As used in this chapter, the following terms shall have the meanings indicated:
AGRICULTURAL ACTIVITYActivities associated with agriculture such as agricultural cultivation, agricultural operation, and animal heavy use areas. This includes the work of producing crops, including tillage, plowing, disking, harrowing, planting or 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.
APPLICANTA landowner, developer, or other person who has filed an application to the Township for approval to engage in any regulated activity as defined in this chapter.
AS-BUILT PLANS (DRAWINGS)Engineering or site plans or drawings that document the actual locations, dimensions and elevations of the improvements, and building components, and changes made to the original design plans. The final version of these documents, or a copy of same, are signed and sealed by a qualified licensed professional and submitted to the Township at the completion of the project, as per the requirements of §
170-502 of this chapter as final as-built plans.
The channel at the top-of-bank or point from where water begins to overflow onto a floodplain.
BASEFLOWPortion 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.
BMP (BEST MANAGEMENT PRACTICE)Activities, facilities, designs, measures, or procedures used to manage stormwater impacts from regulated activities, to provide water quality treatment, infiltration, volume reduction, and/or peak rate control, 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 include certain low-impact development and conservation design practices used to minimize the contact of pollutants with stormwater runoff. These practices aim to limit the total volume of stormwater runoff and manage stormwater at its source by techniques such as protecting natural systems and incorporating existing landscape features. Nonstructural BMPs include, but are not limited to, the protection of sensitive and special value features such as wetlands and riparian areas, the preservation of open space while clustering and concentrating development, the reduction of impervious cover, and the disconnection of rooftops from storm sewers. Structural BMPs are those that consist of a physical system that is designed and engineered 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, bioretention, wet ponds, permeable paving, grassed swales, riparian buffers, sand filters, detention basins, and manufactured devices. Structural and nonstructural stormwater BMPs are permanent appurtenances to the site. [See also "stormwater management facility" and "stormwater control measure (SCM)"].
CFSCubic feet per second.
CHANNELA natural or artificial open drainage feature that conveys, continuously or periodically, flowing water and through which stormwater flows. Channels include, but shall not be limited to, natural and man-made drainageways, swales, streams, ditches, canals, and pipes flowing partly full.
CONSERVATION DESIGNA series of holistic land development design goals that maximize protection of key land and environmental resources, preserve significant concentrations of open space and greenways, evaluate, and maintain site hydrology, and ensure flexibility in development design to meet community needs for complimentary and aesthetically pleasing development. Conservation design encompasses the following objectives: conservation/enhancement of natural resources, wildlife habitat, biodiversity corridors, and greenways (interconnected open space); minimization of environmental impact resulting from a change in land use (minimum disturbance, minimum maintenance); maintenance of a balanced water budget by making use of site characteristics and infiltration; incorporation of unique natural, scenic and historic site features into the configuration of the development; preservation of the integral characteristics of the site as viewed from adjoining roads; and reduction in maintenance required for stormwater management practices. Such objectives can be met on a site through an integrated development process that respects natural site conditions and attempts, to the maximum extent possible, to replicate or improve the natural hydrology of a site.
CONSERVATION PLANA plan written by a planner certified by NRCS 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.
CONVEYANCEA natural or man-made, existing or proposed stormwater management facility, feature or channel used for the transportation or transmission of stormwater from one place to another. For the purposes of this chapter, conveyance shall include pipes, drainage ditches, channels and swales (vegetated and other), gutters, stream channels, and like facilities or features.
DESIGN STORMThe 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. Also see "return period."
DETENTION (or TO DETAIN)Capture and temporary storage of runoff in a stormwater management facility for release at a controlled rate.
DETENTION BASINAn 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.
DETENTION VOLUMEThe volume of runoff that is captured and released into the waters of the commonwealth at a controlled rate.
DEVELOPERA person, company, or organization who seeks to undertake any regulated activities at a site in the Township.
DIAMETER AT BREAST HEIGHT (DBH)The outside bark diameter of a tree at breast height which is defined as 4.5 feet (1.37m) above the forest floor on the uphill side of the tree.
DISTURBED AREALand area disturbed by or where an earth disturbance activity is occurring or has occurred.
DRAINAGE AREAThat land area contributing runoff to a single point (including, but not limited to, the point/line of interest used for hydrologic and hydraulic calculations) and that is enclosed by a natural or man-made ridgeline.
EARTH DISTURBANCE (or 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; road maintenance; land development; building construction; and the moving, depositing, stockpiling, or storing of soil, rock, or earth materials.
EASEMENTA right of use granted by a landowner to allow a grantee the use of the designated portion of land for a specified purpose, such as for stormwater management or other drainage purposes.
EROSIONThe process by which the surface of the land, including water/stream channels, is worn away by water, wind, or chemical action.
