For the purposes of this chapter, certain terms and words used herein shall be interpreted as follows:
A. 
Words used in the present tense include the future tense; the singular number includes the plural, and the plural number includes the singular; words of masculine gender include feminine gender; and words of feminine gender include masculine gender.
B. 
The word "includes" or "including" shall not limit the term to the specific example but is intended to extend its meaning to all other instances of like kind and character.
C. 
The word "person" includes an individual, firm, association, organization, partnership, trust, company, corporation, unit of government, or any other similar entity.
D. 
The words "shall" and "must" are mandatory; the words "may" and "should" are permissive.
E. 
The words "used" or "occupied" include the words "intended, designed, maintained, or arranged to be used, occupied or maintained."
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 ACTIVITY
Activities associated with agriculture, such as agricultural cultivation, agricultural operation, and animal heavy use areas. This includes the work of producing crops, including tillage, land clearing, plowing, disking, harrowing, planting, harvesting crops or pasturing and raising of livestock and installation of conservation measures. Construction of new buildings or impervious area is not considered an agricultural activity.
ALLUVIAL SOIL
A. 
Deposits of unconsolidated materials, such as gravel, sand, clay, and various mixtures of these, deposited by running water. The following soils in Warrington Township are alluvial:
(1) 
Bowmansville-Knauers silt loam (Bo).
(2) 
Hatboro silt loam (Ha).
(3) 
Rowland silt loam (Ro).
B. 
Soils are described and delineated in the most recent version of the Bucks County Soil Survey in effect, as published electronically by the Natural Resources Conservation Service, as amended from time to time.
[Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I)]
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 as the result of changing the land cover, including the water, vegetation and bare soil.
APPLICANT
A person who has filed an application for approval to engage in any regulated activity defined in § 288-5 of this chapter.
AS-BUILT DRAWINGS
Engineering or site drawings maintained by the contractor as he constructs the project and upon which he documents the actual locations of the building components and changes to the original contract documents. These documents, or a copy of same, are turned over to the qualified professional at the completion of the project.
BANKFULL
The channel at the top-of-bank or point from where water begins to overflow onto a floodplain.
BASE FLOW
The portion of stream discharge derived from groundwater; the sustained discharge that does not result from direct runoff or from water diversions, reservoir releases, piped discharges, or other human activities.
BEST MANAGEMENT PRACTICES (BMPS)
Activities, facilities, designs, measures, or procedures used to manage stormwater impacts from regulated activities, to meet state water quality requirements, to promote groundwater recharge, and to otherwise meet the purposes of this chapter. Stormwater BMPs are commonly grouped into one of two broad categories or measures: structural or nonstructural. In this chapter, "nonstructural BMPs or measures" refer to operational and/or behavior-related practices that attempt to minimize the contact of pollutants with stormwater runoff, whereas "structural BMPs or measures" are those that consist of a physical device or practice that is installed to capture and treat stormwater runoff. Structural BMPs include but are not limited to a wide variety of practices and devices, from large-scale retention ponds and constructed wetlands to small-scale underground treatment systems, infiltration facilities, filter strips, low-impact design, bioretention, wet ponds, permeable paving, grassed swales, riparian or forested buffers, sand filters, detention basins, and manufactured devices. Structural stormwater BMPs are permanent appurtenances to the project site.
BIORETENTION
A stormwater retention area that utilizes woody and herbaceous plants and soils to remove pollutants before infiltration occurs.
BUFFER
The area of land immediately adjacent to any stream, measured perpendicular to and horizontally from the top-of-bank on both sides of a stream (see "top-of-bank").
CHANNEL
An open drainage feature through which stormwater flows. Channels include but shall not be limited to natural and man-made watercourses, swales, streams, ditches, canals, and pipes that convey continuously or periodically flowing water.
CISTERN
An underground reservoir or tank for storing rainwater.
CONSERVATION DISTRICT
The Bucks County Conservation District.
CULVERT
A structure, with its appurtenant works, which carries water under or through an embankment or fill.
CURVE NUMBER
The value used in the Soil Cover Complex Method. It is a measure of the percentage of precipitation which is expected to run off from the watershed and is a function of the soil, vegetative cover, and tillage method.
DAM
A man-made barrier, together with its appurtenant works, constructed for the purpose of impounding or storing water or another fluid or semifluid. A dam may include a refuse bank, fill or structure for highway, railroad or other purposes which impounds or may impound water or another fluid or semifluid.
