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 at a rate greater
than would occur because of the natural process alone.
ACCESS EASEMENT
A right granted by a landowner to a grantee, allowing entry
for the purpose of inspecting, maintaining and repairing SWM facilities.
ACT 167 PLAN
A plan prepared under the authority of the Stormwater Management
Act.
AGRICULTURAL ACTIVITY
Activities associated with agriculture, such as agricultural
cultivation, agricultural operation, and animal heavy use areas. This
includes the work of producing crops and raising livestock including
tillage, land clearing, plowing, disking, harrowing, planting, harvesting
crops, or pasturing and raising of livestock and installation of conservation
practices. Construction of new buildings or impervious areas 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; earth disturbance activity.
ALTERNATIVE AGRICULTURAL PROCESS
Plan alternative for properties where a development site that is located within the Agricultural District (A) and has an implemented conservation plan verified by the Conservation District may alternatively comply with the requirements of §
190-42.
ANIMAL HEAVY USE AREAS
A barnyard, feedlot, loafing area, exercise lot, or other
similar area on an agricultural operation where due to the concentration
of animals, it is not possible to establish and maintain vegetative
cover of a density capable of minimizing accelerated erosion and sedimentation
by usual planting methods. The term does not include entrances, pathways
and walkways between areas where animals are housed or kept in concentration.
APPLICANT
A landowner and/or developer, as hereinafter defined, including
his heirs, successors and assigns, who has filed an application to
West Donegal Township for approval to engage in any regulated activity
at a development site, located within the Township.
BMP (BEST MANAGEMENT PRACTICES)
Activities, facilities, control measures, planning or procedures
used to minimize accelerated erosion and sedimentation and manage
stormwater to protect, maintain, reclaim, and restore the quality
of waters and the existing and designated uses of waters within this
Commonwealth before, during and after earth disturbance activities.
(NOTE: 25 Pa. Code Chapter 102, Erosion and Sediment Control.) See
also "nonstructural BMP" and "structural BMP."
BMP MANUAL
The Pennsylvania Stormwater Best Management Practices Manual
of December 2006.
BUILDING
Any enclosed or open structure, other than a boundary wall
or fence, occupying more than four square feet of area and/or having
a roof supported by columns, piers, or walls.
CARBONATE GEOLOGY
Limestone or dolomite bedrock. Carbonate geology is often
associated with karst topography.
CERTIFICATE OF COMPLETION
Documentation verifying that all permanent SWM facilities
have been constructed according to the plans and specifications and
approved revisions thereto.
CHAPTER 102
25 Pa. Code Chapter 102, Erosion and Sediment Control.
CHAPTER 105
25 Pa. Code Chapter 105, Dam Safety and Waterway Management.
CHAPTER 106
25 Pa. Code Chapter 106, Floodplain Management.
CISTERN
A reservoir or tank for storing rainwater.
CLEAN WATER ACT
The 1972 Amendments to the Federal Water Pollution Control
Act, P.L. 92-500 of 1972, 33 U.S.C. § 1251 et seq.
CONSERVATION PLAN
A plan written by an NRCS certified planner that identifies
conservation practices and includes site specific BMPs for agricultural
plowing or tilling activities and animal heavy use areas.
CONSERVATION PRACTICES
Practices installed on agricultural lands to improve farmland,
soil and/or water quality which have been identified in a current
conservation plan.
CONVEYANCE
A.
Any structure that carries a flow.
B.
The ability of a pipe, culvert, swale or similar facility to
carry the peak flow from the design storm.
CULVERT
A structure with appurtenant works which can convey a stream
under or through an embankment or fill.
DCNR
The Pennsylvania Department of Conservation and Natural Resources
or any agency successor thereto.
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 SWM systems.
DETENTION BASIN
An impoundment structure designed to manage stormwater runoff
by temporarily storing the runoff and releasing it at a controlled
rate.
DEVELOPER
A person who undertakes any regulated activity of this chapter.
DEVELOPMENT SITE (SITE)
The specific area of land where regulated activities in the
Township are planned, conducted or maintained.
DISAPPEARING STREAM
A stream in an area underlain by limestone or dolomite that
flows underground for a portion of its length.
DISCONNECTED IMPERVIOUS AREA (DIA)
An impervious or impermeable surface that is disconnected
from any stormwater drainage or conveyance system and is redirected
or directed to a pervious area, which allows for infiltration, filtration,
and increased time of concentration.
