[Ord. 2014-04, 4/28/2014, § 23-202]
Unless otherwise stated, the following words shall, for the purpose of this chapter, have the meaning herein indicated:
ACCELERATED EROSIONThe removal of the surface of the land through the combined action of man's activities and natural processes at a rate greater than would occur because of the natural processes alone.
ACT 167 PLANThe watershed stormwater management plan prepared under the authority of the Storm Water Management Act and approved by DEP for the watershed in which the subject property is located.
AGRICULTURAL ACTIVITIESActivities 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.
ALTERATIONAs 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.
ANIMAL HEAVY USE AREASA 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.
APPLICANTA landowner and/or developer, as hereinafter defined, including his heirs, successors and assigns, who has filed an application to the municipality for approval to engage in any regulated activity at a development site located within the municipality.
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. See also BMP, non-structural and BMP, structural.
BMP, NON-STRUCTURALPlanning 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.
BMP, STRUCTURALPhysical devices and practices that capture and treat stormwater runoff which are permanent appurtenances to the development site.
BMP MANUALThe Pennsylvania Stormwater Best Management Practices Manual of December 2006, or most recent version thereof.
CHANNELA natural or artificial watercourse with a definite bed and banks which confine and conduct continuously or periodically flowing water.
CHAPTER 10225 Pa.Code, Chapter 102, "Erosion and Sediment Control."
CHAPTER 10525 Pa.Code, Chapter 105, "Dam Safety and Waterway Management."
CHAPTER 10625 Pa.Code, Chapter 106, "Floodplain Management."
CISTERNA reservoir or tank for storing rainwater.
CLEAN WATER ACTThe 1972 amendments to the Federal Water Pollution Control Act, P.L. 92-500 of 1972, 33 U.S.C. § 1251 et seq.
CONSERVATION PLANA 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 PRACTICESPractices installed on agricultural lands to improve farmland, soil and/or water quality which have been identified in a current conservation plan.
CONVEYANCEThe ability of a pipe, culvert, swale or similar facility to carry the peak flow from the design storm.
CULVERTA structure with appurtenant works which carries a watercourse under or through an embankment or fill.
DAMAn 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. The dam falls under the requirements of 25 Pa.Code, Chapter 105, "Dam Safety and Waterway Management," if the following is true:
(1) The contributory drainage area exceeds 100 acres.
The greatest depth of water measured by upstream toe of the dam at maximum storage elevation exceeds 15 feet.
The impounding capacity at maximum storage elevation exceeds 50 acre-feet.
DCNRThe Pennsylvania Department of Conservation and Natural Resources or any agency successor thereto.
DEPThe Pennsylvania Department of Environmental Protection or any agency successor thereto.
DESIGN STORMThe magnitude of precipitation from a storm event measured in probability of occurrence (e.g., fifty-year storm) and duration (e.g., twenty-four-hour), and used in the design and evaluation of stormwater management facilities.
DETENTION BASINAn impoundment structure designed to manage stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate.
DEVELOPERAny 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, or other regulated activity covered by this chapter.
DEVELOPMENTAny man-made change to improved or unimproved real estate, including, but not limited to, buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations.
DEVELOPMENT SITEThe specific area of land where regulated activities in the Township are planned, conducted or maintained.
DRAINAGE CONVEYANCE FACILITYA stormwater management facility designed to transmit stormwater runoff and shall include streams, channels, swales, pipes, conduits, storm sewers, etc.
DRAINAGE EASEMENTA right granted by a landowner to a grantee, allowing the use of private land for stormwater management purposes 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 MANUALThe Erosion and Sediment Pollution Control Program Manual, Number 363-2134-008, prepared by DEP.
EARTH DISTURBANCEAny activity involving grading, tilling, digging or filling of ground, or stripping of vegetation, or any other activity which causes land to be exposed to the danger of erosion.
EARTH DISTURBANCE ACTIVITYA 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.
EPHEMERAL STREAMA water conveyance which lacks substrates associated with flowing waters and flows only in direct response to precipitation in the immediate watershed or in response to melting snowpack and which is always above the local water table.
EROSIONThe removal of soil particles by the action of water, wind, ice, or other geological agents.
EXISTING CONDITIONSThe initial condition of a development site prior to the proposed construction and the dominant land cover during the five-year period immediately preceding a proposed regulated activity.
FEMAThe Federal Emergency Management Agency, or any agency successor thereto.
FLOODA 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.
FLOODPLAINAn area meeting the definition of floodplain in Chapter
27, "Zoning."
An area meeting the definition of Floodway in Chapter
27, "Zoning." 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 50 feet outward from the top of each stream bank.
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.
GRADEA slope, usually of a road, channel or natural ground specified in percent and shown on plans as specified herein. (To) grade-to finish the surface of a roadbed, top of embankment or bottom of excavation.
