These definitions do not necessarily reflect the definitions contained
in pertinent regulations or statutes, and are intended for this chapter
only.
ACT
The Storm Water Management Act (Act of October 4, 1978, P.L.
864, No. 167; 32 P.S. §§ 680.1 through 680.17, as amended
by Act of May 24, 1984, No. 63).
AGRICULTURAL ACTIVITY
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, unless said building or impervious area
is part of a conservation practice (such as a manure management facility)
and approved by the Indiana County Conservation District and meeting
Natural Resources Conservation Service design standards.
ALLOWABLE DISCHARGE RATE
The predevelopment peak rate of runoff that is discharged
from an outfall on the site after development. It applies uniformly
to all land development or alterations within the project area.
APPLICANT
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.
BEST MANAGEMENT PRACTICE (BMP)
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.
BIORETENTION AREA/RAIN GARDEN
A bioretention area/rain garden is a planted depression that
collects rainwater runoff from impervious areas, like roofs, driveways,
walkways, parking lots, and compacted lawn areas. The bioretention
area/rain garden must have a soil mix that is capable of allowing
rainwater to infiltrate. This reduces rain runoff by allowing stormwater
to soak into the ground. Plantings for the bioretention area/rain
garden would preferably be native plants and the Township recommends
that they be designed by a licensed landscape architect. The purpose
of a bioretention area/rain garden is to improve water quality in
nearby bodies of water.
CHANNEL
A perceptible natural or artificial waterway which periodically
or continuously contains moving water or which forms a connecting
link between two bodies of water. It has a definite bed and banks
which confine water.
CONSERVATION DISTRICT
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 102.
CULVERT
A conduit for the free passage of surface drainage under
a highway, railroad, canal or other embankment.
DEP
Pennsylvania Department of Environmental Protection.
DESIGN CRITERIA
(1)
Engineering guidelines specifying construction details and materials.
(2)
Objectives, results or limits which must be met by a facility,
structure or process in performance of its intended functions.
DESIGN STORM
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."
DETENTION
The slowing, dampening, or attenuating of runoff flows entering
the natural drainage pattern or storm drainage system by temporarily
holding water on a surface area in a detention basin or within the
drainage system.
DETENTION BASIN FOREBAY
A forebay is a small pool located near the inlet of a detention
basin or other stormwater management facility. These devices are designed
as initial storage areas to trap and settle out sediment and heavy
pollutants before they reach the main basin. Installing an earth berm,
gabion wall, or other barrier near the inlet to cause stormwater to
pool temporarily can form the pool area. Forebays act as a pretreatment
feature on a stormwater pond and can greatly reduce the overall pond
maintenance requirements. The minimum forebay volume shall be equal
to 25% of the two-year, twenty-four-hour storm volume.
DETENTION FACILITY
Any pond, reservoir, or basin, or any combination of underground
pipes or tanks constructed to impound or temporarily retard surface
runoff.
DETENTION VOLUME
The volume of runoff that is captured and released into the
waters of the commonwealth at a controlled rate.
DEVELOPER
The person, persons or any corporation, partnership, association
or other entity or any responsible person therein or agent therefore
that undertakes the activities associated with changes in land cover
or contour. The term "developer" is intended to include but not necessarily
be limited to the term "subdivider," "owner" and "builder" even though
the individuals involved in successive stages of a project may vary.
DEVELOPMENT
Any activity, construction, alteration, change in land cover
or contour, or any practice that affects stormwater runoff characteristics.
DISCHARGE
In general, the removal of surface water from a given area;
commonly applied to surface water and groundwater.
DISTURBED AREA
An unstabilized land area where an earth disturbance activity
is occurring or has occurred.
DRAINAGE
The flow or rate of flow from a canal, conduit, channel,
or other hydraulic structure.
DRAINAGE AREA
(1)
The area of a drainage basin or watershed, expressed in acres,
square miles, or other unit of area; also called "catchment area"
or "watershed."
(2)
The area served by a storm sewer system receiving stormwater
and surface water or by a watercourse.
DRAINAGE EASEMENT
A right, granted by a landowner to a grantee, allowing the
use of private land for stormwater management purposes, including
conveyance and detention.
EARTH DISTURBANCE ACTIVITY
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.
EMERGENCY SPILLWAY
A device that will safely convey the runoff from a storm
with a 100-year frequency or larger, through, over, or around the
detention/retention facility.
