The words "used" or "occupied" include the words "intended, designed,
maintained, or arranged to be used, occupied or maintained."
ACCELERATED EROSION
The removal of the surface of the land through the combined
action of man's activity and the natural processes of a rate
greater than would occur because of the natural process alone.
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.
ALTERATION
As applied to land, a change in topography as a result of
the moving of soil and rock from one location or position to another;
also, the changing of surface conditions by causing the surface to
be more or less impervious; land disturbance.
APPLICANT
A landowner or developer who has filed an application for approval to engage in any regulated activities as defined in §
190-304 of this chapter.
AS-BUILT DRAWINGS
Those maintained by the contractor as he constructs the project
and upon which he documents the actual locations of the building components
and changes to the original contract documents. These, or a copy of
the same, are turned over to the engineer at the completion of the
project.
BANKFULL
The channel at the top-of-bank or point where water begins
to overflow onto a floodplain.
BASEFLOW
The portion of stream flow that is sustained by groundwater
discharge.
BIORETENTION
A stormwater retention area which utilizes woody and herbaceous
plants and soils to remove pollutants before infiltration occurs.
BMP (BEST MANAGEMENT PRACTICE)
Activities, facilities, measures or procedures used to manage
stormwater impacts from land development to protect and maintain water
quality and groundwater recharge and to otherwise meet the purposes
of this chapter. Stormwater BMPs are commonly grouped into one or
two broad categories or measures: "structural" or "nonstructural."
In this chapter, nonstructural BMPs or measures refer to operation
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.
BMP MANUAL
Pennsylvania Best Management Practices Manual, December 2006,
as amended.
CHANNEL
An open drainage feature through which stormwater flows.
Channels include, but shall not be limited to, natural and man-made
watercourses, swales, streams, ditches, canals, and pipes that convey
continuously or periodically flowing water.
CHANNEL EROSION
The widening, deepening, and headward cutting of channels
and waterways, due to erosion caused by moderate to large floods.
CISTERN
An underground reservoir or tank for storing rainwater.
CULVERT
A pipe, conduit, or similar structure, including appurtenant
works, which conveys surface water under or through an embankment
or fill.
CURVE NUMBER (CN) VALUE
Used in the Soil Cover Complex Method, it is a measure of
the percentage of precipitation which is expected to run off from
the watershed and is a function of the soil, vegetative cover, and
tillage method.
DAM
An artificial barrier, together with its appurtenant works,
constructed for the purpose of impounding or storing water or another
fluid or semifluid, or a refuse bank, fill or structure for highway,
railroad, or other purposes which does or may impound water or another
fluid or semifluid.
DEP
The Pennsylvania Department of Environmental Protection.
DEPARTMENT
The Pennsylvania Department of Environmental Protection.
DESIGN PROFESSIONAL (QUALIFIED)
A Pennsylvania registered professional engineer, registered
landscape architect, or a registered professional land surveyor trained
to develop stormwater management plans.
DESIGN STORM
The magnitude and temporal distribution of precipitation
from a storm event measured in probability of occurrence (e.g., fifty-year
storm) and duration (e.g., 24 hours), used in the design and evaluation
of stormwater management systems. Also see "return period."
DESIGNEE
The agent of the governing body involved with the administration,
review, or enforcement of any provisions of this chapter by contract
or memorandum of understanding.
DETENTION BASIN
An impoundment structure designed to manage stormwater runoff
by temporarily storing the runoff and releasing it at a predetermined
rate.
DETENTION DISTRICT
Those subareas in which some type of detention is required
to meet the plan requirements and goals of Act 167.
DEVELOPER
A person, partnership, association, corporation, or other
entity, or any responsible person therein or agent thereof, that undertakes
any regulated activity of this chapter.
DEVELOPMENT
Any man-made change to improved or unimproved real estate,
including, but not limited to, the construction or placement of buildings
or other structures, mobile homes, streets and other paving, utilities,
mining, dredging, filling, grading, excavation, or drilling operations,
and the subdivision of land.
