The language set forth in the text of this chapter shall be interpreted in accordance with the following rules of construction:
A. 
Words used or defined in one tense or form shall include other tenses or derivative forms.
B. 
Words in the singular number shall include the plural number, and words in the plural number shall include the singular number.
C. 
The masculine gender shall include the feminine and neuter. The feminine gender shall include the masculine and neuter. The neuter gender shall include the masculine and feminine.
D. 
The word "person" includes individuals, firms, partnerships, joint ventures, trusts, trustees, estates, corporations, associations, and any other similar entities.
E. 
The word "lot" includes the words "plot," "tract," and "parcel."
F. 
The words "shall," "must" and "will" are mandatory in nature and establish an obligation or duty to comply with the particular provision. The words "may" and "should" are permissive.
G. 
The time, within which any act required by this chapter is to be performed, shall be computed by excluding the first day and including the last day. However, if the last day is a Saturday or Sunday or a holiday declared by the United States Congress or the Pennsylvania General Assembly, it shall also be excluded. The word "day" shall mean a calendar day, unless otherwise indicated.
H. 
Any words not defined in this chapter or in Section 107 of the MPC shall be construed as defined in standard dictionary usage.
I. 
References to officially adopted regulations, standards, or publications of DEP or other governmental agencies shall include the regulation, publication, or standard in effect on the date when a SWM site plan is first filed. It is the intent of the Borough Council in enacting this section to incorporate such changes to statutes, regulations, and publications to the extent authorized by 1 Pa.C.S.A. § 1937.
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.[1]
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.
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 the Borough for approval to engage in any regulated activity at a development site located within the Borough.
BMP (BEST MANAGEMENT PRACTICE)
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: See § 315-97A.) See also "nonstructural BMP" and "structural BMP."
BMP MANUAL
The Pennsylvania Stormwater Best Management Practices Manual of December 2006, or most recent version thereof.
BOROUGH
The Borough of Millersville, Lancaster County, Pennsylvania.
BOROUGH COUNCIL
The governing body of the Borough.
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 DISTRICT
The Lancaster County Conservation District or any agency successor thereto.
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. 
(n) Any structure that carries a flow.
B. 
(v) 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.
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.
DCNR
The Pennsylvania Department of Conservation and Natural Resources or any agency successor thereto.
DEP also PA DEP or PADEP
The Pennsylvania Department of Environmental Protection or any agency successor to the Pennsylvania Department of Environmental Protection.
DESIGNEE
The agent of Millersville Borough involved with the administration, review or enforcement of any provisions by Borough Council action.
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 Borough 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.
DISTURBED AREA
A land area where an earth disturbance activity is occurring or has occurred.
DRAINAGE CONVEYANCE FACILITY
A SWM facility designed to transmit stormwater runoff, including streams, channels, swales, pipes, conduits, storm sewers, etc.
DRAINAGE EASEMENT
Rights to occupy and use another person's real property for the installation and operation of SWM 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 Erosion and Sediment Pollution Control Program Manual, Number 363-2134-008, prepared by DEP.
E&S PLAN (also EROSION AND SEDIMENT CONTROL PLAN)
A site-specific plan consisting of both drawings and a narrative that identifies BMPs to minimize accelerated erosion and sedimentation before, during, and after earth disturbance activities.
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: See § 315-97A.)
ENVIRONMENTALLY SENSITIVE AREA
Slopes greater than 15%, shallow bedrock [located within six feet of ground surface (NOTE: See § 315-97B.)], 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.
EXISTING CONDITIONS
The dominant land cover during the five-year period immediately preceding a proposed regulated activity.
FEMA
The Federal Emergency Management Agency and 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: See § 315-97C.)
FLOODPLAIN
As defined in Chapter 380, Zoning.
FLOOD PLAIN MANAGEMENT ACT
Act of October 4, 1978, P.L. 851, No. 166, as amended, 32 P.S. § 679.101 et seq.
FLOODWAY
As defined in Chapter 380, Zoning.
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 elevation of the design high water and the top of a dam, levee, tank, basin or diversion ridge. The vertical distance is required as a safety margin in a pond or basin.
FREQUENCY
The probability or chance that a given storm event/flood will be equaled or exceeded in a given year.
GRADE
A. 
(n) A slope, usually of a road, channel or natural ground specified in percent and shown on plans as specified herein.
B. 
(v) To finish the surface of a roadbed, top of embankment or bottom of excavation.
GREEN INFRASTRUCTURE
Systems and practices that use or mimic natural processes to infiltrate, evapotranspire, or reuse stormwater on the site where it is generated.
[Added 9-27-2022 by Ord. No. 2022-04]
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.
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. 
(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 inches/hour).
B. 
Soils 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 inches/hour).
C. 
Soils 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 inches/hour).
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 0 to 0.05 inches/hour).
ILLICIT CONNECTION
Any man-made physical connection or prohibited connection to the MS4 that conveys an illicit discharge.
[Added 9-27-2022 by Ord. No. 2022-04]
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 § 315-81E.
[Added 9-27-2022 by Ord. No. 2022-04]
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, stone, and compacted soil shall be considered impervious surface if they prevent infiltration.