DEPARTMENT
The Pennsylvania Department of Environmental Protection (PADEP).
DESIGNEE
An agent of Bucks County, the Bucks County Conservation District, and/or an agent of the Board of Supervisors of Warrington Township involved with the administration, review, or enforcement of any provisions of this chapter by contract or memorandum of understanding.
DESIGN PROFESSIONAL (QUALIFIED)
A Pennsylvania-registered professional engineer, registered landscape architect or registered professional land surveyor trained to develop stormwater management plans.
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 designed to collect and retard stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate. Detention basins are designed to drain completely soon after a rainfall event and become dry until the next rainfall event.
DETENTION VOLUME
The volume of runoff that is captured and released into the waters of the commonwealth at a controlled rate.
DEVELOPER
Any landowner, agent of such landowner, or tenant with the permission of such landowner who makes or causes to be made a subdivision of land or a land development.
DEVELOPMENT
Any human-induced change to improved or unimproved real estate, whether public or private, including but not limited to land development, construction, installation, or expansion of a building or other structure, land division, street construction, drilling, and site alteration such as embankments, dredging, grubbing, grading, paving, parking or storage facilities, excavation, filling, stockpiling, or clearing. As used in this chapter, development encompasses both new development and redevelopment.
DEVELOPMENT SITE
The specific tract or parcel of land where any regulated activity set forth in § 288-5 is planned, conducted, or maintained.
DIFFUSED DRAINAGE DISCHARGE
Drainage discharge that is not confined to a single point location or channel, including sheet flow or shallow concentrated flow.
DISCHARGE
A. 
(verb) To release water from a project, site, aquifer, drainage basin or other point of interest.
B. 
(noun) The rate and volume of flow of water, such as in a stream, generally expressed in cubic feet per second. See also "peak discharge."
DISCHARGE POINT
The point of discharge for a stormwater facility.
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 as specified in Appendix F, Disconnected Impervious Area.[1]
DISTURBED AREAS
Unstabilized land area where an earth-disturbance activity is occurring or has occurred.
DITCH
A man-made waterway constructed for irrigation or stormwater conveyance purposes.
DRAINAGE CONVEYANCE FACILITY
A stormwater management facility, designed to transport stormwater runoff, that includes channels, swales, pipes, conduits, culverts, and storm sewers.
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 municipality after the SWM site plan has been approved.
EARTH-DISTURBANCE ACTIVITY
A construction or other human activity that disturbs the surface of land, including but not limited to clearing and grubbing, grading, excavations, embankments, land development, agricultural plowing or tilling, timber-harvesting activities, road-maintenance activities, mineral extraction, and the moving, depositing, stockpiling, or storing of soil, rock or earth materials.
EMERGENCY SPILLWAY
A conveyance area that is used to pass a peak discharge greater than the maximum design storm controlled by the stormwater facility.
ENCROACHMENT
A structure or activity that changes, expands, or diminishes the course, current or cross section of a watercourse, floodway or body of water.
EROSION
The process by which the surface of the land, including water/stream channels, is worn away by water, wind, or chemical action.
EROSION AND SEDIMENT CONTROL PLAN
A site-specific plan identifying BMPs to minimize accelerated erosion and sedimentation. For agricultural plowing or tilling activities, the erosion and sediment control plan is that portion of a conservation plan identifying BMPs to minimize accelerated erosion and sedimentation.
EXCEPTIONAL-VALUE WATERS
Surface waters of high quality which satisfy Pennsylvania Code, Title 25, Environmental Protection, Chapter 93, Water Quality Standards, § 93.4b(b) (relating to antidegradation).
EXISTING CONDITIONS
The initial condition of a project site prior to the proposed alteration.
EXISTING RECHARGE AREA
An undisturbed surface area or depression where stormwater collects and a portion of which infiltrates and replenishes the groundwater.
EXISTING RESOURCES AND SITE ANALYSIS MAP
A base map which identifies fundamental environmental site information, including floodplains, wetlands, topography, vegetative site features, natural areas, prime agricultural land and areas supportive of endangered species.
FLOOD
A temporary condition of partial or complete inundation of land areas from the overflow of streams, rivers and other waters of the commonwealth.
