A.
For the purposes of this chapter, certain terms and words used herein
shall be interpreted as follows:
(1)
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.
(2)
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.
(3)
The word "person" includes an individual, firm, association,
organization, partnership, trust, company, corporation or any other
similar entity.
(4)
The words "shall" and "must" refers to items which are mandatory;
the words "may" and "should" refer to items which are permissive.
(5)
The words "used or occupied" include the words "intended, designed,
maintained or arranged to be used, occupied or maintained."
B.
The definitions in § 247-201 do not necessarily reflect the definitions contained in pertinent regulations or statutes, and are intended for this chapter only.
C.
AASHTO
ACCELERATED EROSION
AGRICULTURAL ACTIVITIES
ALTERATION
APPLICANT
AS-BUILT DRAWINGS
ATTENUATE
BANKFULL
BASEFLOW
BERM
BIORETENTION
BMP (BEST MANAGEMENT PRACTICE)
BMP MANUAL
CHANNEL EROSION
CISTERN
CODE ENFORCEMENT OFFICER
CONSERVATION DISTRICT
CONSERVATION EASEMENT
CULVERT
DAM
DEP
DESIGN PROFESSIONAL (QUALIFIED)
DESIGN STORM
DESIGNEE
DETENTION BASIN
DETENTION VOLUME
DEVELOPER
DEVELOPMENT SITE
DIFFUSED DRAINAGE DISCHARGE
DISCHARGE
DISTURBED AREA
DOWNSLOPE PROPERTY LINE(S)
DRAINAGE CONVEYANCE FACILITY
DRAINAGE EASEMENT
DRAINAGE PERMIT
DRAINAGE PLAN
EARTH DISTURBANCE ACTIVITY
EMERGENCY SPILLWAY
ENCROACHMENT
ENERGY DISSIPATER
EPA
EROSION
EROSION AND SEDIMENT POLLUTION CONTROL PLAN (E&S PLAN)
EXCEPTIONAL VALUE WATERS
EXISTING CONDITIONS
FEMA
FLOOD
FLOODPLAIN
FLOODWAY
FOREST MANAGEMENT/TIMBER OPERATIONS
FREEBOARD
GOVERNING BODY
GRADE
(TO) GRADE
GRASSED WATERWAY
GREEN INFRASTRUCTURE
GROUNDWATER RECHARGE
HIGH QUALITY WATERS
HOT SPOT
HYDROGRAPH
HYDROLOGIC REGIME (NATURAL)
HYDROLOGIC SOIL GROUP
IMPERVIOUS SURFACE (IMPERVIOUS AREA)
IMPOUNDMENT
INFILL
INFILTRATION
INFILTRATION FACILITY
INLET
INVERT
KARST
LAND DEVELOPMENT
(1)
(a)
(b)
(2)
(3)
LAND/EARTH DISTURBANCE
LEVEL SPREADER
LIMITING ZONE
(1)
(2)
(3)
(4)
LOADING
LOW IMPACT DEVELOPMENT (LID)
MAINTENANCE
MANNING EQUATION (IN MANNING FORMULA)
MCCD
MCHD
MS4
MUNICIPALITY
NATURAL HYDROLOGIC REGIME
NONPOINT SOURCE POLLUTION
NPDES
NRCS
OBSERVATION PORT
OPEN CHANNEL
OUTFALL
OUTLET
OWNER
PA DOT or PennDOT
PARKING LOT STORAGE
PEAK DISCHARGE
PERENNIAL STREAMS
PERVIOUS SURFACE (PERVIOUS AREA)
PIPE
PLANNING COMMISSION
POINT SOURCE
PREDEVELOPMENT
PRETREATMENT
PROJECT SITE
QUALIFIED PROFESSIONAL
RAINFALL INTENSITY
RATIONAL FORMULA or RATIONAL METHOD
RECHARGE AREA
RECONSTRUCTION
RECORD DRAWINGS
REGULATED EARTH DISTURBANCE ACTIVITY
(1)
(a)
(b)
(c)
(d)
(e)
(f)
RELEASE RATE
RETENTION BASIN
RETENTION VOLUME/REMOVED RUNOFF
RETURN PERIOD
RIPARIAN BUFFER
RISER
ROOFTOP DETENTION
RUNOFF
SALDO
SEDIMENT
SEDIMENT BASIN
SEDIMENT POLLUTION
SEDIMENTATION
SEEPAGE PIT/SEEPAGE TRENCH
SEPARATE STORM SEWER SYSTEM
SHEET FLOW
SOIL-COVER-COMPLEX METHOD
SOURCE WATER PROTECTION AREA (SWPA)
SPECIAL PROTECTION SUBWATERSHEDS
SPILLWAY
STATE WATER QUALITY REQUIREMENTS
STORAGE INDICATION METHOD
STORM FREQUENCY
STORM SEWER
STORMWATER
STORMWATER MANAGEMENT FACILITY
STORMWATER MANAGEMENT PERMIT
STORMWATER MANAGEMENT SITE PLAN
STREAM
SUBAREA
SUBDIVISION
SWALE
TIMBER OPERATIONS
TIME-OF-CONCENTRATION (Tc)
TOWNSHIP
TOWNSHIP ENGINEER (MUNICIPAL ENGINEER)
TOWNSHIP MANAGER
TR-55
USDA
WATER TABLE
WATERCOURSE
WATERS OF THE COMMONWEALTH
WATERSHED
WELLHEAD
WELLHEAD PROTECTION AREA
WETLAND
WOODLANDS
As used in this chapter, the following terms shall have the meanings
indicated:
American Association of State Highway and Transportation
Officials.
