[Ord. No. 243, 3/19/2008]
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 ACTIVITIES
The work of producing crops and raising livestock including
tillage, plowing, disking, harrowing, pasturing and installation of
conservation measures. For purposes of regulation by this chapter
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 person who has filed an application for approval to engage in any regulated activities as defined in §
25-105 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
same, are turned over to the Township 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.
BASE FLOW
Portion of stream discharge derived from groundwater; the
sustained discharge that does not result from direct runoff or from
water diversions, reservoir releases, piped discharges, or other human
activities.
BIORETENTION
A stormwater retention area which utilizes woody and herbaceous
plants and soils to remove pollutants before infiltration occurs.
BMP (BEST MANAGEMENT PRACTICE)
Methods, measures or practices to prevent or reduce surface
runoff and/or water pollution, including but not limited to, structural
and nonstructural stormwater management practices and operation and
maintenance procedures. See also "nonstructural best management practice
(BMP)."
BUFFER
The area of land immediately adjacent to any stream, measured
perpendicular to and horizontally from the top-of-bank on both sides
of a stream. (See "top of bank.")
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.
CHANNEL EROSION
The widening, deepening, and headward cutting of small channels
and waterways, caused by stormwater runoff or bankfull flows.
CISTERN
An underground reservoir or tank for storing rainwater.
CULVERT
A structure with appurtenant works, which carries water under
or through an embankment or fill.
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.
DEPARTMENT
The Pennsylvania Department of Environmental Protection.
DESIGN PROFESSIONAL (QUALIFIED)
Any person licensed by the Pennsylvania Department of State
or otherwise qualified by law to perform the work required by the
Chapter.
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.
DESIGNATED WATERSHED (ACT 167)
A Watershed which is listed under the Pennsylvania Department
of Environmental Protection's "Index of Designated Watersheds
(Stormwater Management)" pursuant to the Stormwater Management Act
P.L. 864, No. 167, October 4, 1978, and published in the Pennsylvania
Bulletin on May 31, 1980 and August 9, 1980, as amended on November
19, 1991, April 21, 1992, June 21, 1994, April 16, 1996, April 15,
1997 and December 16, 1997).
DESIGNEE
The agent of the Berks County Planning Commission, Berks
County Conservation District and/or 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 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 shortly after
any given rainfall event and are dry until the next rainfall event.
DEVELOPER
A person that seeks to undertake any regulated activities
at a project site in the Township.
DEVELOPMENT
Any human-induced change to improved or unimproved real estate,
whether public or private, including but not limited to land development,
construction, installation, or expansion of a building or other structure,
land division, street construction, drilling, and site alteration
such as embankments, dredging, grubbing, grading, paving, parking
or storage facilities, excavation, filling, stockpiling, or clearing.
As used in this chapter, development encompasses both new development
and redevelopment.
DEVELOPMENT SITE
The specific tract of land where any regulated activities
in the Township are planned, conducted or maintained.
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 (volume per unit of time). See also "peak discharge."
DISTURBED AREAS
Unstabilized land area where an earth disturbance activity
is occurring or has occurred.
DITCH
An artificial waterway for irrigation or stormwater conveyance.
DOWNSLOPE PROPERTY LINE
That portion of the property line of the lot, tract, or parcels
of land being developed located such that overland or pipe flow from
the site would be directed towards it.
DRAINAGE CONVEYANCE FACILITY
A stormwater management facility designed to transmit stormwater
runoff and shall include 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 after the drainage plan has
been approved.
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 §
25-403.
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, 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.
ENCROACHMENT
A structure or activity that changes, expands or diminishes
the course, current or cross section of a watercourse, floodway or
body of water.
EROSION
The process by which the surface of the land, including channels,
is worn away by water, wind, or chemical action.
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 anti-degradation).
EXISTING CONDITIONS
The initial condition of a project site prior to the proposed
alteration. If the initial condition of the site is undeveloped land,
the land use shall be considered as "meadow" unless the natural land
cover is proven to generate lower curve numbers or Rational "C" value,
such as forested lands.