FLOODPLAIN
Any land area susceptible to inundation by water from any natural source or as delineated by applicable Department of Housing and Urban Development, Federal Insurance Administration, Flood Hazard Boundary Maps as being a special flood hazard area.
FLOODWAY
The channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height.
FOREST MANAGEMENT/TIMBER OPERATIONS
Planning and associated activities necessary for the management of forest land. These include timber inventory and preparation of forest management plans, silvicultural treatment, cutting budgets, logging road design and construction, timber harvesting, and reforestation.
FREEBOARD
A vertical distance between the elevation of the design high water and the top of a dam, levee, tank, basin, swale, or diversion berm. The space is required as a safety margin in a pond or basin.
GOVERNING BODY
Elected municipal officials of municipalities (e.g., Township Supervisors).
GRADE
A. 
(noun) A slope, usually of a road, channel or natural ground, specified in percent and shown on plans as specified herein.
B. 
(verb) To finish the surface of a roadbed, the top of an embankment, or the bottom of excavation.
GROUNDWATER
Water beneath the earth's surface that supplies wells and springs and is often between saturated soil and rock.
GROUNDWATER RECHARGE
The replenishment of existing natural underground water supplies from rain or overland flow.
HEC-HMS
The United States Army Corps of Engineers, Hydrologic Engineering Center (HEC) - Hydrologic Modeling System (HMS). This model was used to model the Neshaminy Creek watershed during the Act 167 Plan development and was the basis for the standards and criteria of this chapter.
HIGH-QUALITY WATERS
Surface waters having a quality which exceeds levels necessary to support propagation of fish, shellfish and wildlife and recreation in and on the water by satisfying Pennsylvania Code, Title 25, Environmental Protection, Chapter 93, Water Quality Standards, § 93.4b(a).
HOT SPOT
An area where land use or activity generates highly contaminated runoff, with concentrations of pollutants in excess of those typically found in stormwater. Typical pollutant loadings in stormwater may be found in Chapter 8, Section 6, of the Pennsylvania Stormwater Best Management Practices Manual, Pennsylvania Department of Environmental Protection (PADEP) No. 363-0300-002 (2006). More information concerning hotspots may be found in § 288-15A of this chapter.
HYDRIC SOILS
Soils classified as hydric in map unit descriptions located in the most recent version of the Bucks County Soil Survey, as electronically published by the Natural Resources Conservation Service, as amended from time to time.
[Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I)]
HYDROGRAPH
A graph representing the discharge of water versus time for a selected point in the drainage system.
HYDROLOGIC REGIME
The hydrologic cycle or balance that sustains the quality and quantity of stormwater, base flow, storage, and groundwater supplies under natural conditions.
HYDROLOGIC SOIL GROUP
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.
IMPERVIOUS SURFACE
A surface that prevents the infiltration of water into the ground. Impervious surfaces include but are not limited to streets, sidewalks, pavement roofs or driveway areas. Any surface areas designed to be pavers, gravel or crushed stone shall be regarded as impervious surfaces.
IMPOUNDMENT
A retention or detention basin designed to retain stormwater runoff and release it at a controlled rate.
INFILL DEVELOPMENT
Development that occurs on smaller parcels that remain undeveloped but are within or in very close proximity to urban or densely developed areas. Infill development usually relies on existing infrastructure and does not require an extension of water, sewer or other public utilities.
INFILTRATION
Movement of surface water into the soil, where it is absorbed by plant roots, evaporated into the atmosphere, or percolated downward to recharge groundwater.
INFILTRATION STRUCTURE
A structure designed to direct runoff into the underground water (e.g., French drains, seepage pits, or seepage trenches).
INITIAL ABSTRACTION (IA)
The value used to calculate the volume or peak rate of runoff in the Soil Cover Complex Method. It represents the depth of rain retained on vegetation plus the depth of rain stored on the soil surface plus the depth of rain infiltrated prior to the start of runoff.
INLET
The upstream end of any structure through which water may flow.
INTERMITTENT STREAM
A stream that flows only part of the time. Flow generally occurs for several weeks or months in response to seasonal precipitation or groundwater discharge.
KARST
A type of topography or landscape characterized by 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
A. 