DEVELOPMENT PLAN
The provisions for development, including a planned residential
development, a plat of subdivision, all covenants relating to use,
location and bulk of buildings and other structures, intensity of
use or density of development, streets, ways and parking facilities,
common open space and public facilities. The phrase "provisions of
development plan," when used in this chapter, shall mean the written
and graphic materials referred to in this definition.
DEVELOPMENT SITE
The specific tract of land for which a regulated activity
is proposed.
DIFFUSED DRAINAGE DISCHARGE
Drainage discharge not confined to a single point location
or channel, such as sheet flow or shallow concentrated flow.
DISCHARGE
(1)
(verb) To release water from a project, site, aquifer, drainage
basin or other point of interest.
(2)
(noun) The rate and volume of flow of water, such as in a stream,
generally expressed in cubic feet per second (cfs).
DISCONNECTED IMPERVIOUS AREA (DIA)
An impervious surface that is disconnected from any stormwater
drainage or conveyance system and is redirected or directed to a pervious
area, which allows for infiltration, filtration, and increased time
of concentration.
DISTURBED AREAS
Unstabilized land area where an earth disturbance activity
is occurring or has occurred.
DOWNSLOPE PROPERTY LINE
That portion of the property line of the lot, tract, or parcels
of land being developed, located such that all overland or pipe flow
from the site would be directed toward it.
DOWNSTREAM HYDRAULIC CAPACITY ANALYSIS
Any downstream capacity hydraulic analysis conducted in accordance
with this chapter shall use the following criteria for determining
adequacy for accepting increased peak flow rates:
(1)
Natural or man-made channels or swales must be able to convey
the increased rate of runoff associated with a two-year return period
event within their banks at velocities consistent with protection
of the channels from erosion. Acceptable velocities shall be based
upon criteria included in the DEP Erosion and Sediment Pollution Control
Program Manual.
(2)
Natural or man-made channels or swales must be able to convey
the increased twenty-five-year return period rate of runoff without
creating any hazard to persons or property.
(3)
Culverts, bridges, storm sewers or any other facilities which
must pass or convey flows from the tributary area must be designed
in accordance with DEP Chapter 105 regulations (if applicable) and,
at a minimum, pass the increased twenty-five-year return period rate
of runoff.
(4)
No new channels or conveyance facilities shall be authorized
by this language.
DRAINAGE CONVEYANCE FACILITY
A stormwater management facility designed to transmit stormwater
runoff which shall include streams, channels, swales, pipes, conduits,
culverts, storm sewers, etc.
DRAINAGE EASEMENT
A right granted by a landowner to a grantee, allowing the
use of private land for stormwater management purposes.
DRAINAGE PERMIT
A permit issued by the Township governing body after the
drainage plan has been approved. Said permit is issued prior to or
with the final Borough approval.
DRAINAGE PLAN
The documentation of the stormwater management system, if any, to be used for a given development site, the contents of which are established in §
190-402.
EARTH DISTURBANCE ACTIVITY
A construction or other human activity which disturbs the
surface of land, including, but not limited to, clearing and grubbing,
grading, excavations, embankments, land development, agricultural
plowing or tilling, timber harvesting activities, road maintenance
activities, building construction, mineral extraction, and the moving,
depositing, stockpiling or storing of soil, rock or earth materials.
EMERGENCY SPILLWAY
A conveyance area that is used to pass peak discharge greater
than the maximum design storm controlled by the stormwater facility.
ENGINEER
A licensed professional civil engineer registered by the
Commonwealth of Pennsylvania.
EROSION
The movement of soil particles by the action of water, wind,
ice, or other natural forces.
EXCEPTIONAL VALUE WATERS
Surface waters of high quality which satisfy Pennsylvania
Code Title 25 Environmental Protection, Chapter 93, Water Quality
Standards, § 93.4b(b) (relating to antidegradation).