FLOOD
A temporary condition of partial or complete inundation of
land areas from the overflow of streams, rivers, and other waters
of this commonwealth.
FLOODPLAIN
Any land area susceptible to inundation by water from any
natural source or delineated by applicable Department of Housing and
Urban Development, Federal Insurance Administration Flood Hazard Boundary-Mapped
as being a special flood hazard area.
FLOODWAY
The channel of the watercourse and those portions of the
adjoining floodplains, which 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-bank.
FLUVIAL GEOMORPHOLOGY
The study of landforms associated with river channels and
the processes that form them.
FOREST MANAGEMENT/TIMBER OPERATIONS
Planning and activities necessary for the management of forest
land with no change of land use proposed. These include timber inventory
and preparation of forest management plans, silvicultural treatment,
cutting budgets, logging road design and construction, timber harvesting
and reforestation.
FREEBOARD
A vertical distance between the elevation of the design high-water
and the top of a dam, levee, tank, basin, swale, or diversion berm.
The space is required as a safety margin in a pond or basin.
GRADE
A slope, usually of a road, channel or natural ground specified
in percent and shown on plans as specified herein. (To) grade to finish
the surface of a roadbed, top of embankment or bottom of excavation.
GRASSED WATERWAY
A natural or constructed waterway, usually broad and shallow,
covered with erosion-resistant grasses, used to convey surface water.
GROUNDWATER
Water beneath the earth's surface, often between saturated
soil and rock that supplies wells and springs.
GROUNDWATER RECHARGE
Replenishment of existing natural underground water supplies
without degrading groundwater quality.
HEC-HMS
The U.S. Army Corps of Engineers, Hydrologic Engineering
Center (HEC) - Hydrologic Modeling System (HMS). This model was used
to model the Schuylkill River watershed during the Act 167 Plan development
and was the basis for the Standards and Criteria of this chapter.
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).
HOTSPOTS
Areas where land use or activities generate highly contaminated
runoff, with concentrations of pollutants in excess of those typically
found in stormwater.
HYDROGRAPH
A graph of discharge versus time for a selected point in
the drainage system.
HYDROLOGIC REGIME (NATURAL)
The hydrologic cycle or balance that sustains quality and
quantity of stormwater, baseflow, storage, and groundwater supplies
under natural conditions.
HYDROLOGIC SOIL GROUP
A classification of soils by the Natural Resources Conservation
Service, formerly the Soil Conservation Service, 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.
IMPERVIOUS SURFACE
A surface that prevents the infiltration of water into the
ground. Impervious surface includes, but is not limited to, any roof,
parking or driveway areas, and any new streets and sidewalks. Any
surface areas designed to be gravel or crushed stone shall be assumed
to be 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 percolates downward
to recharge groundwater.
INFILTRATION STRUCTURES
A structure designed to direct runoff into the underground
water (e.g., french drains, seepage pits, seepage trench).
INLET
The upstream end of any structure through which water may
flow.
INTERMITTENT STREAM
A stream that flows only part of the time. Flow generally
occurs for several weeks or months in response to seasonal precipitation,
due to groundwater discharge.
LAND DEVELOPMENT
Any of the following activities:
(a)
The improvement of one lot 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 proposed 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;
(c)
Development in accordance with Section 503(1.1) of the PA Municipalities
Planning Code.
LIMITING ZONE
A soil horizon or condition in the soil profile or underlying
strata which includes one of the following:
(a)
A seasonal high water table, whether perched or regional, determined
by direct observation of the water table or indicated by soil mottling.
(b)
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.
(c)
A rock formation, other stratum or soil condition which is so
slowly permeable that it effectively limits downward passage of water.
LOT
A designated parcel, tract or area of land established by
a plat or otherwise as permitted by law and to be used, developed
or built upon as a unit.
