§ 505-112. Definitions.

As used in this Part, the following terms shall have the meanings indicated:

   ACCELERATED EROSION — The removal of the surface of the land through the combined action of man's activity and the natural processes of a rate greater than would occur because of the natural process alone.

   AGRICULTURAL ACTIVITIES — The work of producing crops and raising livestock including tillage, plowing, disking, harrowing, pasturing and installation of conservation measures. For purposes of regulation by this Part, construction of new buildings or impervious area is not considered an agricultural activity.

   ALTERATION — As applied to land, a change in topography as a result of the moving of soil and rock from one location or position to another; also the changing of surface conditions by causing the surface to be more or less impervious; land disturbance.

   AS-BUILT DRAWINGS — Those 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, or a copy of same, are turned over to the engineer, Municipal Engineer, and municipality in the current City standard format for hard copy, electronic copy, and reproducibles at the completion of the project. See also "record drawing" in this section.

   APPLICANT — A person who has filed an application for approval to engage in any regulated activities as defined in § 505-105 of this Part.

   BANKFULL — The channel at the top-of-bank or point where water begins to overflow onto a floodplain.

   BASEFLOW — 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.

   BIORETENTION — A stormwater retention area which utilizes woody and herbaceous plants and soils to remove pollutants before infiltration occurs.

   BMP (BEST MANAGEMENT PRACTICE) — Methods, measures or practices to prevent or reduce surface runoff and/or water pollution including, but not limited to, structural and nonstructural stormwater management practices and operation and maintenance procedures. See also "nonstructural best management practices (BMPs)."

   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 — 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.

   CHANNEL EROSION — The widening, deepening, and headward cutting of small channels and waterways, caused by stormwater runoff or bankfull flows.

   CISTERN — An underground reservoir or tank for storing rainwater.

   CONSERVATION DISTRICT — The Berks County Conservation District.

   CULVERT — A structure with appurtenant works which carries water 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.

   DEPARTMENT — The Pennsylvania Department of Environmental Protection.

   DESIGNEE — The agent of the Berks County Planning Commission, Berks County Conservation District and/or agent of the governing body involved with the administration, review or enforcement of any provisions of this Part by contract or memorandum of understanding.

   DESIGN PROFESSIONAL (QUALIFIED) — A Pennsylvania registered professional engineer, registered landscape architect, professional geologist, qualified soils scientist or a registered professional land surveyor qualified to perform the specific design task at hand based upon the applicable code of ethics.

   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.

   DESIGNATED WATERSHED (ACT 167) — A watershed which is listed under the Pennsylvania Department of Environmental Protection's "Index of Designated Watersheds (Stormwater Management)" pursuant to the Stormwater Management Act, P.L. 864, No. 167, October 4, 1978, 5 and published in the Pennsylvania Bulletin on May 31, 1980, and August 9, 1980, as amended on November 19, 1991, April 21, 1992, June 21, 1994, April 16, 1996, April 15, 1997, and December 16, 1997.

   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 shortly after any given rainfall event and are dry until the next rainfall event.

   DEVELOPER — A person that seeks to undertake any regulated activities at a project site in the municipality.

   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 Part, "development" encompasses both new development and redevelopment.

   DEVELOPMENT SITE — The specific tract of land where any regulated activities in the municipality are planned, conducted or maintained.

   DIFFUSED DRAINAGE DISCHARGE — Drainage discharge not confined to a single point location or channel, such as 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 (volume per unit of time). See also "peak discharge."

   DISCHARGE POINT — The point of discharge for a stormwater facility.

   DISTURBED AREAS — Unstabilized land area where an earth disturbance activity is occurring or has occurred.

   DITCH — An artificial waterway for irrigation or stormwater conveyance.

   DOWNSLOPE PROPERTY LINE — That portion of the property line of the lot, tract, or parcels of land being developed located such that overland or pipe flow from the site would be directed towards it.

   DRAINAGE CONVEYANCE FACILITY — A stormwater management facility designed to transmit stormwater runoff and shall include channels, swales, pipes, conduits, culverts, storm sewers, etc.