EROSION AND SEDIMENT (E&S) CONTROL PLANA plan required by the conservation district or the Township to minimize accelerated erosion and sedimentation, and that must be prepared and approved per the applicable requirements.
EVAPOTRANSPIRATION (ET)The combined processes of evaporation from the water or soil surface and transpiration of water by plants.
FEMAFederal Emergency Management Agency.
FLOODA temporary condition of partial or complete inundation of land areas from the overflow of streams, rivers, and other waters of this commonwealth.
FLOODPLAINAny land area susceptible to inundation by water from any natural source or delineated by applicable FEMA maps and studies as being a special flood hazard area.
FLOODWAYThe channel of the watercourse and those portions of the adjoining floodplains that are reasonably required to carry and discharge the 100-year flood (also called the "base flood" or "1% annual chance 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 floodway, it is assumed, absent evidence to the contrary, that the floodway extends from the centerline of the stream and to 50 feet beyond the top of the bank of the stream on both sides.
FOREST MANAGEMENT/TIMBER OPERATIONSPlanning and activities necessary for the management of forest lands. These include timber inventory, preparation of forest management plans, silvicultural treatment, cutting budgets, logging road design and construction, timber harvesting, site preparation, and reforestation.
FREEBOARDA vertical distance between the design high-water elevation and the elevation of 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.
GEOTEXTILEA fabric manufactured from synthetic fiber that is used to achieve specific objectives, including infiltration, separation between different types of media (i.e., between soil and stone), or filtration.
GRADE/GRADINGA. (noun) A slope, usually of a road, channel, or natural ground, specified in percent and shown on plans as specified herein.
(verb) To finish the surface of a roadbed, the top of an embankment, or the bottom of an excavation.
GREEN INFRASTRUCTURESystems and practices that use or mimic natural processes to infiltrate, evapotranspire, or reuse stormwater on the site where it is generated.
GROUNDWATERWater that occurs in the subsurface and fills or saturates the porous openings, fractures and fissures of underground soils and rock units.
GROUNDWATER RECHARGEThe replenishment of existing natural groundwater supplies from infiltration of rain or overland flow.
HEC-1The U.S. Army Corps of Engineers, Hydrologic Engineering Center (HEC), hydrologic runoff model.
HEC-HMSThe U.S. Army Corps of Engineers, Hydrologic Engineering Center (HEC), Hydrologic Modeling System (HMS).
HIGH TUNNELA structure which meets the following:
A. Is used for the production, processing, keeping, storing, sale or shelter of an agricultural commodity as defined in Section 2 of the Act of December 19, 1974 (P.L. 973, No. 319), known as the "Pennsylvania Farmland and Forest Land Assessment Act of 1974," or for the storage of agricultural equipment or supplies; and
Is constructed with all the following:
(1) Has a metal, wood, or plastic frame;
When covered, has a plastic, woven textile, or other flexible covering; and
Has a floor made of soil, crushed stone, matting, pavers, or a floating concrete slab.
HOT SPOTSAreas where prior or existing land use or activities can potentially generate highly contaminated runoff with concentrations of pollutants in excess of those typically found in stormwater.
HYDROLOGIC REGIMEThe hydrologic system, cycle or balance that sustains the quality and quantity of stormwater, stream baseflow, storage, and groundwater supplies under natural conditions.
HYDROLOGIC SOIL GROUP (HSG)A classification of soils by the Natural Resources Conservation Service (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.
IMPERVIOUS SURFACEA surface that has been compacted or covered with a layer of material so that it prevents or is resistant to infiltration of water, including, but not limited to, structures such as roofs, buildings, storage sheds, pools; other solid, paved or concrete areas such as streets, driveways, sidewalks, parking lots, patios, tennis or other paved courts; or athletic playfields comprised of synthetic turf materials. For the purposes of determining compliance with this chapter, compacted soils or stone surfaces used for vehicle parking and movement shall be considered impervious. Uncompacted gravel areas with no vehicular traffic, such as gardens, walkways, or patios areas, shall be considered pervious per review by the Township Engineer. Surfaces that were designed to allow infiltration (i.e., pavers and areas of porous pavement) are not to be considered impervious surface if designed to function as a BMP per review on a case-by-case basis by the Township Engineer, based on appropriate documentation and condition of the material, etc. Additionally, for the purposes of determining compliance with this chapter, the total horizontal projection area of all ground-mounted and freestanding solar collectors, including solar photovoltaic cells, panels, and arrays, shall be considered pervious so long as the designs note that natural vegetative cover will be preserved and/or restored underneath the solar photovoltaic cells, panels, and arrays, and the area disturbed is planned as a vegetated pervious surface.
INFILTRATIONMovement of surface water into the soil, where it is absorbed by plant roots, evaporated into the atmosphere, or percolated downward to recharge groundwater.