MAIN STEM (MAIN CHANNEL)
Any stream segment or other runoff conveyance facility used
as a reach in the Schuylkill River 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.
NATURAL RECHARGE AREA
Undisturbed surface area or depression where stormwater collects,
and a portion of which infiltrates and replenishes the underground
and groundwater.
NON-STORMWATER DISCHARGES
Water flowing in stormwater collection facilities, such as
pipes or swales, which is not the result of a rainfall event or snowmelt.
NON-POINT-SOURCE POLLUTION
Pollution that enters a water body from diffuse origins in
the watershed and does not result from discernible, confined, or discrete
conveyances.
NONSTRUCTURAL BEST MANAGEMENT PRACTICE (BMPS)
Methods of controlling stormwater runoff quantity and quality,
such as innovative site planning, impervious area and grading reduction,
protection of natural depression areas, temporary ponding on site
and other techniques.
NPDES
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.
NRCS
Natural Resource Conservation Service (previously SCS).
OUTFALL
"Point source" as described in 40 CFR 122.2 at the point
where the Township's storm sewer system discharges to surface
waters of the commonwealth.
OUTLET
Points of water disposal to a stream, river, lake, tidewater
or artificial drain.
PARENT TRACT
The parcel of land from which a land development or subdivision
originates, determined from the date of the Township's adoption
of this chapter.
PARKING LOT STORAGE
Involves the use of parking areas as temporary impoundments
with controlled release rates during rainstorms.
PEAK DISCHARGE
The maximum rate of stormwater runoff from a specific storm
event.
PIPE
A culvert, closed conduit, or similar structure (including
appurtenances) that conveys stormwater.
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, as defined in state regulations
at 25 Pa. Code 92.1.
POST CONSTRUCTION
Period after construction where disturbed areas are stabilized,
stormwater controls are in place and functioning and all proposed
improvements in the approved land development plan are completed.
PRETREATMENT
Techniques employed in stormwater BMPs to provide storage or filtering to trap coarse materials and other pollutants before they enter the system, but not necessarily meet the water quality volume requirements of §
25-306.
PROJECT SITE
The specific area of land where any regulated earth disturbance
activities in the Township are planned, conducted or maintained.
RECHARGE
The replenishment of groundwater through the infiltration
of rainfall, other surface waters, or land application of water or
treated wastewater.
RECONSTRUCTION
Demolition of, and subsequent rebuilding of impervious surface.
RECORD DRAWINGS
Original documents revised to suit the as-built conditions
and subsequently provided by the engineer to the client. The engineer
takes the contractor's as-builts, reviews them in detail with
his/her own records for completeness, then either turns these over
to the client or transfers the information to a set of reproducibles,
in both cases for the client's permanent records.
REDEVELOPMENT
The demolition, construction, reconstruction, alteration,
or improvement exceeding 2,000 square feet of land disturbance performed
on sites where existing land use is commercial, industrial, institutional,
or multifamily residential. Maintenance activities such as top-layer
grinding and re-paving are not considered to be redevelopment. Interior
remodeling projects and tenant improvements are also not considered
to be redevelopment. Utility trenches in streets are not considered
redevelopment unless more than 50% of the street width is removed
and re-paved.
REGULATED ACTIVITIES
Any actions or proposed actions that involve the alteration
or development of land in a manner that may affect stormwater runoff.
RELEASE RATE
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.
REPAVING
Replacement of the impervious surface that does not involve
reconstruction of an existing paved (impervious) surface.
REPLACEMENT PAVING
Reconstruction of and full replacement of an existing paved
(impervious) surface.
RETENTION BASIN
A structure in which stormwater is stored and not released
during the storm event. Retention basins do not typically have an
outlet to other down stream conveyance features such as channels,
storm sewer, or other surface waters. Generally, these features empty
via recharge and must infiltrate stored water in no more than four
days. These features may have an emergency spillway or other overflow
device for large events.
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 of
once every twenty-five 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 the 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.
SALDO
The Township Subdivision and Land Development Ordinance.