EXISTING CONDITIONS
The initial condition of a project site prior to the proposed
construction. Farm field, disturbed earth, or undeveloped cover conditions
of a site or portions of a site used for modeling purposes shall be
considered "meadow" unless the natural ground cover generates lower
curve numbers or Rational "C" value, such as forested land. Existing
man-made impervious surfaces shall be considered as "meadow" when
developing "cover complex" calculations.
FLOOD
A temporary inundation by surface water of normally dry land
areas.
FLOODPLAIN
Any areas of Nockamixon Township, classified as special flood
hazard areas (SFHAs) in the Flood Insurance Study (FIS) and the accompanying
Flood Insurance Rate Maps (FIRMs) dated March 16, 2015, and issued
by the Federal Emergency Management Agency (FEMA) or the most recent
revision thereof, including all digital data developed as part of
the Flood Insurance Study. For areas abutting streams and watercourses
where the one-hundred-year floodplain (one-percent annual chance flood)
has not been delineated by the Flood Insurance Study, the applicant
shall submit a floodplain identification study. The study prepared
by a registered professional engineer expert in the preparation of
hydrologic and hydraulic studies shall be used to delineate the one-hundred-year
floodplain. The floodplain study shall be subject to the review and
approval of the Township. All areas inundated by the one-hundred-year
flood shall be included in the floodplain area.
FLOODWAY
The channel of a river or other watercourse and adjacent
land areas that must be reserved in order to discharge the base flood
without cumulatively increasing the water surface elevation more than
one foot.
FOREST MANAGEMENT/TIMBER OPERATIONS
Planning and activities necessary for the management of forest
land. These include timber inventory and preparation of forest management
plans, silvicultural treatment, cutting budgets, logging road design
and construction, timber harvesting, site preparation, and reforestation.
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.
GRADE
(1)
(noun) A slope usually of a street, other public way, land area,
drainage facility or pipe specified in percent.
(2)
(verb) To finish the surface of a road bed, top of embankment
or bottom of excavation, and general grading of property.
GRASSED WATERWAY
A natural or constructed waterway, usually broad and shallow,
covered with erosion-resistant grasses, used to conduct surface water
from cropland.
HEC-HMS
The United States Army Corps of Engineers, Hydrologic Engineering
Center (HEC) - Hydrologic Modeling System (HMS).
HIGH-QUALITY WATERS
Surface waters having quality which exceeds levels necessary
to support propagation of fish, shellfish, and wildlife and recreation
in and on the water by satisfying Pennsylvania Code Title 25 Environmental
Protection, Chapter 93, Water Quality Standards, § 93.4b(a).
HOT SPOT
An area where land use or activity generates highly contaminated
runoff, with concentrations of pollutants in excess of those typically
found in stormwater. Typical pollutant loadings in stormwater may
be found in Chapter 8, Section 6, of the Pennsylvania Stormwater Best
Management Practices Manual, Pennsylvania Department of Environmental
Protection (PADEP) No. 363-0300-002 (2006). More information concerning
hot spots may be found in Appendix G of this chapter.
HYDRIC SOIL
A soil that is saturated, flooded, or ponded long enough
during the growing season to develop an aerobic condition in the upper
part.
HYDROLOGIC REGIME (NATURAL)
The hydrologic cycle or balance that sustains quality and
quantity of stormwater, base flow, storage, and groundwater supplies
under the natural conditions.
HYDROLOGIC SOIL GROUP
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 indentified 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 (NCRS).
HYETOGRAPH
A graphical representation of average rainfall, rainfall
excess rates, or volumes over specified areas during successive units
of time during a storm.