DISTURBED AREA
A land area where an earth disturbance activity is occurring
or has occurred.
DRAINAGE EASEMENT
Rights to occupy and use another person's real property for
the installation and operation of stormwater management facilities,
or for the maintenance of natural drainageways to preserve and maintain
a channel for the flow of stormwater therein, or to safeguard health,
safety, property, and facilities.
E&S
Erosion and sediment.
E&S MANUAL
The DEP Erosion and Sediment Pollution Control Program Manual,
No. 363-2134-008.
EARTH DISTURBANCE ACTIVITY
A construction or other human activity which disturbs the
surface of the land, including, but not limited to, clearing and grubbing;
grading; excavations; embankments; land development; agricultural
plowing or tilling; operation of animal heavy use areas; timber harvesting
activities; road maintenance activities; oil and gas activities; well
drilling; mineral extraction; building construction; and the moving,
depositing, stockpiling, or storing of soil, rock, or earth materials.
(NOTE: 25 Pa. Code Chapter 102, Erosion and Sediment Control.)
ENVIRONMENTALLY SENSITIVE AREA
Slopes greater than 15%, shallow bedrock [located within
six feet of ground surface) (NOTE: Minnesota Pollution Control Agency.)],
wetlands, natural heritage areas and other areas designated as conservation
or preservation in Greenscapes, the Green Infrastructure Element of
the County Comprehensive Plan, where encroachment by land development
or land disturbance results in degradation of the natural resource.
EROSION
The natural process by which the surface of the land is worn
away by water, wind, or chemical action. See also "accelerated erosion"
as defined above.
EXEMPTION
A release from meeting ordinance requirements when project conditions meet the criteria listed in §
190-41A.
EXISTING CONDITIONS
The dominant land cover during the five-year period immediately
preceding a proposed regulated activity.
FEMA
The Federal Emergency Management Agency or any agency successor
thereto.
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.
FLOOD FRINGE
That portion of the floodplain outside of the floodway. (NOTE:
Code of Federal Regulations, Title 44, Emergency Management and Assistance,
§ 9.4, Definitions.)
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, the area of inundation
that functions as a storage or holding area for floodwater to a width
required to contain a base flood of which there is a one-percent chance
of occurrence in any given year. The floodplain contains both the
floodway and the flood fringe.
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. (NOTE: 25 Pa. Code Chapter 105.)
FOREST MANAGEMENT/TIMBER OPERATIONS
Planning and activities necessary for the management of forest
land. These include conducting a 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 maximum design high-water
elevation and the top of a dam, embankment, levee, tank, basin, or
diversion ridge.
FREQUENCY
The probability or chance that a given storm event/flood
will be equaled or exceeded in a given year.
GRADE
(n) A slope, usually of a road, channel or natural ground
specified in percent and shown on plans as specified herein. (v) To
finish the surface of a roadbed, top of embankment or bottom of excavation.
GROUNDWATER RECHARGE
The process by which water from above the ground surface
is added to the saturated zone of an aquifer, either directly or indirectly.
HIGH TUNNEL
A structure which meets the following:
[Added 2-11-2019 by Ord.
No. 234-2019]
A.
Is used for the production, processing, keeping, storing, sale
or shelter of an agricultural commodity as defined in Section 2 of
the Act of December 19, 1974 (P.L. 973, No. 319), known as the "Pennsylvania
Farmland and Forest Land Assessment Act of 1974," or for the storage of agricultural equipment or supplies.
B.
Is constructed consistent with all of the following:
(1)
Has a metal, wood or plastic frame.
(2)
When covered, has a plastic, woven textile or other flexible
covering.
(3)
Has a floor made of soil, crushed stone, matting, pavers or
a floating concrete slab.
HYDROLOGIC SOIL GROUP (HSG)
Refers to soils grouped according to their runoff-producing
characteristics by NRCS. There are four runoff potential groups ranging
from A to D.
A.
GROUP A(Low runoff potential) Soils having high infiltration rates even when thoroughly wetted and consisting chiefly of deep, well to excessively drained sands or gravels. These soils have a high rate of water transmission (greater than 0.30 inch/hour).
B.
GROUP BSoils having moderate infiltration rates when thoroughly wetted and consisting chiefly of moderately deep to deep, moderately well- to well-drained soils with moderately fine to moderately coarse textures. These soils have a moderate rate of water transmission (from 0.15 to 0.30 inch/hour).