SEDIMENT BASIN
A barrier, dam, retention or detention basin located and
designed to retain rock, sand, gravel, silt, or other material transported
by water during construction.
SEDIMENT POLLUTION
The placement, discharge or any other introduction of sediment
into the waters of the commonwealth.
SEDIMENTATION
The process by which mineral or organic matter is accumulated
or deposited by the movement of water or air.
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 underground water.
SEPARATE STORM SEWER SYSTEM
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.
SHALLOW CONCENTRATED FLOW
Stormwater runoff flowing in shallow, defined ruts prior
to entering a defined channel or waterway.
SHEET FLOW
A flow process associated with broad, shallow water movement
on sloping ground surfaces that is not channelized or concentrated.
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).
SPECIAL GEOLOGIC FEATURES
Carbonate bedrock features, including but not limited to
closed depressions, existing sinkholes, fracture traces, lineaments,
joints, faults, caves and pinnacles, which may exist and must be identified
on a site when stormwater management BMPs are being considered.
SPILLWAY
A conveyance that is used to pass the peak discharge of the
maximum design storm controlled by the stormwater facility.
STATE WATER QUALITY REQUIREMENTS
The regulatory requirements to protect, maintain, reclaim,
and restore water quality under Pennsylvania Code Title 25 and the
Clean Streams Law.
STORAGE INDICATION METHOD
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.
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
The surface runoff generated by precipitation reaching the
ground surface.
STORMWATER MANAGEMENT FACILITY
Any structure, natural or man-made, that, due to its condition,
design, or construction, conveys, stores, or otherwise affects stormwater
runoff quality, rate or quantity. Typical stormwater management facilities
include, but are not limited to, detention and retention basins, open
channels, storm sewers, pipes, and infiltration structures.
STORMWATER MANAGEMENT PLAN
The plan for managing those land use activities that will
influence stormwater runoff quality and quantity and that would impact
the Tributaries to the Schuylkill River Watershed adopted by Berks
County as required by the Act of October 4, 1978, P.L. 864, (Act 167),
and known as the "The Tributaries to The Schuylkill River in Berks
County Act 167 Stormwater Management Plan".
STORMWATER MANAGEMENT SITE PLAN
The plan prepared by the applicant or his representative
indicating how stormwater runoff will be managed at the particular
site of interest according to this chapter.
STREAM BUFFER
The land area adjacent to each side of a stream, essential
to maintaining water quality. (See "buffer.")
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 (SUBWATERSHED)
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, partition by the court
for distribution to heirs or devisees, 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
dwelling, shall be exempted.
SURFACE WATERS OF THE COMMONWEALTH
Any and all rivers, streams, creeks, rivulets, ditches, watercourses,
storm sewers, lakes, dammed water, wetlands, ponds, springs, and all
other bodies or channels of conveyance of surface, or parts thereof,
whether natural or artificial, within or on the boundaries of this
commonwealth.
SWALE
A low lying stretch of land which gathers or carries surface
water runoff.
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.
TOWNSHIP
The Township of Amity, Berks County, Pennsylvania.
TOWNSHIP ENGINEER
A professional engineer licensed as such in the Commonwealth
of Pennsylvania, duly appointed as the engineer for the Township.
VERNAL POND
Seasonal depressional wetlands that are covered by shallow
water for variable periods from winter to spring, but may be completely
dry for most of the summer and fall.
WATERCOURSE
A channel or conveyance of surface water having defined bed
and banks, whether natural or artificial, with perennial or intermittent
flow.
WATERS OF THE COMMONWEALTH
Any and all rivers, streams, creeks, rivulets, 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 body
of water, whether natural or artificial.
WELLHEAD
(a)
A structure built over a well.
(b)
The source of water for a well.
WELLHEAD PROTECTION AREA
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 toward and reach the water source.
WET BASIN
Pond for urban runoff management that is designed to detain
urban runoff and always contains water.
WETLAND
Those 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, fens, and similar areas.