GRASSED WATERWAYA natural or constructed waterway, usually broad and shallow, covered with erosion-resistant grasses, used to conduct surface water from cropland.
GROUNDWATER RECHARGEReplenishment of existing natural underground water supplies and aquifer by adding water from above the ground surface.
HIGH TUNNELA structure which meets the following:
[Added by Ord. No. 2019-06, 10/14/2019]
(1) Is used for the production, processing, keeping, storing, sale or shelter of an agricultural commodity as defined in Section 2 of the Act of December 19, 1974 (P.L. 973, No. 319), known as the "Pennsylvania Farmland and Forest Land Assessment Act of 1974," or for the storage of agricultural equipment or supplies.
Is constructed consistent with all of the following:
(a) Has a metal, wood or plastic frame.
When covered, has a plastic, woven textile or other flexible covering.
Has a floor made of soil, crushed stone, matting, pavers or a floating concrete slab.
ILLICIT CONNECTIONAny man-made physical connection or prohibited connection to the MS4 that conveys an illicit discharge.
[Added by Ord. No. 2022-06, 9/12/2022]
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 §
23-607.
[Added by Ord. No. 2022-06, 9/12/2022]
Surfaces which prevent the infiltration of water into the ground. All structures, buildings, parking areas, driveways, roads, streets, sidewalks, decks, and any areas of concrete, asphalt, packed stone, and compacted soil shall be considered impervious surface if they prevent infiltration.
IMPOUNDMENTA 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 STRUCTURESA structure 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).
INLETA surface connection to a closed drain. The upstream end of any structure through which water may flow.
INTERMITTENT STREAMA body of water flowing in a channel or bed composed primarily of substrates associated with flowing water, which, during periods 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.
LAND DEVELOPMENTAn activity meeting the definition of land development in Chapter
22, "Subdivision and Land Development."
A rock formation, other stratum, or soil condition which is so slowly permeable that it effectively limits downward passage of effluent. Season high water tables, whether perched or regional, also constitute a limiting zone.
LINEAMENTA fracture on the order of tens of kilometers long usually extending to the basement below sedimentary rock.
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.
MPCThe Pennsylvania Municipalities Planning Code, Act of 1968, P.L. 805, No. 247, as reenacted and amended, 53 P.S. § 10101 et seq.
MUNICIPAL SEPARATE STORM SEWERA 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: (1) 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; (2) designed or used for collecting or conveying stormwater; (3) not a combined sewer; and (4) 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).
NATURAL GROUND COVERGround cover which mimics the infiltration characteristics of predominant hydrologic soil group found at the site.
NONPOINT SOURCE POLLUTIONPollution that enters a body of water from diffuse origins in the watershed and does not result from discernible, confined, or discrete conveyances.
NRCSNational Resources Conservation Service (previously SCS).
OPEN CHANNELA drainage element in which stormwater flows with an open surface. Open channels include, but shall not be limited to, natural and man-made drainage ways, swales, streams, ditches, canals, and pipes flowing partly full.
OUTFALLPoint where water flows from a conduit, stream, or drain.
OUTLETPoints of water disposal from a stream, river, lake, tidewater or artificial drain.
PARENT TRACTAll contiguous land held in single and separate ownership, regardless of whether (1) such land is divided into one or more lots, parcels, purparts or tracts; (2) such land was acquired by the landowner at different times or by different deeds, devise, partition or otherwise; or (3) such land is bisected by public or private streets or rights-of-way, which was held by the landowner or his predecessor in title on October 19, 2003.
PARKING LOT STORAGEInvolves the use of impervious parking areas as temporary impoundments with controlled release rates during rainstorms.
PEAK DISCHARGEThe maximum rate of flow of water at a given point and time resulting from a specified storm event.
PENNDOTThe Pennsylvania Department of Transportation or any agency successor thereto.
PERVIOUS AREAAny material/surface that allows water to pass through at a rate equal to or greater than natural ground cover.
QUALIFIED PERSONAny person licensed by the Pennsylvania Department of State or otherwise qualified by law to perform the work required by this chapter.
RATE CONTROLSWM controls used to manage the peak flows for the purposes of channel protection and flood mitigation.
REDEVELOPMENTAny physical improvement to a previously developed lot that involves earthmoving, removal, or addition of impervious surfaces.
REGIONAL STORMWATER MANAGEMENT PLANPlan 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 ACTIVITIESActivities, 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 by Ord. No. 2022-06, 9/12/2022]
(1) Land development subject to the requirements of Chapter
22, Subdivision and Land Development;
Removal of ground cover, grading, filling or excavation;
Construction of new or additional impervious or semi-impervious surfaces (driveways, parking lots, etc.) and associated improvements;
Construction of new buildings or additions to existing buildings;
Installation or alteration of stormwater management facilities and appurtenances thereto;
Diversion or piping of any watercourse;
Any other regulated activities where the Township determines that said activities may affect any existing watercourse's stormwater management facilities or stormwater drainage patterns; and
Any activities where the Township determines that said activities may affect the water quality of stormwater discharges or generate nonstormwater discharges to the MS4 and/or receiving water bodies.