   DRAINAGE EASEMENT — A right granted by a landowner to a grantee, allowing the use of private land for stormwater management purposes.

   DRAINAGE PERMIT — A permit issued by the municipal governing body after the drainage plan has been approved.

   DRAINAGE PLAN — The documentation of the stormwater management system, if any, to be used for a given development site, the contents of which are established in § 505-143.

   EARTH DISTURBANCE ACTIVITY — A construction or other human activity which 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 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 channels, is worn away by water, wind, or chemical action.

   EROSION AND SEDIMENT CONTROL PLAN — A plan for a project site which identifies 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. If the initial condition of the site is undeveloped land, the land use shall be considered as "meadow" unless the natural land cover is proven to generate lower curve numbers or Rational "C" value, such as forested lands.

   FLOOD — A temporary condition of partial or complete inundation of land areas from the overflow of streams, rivers, and other waters of this commonwealth.

   FLOODPLAIN — Any land area susceptible to inundation by water from any natural source or delineated by applicable Department of Housing and Urban Development, Federal Insurance Administration Flood Hazard Boundary — Mapped as being a special flood hazard area.

   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-bank.

   FLUVIAL GEOMORPHOLOGY — The study of landforms associated with river channels and the processes that form them.

   FOREST MANAGEMENT/TIMBER OPERATIONS — Planning and activities necessary for the management of forest land with no change of land use proposed. 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.

   GRADE —

   A.   A slope, usually of a road, channel or natural ground specified in percent and shown on plans as specified herein.

   B.   (To) grade: To finish the surface of a roadbed, top of embankment or bottom of excavation.

   GRASSED WATERWAY — A natural or constructed waterway, usually broad and shallow, covered with erosion-resistant grasses, used to convey surface water.

   GROUNDWATER — Water beneath the earth's surface, often between saturated soil and rock that supplies wells and springs.

   GROUNDWATER RECHARGE — Replenishment of existing natural underground water supplies without degrading groundwater quality.

   HEC-HMS — The U.S. Army Corps of Engineers, Hydrologic Engineering Center (HEC) – Hydrologic Modeling System (HMS). This model was used for modeling during the Act 167 Plan development and was the basis for the standards and criteria of this Part.

   HIGH-QUALITY WATERS — Surface waters having 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).

   HOTSPOTS — Areas where land use or activities generate highly contaminated runoff, with concentrations of pollutants in excess of those typically found in stormwater.

   HYDROGRAPH — A graph of discharge versus time for a selected point in the drainage system.

   HYDROLOGIC REGIME (NATURAL) — The hydrologic cycle or balance that sustains quality and quantity of stormwater, baseflow, 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 surface includes, but is not limited to, any roof, parking or driveway areas, and any new streets and sidewalks. Any surface areas designed to be gravel or crushed stone shall be assumed to be impervious surfaces.

   IMPROVEMENTS AGREEMENT — An agreement made between the municipality and the developer that an approved subdivision and land development plan will be constructed according to the approved drawings and abide to specific conditions specified in the agreement.

   IMPOUNDMENT — A retention or detention basin designed to retain stormwater runoff and release it at a controlled rate.

   INFILL — Development that occurs on smaller parcels that remain undeveloped but are within or very close proximity to urban areas. The development 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 percolates downward to recharge groundwater.

   INFILTRATION STRUCTURES — A structure designed to direct runoff into the underground water (e.g., french drains, seepage pits, seepage trench).

   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, due to groundwater discharge.

   LAND DEVELOPMENT — Any of the following activities:

   A.   The improvement of one lot or two or more contiguous lots, tracts, or parcels of land for any purpose involving:

      (1)   A group of two or more 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.

      (2)   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.

   B.   A subdivision of land.

   C.   Development in accordance with § 503(1.1) of the Pennsylvania Municipalities Planning Code.6

   LIMITING ZONE — A soil horizon or condition in the soil profile or underlying strata which includes one of the following:

   A.   A seasonal high water table, whether perched or regional, determined by direct observation of the water table or indicated by soil mottling.

   B.   A rock with open joints, fracture or solution channels, or masses of loose rock fragments, including gravel, with insufficient fine soil to fill the voids between the fragments.