C.
GROUP CSoils having slow infiltration rates when thoroughly wetted and consisting chiefly of soils with a layer that impedes downward movement of water, or soils with moderately fine to fine texture. These soils have a slow rate of water transmission (from 0.05 to 0.15 inch/hour).
D.
GROUP D(High runoff potential) Soils having very slow infiltration rates when thoroughly wetted and consisting chiefly of clay soils with a high swelling potential, soils with a permanent high-water table, soils with a clay pan or clay layer at or near the surface, and shallow soils over nearly impervious material. These soils have a very slow rate of water transmission (from zero to 0.05 inch/hour).
ILLICIT CONNECTION
Any man-made physical connection or prohibited connection
to the MS4 that conveys an illicit discharge.
[Added 9-12-2022 by Ord.
No. 250-2022]
ILLICIT DISCHARGE
Any discharge to the MS4 that is not composed entirely of stormwater or polluted stormwater, except for discharges allowed under an NPDES permit, discharges conditionally allowed under the MS4 permit, and discharges authorized by this chapter as set forth in §
190-101D.
[Added 9-12-2022 by Ord.
No. 250-2022]
IMPERVIOUS SURFACE (IMPERVIOUS AREA)
Surfaces which prevent the infiltration of water into the
ground. All structures, buildings, parking areas, driveways, roads,
streets, sidewalks, decks, and any areas of concrete, asphalt, packed
stone, and compacted soil shall be considered impervious surface if
they prevent infiltration. In addition, other areas determined by
the Township Engineer to be impervious within the meaning of this
definition will also be classified as impervious surfaces.
IMPOUNDMENT
A retention or detention facility designed to retain stormwater
runoff and infiltrate it into the ground (in the case of a retention
basin) or release it at a controlled rate (in the case of a detention
basin).
INFILTRATION STRUCTURES
A structure designed to direct runoff into the ground (e.g.
french drains, seepage pits, seepage trench, rain gardens, vegetated
swales, pervious paving, infiltration basins, etc.).
INLET
A surface connection to a closed drain. The upstream end
of any structure through which water may flow.
INTERMITTENT
A natural, transient body or conveyance of water that exists
for a relatively long time, but for weeks or months of the year is
below the local water table and obtains its flow from both surface
runoff and groundwater discharges.
INVASIVE VEGETATION (INVASIVES)
Plants which grow quickly and aggressively, spreading, and
displacing other plants. Invasives typically are introduced into a
region far from their native habitat. See also Invasive Plants in
Pennsylvania by the Department of Conservation and Natural Resources
at www.dcnr.state.pa.us/forestry/plants/invasiveplants/index.htm.
KARST
A type of topography or landscape characterized by features
including but not limited to surface depressions, sinkholes, rock
pinnacles/uneven bedrock surface, underground drainage, and caves.
Karst is formed on carbonate rocks, such as limestone or dolomite.
LAND DEVELOPMENT
Any activity meeting the definition of "land development" in Chapter
200, Subdivision and Land Development.
LANDOWNER
The legal or beneficial owner or owners of land including
the holder of an option or contract to purchase (whether or not such
option or contract is subject to any condition), a lessee if he is
authorized under the lease to exercise the rights of the landowner,
or other person having a proprietary interest in land.
LIMITING ZONE
A rock formation, other stratum, or soil condition which
is so slowly permeable that it effectively limits downward passage
of effluent. (NOTE: 25 Pa. Code Chapter 71, Administration of Sewage
Facilities Planning Program, § 71.1.) Seasonal high-water
tables, whether perched or regional also constitute a limiting zone.
LINEAMENT
A linear feature in a landscape which is an expression of
an underlying geological structure such as a fault.
MANNING'S EQUATION
An equation 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. Manning's
Equation assumes steady, gradually varied flow.
MAXIMUM EXTENT PRACTICABLE (MEP)
Applies when the applicant demonstrates to the Township's
satisfaction that the performance standard is not achievable. The
applicant shall take into account the best available technology, cost
effectiveness, geographic features, and other competing interests
such as protection of human safety and welfare, protection of endangered
and threatened resources, and preservation of historic properties
in making the assertion that the performance standard cannot be met
and that a different means of control is appropriate. (NOTE: Based
on the definition in Wisconsin Department of Natural Resources Administrative
Rule NR 151.006.)