INFILTRATION FACILITYA stormwater BMP designed to collect and discharge runoff into the subsurface in a manner that allows infiltration into underlying soils and groundwater (e.g., french drains, seepage pits, or seepage trenches, etc.).
INTERMITTENT STREAMA defined channel in which surface water is absent during a portion of the year, in response to seasonal variations in precipitation or groundwater discharge.
INVERTThe lowest surface, the floor or bottom of a culvert, pipe, drain, sewer, channel, basin, BMP, or orifice.
KARSTA type of topography that is formed over limestone or other carbonate rock formations by dissolving or solution of the rock by water, and that is characterized by closed depressions, sinkholes, caves, a subsurface network of solution conduits and fissures through which groundwater moves, and no perennial surface drainage features.
LAND DEVELOPMENTAny 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; or
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;
Development in accordance with Section 503(1.1) of the Pennsylvania Municipalities Planning Code (as amended).
LANDOWNERThe 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 they are authorized under the lease to exercise the rights of the landowner, or other person having a proprietary interest in the land.
LICENSED PROFESSIONALA Pennsylvania registered professional engineer, registered landscape architect, registered professional land surveyor, or registered professional geologist, or any person licensed by the Pennsylvania Department of State or qualified by law to perform the work required by the ordinance within the Commonwealth of Pennsylvania.
LIMITING ZONEA soil horizon or condition in the soil profile or underlying strata that 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 other subsurface or soil conditions.
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.
A rock formation, other stratum, or soil condition that is so slowly permeable that it effectively limits downward passage of water.
LOW-IMPACT DEVELOPMENT (LID)Site design approaches and small-scale stormwater management practices that promote the use of natural systems for infiltration, evapotranspiration, and reuse of rainwater. LID can be applied to new development, urban retrofits, and revitalization projects. LID utilizes design techniques that infiltrate, filter, provide evapotranspiration and store runoff close to its source. Rather than rely on costly large-scale conveyance and treatment systems, LID addresses stormwater through a variety of small, cost-effective landscape features located on-site.
MAINTENANCEThe action taken to restore or preserve the as-built functional design of any stormwater management facility or system.
MFEMPMushroom farm environmental management plan.
MPCAct of July 31, 1968, P.L. 805, No. 247, 53 P.S. §
10101 et seq., as amended, the Pennsylvania Municipalities Planning Code, Act 247.
Municipal separate storm sewer system.
NEW DEVELOPMENTAny regulated activity involving placement or construction of new impervious surface or grading over existing pervious land areas not classified as redevelopment as defined in this chapter.
NOAANational Oceanic and Atmospheric Administration.
NONPOINT SOURCE POLLUTIONPollution that enters a water body from diffuse origins in the watershed and does not result from discernible, confined, or discrete conveyances.
NONSTORMWATER DISCHARGESWater flowing in stormwater collection facilities, such as pipes or swales, which is not the result of a rainfall event or snowmelt.
NPDESNational 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.
NRCSNatural Resource Conservation Service (previously Soil Conservation Service, SCS), an agency of the U.S. Department of Agriculture.
PADEPPennsylvania Department of Environmental Protection.
PARENT TRACTThe parcel of land from which a land development or subdivision originates, determined from the date of municipal adoption of this chapter.
PEAK DISCHARGEThe maximum rate of stormwater runoff from a specific storm event.
PENNDOTPennsylvania Department of Transportation.
PETA domesticated animal (other than a disability assistance animal) kept for amusement or companionship.
POINT SOURCEAny 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.
Period after construction during which disturbed areas are stabilized, stormwater controls are in place and functioning, and all proposed improvements approved by the Township are completed.
PREDEVELOPMENTGround cover conditions assumed to exist within the proposed disturbed area prior to commencement of the regulated activity for the purpose of calculating the predevelopment water quality volume, infiltration volume, and peak flow rates as required in this chapter.
PRETREATMENTTechniques employed in stormwater BMPs to provide storage or filtering, or other methods to trap or remove coarse materials and other pollutants before they enter the stormwater system, but may not necessarily be designed to meet the entire water quality volume requirements of this chapter.
RECHARGEThe replenishment of groundwater through the infiltration of rainfall, other surface waters, or land application of water or treated wastewater.
REDEVELOPMENTAny regulated activity that involves demolition, removal, reconstruction, or replacement of existing impervious surface(s).
REGULATED ACTIVITYAny earth disturbance activity(ies) or any activity that involves the alteration or development of land in a manner that may affect stormwater runoff.
REGULATED IMPERVIOUS SURFACEProposed impervious surface as part of a current proposed activity and all existing impervious surfaces installed after January 15, 2014, as part of previous activity.