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 Invasive Plants in Pennsylvania by the DCNR.
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 325, Subdivision and Land Development Ordinance.
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.
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: See § 315-97L.) 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 Borough'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: See § 315-97E.)
MPC
The Pennsylvania Municipalities Planning Code, Act of 1968, P.L. 805, No. 247, as reenacted and amended, 53 P.S. § 10101 et seq.
MUNICIPALITY
The Borough of Millersville, Lancaster County, Pennsylvania.
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).
MUNICIPAL SEPARATE STORM SEWER SYSTEM PERMIT (MS4 PERMIT)
The NPDES permit regulating discharges from the MS4 issued to the Borough by DEP.
[Added 9-27-2022 by Ord. No. 2022-04]
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 DRAINAGEWAY
An existing channel for water runoff that was formed by natural processes.
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.
PERSON
An individual, partnership, public or private association or corporation, or a governmental unit, public utility or any other legal entity whatsoever which is recognized by law as the subject of rights and duties.
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 Millersville Borough, Lancaster County, Pennsylvania.
PLANS
The SWM and erosion and sediment control plans and narratives.
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 on the basis of data obtained from the National Oceanographic and Atmospheric Administration (NOAA).
PROCESS WASTEWATER
Water that comes in contact with any raw material, product, by-product, or waste during any production or industrial process.
PROJECT SITE
The specific area of land where any regulated activities are planned, conducted, or maintained.
[Added 9-27-2022 by Ord. No. 2022-04]
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.
RATIONAL FORMULA (RATIONAL METHOD)
A rainfall-runoff relation used to estimate peak flow.
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 9-27-2022 by Ord. No. 2022-04]
A. 
Land development subject to the requirements of Chapter 325, 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 Borough determines that said activities may affect any existing watercourse's stormwater management facilities or stormwater drainage patterns; and
H. 
Any activities where the Borough determines that said activities may affect the water quality of stormwater discharges or generate nonstormwater discharges to the MS4 and/or receiving water bodies.
RELEASE RATE
For a specific design storm or list of design storms, the percentage of peak flow rate for existing conditions which may not be exceeded for the proposed conditions.
RELEASE RATE MAP
A graphical representation of the release rates for a specific area.
RETENTION BASIN
A SWM facility that includes a permanent pool for water quality treatment and additional capacity above the permanent pool for temporary runoff storage.
RETENTION VOLUME/REMOVED RUNOFF
The volume of runoff that is captured and not released directly into the surface waters of the commonwealth during or after a storm event.
[Added 9-27-2022 by Ord. No. 2022-04]
RETURN
The average interval, in years, within which a storm event of a given magnitude can be expected to occur one time. For example, the twenty-five-year return period rainfall would be expected to occur on average once every 25 years, or, stated another way, the probability of a twenty-five-year storm occurring in any one year is 0.04, i.e., a 4% chance.
[Added 9-27-2022 by Ord. No. 2022-04]
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.
RIPARIAN BUFFER
A BMP that is an area of permanent vegetation along a 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: See § 315-97F.)
RIPARIAN CORRIDOR EASEMENT
An easement created for the purpose of protecting and preserving a riparian corridor.
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.
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.
ROAD MAINTENANCE
Earth disturbance activities within the existing road cross section, such as grading and repairing existing unpaved road surfaces, cutting road banks, cleaning or clearing drainage ditches and other similar activities.
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: See § 315-97A.)
SEDIMENTATION
The action or process of forming or depositing sediment in waters of this commonwealth. (NOTE: See § 315-97A.)
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.
SEMI-IMPERVIOUS/SEMIPERVIOUS SURFACE
A surface which prevents some infiltration of water into the ground.
SHEET FLOW
Runoff which flows over the ground surface as a thin, even layer, not concentrated in a channel.
SMALL PROJECT
Regulated activities that do not create more than 2,000 square feet of impervious area or involve the removal of ground cover, grading, filling, or excavation of more than one acre, and do not require the submission of a subdivision or land development plan.
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).
SOIL GROUP, HYDROLOGIC
See "hydrologic soil group."
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: See § 315-97G.)
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 MANAGEMENT ACT
Act of October 4, 1978, P.L. 864, No. 167, as amended, 32 P.S. § 680.1 et seq.
STORMWATER MANAGEMENT BEST MANAGEMENT PRACTICES (SWM BMP)
See "BMPs."
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 OPERATION AND MAINTENANCE PLAN (O & M PLAN)
A plan, including a narrative, to ensure proper functioning of the SWM facilities in accordance with Article VI of this chapter.
STORMWATER MANAGEMENT SITE PLAN (SWM SITE PLAN)
The plan prepared by the developer or his representative indicating how stormwater runoff will be managed at a particular development site according to this chapter.
STREAM
A watercourse.
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: See § 315-97H.)
SUBDIVISION
A subdivision as defined in the MPC.
SWALE
A low-lying stretch of land which gathers or carries surface water runoff.
SWM
Stormwater management.
SWM SITE PLAN
A stormwater management site plan.
TIMBER OPERATIONS
See "forest management."
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.
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.
[1]
Editor's Note: See 32 P.S. § 680.1 et seq.