[Ord. 183-2013, 12/2/2013, § 2]
Terms used in this chapter shall be defined as follows:
The removal of the surface of the land through the combined
action of human activities and the natural processes, at a rate greater
than would occur because of the natural process alone.
Farming and other activities related to the cultivation of
soil, production of crops and the raising of livestock; includes mushroom
growing and nursery and sod operations.
Activities associated with agriculture such as agricultural
cultivation, agricultural operation, and animal heavy use areas. This
includes the work of producing crops including tillage, plowing, disking,
harrowing, planting or 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.
Consisting of or formed from material such as gravel, sand,
silt or clay deposited by flowing water and showing little or no modification
of the original material by soils-forming processes. Typical alluvial
soils as identified in the soil survey, Chester and Delaware Counties,
Pennsylvania, include Chewacla, Congaree, Lindside, and Rowland.
The specified characteristics of the land surface (e.g.,
meadow) prior to a proposed disturbance or prior to a rainfall event
(e.g., amount of moisture in the soil); the basis for calculating
increases in runoff attributable to the disturbance or storm which
must be controlled.
A landowner or developer, including heirs, successors and
assigns, who has filed an application for a land disturbance permit
under this chapter.
Well-compacted earth-filled ridge.
Activities, facilities, designs, measures or procedures used
to manage stormwater impacts from regulated earth disturbance activities,
to meet state water quality requirements, to promote groundwater recharge
and to otherwise meet the purposes of this chapter. BMP's include,
but are not limited to, infiltration, filter strips, low impact design,
bioretention, water ponds, permeable paving, grassed swales, forested
buffers, sand filters and detention basins. BMP's can be nonstructural
(preventative actions) and structural (treatment facilities). BMP's
may be described in the Pennsylvania Best Management Practices Manual
(the "BMP Manual"), which may be supplemented from time to time, and
publications of the DEP.
A natural or artificial lake, pond, reservoir, swamp, marsh,
or wetland, stream or other watercourse.
Cubic feet per second.
Reservoir or tank for storing water, especially stormwater.
A plan written by a planner certified by NRCS that identifies
conservation practices and includes site specific BMPs for agricultural
plowing or tilling activities and animal heavy use areas.
Practices installed on agricultural lands to improve farmland,
soil and/or water quality which have been identified in a current
conservation plan.
The diameter of a tree at breast height, measured 4.5 feet
from the ground surface.
Pennsylvania Department of Environmental Protection.
The magnitude of precipitation from a storm event against
which stormwater management facilities shall be designed as protection;
measured in probability of occurrence/frequency (e.g., fifty-year
storm) and duration (e.g., twenty-four-hour).
An impoundment designed to collect and retard stormwater
runoff by temporarily storing the runoff and releasing it at a pre-determined
rate. Detention basins are designed to drain completely within 48
hours after any given rainfall event and are dry until the next rainfall
event.
Any alteration or construction on previously undeveloped
land that alters the hydrologic regime, such as placement or construction
of new impervious surface or grading over existing pervious land areas,
and is not classified as re-development.
Land area disturbed by or where an earth disturbance activity
is occurring or has occurred.
Channel or ditch, together with a ridge, constructed across
a sloping land surface on the contour or with predetermined grades
to intercept and divert surface runoff before it gains sufficient
volume and velocity to create harmful erosion.
A right-of-way granted to use private land to facilitate
the flow of water, within which the owner shall erect no permanent
structures but may use the land in any other way not inconsistent
with the grantee's right or other applicable regulations.
A land disturbance not primarily associated with increases
in impervious surface; e.g., agriculture, logging, quarrying.
A construction or other human activity which disturbs the
surface of the land, including, but not limited to, clearing and grubbing;
grading; excavations; embankments; road maintenance; land development;
building construction; and the moving, depositing, stockpiling, or
storing of soil, rock, or earth materials.
A concrete or stone structure designed to reduce the velocity
and force of a concentrated flow of water.
A wearing away of soil by action of wind, water, geologic,
or other agents.
A geotextile material designed to prevent upward or downward
movement of soil or other solids while permitting water movement.
Replenishment through infiltration of geologic strata and
rock or soil interstices which have the capacity to store water.
A supply of water which is drawn from wells or springs.
The depth at which soil particles approach saturation with
water.
Properties, distribution and effects of water on the earth's
surface, in the soil and underlying rocks and in the atmosphere.
A surface that has been compacted or covered with a layer
of material so that it prevents or is resistant to infiltration of
water, including but not limited to: structures such as roofs, buildings,
storage sheds; other solid, paved or concrete areas such as streets,
driveways, sidewalks, parking lots, patios, tennis or other paved
courts; or athletic playfields comprised of synthetic turf materials.
For the purposes of determining compliance with this chapter, compacted
soils or stone surfaces used for vehicle parking and movement shall
be considered impervious. Surfaces that were designed to allow infiltration
(i.e., areas of porous pavement) will be considered on a case-by-case
basis by the Municipal Engineer, based on appropriate documentation
and condition of the material, etc.
Any activity which causes land to be exposed to the danger
of erosion, including clearing, earthmoving, grading, filling, logging
and woodcutting, plowing, and any other activity resulting in the
movement of earth or stripping of vegetative cover.
The felling of trees within a concentrated area, and/or the
removal of trees and logs from a site by means of heavy vehicles.
Any regulated activity involving placement or construction
of new Impervious Surface or grading over existing pervious land areas
not classified as redevelopment as defined in this Part.
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.
Tract of land on which trees and plants are raised or stored
for transplanting or sale.
"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.
The maximum rate of flow of water at a given point and time
resulting from a predetermined storm.
Any area not defined as impervious surface.
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 at 25 Pa. Code
§ 92.1.