Any of the following activities:
(1) 
The improvement of one lot or two or more contiguous lots, tracts or parcels of land for any purpose involving:
(a) 
A group of two or more residential or nonresidential buildings, whether proposed initially or cumulatively, or a single nonresidential building on a lot or lots regardless of the number of occupants or tenure; or
(b) 
The division or allocation of land or space, whether initially or cumulatively, 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.
(2) 
A subdivision of land.
B. 
"Land development" does not include development which involves:
(1) 
The conversion of an existing single-family detached dwelling or single-family semidetached dwelling into not more than three residential units, unless such units are intended to be a condominium;
(2) 
The addition of an accessory building, including a farm building, on a lot or lots subordinate to an existing principal building; or
(3) 
The addition or conversion of buildings or rides within the confines of an enterprise which would be considered an amusement park. For the purposes of this subsection, an "amusement park" is defined as a tract or area used principally as a location for permanent amusement structures or rides. This exclusion shall not apply to newly acquired acreage by an amusement park until initial plans for the expanded area have been approved by the proper authorities.
LOT
A designated parcel, tract or area of land established by a plat or otherwise as permitted by law and to be used, developed or built upon as a unit, together with the required open spaces.
LOW-IMPACT DEVELOPMENT (LID) PRACTICES
Practices that will minimize proposed conditions' runoff rates and volumes, which will minimize needs for artificial conveyance and storage facilities.
MAIN STEM (MAIN CHANNEL)
Any stream segment or other runoff conveyance used as a reach in the Neshaminy Creek hydrologic model.
MANNING EQUATION (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 as the engineer for a municipality, planning agency or joint planning commission.
MUNICIPALITY
Warrington Township, Bucks County, Pennsylvania.
NATURAL HYDROLOGIC REGIME
(See "hydrologic regime.")
NONPOINT-SOURCE POLLUTION
Pollution that enters a water body from diffuse origins in the watershed and does not result from discernible, confined, or discrete conveyances.
NONSTORMWATER DISCHARGES
Water flowing in stormwater collection facilities, such as pipes or swales, which is not the result of a rainfall event or snowmelt.
NPDES
The National Pollutant Discharge Elimination System, the federal government's system for issuance of permits under the Clean Water Act, which is delegated to PADEP in Pennsylvania.
NRCS
The Natural Resources Conservation Service (previously Soil Conservation Service).
OUTFALL
"Point source," as described in 40 CFR 122.2, at the point where the municipality's storm sewer system discharges to surface waters of the commonwealth.
OUTLET
Points of water disposal to a stream, river, lake, tidewater or artificial drain.
PARENT TRACT
The parcel of land from which a land development or subdivision originates, determined from the date of municipal adoption of this chapter.
PEAK DISCHARGE
The maximum rate of stormwater runoff from a specific storm event.
PENN STATE RUNOFF MODEL (PSRM)
The computer-based hydrologic model developed at the Pennsylvania State University.
PERENNIAL STREAM
A stream which contains water at all times except during extreme drought.
PERVIOUS SURFACE
A surface that allows the infiltration of water into the ground.
PIPE
A culvert, closed conduit, or similar structure (including appurtenances) that conveys stormwater.
PLANNING COMMISSION
The Planning Commission of Warrington Township.
POINT SOURCE
Any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, or conduit, from which stormwater is or may be discharged, as defined in state regulations at 25 Pa. Code § 92.1.
POST-CONSTRUCTION
The period after construction during which disturbed areas are stabilized, stormwater controls are in place and functioning and all proposed improvements in the approved land development plan are completed.
PREDEVELOPMENT
(See "existing conditions.")
PRETREATMENT
Techniques employed in stormwater BMPs to provide storage or filtering to trap coarse materials and other pollutants before they enter the system but not necessarily designed to meet the volume requirements of § 288-12.
PROJECT SITE
The specific area of land where any regulated activities in the municipality are planned, conducted, or maintained.
QUALIFIED PROFESSIONAL
Any person licensed by the Pennsylvania Department of State or otherwise qualified by law to perform the work required by this chapter.
RATIONAL METHOD
A rainfall-runoff relation used to estimate peak flow.
RECHARGE
The replenishment of groundwater through the infiltration of rainfall, other surface waters, or land application of water or treated wastewater.