MEADOW
A limited, relatively flat area of low vegetation dominated
by grasses, either in its natural state or used as pasture or for
growing hay.
MODIFICATION
A process for alleviating specific requirements imposed by
this chapter may occur in one of three forms, as follows:
A.
DEFERRALAn approval by the Board of Supervisors to delay the time frame in which to comply with one or more regulations of this chapter.
B.
MODIFICATIONAn approval by the Board of Supervisors to alter/adjust/modify the requirement as specified in this chapter in order to meet the intent of the requirement while accounting for preexisting conditions or constraints.
C.
WAIVERThe granting of full relief of compliance to a specific requirement or standard in this chapter, which in the opinion of the Board of Supervisors will not be detrimental to the general welfare, impair the intent of the regulations or conflict with the Comprehensive Plan.
MPC
The Pennsylvania Municipalities Planning Code, Act of 1968,
P.L. 805, No. 247, as reenacted and amended, 53 P.S. § 10101
et seq.
MUNICIPAL SEPARATE STORM SEWER
A conveyance or system of conveyances (including roads with
drainage systems, municipal streets, catch basins, curbs, gutters,
ditches, man-made channels, or storm drains), which is all of the
following:
A.
Owned or operated by a state, city, town, borough, township,
county, district, association or other public body (created under
state law) having jurisdiction over disposal of sewage, industrial
wastes, stormwater or other wastes;
B.
Designed or used for collecting or conveying stormwater;
C.
Not a combined sewer; and
D.
Not part of a publicly owned treatment works as defined at 40
CFR 122.2.
MUNICIPAL SEPARATE STORM SEWER SYSTEM (MS4)
All separate storm sewers that are defined as "large" or
"medium" or "small" municipal separate storm sewer systems pursuant
to 40 CFR 122.26(b)(18), or designated as regulated under 40 CFR 122.26(a)(1)(v).
NATIONAL POLLUTION DISCHARGE ELIMINATION SYSTEM (NPDES)
A permit issued under 25 Pa. Code Chapter 92a (relating to
National Pollutant Discharge Elimination System permitting, monitoring
and compliance) for the discharge or potential discharge of pollutants
from a point source to surface waters.
NATIVE VEGETATION
Plant species that have evolved or are indigenous to a specific
geographical area. These plants are adapted to local soil and weather
conditions as well as pests and diseases.
NATURAL GROUND COVER
Ground cover which mimics the infiltration characteristics
of predominant hydrologic soil group found at the site.
NONPOINT SOURCE POLLUTION
Any source of water pollution that does not meet the legal
definition of "point source" in Section 502(14) of the Clean Water
Act.
NONSTRUCTURAL BMPS
Planning and design approaches, operational and/or behavior-related
practices which minimize stormwater runoff generation resulting from
an alteration of the land surface or limit contact of pollutants with
stormwater runoff.
NRCS
Natural Resources Conservation Service (previously Soil Conservation
Service, or 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. Open channels may include closed conduits so
long as the flow is not under pressure.
OUTFALL
Point where water flows from a conduit, stream, pipe, or
drain.
PEAK DISCHARGE
The maximum rate of stormwater runoff from a specific storm
event.
PENNDOT
The Pennsylvania Department of Transportation or any agency
successor thereto.
PERMIT
Certificate issued to the applicant by the Township or Township
designated agent acknowledging receipt and satisfactory review of
the submitted application in compliance with the provisions of this
chapter.
PERVIOUS AREA
Any material/surface that allows water to pass through at
a rate equal to or greater than Natural Ground Cover.
PIPE
A culvert, closed conduit, or similar structure (including
appurtenances) that conveys stormwater.
PLANNING COMMISSION
The Planning Commission of the West Donegal Township, Lancaster
County, Pennsylvania.
PLANS
The SWM and erosion and sediment control plans and narratives.
PROCESS WASTEWATER
Water that comes in contact with any raw material, product,
byproduct, or waste during any production or industrial process.
QUALIFIED PERSON
Any person licensed by the Pennsylvania Department of State
or otherwise qualified by law to perform the work required by this
chapter.
RATE CONTROL
SWM controls used to manage the peak flows for the purposes
of channel protection and flood mitigation.
REDEVELOPMENT
Any physical improvement to a previously developed lot that
involves earthmoving, removal, or addition of impervious surfaces.