The removal of the surface of the land through the combined
action of man's activity and the natural processes at a rate
greater than would occur because of the natural process alone.
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.
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.
A landowner, developer, or other person who has filed an
application to Perkiomen Township for approval to engage in any regulated
activity at a project site in the Township.
Drawings 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 Township and Township
Engineer at the completion of the project. As-built drawings are not
considered complete until reviewed and approved by the Township, or
their designee.
To reduce the magnitude of the flow rate by increasing the
time it takes to release a specified volume of runoff (for example
the one-year, twenty-four-hour storm event). Attenuation is a method
of reducing the peak flow rates for post development compared to the
peak flow rates in predevelopment.
The channel at the top of the bank or point where water begins
to overflow onto a floodplain.
The portion of streamflow that is sustained by groundwater
discharge.
Well-compacted earth-filled ridge.
A stormwater retention area which utilizes woody and herbaceous
plants and soils to remove pollutants before infiltration occurs.
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.
PA Stormwater Best Management Practices Manual (No. 363-0300-002),
prepared by the Department of Environmental Protection, dated December
30, 2006, as amended and updated.
The widening, deepening and headward cutting of small channels
and waterways due to erosion caused by moderate to large floods.
An underground reservoir or tank for storing rainwater.
A Township staff member appointed by the Perkiomen Township
Board of Supervisors to be certified under Township codes and ordinances
to engage in the practice of code enforcement. The Code Enforcement
Officer shall enforce and administer all of the provisions of this
chapter and of those other applicable codes and ordinances of the
Township. The duties of the Code Enforcement Officer shall include,
but not be limited to, the undertaking of such investigations and
other activities as may be required to determine compliance with the
applicable codes and ordinances of the Township, to issue all necessary
notices to abate illegal or unsafe conditions to ensure compliance
with the Township's Code of Ordinances for the safety, health
and general welfare of the public and to make inspections and determine
compliance with the applicable codes and ordinances of the Township.
The Code Enforcement Officer shall be authorized to initiate, on behalf
of the Township, appropriate legal actions against persons or other
legal entities for violations of the Township's Code of Ordinances.
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. Locally referred to as the "Montgomery County Conservation
District (MCCD)."
An easement required at the discretion of Perkiomen Township
to preserve and conserve natural areas typically associated with riparian
buffers, streams, wetlands, surface waters, and stormwater management
BMPs.
A structure with appurtenant works which carries a stream
under or through an embankment or fill.
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.
The Pennsylvania Department of Environmental Protection.
A Pennsylvania registered professional engineer (PE), registered
landscape architect (RLA), professional geologist (PG) or a professional
land surveyor (PLS).
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."
The agent of the Montgomery County Planning Commission and/or
agent of the governing body involved with the administration, review
or enforcement of any provisions of this chapter.
An impoundment structure designed to manage stormwater runoff
by temporarily storing the runoff and releasing it slowly at a predetermined
rate.
The volume of runoff that is captured and released into the
waters of the commonwealth at a controlled rate.
See "applicant."
See "project site."
Drainage discharge not confined to a single point location
or channel, such as sheet flow or shallow concentrated flow.
Unstabilized land area where an earth disturbance activity
is occurring or has occurred.
That portion of the property line(s) of the lot, tract or
parcels of land being developed, located such that all overland or
pipe flow from the site would be directed towards it.