ENCROACHMENT
Any structure or activity which in any manner changes, expands
or diminishes the course, current or cross section of any watercourse,
floodway or body of water.
EROSION
The natural process by which the surface of the land is worn
away by water, wind, or chemical action.
EROSION CONTROL
The application of measures to reduce erosion of land surfaces.
EXISTING CONDITIONS
The initial condition of a project site prior to the proposed
construction. If the initial condition of the site is undeveloped
land, the land use shall be considered in good condition.
FEMA
Federal Emergency Management Agency.
FLOOD
A general but temporary condition of partial or complete
inundation of normally dry land areas from the overflow of streams,
rivers, and other waters of the commonwealth.
FLOODPLAIN
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).
FLOODPLAIN RESTORATION
Floodplain restoration is the use of bioengineering practices,
removal of fill material, restructuring of stream channels and/or
the restoration or management of riparian corridors in order to create
a floodplain to compensate for the past loss of floodplains.
FLOODWAY
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.
FOREST MANAGEMENT/TIMBER OPERATIONS
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.
FOREST RESTORATION
Forest restoration is the planting of trees in areas that
have become devoid of original forest cover. The new tree plantings
must be native species of trees. New trees must be a minimum height
of four feet for evergreen trees and six feet for deciduous trees.
It is recommended that forest restoration plans be prepared by a professional
forester who is a member of the Society of American Foresters or the
Association of Consulting Foresters. A professional forester is a
person who has a B.S. or higher degree in forestry from a four-year
school of forestry accredited by the Society of American Foresters.
FREEBOARD
A vertical distance between the elevation of the design high
water and the top of a dam, levee, tank, basin, or diversion ridge.
The space is required as a safety margin in a pond or basin.
GRASSED WATERWAY
A natural or constructed waterway, usually broad and shallow,
covered with erosion-resistant grasses.
GREEN INFRASTRUCTURE
Systems and practices that use or mimic natural processes
to infiltrate, evapotranspire, or reuse stormwater on the site where
it is generated.
GREEN ROOF
A green roof is a conventional roof that is covered with
a layer of vegetation. Also known as "living roofs," green roofs serve
several purposes for a building, such as absorbing rainwater, providing
insulation, creating a habitat for wildlife, and helping to lower
urban air temperatures, and combat the heat island effect. There are
two types of green roofs: intensive roofs, which are thicker and can
support a wider variety of plants but are heavier and require more
maintenance, and extensive roofs, which are covered in a light layer
of vegetation and are lighter than an intensive green roof.
GROUNDWATER
Subsurface water occupying the saturation zone, from which
wells and springs are fed, as well as the base flows for natural streams.
GROUNDWATER RECHARGE
Replenishment of groundwater naturally by precipitation or
runoff or by artificial means by spreading or injection.
HYDROLOGIC SOIL GROUP (HSG)
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 Natural Resources Conservation Service (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 (NRCS1,2).
IMPERVIOUS
Not allowing or allowing only with great difficulty the movement
of water; impermeable.
IMPERVIOUS SURFACE (IMPERVIOUS AREA)
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.
INFILTRATION
The flow or movement of water through the interstices or
pores of a soil or other porous medium; the absorption of stormwater
by the soil.
INFILTRATION STRUCTURE
A structure designed to direct runoff into the ground (e.g.,
french drains, seepage pits, seepage trench).
INLET
A surface structure designed to allow for the inflow of stormwater
flows; the upstream end of any structure through which water may flow.
LAND DEVELOPMENT (DEVELOPMENT)
Inclusive of any or all of the following meanings: (i) the
improvement of one lot or two or more contiguous lots, tracts, or
parcels of land for any purpose involving (a) a group of two or more
buildings or (b) the division or allocation of land or space between
or among two or more existing or prospective occupants by means of,
or for the purpose of streets, common areas, leaseholds, condominiums,
building groups, or other features; (ii) any subdivision of land;
(iii) development in accordance with Section 503(1.1) of the PA Municipalities
Planning Code.
LAND DISTURBANCE
Any activity involving the changing, grading, transportation,
fill and any other activity which causes land to be exposed to the
danger of erosion.
LOW-IMPACT DEVELOPMENT (LID)
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.
MAINTENANCE
The upkeep necessary for efficient operation of physical
properties.
MUNICIPAL ENGINEER
A registered engineer or engineering firm employed by White
Township to assist in administering this chapter.