REGIONAL STORMWATER MANAGEMENT PLAN
A plan to manage stormwater runoff from an area larger than
a single development site. A regional stormwater management plan could
include two adjacent parcels, an entire watershed, or some defined
area in between. Regional stormwater management plans can be prepared
for new development, or as a retrofit to manage runoff from already
developed areas.
REGULATED ACTIVITIES
Activities, including earth disturbance activities, that
involve the alteration or development of land in a manner that may
affect stormwater runoff. Regulated activities shall include, but
not be limited to:
[Amended 9-12-2022 by Ord. No. 250-2022]
A.
Land development subject to the requirements of Chapter
200, Subdivision and Land Development;
B.
Removal of ground cover, grading, filling or excavation;
C.
Construction of new or additional impervious or semi-impervious
surfaces (driveways, parking lots, etc.), and associated improvements;
D.
Construction of new buildings or additions to existing buildings;
E.
Installation or alteration of stormwater management facilities
and appurtenances thereto;
F.
Diversion or piping of any watercourse;
G.
Any other regulated activities where the Township determines
that said activities may affect any existing watercourse's stormwater
management facilities, or stormwater drainage patterns; and
H.
Any activities where the Township determines that said activities
may affect the water quality of stormwater discharges or generate
nonstormwater discharges to the MS4 and/or receiving water bodies.
RETENTION BASIN
A Stormwater Management Facility that includes a permanent
pool for water quality treatment and additional capacity above the
permanent pool for temporary runoff storage.
RIPARIAN
Pertaining to a stream, river or other watercourse. Also,
plant communities occurring in association with any spring, lake,
river, stream or creek through which waters flow at least periodically.
(NOTE: Pennsylvania Department of Environmental Protection. No. 363-0300-002
(December 2006), as amended and updated. Pennsylvania Stormwater Best
Management Practices Manual. Harrisburg, Pennsylvania.)
RIPARIAN BUFFER
A BMP that is an area of permanent vegetation along a watercourse
extending 35 feet from the bank of the watercourse.
RIPARIAN CORRIDOR
A narrow strip of land, centered on a stream or river that
includes the floodplain as well as related riparian habitats adjacent
to the floodplain. (NOTE: Pennsylvania Department of Environmental
Protection. No. 363-0300-002 (December 2006), as amended and updated.
Pennsylvania Stormwater Best Management Practices Manual. Harrisburg,
Pennsylvania.)
RIPARIAN FOREST BUFFER
A type of riparian buffer that consists of permanent vegetation
that is predominantly native trees, shrubs and forbs along a watercourse
that is maintained in a natural state or sustainably managed to protect
and enhance water quality, stabilize stream channels and banks, and
separate land use activities from surface waters.
ROOFTOP DETENTION
Temporary ponding and gradual release of stormwater falling
directly onto roof surfaces by incorporating controlled-flow roof
drains into building designs.
RUNOFF
Any part of precipitation that flows over the land surface.
SCS
United States Department of Agriculture, Soil Conservation
Service (now known as NRCS).
SEDIMENT
Soils or other materials transported by stormwater as a product
of erosion. (NOTE: 25 Pa. Code Chapter 102, Erosion and Sediment Control.)
SEDIMENTATION
The action or process of forming or depositing sediment in
waters of this commonwealth. (NOTE: 25 Pa. Code Chapter 102, Erosion
and Sediment Control.)
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 which flows over the ground surface as a thin, even
layer, not concentrated in a channel.
SINKHOLE
A natural depression, on the ground surface formed by the
dissolution and collapse of a cavern roof. Sinkholes are roughly funnel-shaped
generally occur in limestone regions and are connected to subterranean
passages. Refer to the karst map of the Township in Appendix D.
SMALL STORM EVENT
A storm having a frequency of recurrence of once every two
years or smaller.
SOIL-COVER COMPLEX METHOD
A method of runoff computation developed by the SCS (now
NRCS) that is based on relating soil type and land use/cover to a
runoff parameter called "curve number (CN)." For more information,
see "Urban Hydrology for Small Watersheds," Second edition, Technical
Release No. 55, SCS, June 1986 (or most current edition).
STATE WATER QUALITY REQUIREMENTS
The regulatory requirements to protect, maintain, reclaim,
and restore water quality under Title 25 of the Pennsylvania Code,
the Clean Streams Law and the Clean Water Act.
STORAGE
A volume above or below ground that is available to hold
stormwater.
STORM EVENT
A storm of a specific duration, intensity, and frequency.
