Unless otherwise expressly stated, the following
terms and words used herein shall, for the purposes of this chapter,
have the meanings indicated in this section.
As used in this chapter, the following terms
shall have the meanings indicated:
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 §
290-6 of this chapter.
BMP (BEST MANAGEMENT PRACTICE)
Stormwater structures, facilities and techniques to control,
maintain or improve the quantity and quality of surface runoff.
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
Structure with appurtenant works that 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 semi-fluid, or a refuse bank, fill or structure for highway,
railroad or other purposes which does or may impound water or another
fluid or semi-fluid.
DESIGNEE
The agent of Lewisburg Borough involved with the administration,
review or enforcement of any provisions of this chapter by contract
or memorandum of understanding.
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.
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.
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 municipal governing body after the
drainage plan has been approved. Said permit is issued prior to or
with the final municipal approval.
DRAINAGE PLAN
The plan and documentation prepared by the developer or his
representative indicating how stormwater runoff will be managed and
the stormwater management system, if any, to be used for a given development
site, the contents of which are established in this chapter.
EARTH DISTURBANCE
Any activity including, but not limited to, construction,
mining, timber harvesting and grubbing which alters, disturbs, and
exposes the existing land surface.
EMERGENCY SPILLWAY
A depression in the embankment of a pond or basin that is
used to pass peak discharge greater than the maximum design storm
controlled by the pond.
EROSION
The movement of soil particles by the action of water, wind,
ice, or other natural forces.
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" in good condition
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 (PA DEP) Technical Manual for
Sewage Enforcement Officers (as amended or replaced from time to time
by PA DEP).
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 forestland.
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. (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 (HYDROLOGIC ENGINEERING CENTER HYDROLOGIC MODELING SYSTEM)
The computer-based hydrologic modeling technique adapted
to a particular watershed as part of an official Act 167 Watershed
Plan and calibrated to reflect actual recorded flow values by adjoining
key model input parameters. Miller Run sub-watershed of Bull Run and
West Branch of the Susquehanna have calibrated HEC-HMS models.
IMPERVIOUS SURFACE
A surface that prevents the percolation of water into the
ground. For the purposes of this chapter, impervious surface may include,
but not be limited to, the following: concrete, asphalt, building
coverage, water impoundments, gravel and crushed stone areas, highly
compacted soil, etc.
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.
KARST
A type of topography that is formed over limestone, dolomite,
or gypsum by bedrock solution, and that is characterized by closed
depressions or sinkholes, caves and underground drainage (from AGI,
Glossary of Geology, 1972).
LAND DEVELOPMENT
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 buildings; or
(2)
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.
C.
Development in accordance with Section 503(1.1)
of the PA 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.
LIMESTONE
A rock that is chiefly formed by the accumulation of organic
remains, consisting mainly of calcium carbonate.
MAIN STEM (MAIN CHANNEL)
Any stream segment or other runoff conveyance facility used
as a reach in any Act 167 Watershed Plan hydrologic model runs.
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.
MUNICIPAL ENGINEER
A professional engineer licensed as such in the Commonwealth
of Pennsylvania, duly appointed or retained as the engineer for Lewisburg
Borough.
NOAA
National Oceanic Atmospheric Administration.
[Added 11-15-2022 by Ord. No. 1069]
NONPOINT SOURCE POLLUTION
Pollution that enters a watery body from diffuse origins
in the watershed and does not result from discernible, confined, or
discrete conveyances.
NONSTRUCTURAL BMP'S
Stormwater runoff treatment techniques which use natural
measures to reduce pollution levels, do not require extensive construction
efforts and/or promote pollution reduction by eliminating the pollutant
source. Acceptable nonstructural BMPs are identified in Appendices
B and M.
[Amended 11-15-2022 by Ord. No. 1069]
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.
OUTLET STRUCTURE
A pipe, weir, or other appurtenant works designed to control
the required detention storm.
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 (PSRM)
The computer-based hydrologic modeling technique adapted
to a particular watershed as part of an official Act 167 Watershed
Plan and calibrated to reflect actual recorded flow values by adjoining
key model input parameters. Portions of the Bull Run Watershed not
impacted by the Plan update of 2002 and the Buffalo Creek Watershed
have calibrated PSRM models.
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 meteorological and hydrological conditions that is 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).
PSUEDO-HYDROGRAPH
A hydrograph derived from an established formula without
the need for rainfall-runoff data analysis.
RECHARGE VOLUME (Rev)
The volume of stormwater runoff from a site that must be
infiltrated into the soil to promote the maintenance of groundwater
recharge rates that existed prior to development.
REGULATED ACTIVITIES
Actions or proposed actions that have an impact on stormwater runoff and that are specified in §
290-6 of this chapter.
RELEASE RATE
The percentage of pre-development peak rate of runoff from
a site or subarea to which the post-development 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.
SEDIMENTATION
The process by which mineral or organic matter is accumulated
or deposited by the movement of water.
SEDIMENT BASIN
A barrier, dam, 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.
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.
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 total amount of precipitation reaching the ground surface.
STORMWATER HOTSPOT
A land use or activity that generates higher concentrations
of hydrocarbons, trace metals, or toxicants than are found in typical
stormwater runoff, based on monitoring studies. A list of categories
of typical hotspots is contained in this chapter.
STORMWATER MANAGEMENT CREDITS
Incentive based nonstructural stormwater management applications
that can be incorporated into the site design process to promote water
quality, groundwater recharge, volume control, and other stormwater
objectives. These include conservation of natural areas, disconnection
of rooftop runoff, disconnection of non-rooftop runoff, sheet flow
to buffers, grass channels and environmentally sensitive or low-impact
development.
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 plans for managing stormwater runoff in designated watersheds
adopted by Union County and approved by the PA DEP as required by
the Act of October 4, 1978, P.L. 864 (Act 167), the Stormwater Management
Act.
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 an Act 167 Stormwater
Management Plan.
SUBDIVISION
The division or re-division 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 that 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.
WATER QUALITY VOLUME (WQv)
The storage needed to capture and treat the runoff from 95%
of the average annual rainfall. For Lewisburg Borough, Union County,
the depth of rainfall with 95% of the total of all rainfall events
is 1.53 inches. (Source: National Weather Service/NOAA NOWData from
Jan 2021 to July 2022; https://www.weather.qov/wrh/Climate?wfo=ctp).
[Amended 11-15-2022 by Ord. No. 1069]
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, and similar areas.