IMPERVIOUS SURFACE (AREA)
Impervious surfaces (or areas) are those surfaces that prevent
infiltration of water into the ground. All buildings, parking areas,
driveways, roads, sidewalks, swimming pools, and any areas containing
concrete, asphalt, packed stone, compacted soils, or other equivalent
surfaces shall be considered impervious within this definition. In
addition, other areas determined by the Township Engineer to be impervious
within the meaning of this definition will be classified as impervious
surfaces.
IMPOUNDMENT
A retention or detention basin designed to retain stormwater
runoff and release it at a controlled rate.
INFILL
Development that occurs on smaller parcels that remain undeveloped
but are within or very close proximity to urban areas. The development
relies on existing infrastructure and does not require an extension
of water, sewer or other public utilities.
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.
INFILTRATION STRUCTURES
A structure designed to direct runoff into the ground (e.g.,
french drains, seepage pits, seepage trench, biofiltration swale).
INLET
A surface connection to a closed drain. A structure at the
diversion end of a conduit. The upstream end of any structure through
which water may flow.
INVERT
The inside bottom of a culvert or other conduit.
KARST
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.
LAND DEVELOPMENT
(1)
Any of the following activities:
(a)
The improvement of one or two or more contiguous lots, tracts
or parcels of land for any purpose involving:
[1]
A group of two or more residential or nonresidential buildings,
whether purposed initially or cumulatively, or a single nonresidential
building on a lot or lots regardless of the number of occupants or
tenure; or
[2]
The division or allocation of land or space, whether initially
or cumulatively, 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.
(2)
"Land development" does not include development which involves:
(a)
The conversion of an existing single-family detached dwelling
or single-family semidetached dwelling into not more than three residential
units, unless such units are intended to be a condominium;
(b)
The addition of a residential accessory building, including
farm building, on a lot or lots subordinate to an existing principal
building; or
(c)
The addition or conversion of buildings or rides within the
confines of an enterprise which would be considered an amusement park.
For the purposes of this subsection, an amusement park is defined
as a tract or area used principally as a location for permanent amusement
structures or rides. This exclusion shall not apply to newly acquired
acreage by an amusement park until initial plans for the expanded
area have been approved by the proper authorities.
LAND/EARTH DISTURBANCE
Any activity involving grading, tilling, digging, or filling
of ground or stripping of vegetation or any other activity that causes
an alteration to the natural condition of the land.
LIMITING ZONE
A soil horizon or condition in the soil profile or underlying
strata which includes one of the following:
(1)
A seasonal high-water table, whether perched or regional, determined
by direct observation of the water table or indicated by soil mottling.
(2)
A rock with open joints, fracture or solution channels, or masses
of loose rock fragments, including gravel, with insufficient fine
soil to fill the voids between the fragments.
(3)
A rock formation, other stratum or soil condition, which is
so slowly permeable that it effectively limits downward passage of
effluent.
LOW-IMPACT DEVELOPMENT (LID) PRACTICES
Practices that will minimize proposed conditions runoff rates
and volumes, which will minimize the need for artificial conveyance
and storage facilities.
MAIN STEM (MAIN CHANNEL)
Any stream segment or other runoff conveyance facility used
as a reach in the watershed hydrologic model.
MANNING EQUATION (MANNING FORMULA)
A method for calculation of velocity of flow (e.g., feet
per second) and flow rate (e.g., cubic feet per second) in open channels
based upon channel shape, roughness, depth of flow and slope. "Open
channels" may include closed conduits so long as the flow is not under
pressure.
MUNICIPAL ENGINEER
A professional engineer licensed as such in the Commonwealth of Pennsylvania and appointed by the Township pursuant to Article
V of the Second Class Township Code.
MUNICIPALITY
Nockamixon Township, Bucks County, Pennsylvania.
NONPOINT SOURCE POLLUTION
Pollution that enters a watery body from diffuse origins
in the watershed and does not result from discernible, confined, or
discrete conveyances.
NPDES
National Pollution Discharge Elimination System, the federal
government's system for issuance of permits under the Clean Water
Act, which is delegated to PADEP in Pennsylvania.