A stormwater management facility designed to transmit stormwater
runoff, and shall include streams, channels, swales, pipes, conduits,
culverts, storm sewers, etc.
A right granted by a landowner to a grantee, allowing the
use of private land for stormwater management purposes.
See "stormwater management permit."
See "stormwater management site plant."
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, mineral extraction, and the moving, depositing, stockpiling,
or storing of soil, rock or earth materials.
A conveyance area that is used to pass peak discharge greater
than the maximum design storm controlled by the stormwater facility.
A structure or activity that changes, expands or diminishes
the course, current or cross section of a watercourse, floodway or
body of water.
A concrete, stone, or other similar structure designed to
reduce the velocity and force of a concentrated flow of water.
Environmental Protection Agency.
The natural process by which the surface of the land is worn
away by water, wind, or chemical action.
A plan that is designed to minimize accelerated erosion and
sedimentation. Said plan must be submitted to and approved by the
Montgomery County Conservation District before construction can proceed,
if the disturbance area exceeds one acre or more in totality.
Surface waters of high quality which satisfy Pennsylvania
Code Title 25, Environmental Protection, Chapter 93, Water Quality
Standards, § 93.4b(b) (relating to antidegradation).
The initial condition of a project site prior to a proposed
regulated activity.
Federal Emergency Management Agency.
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 this commonwealth.
Any land area susceptible to inundation by water from any
natural source or delineated as a special flood hazard area on the
applicable National Flood Insurance Program Flood Insurance Rate Map
(FIRM) prepared by the Federal Emergency Management Agency (FEMA).
Also included are areas that comprise Group 13 soils, as listed in
Appendix A of the Pennsylvania Department of Environmental Protection
(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 frequency 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 frequency 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 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.
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.
Board of Supervisors of Perkiomen Township, Montgomery County,
Pennsylvania.
A slope, usually of a road, channel or natural ground, specified
in percent and shown on plans as specified herein.
To finish the surface of a roadbed, top of embankment, or
bottom of excavation.
A natural or constructed waterway, usually broad and shallow,
covered with erosion-resistant grasses, used to convey surface water.
Systems and practices that use or mimic natural processes
to infiltrate, evapotranspire, or reuse stormwater on the site where
it is generated.
Replenishment of existing natural underground water supplies.
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).
Area where land use or activity generates highly contaminated
runoff, with concentrations of pollutants in excess of those typically
found in stormwater, including but not limited to: vehicle salvage
yards and recycling facilities; vehicle fueling stations; vehicle
service and maintenance facilities; vehicle and equipment cleaning
facilities; fleet storage areas (bus, truck, etc.); industrial sites
based on standard industrial codes; marinas (service and maintenance);
outdoor liquid container storage; outdoor loading/unloading facilities;
public works storage areas; facilities that generate or store hazardous
materials; commercial container nurseries; and other land uses and
activities as designated by an appropriate review authority.
A graphical representation of average rainfall, rainfall
excess rates or volumes over specified areas during successive units
of time during a storm.
The hydrologic cycle or balance that sustains quality and
quantity of stormwater, baseflow, storage and groundwater supplies
under natural conditions.
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.
A surface that has been compacted or covered with material
to the extent that it is resistant to infiltration by water, including,
but not limited to, conventional impervious surfaces such as paved
streets, roofs, indoor living space, patios, decks, garages, sheds
and similar structures, compacted stone, sidewalks and compacted earth
or turf. In addition, the following shall be considered impervious
surfaces when used by motor vehicles: graveled areas, bricks, and
cobblestone. Excludes water surfaces associated with pools.
A retention or detention basin designed to retain stormwater
runoff and release it at a controlled rate.
Development that occurs on smaller parcels that remain undeveloped
but are within or in 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.
The passing of stormwater through the soil from the surface.
A permanent stormwater management facility designed to direct
runoff into the ground.
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.
The lowest surface; the floor or bottom of a culvert, drain,
sewer, channel, basin, BMP, or orifice.
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.
The improvement of one lot or two or more contiguous lots, tracts
or parcels of land for any purpose involving:
A group of two or more residential or nonresidential buildings,
whether initially or cumulatively, or a single nonresidential building
on a lot or lots, regardless of the number of occupants or tenure;
or
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.
A subdivision of land.
Development in accordance with Section 503(1.1) of the Pennsylvania
Municipalities Planning Code Act of 1968 (Act 247).[1]
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.