(NOTE: City of Jacksonville website, http://www3.coj.net/Departments/City
Fees/Glossary.aspx.)
STORM SEWER
A system of pipes and/or open channels designed to convey
stormwater.
STORMWATER
Drainage runoff from the surface of the land resulting from
precipitation or snow or ice melt.
STORMWATER EASEMENT
Onsite rights-of-way granted for limited use of private land
for public, quasi-public, or private purpose not inconsistent with
a general property right of the owner, and within which the owner
of the property shall not have the right to use the land in a manner
that violates the right of the grantee. The easement shall be placed
around stormwater management facilities and/or BMP facilities found
onsite. The easement shall be described with metes and bounds at the
time of the approved plan recording or on the as-built plans.
STORMWATER MANAGEMENT FACILITY (SWM FACILITY)
Any structure, natural or man-made, that, due to its condition,
design, or construction, conveys, stores, infiltrates/evaporates/transpires,
cleans or otherwise affects stormwater runoff. Typical SWM facilities
include, but are not limited to, detention and retention basins, open
channels, watercourses, road gutters, swales, storm sewers, pipes,
BMPs, and infiltration structures.
STORMWATER MANAGEMENT SITE PLAN (SWM SITE PLAN)
The plan prepared by the developer or his representative
identifying regulated earth disturbance activities and indicating
how stormwater runoff will be managed at a particular development
site according to this chapter. Stormwater (SWM) plans shall be classified
and addressed as follows:
A.
SMALL PROJECT PLANRegulated activities on existing lots of record that, measured on a cumulative basis from (date of adoption), create additional impervious areas of 1,001 square feet to 2,500 square feet or involve an earth disturbance activity such as removal of ground cover, grading, filling or excavation of an area less than 5,000 square feet and do not involve the alteration of stormwater facilities or watercourses.
B.
(1)
Installation of new impervious or semi-impervious surface between
2,501 and 5,000 square feet; or
(2)
Removal of ground cover, grading, filling, or excavation between
5,000 square feet and an acre (43,560 square feet), except for the
agricultural use of land when operated in accordance with a farm conservation
plan approved by the Conservation District.
C.
(1)
Installation of new impervious or semi-impervious surface that
is either in excess of 5,001 square feet; or
(2)
Diversion of piping of any natural or man-made watercourse;
or
(3)
Any use within the floodplain area; or
(4)
Removal of ground cover, grading, filling, or excavation in
excess of one acre, except for the agricultural use of land when operated
in accordance with a farm conservation plan approved by the Conservation
District.
STRUCTURAL BMPS
Physical devices and practices that capture and treat stormwater
runoff. Structural stormwater BMPs are permanent appurtenances to
the development site.
STRUCTURE
Any man-made object having an ascertainable stationary location
on or in land or water, whether or not affixed to the land. (NOTE:
Lancaster County Model Subdivision and Land Development Ordinance.)
SUBDIVISION
Any activity meeting the definition of subdivision in the
MPC.
SWALE
A low lying stretch of land which gathers or carries surface
water runoff.
SWM
Stormwater management.
TIME OF CONCENTRATION (TC)
The time for surface runoff to travel from the hydraulically
most distant point (representative of the project) 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 STREAMBANK
First substantial break in slope between the edge of the
bed of the stream and the surrounding terrain. The top of streambank
can either be a natural or constructed (that is, road or railroad
grade) feature, lying generally parallel to the watercourse.
TREATMENT TRAIN
The sequencing of structural best management practices to
achieve optimal flow management and pollutant removal from urban stormwater.
USDA
United States Department of Agriculture or any agency successor
thereto.
VOLUME CONTROL
SWM controls, or BMPs, used to remove a predetermined amount
of runoff or the increase in volume between the pre- and post-development
design storm.
WATERCOURSE
A channel or conveyance of surface water having defined bed
and banks, whether natural or artificial, with perennial or intermittent
flow.
WATERSHED
The entire region or area drained by a watercourse.
WATERS OF THIS COMMONWEALTH
Any and all rivers, streams, creeks, rivulets, impoundments,
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 Pennsylvania.
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.
WOODLAND
Land predominantly covered with trees and shrubs. Without
limiting the foregoing, Woodlands include all land areas of 10,000
square feet or greater, supporting at least 100 trees per acre, so
that either:
A.
At least 50 trees are two inches or greater in [diameter at
breast height (DBH)]; or
B.
Fifty trees are at least 12 feet in height.