   C.   A rock formation, other stratum or soil condition which is so slowly permeable that it effectively limits downward passage of water.

   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.

   MAIN STEM (MAIN CHANNEL) — Any stream segment or other runoff conveyance facility used as a reach in the 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 or his designee.

   MUNICIPALITY — City of Reading, Berks County, Pennsylvania.

   NATURAL CONDITION — Existing conditions.

   NATURAL HYDROLOGIC REGIME — See "hydrologic regime."

   NATURAL RECHARGE AREA — Undisturbed surface area or depression where stormwater collects, and a portion of which infiltrates and replenishes the underground and groundwater.

   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.

   NONSTRUCTURAL BEST MANAGEMENT PRACTICES (BMPs) — Methods of controlling stormwater runoff quantity and quality, such as innovative site planning, impervious area and grading reduction, protection of natural depression areas, temporary ponding on site and other techniques.

   NPDES — National Pollutant Discharge Elimination System, the federal government's system for issuance of permits under the Clean Water Act, which is delegated to DEP in Pennsylvania.

   NRCS — Natural Resource Conservation Service (previously SCS).

   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 Part.

   PARKING LOT STORAGE — Involves the use of parking areas as temporary impoundments with controlled release rates during rainstorms.

   PEAK DISCHARGE — The maximum rate of stormwater runoff from a specific storm event.

   PENN STATE RUNOFF MODEL — The computer-based hydrologic model developed at the Pennsylvania State University.

   PIPE — A culvert, closed conduit, or similar structure (including appurtenances) that conveys stormwater.

   PLANNING COMMISSION — The Planning Commission of the City of Reading.

   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 § 92a.2. 7

   POSTCONSTRUCTION — Period after construction where disturbed areas are stabilized, stormwater controls are in place and functioning and all proposed improvements in the approved land development plan are completed.

   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 meet the water quality volume requirements of § 505-126.

   PROJECT SITE — The specific area of land where any regulated earth disturbance activities in the municipality are planned, conducted or maintained.

   RATIONAL FORMULA — 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.

   RECONSTRUCTION — Demolition of and subsequent rebuilding of impervious surface.

   RECORD DRAWINGS — Original documents revised to suit the as-built conditions and subsequently provided by the design professional to the municipality. The design professional takes the contractor's as-builts, reviews them in detail with his/her own records for completeness, then either turns these over to the client or transfers the information to a set of reproducibles, hard copy, and electronic format in the current City standard format, in both cases for the municipality's permanent records. See also "as-built drawings."

   REDEVELOPMENT — The demolition, construction, reconstruction, alteration, or improvement exceeding 2,000 square feet of land disturbance performed on sites where existing land use is commercial, industrial, institutional, or multifamily residential. 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 is removed and repaved.

   REGULATED ACTIVITIES — Actions or proposed actions that have an impact on stormwater runoff quality or quantity and that are specified in § 505-105 of this Part.

   REGULATED EARTH DISTURBANCE ACTIVITY — Earth disturbance activity one acre or more with a point source discharge to surface waters or the municipality's storm sewer system, or five acres or more regardless of the planned runoff. This includes earth disturbance on any portion of, part, or during any stage of, a larger common plan of development.

   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 do not have an outlet other than recharge and must infiltrate stored water in no more than 4 days.

   RETURN PERIOD — The average interval, in years, within which a storm event of a given magnitude can be expected to recur. For example, the twenty-five-year return period rainfall would be expected to recur on the average of once every 25 years.

   RISER — A vertical pipe extending from the bottom of a pond that is used to control the discharge rate from the pond for a specified design storm.

   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.

   ROOFTOP DETENTION — Temporary ponding and gradual release of stormwater falling directly onto flat roof surfaces by incorporating controlled-flow roof drains into building designs.

   RUNOFF — Any part of precipitation that flows over the land surface. SALDO — Subdivision and Land Development Ordinance [Chapter 515].

   SEDIMENT BASIN — A barrier, dam, retention or detention basin located and designed to retain rock, sand, gravel, silt, or other material transported by water during construction.

   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 the movement of water or air.

   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.