NRCS
Natural Resource Conservation Service (previously SCS).
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 drainageways, swales, streams, ditches, canals, and pipes
flowing partly full.
OUTFALL
"Point source" as described in 40 CFR 122.2 at the point
where the municipality's storm sewer system discharges to surface
waters of the commonwealth.
OUTLET
Points of water disposal from a stream, river, lake, tidewater
or artificial drain.
PARENT TRACT
The parcel of land from which a land development or subdivision
originates as of the date of adoption of the original Stormwater Management
Ordinance on September 17, 2002 (Ordinance No. 199); and/or the existing
impervious surface area of a tract of land as of the above date.
PARKING LOT STORAGE
Involves the use of impervious parking areas as temporary
impoundments with controlled release rates during rainstorms.
PEAK DISCHARGE
The maximum rate of stormwater runoff from a specific storm
event.
PENN STATE RUNOFF MODEL (CALIBRATED)
The computer-based hydrologic modeling technique adapted
to the watershed for the Act 167 Plan. The model has been "calibrated"
to reflect actual recorded flow values by adjoining key model input
parameters.
PIPE
A culvert, closed conduit, or similar structure (including
appurtenances) that conveys stormwater.
PMF (PROBABLE MAXIMUM FLOOD)
The flood that may be expected from the most severe combination
of critical meteorologic and hydrologic conditions that are reasonably
possible in any area. The PMF is derived from the probable maximum
precipitation (PMP) as determined on the basis of data obtained from
the National Oceanographic and Atmospheric Administration (NOAA).
PRETREATMENT
Techniques employed in stormwater BMPs to provide storage
or filtering to help trap coarse materials and other pollutants before
they enter the system.
PROJECT SITE
The specific area of land where any regulated activities
in the municipality are planned, conducted, or maintained.
RECHARGE AREA
Undisturbed surface area or depression where stormwater collects,
and a portion of which infiltrates and replenishes the underground
and groundwater.
RECHARGE VOLUME
A calculated volume of stormwater runoff from impervious
areas which is required to be infiltrated at a site and may be achieved
through the use of structural or nonstructural BMPs.
REDEVELOPMENT
Development or modification of real estate which was subject
to a previously approved subdivision or land development plan.
REGULATED ACTIVITIES
Any earth disturbance activities or any activities that involve the alteration or development of land in a manner that may affect stormwater runoff and any activities that may contribute nonstormwater discharges to a regulated (or nonregulated) small MS4. (Refer to §
190-304 of this chapter.)
RELEASE RATE
The percentage of predevelopment peak rate of runoff from
a site or subarea to which the post-development peak rate of runoff
must be reduced to protect downstream areas.
RETENTION BASIN
A basin designed to retain stormwater runoff so that a permanent
pool is established.
RETENTION VOLUME/REMOVED RUNOFF
The volume of runoff that is captured and not released directly
into the surface waters of the 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 recur. For example, the twenty-five-year
return period rainfall would be expected to recur on the average once
every 25 years.
RISER
A vertical pipe extending from the bottom of a pond that
is used to control the discharge rate from the pond for a specified
design storm.
ROAD MAINTENANCE
Earth disturbance activities within the existing road cross
section, such as grading and repairing existing unpaved road surfaces,
cutting road banks, cleaning or clearing drainage ditches and other
similar activities.
ROOF DRAINS
A drainage conduit or pipe that collects water runoff from
a roof and leads it away from a structure.
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 surface.
SEDIMENT BASIN
A barrier, dam, or retention or detention basin located and
designed to retain rock, sand, gravel, silt, or other material transported
by water.
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 the movement of water.
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.
SHEET FLOW
Runoff that flows over the ground surface as a thin, even
layer, not concentrated in a channel.
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.
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 a "curve number (CN)."