RECORD DRAWINGS
Original documents revised to suit the as-built conditions and subsequently provided by the engineer to the client. The engineer reviews the contractor's as-built drawings against his/her own records for completeness and then either turns these over to the client or transfers the information to a set of reproducibles, in both cases for the client's permanent records. Record drawings are not the same as record plans submitted for recording with the county in accordance with the Pennsylvania Municipalities Planning Code (Act 247).[2]
REDEVELOPMENT
Any development that requires demolition or removal of existing structures or impervious surfaces at a site and replacement with new impervious surfaces. Maintenance activities such as top-layer grinding and repaving are not considered to be redevelopment. Interior remodeling projects and tenant improvements are also not considered to be redevelopment. Utility trenches in streets are not considered redevelopment unless more than 50% of the street width, including shoulders, is removed and repaved.
REGULATED ACTIVITIES
Any earth-disturbance activities or any activities that involve the alteration or development of land in a manner that may affect stormwater runoff.
REGULATED EARTH-DISTURBANCE ACTIVITY
Activity involving earth disturbance subject to regulation under 25 Pa. Code, Chapter 92; 25 Pa. Code, Chapter 102; or the Clean Streams Law.[3]
RELEASE RATE
The percentage of existing conditions' peak rate of runoff from a site or subarea to which the proposed conditions' peak rate of runoff must be reduced to protect downstream areas.
REPAVING
Replacement of the impervious surface that does not involve reconstruction of an existing paved (impervious) surface.
REPLACEMENT PAVING
Reconstruction of and full replacement of an existing paved (impervious) surface.
RETENTION BASIN
A structure in which stormwater is stored and not released during the storm event. Retention basins are designed for infiltration purposes and do not have an outlet but will include an emergency spillway or similar device. The retention basin must infiltrate stored water in four days or less.
[Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I)]
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.
RETURN PERIOD
The probability an event will occur in any given year, typically displayed as a whole number, e.g., twenty-five-year event, and represents the inverse of the frequency of that event. For example, the twenty-five-year return period rainfall gives the probability 1/25, or 4%, for which that size storm will occur in any given year.
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.
ROOF DRAINS
A drainage conduit or pipe that collects water runoff from a roof and leads it away from the structure.
RUNOFF
Any part of precipitation that flows over the land surface.
SALDO
The Subdivision and Land Development Ordinance; Chapter 305 of the Code.
SEDIMENT
Soils or other materials transported by surface water as a product of erosion.
SEDIMENT POLLUTION
The placement, discharge or any other introduction of sediment into the waters of the commonwealth.
SEDIMENTATION
The process by which mineral or organic matter is accumulated or deposited by moving wind, water, or gravity. Once this matter is deposited (or remains suspended in water), it is usually referred to as "sediment."
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 underground water. More information on seepage pits may be found in the Pennsylvania BMP Manual, December 2006, Chapter 6, Section 4.
SEPARATE STORM SEWER SYSTEM
A conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels or storm drains) primarily used for collecting and conveying stormwater runoff.
SHALLOW CONCENTRATED FLOW
Stormwater runoff flowing in shallow, defined ruts prior to entering a defined channel or waterway.
SHEET FLOW
A flow process associated with broad, shallow water movement on sloping ground surfaces that is not channelized or concentrated.
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)."
SOURCE WATER PROTECTION AREA (SWPA)
The zone through which contaminants, if present, are likely to migrate and reach a drinking water well or surface water intake.
SPECIAL PROTECTION SUBWATERSHEDS
Watersheds that have been designated in Pennsylvania Code, Title 25, Environmental Protection, Chapter 93, Water Quality Standards, as exceptional-value (EV) or high-quality (HQ) waters.
SPILLWAY
A conveyance that is used to pass the peak discharge of the maximum design storm that is controlled by the stormwater facility.
STATE WATER QUALITY REQUIREMENTS
The regulatory requirements to protect, maintain, reclaim, and restore water quality under Title 25 of the Pennsylvania Code and the Clean Streams Law.[4]
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 conveys intercepted runoff and stormwater from other sources but excludes domestic sewage and industrial wastes.
STORMWATER
The surface runoff generated by precipitation reaching the ground surface.
STORMWATER MANAGEMENT BEST MANAGEMENT PRACTICES
Abbreviated as "BMPs" or "SWM BMPs" throughout this chapter.