RELEASE RATEFor 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.
RETENTION BASINA basin designed to retain stormwater runoff with its primary release of water being through the infiltration of said water into the ground.
RETURN PERIODThe 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 once every 25 years.
RIPARIANPertaining 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 BUFFERA BMP that is an area of permanent vegetation along a watercourse.
RIPARIAN CORRIDORA strip of land, centered on a stream or river that includes the floodplain as well as related riparian habitats adjacent to the floodplain.
RIPARIAN FOREST BUFFERA type of riparian buffer that consists of permanent vegetation that is predominantly native trees, shrubs and forms along a watercourse that is maintained in a natural state or is sustainably managed to protect and enhance water quality, stabilize stream channels and banks, and separate land use activities from surface waters.
ROOFTOP DETENTIONTemporary ponding and gradual release of stormwater falling directly onto flat roof surfaces by incorporating controlled-flow roof drains into building designs.
RUNOFFThat part of precipitation which flows over the land.
SCSSoil Conservation Service, U.S. Department of Agriculture (U.S.D.A.), now referred to as NRCS.
SEDIMENTSolid material, both mineral and organic, that is in suspension, is being transported, or has been moved from its site of origin by water.
SEDIMENT BASINA barrier, dam, retention or detention basin designed to retain sediment.
SEDIMENT POLLUTIONThe 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.
SEDIMENTATIONThe process by which mineral or organic matter is accumulated or deposited by the movement of water.
SEEPAGE PIT/SEEPAGE TRENCHAn area of excavated earth filled with loose stone or similar material and into which stormwater runoff is directed for infiltration into the ground.
SEMI-PERVIOUS SURFACEA surface such as stone, rock or other materials which permits some vertical transmission of water into the ground.
SHEET FLOWRunoff which flows over the ground surface as a thin, even layer, not concentrated in a channel.
SOIL-COVER COMPLEX METHODA 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).
SOIL GROUP, HYDROLOGICA classification of soils by the SCS (now NRCS) 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.
SPILLWAYA depression in the embankment of a pond or basin which is used to pass a post-development one-hundred-year storm peak flow rate.
STATE WATER QUALITY REQUIREMENTSThe 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 INDICATION METHODA 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 FREQUENCYThe 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 SEWERA system of pipes, conduits, swales or other similar structures including appurtenant works which carries intercepted runoff, and other drainage, but excludes domestic sewage, industrial wastes and other unauthorized discharges.
STORMWATERDrainage runoff from the surface of the land resulting from precipitation or snow or ice melt.
STORMWATER MANAGEMENTA program of controls and measures designed to regulate the quantity and quality of stormwater runoff from a development while promoting the protection and conservation of ground waters and groundwater recharge.
STORMWATER MANAGEMENT FACILITIESAny 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 PLANA plan prepared by an applicant indicating how stormwater runoff will be managed at a particular development site according to this chapter.
STRUCTUREAny man-made object having an ascertainable stationary location on or in land or water, whether or not affixed to the land.
STREAM ENCLOSUREA bridge, culvert or other structure in excess of 100 feet in length upstream to downstream which encloses a regulated water of this Commonwealth.
SUBDIVISIONA subdivision of land as defined in the MPC.
SUBSTRATESInorganic sediments which are 0.05 millimeter in diameter or larger and include sands, gravel, pebbles, cobbles and boulders, based upon Wentworth's classification.
SWALEAny man-made ditch designed to convey stormwater directly to another stormwater management facility or surface waters.
SWMStormwater 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.
TOWNSHIPThe Township of Penn, Lancaster County, Pennsylvania.
TR-20 (CALIBRATED)The computer-based hydrologic modeling technique adapted to the watershed in which the subject property is located by the applicable Act 167 Plan. The model has been "calibrated" to reflect published and observed flow values by adjusting key input model parameters.
VOLUME CONTROLSWM controls, or BMPs, used to remove a predetermined amount of runoff or the increase in volume between the pre- and post-development design storm.
WATERCOURSEA permanent or intermittent stream, river, brook, run, creek, channel, swale, pond, lake or other body of surface water carrying or holding surface water, whether natural or artificial.
WATERS OF THE COMMONWEALTHAny 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.
WATERSHEDThe entire region or area drained by a river or other body of water, whether natural or man-made.
WETLANDSThose areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions, including swamps, marshes, bogs, ferns, and similar areas.