A stormwater management facility perpendicular to the direction
of slope and extending across the width of the slope for the purpose
of intercepting surface runoff and spreading it behind the stormwater
management facility to enhance infiltration and reduce erosion and
runoff from the slope. The purpose of a level spreader is to prevent
concentrated erosive flows from occurring and to spread out stormwater
runoff uniformly over the ground as sheet flow.
A soil horizon or condition in the soil profile or underlying
strata which includes one of the following:
A seasonal high-water table, whether perched or regional, determined
by direct observation of the water table or indicated by soil mottling.
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.
A rock formation, other stratum or soil condition which is so
slowly permeable that it effectively limits downward passage of effluent.
The presence of karst geologic features which may limit the
feasibility of infiltration due to risk of sinkhole activity.
The total amount (generally measured in pounds or kilograms
per acre per year) of material (sediment, nutrients, oxygen-demanding
material, or other chemicals or compounds) brought into a lake, stream,
or water body by inflowing streams, runoff, direct discharge through
pipes, groundwater, the air (aerial or atmospheric deposition) and
other sources over a specific period of time (often annually).
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.
The actions taken to restore or preserve the as-built functional
design of any facility or system.
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 underpressure.
Montgomery County Conservation District.
Montgomery County Health Department.
Municipal separate storm sewer system.
Perkiomen Township, Montgomery County, Pennsylvania.
See "hydrologic regime."
Pollution that enters a body of water from diffuse origins
in the watershed and does not result from confined or discrete conveyances.
National Pollutant Discharge Elimination System, the federal
government's system for issuance of permits under the Clean Water
Act, which is delegated to DEP in Pennsylvania.
Natural Resources Conservation Service (previously SCS) of
the USDA.
A device installed within stormwater BMPs which allows for
the observation of infiltration below grade which is visible through
a cleanout or port which is accessible from the ground surface.
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.
Point where water flows from a conduit, stream or drain.
Points of water disposal from a stream, river, lake, tidewater
or artificial drain.
The legal or beneficial owner or owners of land, including
the holder of an option or contract to purchase (whether or not such
option or contract is subject to any condition), a lessee if he is
authorized under the lease to exercise the rights of the landowner,
or other person having a proprietary interest in land.
Pennsylvania Department of Transportation.
Involves the use of impervious parking areas as temporary
impoundments with controlled release rates during rainstorms.
The maximum rate of stormwater runoff from a specific storm
event.
Streams that flow throughout the majority of the year in
a defined channel. Perennial streams derive their flow from both groundwater
and runoff, and the groundwater table never drops below the streambed.
Any area not defined as impervious area.
A culvert, closed conduit, or similar structure (including
appurtenances) that conveys stormwater.
The Planning Commission of Perkiomen Township.
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, as defined in state regulations
at 25 Pa. Code § 92a.2.
Undeveloped/natural condition.
Techniques employed in stormwater BMPs to provide storage
or filtering to help trap coarse materials and other pollutants before
they enter the system.
The specific area of land where any regulated activities
in Perkiomen 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.
The depth of accumulated rainfall per unit time.
A method for computing quantities of stormwater runoff. The
rational formula relates runoff to rainfall by the following equation:
Q = c * i * a where; Q = peak runoff in cubic feet per second; c =
runoff coefficient which is actually the ratio of the peak runoff
rate to the average rainfall rate for a period known as the time of
concentration; i = average rainfall intensity in inches per hour for
a period equal to the time of concentration; and a = drainage area
in acres.
Undisturbed surface area or depression where stormwater collects
and a portion of which infiltrates and replenishes the underground
and groundwater.
The process by which existing developed area is adaptively
reused, rehabilitated, restored, renovated and/or expanded. The development
relies on existing infrastructure and does not require an extension
of water, sewer or other public utilities.
See "as-built drawings."
Activity involving earth disturbance subject to regulation
under 25 Pa. Code Chapter 92a, 25 Pa. Code Chapter 102, or the Clean
Streams Law.[2]
Including, but not limited to, the following:
Any earth disturbance activity associated with land development
and/or redevelopment.
Any earth disturbance activity associated with any subdivision.
Construction of new or additional impervious or semipervious surfaces (driveways, parking lots, patios, tennis courts, etc.) which are not exempt per § 247-302.
Construction of new buildings or additions to existing buildings.
Diversion or piping of any natural or man-made stream channel.
Installation of BMPs and/or stormwater management facilities
or appurtenances thereto.
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.
An impoundment in which stormwater is stored and not released
during the storm event. Stored water may be released from the basin
at some time after the end of the storm.
