:
"structural" or "nonstructural." In this chapter, nonstructural BMPs
or measures refer to operational and/or behavior-related practices
that attempt to minimize the contact of pollutants with stormwater
runoff whereas structural BMPs or measures are those that consist
of a physical device or practice that is installed to capture and
treat stormwater runoff. Structural BMPs include, but are not limited
to, a wide variety of practices and devices, from large-scale retention
ponds and constructed wetlands, to small-scale underground treatment
systems, infiltration facilities, filter strips, low-impact design,
bioretention, wet ponds, permeable paving, grassed swales, riparian
or forested buffers, sand filters, detention basins, and manufactured
devices. Structural stormwater BMPs are permanent appurtenances to
the project site.
A conservation district, as defined in Section 3(c) of the
Conservation District Law [3 P.S. § 851(c)] that has the
authority under a delegation agreement executed with DEP to administer
and enforce all or a portion of the regulations promulgated under
25 Pa. Code Chapter 102.
The Pennsylvania Department of Environmental Protection.
The magnitude and temporal distribution of precipitation
from a storm event measured in probability of occurrence (e.g., a
five-year storm) and duration (e.g., 24 hours) used in the design
and evaluation of stormwater management systems. Also see "return
period."
A qualified professional as defined herein, or organization
such as the Allegheny County Conservation District, that has been
designated by the Township to be the reviewer of SWM site plans for
the Township, and shall be understood to be the reviewer where indicated
as the Township within this chapter.
An impoundment designed to collect and retard stormwater
runoff by temporarily storing the runoff and releasing it at a predetermined
rate. Detention basins are designed to drain completely in a designed
period after a rainfall event, and to become dry until the next rainfall
event.
The volume of runoff that is captured and released into the
waters of this commonwealth at a controlled rate.
See "project site."
An unstabilized land area where an earth disturbance activity
is occurring or has occurred.
All facilities and natural features used for the movement
of stormwater through and from a drainage area, including, but not
limited to, any and all of the following, conduits, pipes and appurtenant
features, channels, ditches, culverts, streets, swales, and gutters,
as well as all watercourses, water bodies, and wetlands.
A construction or other human activity which disturbs the
surface of the land, including, but not limited to, clearing and grubbing;
grading; excavations; embankments; road maintenance; building construction;
and the moving, depositing, stockpiling, or storing of soil, rock,
or earth materials.
The natural process by which the surface of the land is worn
away by water, wind, or chemical action.
The dominant land cover during the five-year period immediately
preceding a proposed regulated activity.
Federal Emergency Management Agency.
Any land area susceptible to inundation by water from any
natural source or delineated by applicable FEMA maps and studies as
being a special flood hazard area. Also includes areas that comprise
Group 13 Soils, as listed in Appendix A of the Pennsylvania DEP Technical
Manual for Sewage Enforcement Officers (as amended or replaced from
time to time by DEP).
The channel of the watercourse and those portions of the
adjoining floodplains that are reasonably required to carry and discharge
the 100-year flood. Unless otherwise specified, the boundary of the
floodway is as indicated on maps and flood insurance studies provided
by FEMA. In an area where no FEMA maps or studies have defined the
boundary of the 100-year floodway, it is assumed, absent evidence
to the contrary, that the floodway extends from the stream to 50 feet
from the top of the bank of the stream.
Planning and activities necessary for the management of forestland.
These include conducting a timber inventory, preparation of forest
management plans, silvicultural treatment, cutting budgets, logging
road design and construction, timber harvesting, site preparation,
and reforestation.
Systems and practices that use or mimic natural processes
to infiltrate, evapotranspire, or reuse stormwater on the site where
it is generated.
Water beneath the earth's surface that supplies wells
and springs and is within the saturated zone of soil and rock.
The replenishment of existing natural underground water supplies
from precipitation or overland flow.
Infiltration rates of soils vary widely and are affected
by subsurface permeability as well as surface intake rates. Soils
are classified into four HSGs (A, B, C, and D) according to their
minimum infiltration rate, which is obtained for bare soil after prolonged
wetting. The NRCS defines the four groups and provides a list of most
of the soils in the United States and their group classification.
The soils in the area of the development site may be identified from
a soil survey report that can be obtained from local NRCS offices
or conservation district offices. Soils become less pervious as the
HSG varies from A to D (NRCS).[1]
A surface that prevents the infiltration of water into the
ground. Impervious surfaces (or areas) shall include, but not be limited
to, roofs; additional indoor living spaces, patios, garages, storage
sheds and similar structures; and any new streets or sidewalks. Decks,
parking areas, and driveway areas are not counted as impervious areas
if they do not prevent infiltration.