Period after construction during which disturbed areas are
stabilized, stormwater controls are in place and functioning, and
all proposed improvements in the approved land development plan are
completed.
Land cover conditions assumed to exist within the proposed
Disturbed Area prior to commencement of the regulated activity for
the purpose of calculating the predevelopment water quality volume,
infiltration volume, and peak flow rates as required in this Part.
All new, additional and replacement impervious surfaces.
A method for computing quantities of stormwater runoff. The
rational formula relates runoff to rainfall by the following:
Q = cia
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Q
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=
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peak runoff in cubic feet per second.
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c
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=
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runoff coefficient which is actually the ratio of the peak runoff
rate of the average rainfall rate for a period known as the time of
concentration.
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i
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=
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average rainfall intensity in inches per hour for a period equal
to the time of concentration.
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a
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=
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drainage area in acres.
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The storm duration-frequency-intensity curves and runoff coefficient
tables found in PennDOT Design Manual, Part 2, will be used for determining
peak runoff.
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See "groundwater recharge."
Any regulated activity that involves demolition, removal,
reconstruction, or replacement of existing Impervious Surface(s).
Any earth disturbance activity(ies) or any activity that
involves the alteration or development of land in a manner that may
affect stormwater runoff.
Any activity involving earth disturbance subject to regulation
under 25 Pa. Code, Chapter 92, Chapter 102, or the Clean Streams Law.
A volume of flow being released from a detention structure
per specified unit of time (e.g., gallons per minute) or designated
design storm (e.g., ten-year predevelopment storm.)
A basin, either natural or artificial, which contains or
will contain the water or other fluid impounded by a dam.
A stabilized structure of stone, concrete or treated wood
designed to prevent the erosion or collapse of a rockfaced or earthfaced
cut or fill.
An impoundment designed to collect and infiltrate into geologic
strata a certain amount of stormwater from a catchment area and which
also may be designed to detain water from a catchment area. Unlike
detention basins, retention basins may contain permanent water, and
thus may be considered man-made lakes or ponds.
Land adjoining and immediately upgradient from rivers or
streams that is vegetated with a combination of trees, shrubs, and
herbaceous plants.
Earth disturbance activities within the existing road cross-section,
such as grading and repairing existing un-paved road surfaces, cutting
road banks, cleaning or clearing drainage ditches, and other similar
activities.
The surface and subsurface network of roots which support
a tree.
That portion of a total volume of water which can be expected
to flow off a particular surface.
Soil Conservation Service, United States Department of Agriculture.
Solid material, both mineral and organic, that is in suspension,
is being transported or has been moved from its site of origin by
water.
A retention or detention basin located and designed to retain
rock, sand, gravel, silt, and other stormwater transported material
through trapping, screening, settling, etc.
A broad area of excavated earth, filled with loose stone
or other particles, to which surface water is directed for infiltration
into geologic storage.
A linear excavation of the earth, filled with loose stone
or similar materials, to which surface water is directed for infiltration
to geologic storage.
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.
Total area of land in the Municipality where any proposed
regulated activity, as defined in this Part, is planned, conducted,
or maintained or that is otherwise impacted by the regulated activity.
A mathematical method of runoff computation developed by
the Soil Conservation Service of the United States Department of Agriculture
as published in the 1986 edition of Urban Hydrology for Small Watersheds
(Technical Release No. 55).
A place where water flows naturally from a rock or soil upon
the land or into a body of surface water.
A system of pipes and/or open channels that convey intercepted
runoff and stormwater from other sources, but excludes domestic sewage
and industrial wastes.
Water which surfaces, flows or collects during and subsequent
to rain or snowfall.
Procedures involved in the control of water that runs off
the surface of the land from rain and melting snow.
A natural watercourse with perennial or intermittent flow.
A retention or detention basin that is visually inconspicuous,
wherein a layer of soil or other surface material overlays the entire
volume of stored stormwater.
A low-lying stretch of land (natural) which collects or carries
surface water runoff.
Crops requiring cultivation of soil.
Duly appointed employee or independent contractor performing
engineering services for the Township or such individual appointed
by the Supervisors to perform the duties and services designated herein.
Shrubs, small trees, vines, and other plants.
An area of land or portion of a property with no existing
impervious surface.
Soil subject to erosion due to lack of vegetation or inherent
nature of soil structure.
Rivers, streams, creeks, rivulets, impoundments, ditches,
watercourses, reservoirs, storm sewers, lakes, dammed water, ponds,
springs, and other bodies or channels of conveyance of surface and
underground water, or their parts, whether natural or artificial,
within or on the boundaries of Charlestown Township.
A channel or conveyance of surface water having defined bed
and banks, whether natural or artificial.
The area upstream and tributary to a point along a stream,
lake, drainage facility or any point of interest that contributes
runoff to that point.
Those areas that are inundated or saturated by surface water
or groundwater at a frequency and duration sufficient to support,
and which under normal conditions do support, a prevalence of vegetation
typically adapted for life in saturated soil conditions. Wetlands
generally include swamps, marshes, bogs, and similar area. For purposes
of regulation under this Part, wetlands shall be construed to be all
areas meeting the definition of wetlands, as then currently specified
by the United States Army Corps of Engineers and/or the Pennsylvania
Department of Environmental Protection. In any situation in which
these sources or areas do not coincide, the more inclusive area shall
be considered to be wetlands under this chapter.
Any land area of at least 0.25 acre with a natural or naturalized
ground cover (excluding manicured turf grass) and that has an average
density of two or more viable trees per 1,500 square feet with a DBH
of six inches or greater and where such trees existed at any time
within three years of the time of land development application submission
of the proposed project. The land area to be considered woods shall
be measured from the outer drip lines of the outer trees.