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 recur. For example, the twenty-five-year
return period rainfall would be expected to recur on the average of
once every 25 years.
A permanent area of land adjoining and immediately upgradient
from rivers, streams, lakes, ponds, and wetlands that is vegetated
with a combination of trees, shrubs, and herbaceous plants. A riparian
buffer functions to maintain the integrity of stream channels to reduce
the impact of upland sources of pollution by trapping, filtering and
converting sediments, nutrients, and other chemicals, and supply food,
cover and thermal protection to fish and other wildlife.
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.
Temporary ponding and gradual release of stormwater falling
directly onto flat roof surfaces by incorporating controlled-flow
roof drains into building designs.
Any part of precipitation that flows over the land surface.
Chapter 264, Subdivision and Land Development, of the Code of the Township of Perkiomen.
Soils or other materials transported by surface water as
a product of erosion.
A barrier, dam or retention or detention basin located and
designed to retain rock, sand, gravel, silt or other material transported
by water.
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 the DEP Erosion
and Sediment Pollution Control Program Manual.
The process by which mineral or organic matter is accumulated
or deposited by the movement of water.
An area of excavated earth filled with loose stone or similar
coarse material into which surface water is directed for infiltration
into the ground.
A conveyance or system of conveyances (including roads with
drainage systems, municipal streets, catch basins, curbs, gutters,
ditches, man-made channels or storm drains) primarily used for collecting
and conveying stormwater runoff.
Runoff that flows over the ground surface as a thin even
layer, not concentrated in a channel.
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)."
The zone through which contaminants are likely to migrate
and reach a drinking water well or surface water intake.
Watersheds for which the receiving waters are exceptional
value (EV) or high quality (HQ) waters.
A conveyance that is used to pass the peak discharge of the
maximum design storm controlled by the stormwater facility.
The regulatory requirements to protect, maintain, reclaim,
and restore water quality under Title 25 of the Pennsylvania Code
and the Clean Streams Law.[3]
A reservoir-routing procedure based on solution of the continuity
equation (inflow minus outflow equals the change in storage), with
outflow defined as a function of storage volume and depth.
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."
A system of pipes and/or open channels that conveys intercepted
runoff and stormwater from other sources, but excludes domestic sewage
and industrial wastes.
Drainage runoff from the surface of the land resulting from
precipitation or snow or ice melt.
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, inlets and infiltration facilities.
A permit issued by the Township Code Enforcement Officer
after the stormwater management site plan has been approved. Said
permit is issued prior to or with the final municipal approval.
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, contents of which are established
herein. See "drainage plan."
A body of water that flows in a defined and naturally occurring
channel.
The smallest drainage unit of a watershed for which stormwater
management criteria have been established in the stormwater management
plan.
As defined in the Pennsylvania Municipalities Planning Code,
Act of July 31, 1968, P.L. 805, No. 247.[4]
A low-lying stretch of land which gathers or carries surface
water runoff.
See "forest management."
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.
Perkiomen Township, Montgomery County, Pennsylvania.
The Township's appointed engineering representative
and/or consultant who maintains a professional engineering (PE) license
in Pennsylvania.
The appointed or acting Perkiomen Township Manager by the
Board of Supervisors.
A method for determining runoff volumes and rates developed
by NRCS.
United States Department of Agriculture.
The uppermost level of saturation of pore space or fractures
by subsurface water in an aquifer. "Seasonal high water table" refers
to a water table that rises and falls with the seasons due either
to natural or human-made causes.
A river, brook, creek or a channel or ditch for water, whether
natural or man-made, with perennial flow.
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.
The point at which a groundwater well bore hole meets the
surface of the ground.
The surface and subsurface area surrounding a water supply
well, well field, spring or infiltration gallery supplying a public
water system, through which contaminants are reasonably likely to
move towards and reach the water source.
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. Development in wetlands
is regulated by the U.S. Army Corps of Engineers and the Pennsylvania
Department of Environmental Protection. Identification of wetlands
should be based upon the Federal Manual for Identifying and Delineating
Wetlands, an interagency publication of the United States Army Corps
of Engineers, US EPA, United States Fish and Wildlife Service, and
USDA Soil Conservation Service, dated January 1989, as amended.
Areas, groves or stands of mature or largely mature trees
(i.e., greater than six inches in caliper) covering an area greater
than 1/4 acre or groves of mature trees (greater than 12 inches in
caliper) consisting of more than 10 individuals.