Movement of surface water into the soil, where it is absorbed
by plant roots, evaporated into the atmosphere, or percolated downward
to recharge groundwater.
DCNR defines invasive plants as those species that are not
native to the state, grow aggressively, and spread and displace native
vegetation. (See http://www.dcnr.state.pa.us/cs/groups/public/documents/document/dcnr_010314.pdf
for a list of invasive species.)
A type of topography or landscape characterized by surface
depressions, sinkholes, rock pinnacles/uneven bedrock surface, underground
drainage, and caves. Karst is formed on carbonate rocks, such as limestone
or dolomite.
Inclusive of any or all of the following meanings:
Site design approaches and small-scale stormwater management
practices that promote the use of natural systems for infiltration,
evapotranspiration, and reuse of rainwater. LID can be applied to
new development, urban retrofits, and revitalization projects. LID
utilizes design techniques that infiltrate, filter, evaporate, and
store runoff close to its source. Rather than rely on costly large-scale
conveyance and treatment systems, LID addresses stormwater through
a variety of small, cost-effective landscape features located on-site.
Municipal separate storm sewer system.
Township of Wilkins, Allegheny County, Pennsylvania.
Plant species that have historically grown in Pennsylvania
and are not invasive species as defined herein.
USDA Natural Resources Conservation Service (previously "SCS").
The maximum rate of stormwater runoff from a specific storm
event.
Any area not defined as impervious.
The specific area of land where any regulated activities
in the Township are planned, conducted, or maintained.
Any person licensed by the Pennsylvania Department of State
or otherwise qualified by law to perform the work required by this
chapter.
Any earth disturbance activities or any activities that involve
the alteration or development of land in a manner that may affect
stormwater runoff.
Activity involving earth disturbance subject to regulation
under 25 Pa. Code Chapter 92, 25 Pa. Code Chapter 102, or the Clean
Streams Law.[3]
The percentage of existing conditions peak rate of runoff
from a site or subarea to which the proposed conditions peak rate
of runoff must be reduced to protect downstream areas.
A watershed or portion of a watershed for which a release
rate has been established by an adopted Act 167 stormwater management
plan.
The volume of runoff that is captured and not released directly
into the surface waters of this commonwealth during or after a storm
event.
The average interval, in years, within which a storm event
of a given magnitude can be expected to occur one time. For example,
the twenty-five-year return period rainfall would be expected to occur
on average once every 25 years; or stated in another way, the probability
of a twenty-five-year storm occurring in any one year is 0.04 (i.e.,
a 4% chance).
A permanent vegetated area of trees and shrubs located adjacent
to streams, lakes, ponds and wetlands.
Any part of precipitation that flows over the land.
Soils or other materials transported by surface water as
a product of erosion.
The regulatory requirements to protect, maintain, reclaim,
and restore water quality under Title 25 of the Pennsylvania Code
and the Clean Streams Law.[4]
Drainage runoff from the surface of the land resulting from
precipitation or snow or ice melt.
Abbreviated as "BMPs" or "SWM BMPs" throughout this chapter.
Any structure, natural or man-made, that, due to its condition,
design, or construction, conveys, stores, or otherwise affects stormwater
runoff. Typical stormwater management facilities include, but are
not limited to, detention and retention basins; open channels; storm
sewers; pipes; and infiltration facilities.
The plan prepared by the developer or his representative
indicating how stormwater runoff will be managed at the development
site in accordance with this chapter. Stormwater management site plan
will be designated as "SWM site plan" throughout this chapter.
A channel or conveyance of surface water having a defined
bed and banks, whether natural or artificial, with perennial or intermittent
flow.
As defined in the Pennsylvania Municipalities Planning Code,
Act of July 31, 1968, P.L. 805, No. 247.[5]
United States Department of Agriculture.
Any and all rivers, streams, creeks, rivulets, impoundments,
ditches, watercourses, storm sewers, lakes, dammed water, wetlands,
ponds, springs, and all other bodies or channels of conveyance of
surface and underground water, or parts thereof, whether natural or
artificial, within or on the boundaries of this commonwealth.
Region or area drained by a river, watercourse, or other
surface water of this commonwealth.
Areas that are inundated or saturated by surface water or
groundwater at a frequency and duration sufficient to support, and
that under normal circumstances do support, a prevalence of vegetation
typically adapted for life in saturated soil conditions, including
swamps, marshes, bogs, and similar areas.