NONPOINT SOURCE POLLUTION
Pollution that enters a water body from diffuse origins in
the watershed and does not result from discernible, confined, or discrete
conveyances.
OFF-SITE CONTROLS
Those stormwater flows that are generated on property that
is not part of the land being developed.
OPEN CHANNEL
A drainage element in which stormwater flows with an open
surface. Open channels include but shall not be limited to natural
and man-made drainage ways, swales, streams, ditches, canals, and
pipes flowing partly full.
OUTFALL
(1)
The point, location or structure where drainage discharges from
a sewer, drain or other conduit.
(2)
The conduit leading to the ultimate discharge point.
OUTLET CONTROL STRUCTURE
The means of controlling the relationship between the headwater
elevation and the discharge, placed at the outlet or downstream end
of any structure through which water may flow.
PEAK DISCHARGE
The maximum rate of flow of water at a given point and time
resulting from a specified storm event.
PERVIOUS (POROUS) PAVEMENT
Pervious (porous) pavement is a special type of pavement
with a high porosity that allows water from precipitation and other
sources to pass directly through, thereby reducing the runoff from
a site and allowing groundwater recharge. Pervious pavement can be
concrete, brick pavers and other types of material that allow for
infiltration.
POINT SOURCE
Any discernible, confined, and discrete conveyance, including
but not limited to any pipe, ditch, channel, tunnel, or conduit from
which stormwater is or may be discharged.
PRIVATE ENTITY
A partnership, corporation, homeowners' association,
condominium association, or any other similar associations, as distinguished
from an individual lot owner.
PROJECT SITE
The specific area of land where any regulated activities
in the Township are planned, conducted, or maintained.
QUALIFIED PROFESSIONAL
Any person licensed by the Pennsylvania Department of State
or otherwise qualified by law to perform the work required by this
chapter.
RECURRENCE INTERVAL
The average interval of time, stated in years, within which
a given storm event will be equaled or exceeded once.
REDEVELOPMENT
A change to previously existing, improved property. This
includes but is not limited to the demolition or building of structures,
filling, grading, paving; including the conversion of gravel areas
to pavement, or excavating. Redevelopment excludes ordinary maintenance
activities such as remodeling of buildings on the existing footprint,
resurfacing and/or repaving of existing paved areas, and exterior
changes or improvements that do not materially increase or concentrate
stormwater runoff or cause additional nonpoint source pollution.
REGIONAL STORMWATER DETENTION FACILITY
A stormwater facility that controls runoff from more than
one development site used by developers when it is more cost effective
than providing a stormwater management facility for each development
separately.
REGULATED ACTIVITIES
Any earth disturbance activities that involve the alteration
or development of land in a manner that may affect stormwater runoff.
RELEASE RATE PERCENTAGE
The percentage of predevelopment peak rate of runoff from
a watershed subarea which defines the allowable post-development peak
discharge from any development site in that subarea. This release
rate applies uniformly to all land development or alterations within
the subarea. A delineation of the release rate percentages by subarea
is shown on the Municipal Stormwater Management District Map.
RESIDENTIAL DEVELOPMENT
Any earth disturbance and/or construction that occurs on a residential lot and is not subject to the requirements of Chapter
275, Subdivision and Land Development, of the Code of the Township of White. A residential lot would contain a single-family home or similar dwelling. Earth disturbance and/or construction activities could include, but are not limited to, a new dwelling or addition to an existing dwelling, accessory structure (garage, shed, pool, etc.), and/or driveway creation or modification thereof.
RETENTION BASIN (POND)
An impoundment designed to collect and retard stormwater
runoff by temporarily storing the runoff and releasing it at a predetermined
rate. Retention basins may also be designed to permanently retain
additional stormwater runoff. Retention basins are designed to retain
a permanent pool of water during dry weather.
RETENTION FACILITY
A basin or pond, usually enclosed by artificial dikes, that
retains a permanent pool of water and is used to retard stormwater
runoff by temporarily storing the runoff and releasing it at a predetermined
rate.
RETENTION VOLUME/REMOVED RUNOFF
The volume of runoff that is captured and not released directly
into the surface waters of this commonwealth during or after a storm
event.
RETURN PERIOD
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).
RIPARIAN BUFFER
A permanent area of trees and shrubs located adjacent to
streams, lakes, ponds, and wetlands.