STORMWATER MANAGEMENT FACILITY
Any structure, natural or man-made, that, due to its condition, design, or construction, conveys, stores, or otherwise affects stormwater runoff quality, rate or quantity. 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 watershed plan, known as the "Neshaminy Creek Watershed Act 167 Stormwater Management Plan," for managing those land use activities that will influence stormwater runoff quality and quantity and that would impact the Neshaminy Creek watershed, adopted by Bucks and Montgomery Counties as required by the Act of October 4, 1978, P.L. 864 (Act 167).
STORMWATER SWM SITE PLAN
The plan prepared by the applicant or his representative indicating how stormwater runoff will be managed at the particular site of interest according to this chapter.
STREAM
Any stream, channel, or stream protection area for conveyance of surface water, whether natural or artificial, with perennial or intermittent flow. Streams shall be classified as follows:
A. 
TYPE IArea along a water-conveyance facility supported by stormwater runoff from a watershed area of 100 acres or more. The width of each stream shall be determined by the more-extensive limits of the following:
(1) 
Floodplain: the 100-year flood line and/or elevations as delineated in the Flood Insurance Study for Warrington Township, as prepared by the United States Department of Housing and Urban Development/Federal Insurance Administration.
(2) 
Alluvial soils.
(3) 
Calculated flood limit: the line and/or elevation as established by analysis of the drainage areas using approved USDA Soil Conservation Service or United States Army Corps of Engineers methods for a 100-year-frequency storm event.
B. 
TYPE IIA water-conveyance facility supported by stormwater runoff from a watershed area of less than 100 acres. The width of each stream shall be determined by the more-extensive limits of the following:
(1) 
Alluvial soils.
(2) 
Calculated flood limit: the line and/or elevation as established by analysis of the drainage area using approved USDA Soil Conservation Service or United States Army Corps of Engineers methods for a 100-year-frequency storm event.
STREAM BANK EROSION
The widening, deepening, or headward cutting of channels and waterways caused by stormwater runoff or bankfull flows.
STREAM BUFFER
The land area adjacent to each side of a stream, essential to maintaining water quality. (See "buffer.")
STREAM ENCLOSURE
A bridge, culvert, or other structure in excess of 100 feet in length, upstream to downstream, which encloses a regulated water of the commonwealth.
SUBAREA (SUBWATERSHED)
The smallest drainage unit of a watershed for which stormwater management criteria have been established in the stormwater management plan.
SUBDIVISION
The division or redivision of a lot, tract or parcel of land by any means into two or more lots, tracts, parcels or other divisions of land, including changes in existing lot lines for the purpose, whether immediate or future, of lease, partition by the court for distribution to heirs or devisees, transfer of ownership, or building or lot development, provided 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 dwelling, shall be exempted.
SURFACE 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 waters, or parts thereof, whether natural or artificial, within or on the boundaries of the commonwealth.
SWALE
A low-lying stretch of land that gathers or carries surface water runoff.
SWM SITE PLAN
The documentation of the stormwater management system to be used for a given development site, the contents of which are established in § 288-17.
TIMBER OPERATIONS
See "forest management."
TIME-OF-CONCENTRATION (TC)
The time required 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-BANK
The highest point of elevation in a stream channel cross section at which a rising water level just begins to flow out of the channel and over the floodplain.
VEGETATED SWALE
A natural or man-made waterway, usually broad and shallow, covered with erosion-resistant grasses, used to convey surface water.
VERNAL POOL
Seasonal depressional wetlands that are covered by shallow water for variable periods from winter to spring but may be completely dry for most of the summer and fall.
WATERCOURSE
A channel or conveyance of surface water having a defined bed and banks, whether natural or artificial, with perennial or intermittent flow.
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 the commonwealth.
WATERSHED
A region or area drained by a river, watercourse, or other body of water, whether natural or artificial.
WET BASIN
A pond for urban runoff management that is designed to detain urban runoff and always contains water.
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. Wetlands generally include swamps, marshes, bogs, fens, and similar areas. Wetland areas demonstrate hydric characteristics of soils, vegetation, and/or water table as specified by the United States Army Corps of Engineers and the Pennsylvania Department of Environmental Protection.
[1]
Editor's Note: Appendix F is on file in the Township offices.
[2]
Editor's Note: See 53 P.S. § 10101 et seq.
[3]
Editor's Note: See 35 P.S. § 691.1 et seq.
[4]
Editor's Note: See 35 P.S. § 691.1 et seq.