Terms:
ACCELERATED EROSION
The removal of the surface of the land through the combined
action of man's activities and natural processes at a rate greater
than would occur because of the natural processes alone.
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 §
257-4 of this chapter.
BEST MANAGEMENT PRACTICE (BMP)
Stormwater structures and facilities designed or used to
maintain or improve the water quality of surface runoff. BMP's may
be structural (basins and seepage pits), nonstructural (vegetation
filter strips and buffers) or managerial techniques (maintenance practices)
that may be used singly or in combination to achieve water quality.
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.
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 (DESIGNATED REPRESENTATIVE)
Any person or consultant designated by the Township governing
body to administer, review or enforce the provisions of this chapter
whether by contract or by 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.
DEVELOPER and/or SUBDIVIDER
A person, partnership, association, corporation, or other
entity, or any responsible person therein or agent thereof, that undertakes
any PA DEP regulated activity of this chapter.
DEVELOPMENT SITE
The specific tract of land for which a regulated activity
is proposed.
DRAINAGE EASEMENT
A right granted by a landowner to a grantee, allowing the
use of private land for stormwater management purposes.
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 this chapter; Stormwater Management Plan and Report
Package.
ENGINEER
A person, partnership or corporation which shall have a license
issued by the Commonwealth of Pennsylvania as a professional engineer
and which shall prepare all stormwater management plans and reports
required under this chapter and which shall seal with the professional
seal all plans and documents submitted under this chapter.
EROSION
The movement of soil particles by the action of water, wind,
ice, or other natural forces.
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
Maps 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 (PA DEP) Technical Manual for
Sewage Enforcement Officers (as amended or replaced from time to time
by PA DEP).
GRADE
The inclination, with the horizontal, of a road, unimproved
land, etc., which is generally expressed by stating the vertical rise
or fall as a percentage of the horizontal distance.
IMPROVEMENTS
Those physical additions and changes to the land that may
be necessary to produce usable and desirable lots.
INFILTRATION STRUCTURE
A structure designed to direct runoff into the ground (e.g.,
French drains, seepage pits, seepage trench).
LAND DEVELOPMENT
(1)
The improvement of one lot or two of more contiguous lots, tracts,
or parcels of land for any purpose involving a) a group of two or
more buildings, or b) the division or allocation of land or space
between or among two or more existing or prospective occupants by
means of, or for the of streets, common areas, leaseholds, condominiums,
building groups, or other features;
(3)
Any lot improvements regulated under Chapter
320, Zoning.
LAND 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 plan or otherwise as permitted by law and to be used, developed
or built upon as a unit.
MUNICIPALITY
Cross Creek Township, Washington County, Pennsylvania.
NRCS
U.S. Department of Agriculture Natural Resources Conservation
Service.
[Amended at time of adoption of Code (see Ch. 1, General
Provisions, Art. I)]
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.
PEAK DISCHARGE
The maximum rate of stormwater runoff from a specified storm
event.
PERFORMANCE GUARANTEE
Any security which may be accepted in lieu of a requirement
that certain improvements be made before the Township gives final
approval of a plan, including performance bonds, escrow agreements,
letters of credit, and any other collateral or surety agreements.
PIPE
A culvert, closed conduit, or similar structure (including
appurtenances) that conveys stormwater.
PLAN, FINAL
A complete and exact subdivision or land development plan (including all required supplementary data), prepared for official recording of a major subdivision, to define property rights and proposed streets and other improvements, prepared by a registered surveyor, all as more fully set forth in Chapter
270, Subdivision and Land Development.
PLAN, PRELIMINARY
A tentative subdivision or land development plan (including all required supplementary data), in lesser detail than a final plan, showing, among other things, topographical data and approximate proposed street and lot layout as a basis for consideration of a major subdivision prior to preparation of a final plan, all as more fully set forth in Chapter
270, Subdivision and Land Development.
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 an area. The PMF is derived from the probable maximum
precipitation (PMP) as determined on the basis of data obtained from
the National Oceanographic and Atmospheric Administration (NOAA).
REGULATED ACTIVITIES
Actions or proposed actions that have an impact on stormwater
runoff and that are specified in this chapter.
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,
once every 25 years.
RUNOFF
Any part of precipitation that flows over the land surface.
SEDIMENT BASIN
A barrier, dam, retention, or detention basin located and
designed to retain rock, sand, gravel, silt, or other material transported
by water.
SEDIMENTATION
The process of 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.
SOIL COVER COMPLEX METHOD
A method of runoff computation developed by the NRCS that
is based on relating soil type and land use cover to a runoff parameter
called a curve number (CN).
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 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 total amount of 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. Typical stormwater management facilities include, but are
not limited to, detention and retention basins, open channels, storm
sewers, pipes, and infiltration structures.
STREAM ENCLOSURE
A bridge, culvert or other structure in excess of 100 feet
in length upstream to downstream which encloses a regulated water
of this commonwealth.
SUBAREA
The smallest drainage unit of a watershed for which stormwater
management criteria have been established in the stormwater management
plan.
SUBDIVISION
The division or redivision of a lot, tract, or parcel of
land by any means into two or more lots, tracts, parcels or other
divisions of land including changes in existing lot lines for the
purpose, whether immediate or future, of lease, transfer of ownership,
or building or lot development.
WAIVER
Intentional relinquishing of a specific right, claim or privilege
by the governing body.
WETLAND
Those areas that are inundated or saturated by surface water
or groundwater at a frequency and duration sufficient to support,
and that under normal circumstances do support, a prevalence of vegetation
typically adapted for life in saturated soil conditions, including
swamps, marshes, bogs, ferns, and similar areas.