ROOFTOP DETENTION
Temporary ponding and gradual release of stormwater falling
directly onto flat roof surfaces by incorporating controlled-flow
roof drains into building designs.
RUNOFF
Any part of precipitation that flows over the land.
RUNOFF CHARACTERISTICS
The surface components of any watershed which affect the
rate, amount and direction of stormwater runoff. These may include
but not be limited to vegetation, soils, slopes, and man-made landscape
alterations.
SCS
United States Department of Agriculture Soil Conservation
Service.
SEDIMENT
Soils or other materials transported by surface water as
a product of erosion.
SEDIMENT POLLUTION
The placement, discharge, or any other introduction of sediment
into the waters of the commonwealth occurring from the failure to
design, construct, implement, or maintain control measures and control
facilities in accordance with the requirements of this chapter.
SEDIMENTATION
The process by which mineral or organic matter is accumulated
or deposited by moving water, wind, or gravity.
SEEPAGE PIT/SEEPAGE TRENCH
An area of excavated earth filled with loose stone or similar
coarse material, into which surface water is directed for infiltration
into the ground.
SEEPAGE TANK
A subsurface concrete tank surrounded by stone, into which
surface water is directed for infiltration into the ground.
SHEET FLOW
Stormwater runoff that flows over the ground surface as a
thin, even layer, not concentrated in a channel.
SOIL COVER COMPLEX METHOD
A method of runoff computation developed by the NRCS that
is based on relating soil type and land use/cover to a runoff parameter
called "curve number (CN)."
SOIL GROUP, HYDROLOGIC
A classification of soils by the NRCS into four runoff potential
groups. The groups range from A soils, which are very permeable and
produce little runoff, to D soils, which are not very permeable and
produce much more runoff.
SPILLWAY
A depression in the embankment of a pond or basin which is
used to pass peak discharges greater than the maximum design storm
controlled by the pond.
STATE WATER QUALITY REQUIREMENTS
The regulatory requirements to protect, maintain, reclaim
and restore water quality under Title 25 of the Pennsylvania Code
and the Clean Streams Law.
STORM FREQUENCY
The average interval in years over which a storm event of
a given precipitation volume can be expected to occur.
STORM SEWER
A sewer that carries intercepted surface runoff, street water,
and other drainage but excludes domestic sewage and industrial waste.
STORMWATER
Drainage runoff from the surface of the land resulting from
precipitation or snow or ice melt.
STORMWATER COLLECTION/CONVEYANCE SYSTEM
Natural or man-made structures that collect and transport
stormwater through or from a drainage area to the point of final outlet
including, but not limited to, any of the following: conduits and
appurtenant features, canals, channels, ditches, streams, culverts,
and streets.
STORMWATER MANAGEMENT FACILITY
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.
STORMWATER MANAGEMENT SITE PLAN
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.
STORMWATER MANAGEMENT SYSTEM
All of the facilities, to include, but not limited to, the
outlet structure, storage basins, collection/conveyance systems, swales,
etc., that make up the entire stormwater system as depicted on the
stormwater management plan intended to control the rate of runoff
from a development site.
STORMWATER REUSE
Entails storing stormwater runoff and then using it as a
source of irrigation water or other nonpotable use. The philosophy
behind the practice is that the lowest-quality water should be used
for the lowest-quality need.
STORMWATER RUNOFF
The flow of water over and/or in water bodies that results
from and occurs during and immediately following a rainfall event.
STREAM RESTORATION
Stream restoration is the use of bioengineering practices,
native material revetments, channel stability structures, and/or the
restoration or management of riparian corridors in order to protect
upland BMPs, restore the natural function of the stream corridor,
and improve water quality by reducing sedimentation to streams from
stream bank erosion.
SUBBASIN
A specific area contributing runoff to a predefined point.
SUBDIVISION
As defined in The Pennsylvania Municipalities Planning Code, Act of July 31,1968, P.L. 805, No. 247.
SWALE
A low-lying stretch of land which gathers or carries surface
water runoff.
TOWNSHIP
Township of White, Indiana County.
USDA
United States Department of Agriculture.
USDA
United States Department of Agriculture.
WATERCOURSE
Any channel for conveyance of surface water having a defined
bed and banks, whether natural or artificial, with perennial or intermittent
flow.
WATERS OF THIS COMMONWEALTH
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.
WATERSHED
Region or area drained by a river, watercourse, or other
surface water of this commonwealth.
WETLAND
Areas that are inundated or saturated by surface 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.