   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 AREAS (SWPA) — The zone through which contaminants, if present, are likely to migrate and reach a drinking water well or surface water intake.

   SPECIAL GEOLOGIC FEATURES — Carbonate bedrock features including, but not limited to, closed depressions, existing sinkholes, fracture traces, lineaments, joints, faults, caves and pinnacles, which may exist and must be identified on a site when stormwater management BMPs are being considered.

   SPECIAL PROTECTION SUBWATERSHEDS — Watersheds for which the receiving waters are exceptional value (EV) or high-quality (HQ) waters.

   SPILLWAY — A conveyance that is used to pass the peak discharge of the maximum design storm controlled by the stormwater facility.

   STATE WATER QUALITY REQUIREMENTS — As defined under state regulations, protection of designated and existing uses (see 25 Pa. Code, Chapters 93 and 96), including:

   A.   Each stream segment in Pennsylvania has a designated use, such as "cold water fishery" or "potable water supply," which are listed in Chapter 93. These uses must be protected and maintained, under state regulations.

   B.   "Existing uses" are those attained as of November 1975, regardless whether they have been designated in Chapter 93. Regulated earth disturbance activities must be designed to protect and maintain existing uses and maintain the level of water quality necessary to protect those uses in all streams, and to protect and maintain water quality in special protection streams.

   C.   Water quality involves the chemical, biological and physical characteristics of surface water bodies. After regulated earth disturbance activities are complete, these characteristics can be impacted by addition of pollutants such as sediment, and changes in habitat through increased flow volumes and/or rates as a result of changes in land surface area from those activities. Therefore, permanent discharges to surface waters must be managed to protect the stream bank, streambed and structural integrity of the waterway, to prevent these impacts.

   STORAGE INDICATION METHOD — A reservoir routing procedure based on solution of the continuity equation (inflow minus outflow equals the change in storage) with outflow defined as a function of storage volume and depth.

   STORM FREQUENCY — The number of times that a given storm "event" occurs or is exceeded on the average in a stated period of years. See "return period."

   STORM SEWER — A system of pipes and/or open channels that convey intercepted runoff and stormwater from other sources, but excludes domestic sewage and industrial wastes.

   STORMWATER — The surface runoff generated by precipitation reaching the ground surface.

   STORMWATER MANAGEMENT DISTRICT — Those subareas in which some type of detention is required to meet the plan requirements and the goals of Act 167.

   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 plan for managing those land use activities that will influence stormwater runoff quality and quantity and that would impact the Tulpehocken Creek and Schuylkill River Watersheds in the City of Reading adopted by Berks County as required by the Act of October 4, 1978, P.L. 864 (Act 167), and known as the "Tulpehocken Creek Watershed Act 167 Stormwater Management Plan" and the "Schuylkill River Watershed Act 167 Stormwater Management Plan."

   STORMWATER MANAGEMENT SITE PLAN — The plan prepared by the applicant or developer or his representative indicating how stormwater runoff will be managed at the particular site of interest according to this Part.

   STREAM — A natural watercourse.

   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 this 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, however, that the subdivision by lease of land for agricultural purposes into parcels of more than 10 acres, not involving any new street or easement of access or any residential 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, or parts thereof, whether natural or artificial, within or on the boundaries of this commonwealth.

   SWALE — A low-lying stretch of land which gathers or carries surface water runoff.

   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-BANK — 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.

   VERNAL POND — 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 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 this commonwealth.

   WATERSHED — Region or area drained by a river, watercourse or other body of water, whether natural or artificial.

   WELLHEAD —

   A.   A structure built over a well.

   B.   The source of water for a well.

   WELLHEAD PROTECTION AREA — The surface and subsurface area surrounding a water supply well, well field, spring or infiltration gallery supplying a public water system, through which contaminants are reasonably likely to move toward and reach the water source.

   WET BASIN — 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 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, fens, and similar areas.

5.   Editor's Note: See 32 P.S. § 680.1 et seq.

6.   Editor's Note: See 53 P.S. § 10503(1.1).

7.   Editor's Note: Amended during codification (see Ch. 1, General Provisions, Part 2).