Definitions.
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. 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 §
251-4 of this chapter.
BMP (BEST MANAGEMENT PRACTICE)
Activities, structures, facilities, designs, measures, procedures,
and techniques used to control, maintain or improve the quantity and
quality of surface runoff; 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. See
also "structural BMP" and "nonstructural BMP."
[Amended 7-14-2014 by Ord. No. 2014-04]
CHANNEL EROSION
The widening, deepening and headward cutting of small channels
and waterways due to erosion caused by moderate to large floods.
CISTERN
An underground reservoir or tank for storing rainwater.
CULVERT
A structure with appurtenant works which carries a stream
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.
DEP (or PA DEP or PADEP)
The Pennsylvania Department of Environmental Protection,
or any agency successor to the Pennsylvania Department of Environmental
Protection.
[Added 7-14-2014 by Ord. No. 2014-04]
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.
DESIGNEE
The agent of the Office of the Borough Engineer of the Borough
of Chambersburg or other authorized representative of the Borough
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 the 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 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.
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 towards it.
DRAINAGE CONVEYANCE FACILITY
A stormwater management facility designed to transmit stormwater
runoff and 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 Borough of Chambersburg 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 §
251-22.
[Amended 7-14-2014 by Ord. No. 2014-04]
EARTH DISTURBANCE
Any activity including, but not limited to, construction,
mining, timber harvesting and grubbing which alters, disturbs and
exposes the existing land surface.
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 Protections, 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. 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 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.
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. Also included are
areas that comprise Group 13 Soils, as listed in Appendix A of the
Pennsylvania Department of Environmental Protection (PADEP) Technical
Manual for Sewage Enforcement Officers (as amended or replaced from
time to time by PADEP).
[Amended 7-14-2014 by Ord. No. 2014-04]
FLOODWAY
The channel of the watercourse and those portions of the
adjoining floodplains which are reasonably required to carry and discharge
the one-hundred-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 one-hundred-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.
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
A slope, usually of a road, channel or natural ground, specified
in percent and shown on plans as specified herein.
(1)
(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 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).
IMPOUNDMENT
A retention or detention basin designed to retain stormwater
runoff and release it at a controlled rate.
INFILTRATION STRUCTURES
A structure designed to direct runoff into the ground (e.g.,
french drains, seepage pits, seepage trench).
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.
LAND DEVELOPMENT
(1)
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 buildings or the division or allocation of land or
space between or among two or more existing or prospective occupants
by means of or for the purpose of streets, common areas, leaseholds,
condominiums, building groups or other features;
(3)
Development in accordance with Section 503(1.1)
of the Pennsylvania Municipalities Planning Code.
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.
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.
[Added 7-14-2014 by Ord. No. 2014-04]
MAIN STEM (MAIN CHANNEL)
Any stream segment or other runoff conveyance facility used
as a reach in the Conococheague Creek hydrologic model.
MANNING EQUATION IN (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.
MUNICIPALITY
Borough of Chambersburg, Franklin County, Pennsylvania.
NONPOINT SOURCE POLLUTION
Pollution that enters a water body from diffuse origins in
the watershed and does not result from discernible, confined or discrete
conveyances.
NONSTRUCTURAL BMP
Planning and design approaches, operational and/or behavior-related
practices that minimize stormwater runoff generation resulting from
an alteration of the land surface or limit contact of pollutants with
stormwater runoff.
[Added 7-14-2014 by Ord. No. 2014-04]
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 where water flows from a conduit, stream or drain.
OUTLET
Points of water disposal from a stream, river, lake, tidewater
or artificial drain.
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 Conococheague Creek watershed for the Act 167 Plan. The model
has been "calibrated" to reflect actual recorded flow values by adjoining
key model input parameters.
PERSON
An individual, partnership, corporation, trust, unincorporated
association, or other similar entity.
[Added 7-14-2014 by Ord. No. 2014-04]
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 based on data obtained from the
National Oceanographic and Atmospheric Administration (NOAA).
QUALIFIED DESIGN PROFESSIONAL
A Pennsylvania registered professional engineer, registered
landscape architect or a registered professional land surveyor trained
and certified to develop stormwater management plans.
REGULATED ACTIVITIES
Actions or proposed actions that may have an impact on stormwater
runoff or may contribute nonstormwater discharges to a regulated small
MS4. Any redirection of an existing discharge shall constitute a regulated
activity.
[Amended 7-14-2014 by Ord. No. 2014-04]
REGULATED EARTH DISTURBANCE ACTIVITIES
Activity involving earth disturbance subject to regulation
under 25 Pa. Code § 92a, 20 Pa. Code § 102, or
the Clean Streams Law.
[Added 7-14-2014 by Ord. No. 2014-04]
RELEASE RATE
The percentage of predevelopment peak rate of runoff from
a site or subarea to which the postdevelopment peak rate of runoff
must be reduced to protect downstream areas.
RETENTION BASIN
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.
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 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.
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-COVER COMPLEX METHOD
A method of runoff computation developed by the NRCS that
is based on relating soil type and land use/cover to a runoff parameter
called "curve number" (CN).
SOIL GROUP, HYDROLOGIC
A classification of soils by the 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.
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.
[Added 7-14-2014 by Ord. No. 2014-04]
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
Drainage runoff from the surface of the land resulting from
precipitation or snow or ice melt.
[Amended 7-14-2014 by Ord. No. 2014-04]
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 PLAN
The plan for managing stormwater runoff in the Borough of
Chambersburg consistent with the plan adopted by Franklin County as
required by the Act of October 4, 1978, P.L. 864, (Act 167), and known
as the "Conococheague Creek Watershed Action Act 167 Stormwater Management
Plan."
STORMWATER MANAGEMENT SITE PLAN
The plan prepared by the developer or his representative
indicating how stormwater runoff will be managed at the particular
site of interest according to this chapter.
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.
STRUCTURAL BMP
Physical devices and practices that capture and treat stormwater
runoff. Structural BMPs are permanent appurtenances to the development
site.
[Added 7-14-2014 by Ord. No. 2014-04]
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, 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
dwellings, shall be exempt.
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.
WATERCOURSE
A stream of water; river; brook; creek; or a channel or ditch
for water, whether natural or man-made.
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.
WETLAND
Those areas that are inundated or saturated by surface or
ground water 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.