SOILS ON FLOODPLAIN
Areas subject to periodic flooding listed in the Official
Soil Survey provided by the United States Department of Agriculture,
Natural Resource Conservation Service, Web Soil Survey (http://websoilsurvey.nrcs.usda.gov/),
as soils having a flood frequency other than none.
SPILLWAY
A depression in the embankment of a pond or basin which is
used to pass peak discharge 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.
STORAGE INDICATION METHOD
A reservoir routing procedure based on the solution of the
continuity equation (inflow minus outflow equals the change in storage)
with outflow defined as a function of storage volume and depth.
STORM FREQUENCY
The number of times that a given storm event occurs or is
exceeded on the average in a stated period of years. See "return period."
STORM SEWER
A system of pipes and/or open channels that convey intercepted
runoff and stormwater from other sources, but excludes domestic sewage
and industrial wastes.
STORMWATER
Drainage runoff from the surface of the land resulting from
precipitation or snow or ice melt.
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 structures.
STORMWATER MANAGEMENT PERMIT
A permit issued by the township governing body after the
drainage plan has been approved. Said permit is issued prior to or
with the final Township approval.
STORMWATER MANAGEMENT PLAN
The plans for managing stormwater runoff within the Township
adopted as required by the Act of October 4, 1978, P.L. 864 (Act 167),
as amended, and known as the "Stormwater Management Act"; including the Perkiomen Creek watershed and Tohickon Creek
watershed plans as adopted by Bucks County.
STREAM ENCLOSURE
A bridge, culvert or other structure in excess of 100 feet
in length upstream to downstream which encloses a regulated water
of this commonwealth.
SUBAREA
The smallest drainage unit of a watershed for which stormwater
management criteria have been established in the stormwater management
plan.
SUBDIVISION
The division or redivision of a lot, tract, or parcel of
land by any means into two or more lots, tracts, parcels or other
divisions of land, including changes in existing lot lines, for the
purpose, whether immediate or future, of lease, transfer of ownership,
or building or lot development, provided, however, that the subdivision
by lease of land for agricultural purposes into parcels of more than
10 acres, not involving any new street or easement of access or any
residential dwellings, shall be exempt.
SWALE
A low-lying stretch of land which gathers or carries surface
water runoff.
SWM
See "stormwater management facility."
TIME OF CONCENTRATION (Tc)
The time for surface runoff to travel from the hydraulically
most distant point of the watershed to a point of interest within
the watershed. This time is the combined total of overland flow time
and flow time in pipes or channels, if any.
TOP OF BANK
Highest point of elevation in a stream channel cross section
at which a rising water level just begins to flow out of the channel
and over the floodplain.
TRIBUTARY AREA
The portion of a watershed that contributes runoff to a particular
point in that watershed.
WATER QUALITY VOLUME
A calculated volume of stormwater runoff from impervious
areas which is required to be captured and treated at a site and may
be achieved through use of structural or nonstructural BMPs. Numerically,
the water quality volume is a product of the volumetric runoff coefficient,
the site area, and a depth of rainfall of one inch.
WATERCOURSE
An intermittent or perennial stream of water, river, brook,
creek, or swale identified on USGS or SCS mapping; and/or delineated
waters of the commonwealth.
WATERS OF THE 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
Those 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, ferns, and similar areas.
WETLAND DELINEATION
The process by which wetland limits are determined. Wetlands
must be delineated by a qualified specialist according to the 1989
Federal Manuals (as amended) for the delineation of jurisdictional
wetlands (whichever is greater) or according to any subsequent federal
or state regulation. Qualified specialists shall include those persons
being certified professional soil scientists as registered with the
Registry of Certified Professionals in Agronomy Crops and Soils (ARCPACS);
or as contained on a consultant's list of Pennsylvania Association
of Professional Soil Scientists (PAPSS); or as registered with National
Society of Consulting Soil Scientists (NSCSS); or as certified by
state and/or federal certification programs; or by a qualified biologist/ecologist.