RETENTION BASINAn impoundment that is designed to temporarily detain a certain amount of stormwater from a catchment area and which may be designed to permanently retain stormwater runoff from the catchment area; retention basins always contain water.
RETENTION or TO RETAINThe prevention of direct discharge of stormwater runoff into surface waters or water bodies during or after a storm event by permanent containment in a pond or depression; examples include systems which discharge by percolation to groundwater, exfiltration, and/or evaporation processes and which generally have residence times of less than three days.
RETENTION VOLUME/REMOVED RUNOFFThe volume of runoff that is captured and not released directly into the surface waters of the commonwealth during or after a storm event.
RETURN PERIODThe 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 in another way, the probability of a twenty-five-year storm occurring in any one year is 0.04 (i.e., a 4% chance).
RIPARIANPertaining to anything connected with or immediately adjacent to the banks of a stream or other body of water.
RIPARIAN BUFFERAn area of land adjacent to a body of water and managed to maintain vegetation to protect the integrity of stream channels and shorelines, to reduce the impact of upland sources of pollution by trapping, filtering, and converting sediments, nutrients, and other chemicals, and to supply food, cover and thermal protection to fish and other aquatic species and wildlife.
RUNOFFAny part of precipitation that flows over the land surface.
SALDOSee "Subdivision and Land Development Ordinance."
SCSSoil Conservation Service, now known as "the Natural Resources Conservation Service."
SEDIMENTSoil or other materials transported by, suspended in or deposited by surface water as a product of erosion.
SEPARATE STORM SEWER SYSTEMA 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.
SHEET FLOWA flow process associated with broad, shallow water movement on sloping ground surfaces that is not channelized or concentrated.
SITETotal area of land in the Township where any proposed regulated activity, as defined in this chapter, is planned, conducted, or maintained or that is otherwise impacted by the regulated activity.
SOIL COVER COMPLEX METHODA method of runoff computation developed by NRCS that is based on relating soil type and land use/cover to a runoff parameter called curve number (CN).
STATE WATER QUALITY REQUIREMENTSThe regulatory requirements to protect, maintain reclaim, and restore water quality under Pennsylvania Code Title
25 and the Clean Streams Law.
Drainage runoff from the surface of the land resulting from precipitation or snow or ice melt.
STORMWATER CONTROL MEASUREPhysical features used to effectively control, minimize, and treat stormwater runoff. [See "best management practice (BMP)."]
STORMWATER MANAGEMENT (SWM) SITE PLANThe plan prepared by the applicant or its representative, in accordance with the requirements of Article
IV of this chapter, indicating how stormwater runoff will be managed at a particular site in accordance with this chapter, and including all necessary design drawings, calculations, supporting text, and documentation to demonstrate that ordinance requirements have been met, herein referred to as "SWM site plan." All references in this chapter to final or approved SWM site plans shall incorporate the approved SWM site plan and all subsequent approved revisions thereto.
Any feature, natural or man-made, that, due to its condition, design, or construction, conveys, stores, or otherwise affects stormwater runoff quality, rate, or quantity, including best management practices and stormwater control measures. Typical stormwater management facilities include, but are not limited to, detention and retention basins, open channels, storm sewers, pipes, and infiltration facilities.
SUBDIVISIONThe division or redivision of a lot, tract, or parcel of land as defined in the Pennsylvania Municipalities Planning Code, Act of July 31, 1968, P.L. 805, No. 247 (as amended).
SWALEAn artificial or natural waterway or low-lying stretch of land that gathers and conveys stormwater or runoff, and is generally vegetated for soil stabilization, stormwater pollutant removal, and infiltration.
TOP-OF-BANKHighest point of elevation of the bank of a stream or channel cross section at which a rising water level just begins to flow out of the channel and into the floodplain.
TOWNSHIP ENGINEER/MUNICIPAL ENGINEERA professional engineer licensed as such in the commonwealth of Pennsylvania, duly appointed as the engineer for a Township, planning agency, or joint planning commission.
USDAUnited States Department of Agriculture.
WATER TABLEThe upper most level of saturation of pore space or fractures by groundwater. Seasonal high-water table refers to a water table that rises and falls with the seasons due either to natural or man-made causes.
WATERCOURSEA channel or conveyance of surface water having a defined bed and banks, whether natural or artificial, with perennial or intermittent flow.
WATERS OF THE COMMONWEALTHAny 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 water and underground water, or parts thereof, whether natural or artificial, within or on the boundaries of the commonwealth.
WATERSHEDRegion or area drained by a river, watercourse, or other body of water, whether natural or artificial.
WETLANDThose 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.
WOODSAny land area of at least 0.25 acre with a natural or naturalized ground cover (excluding manicured turf grass) and that has an average density of two or more viable trees per 1,500 square feet with a DBH of six inches or greater and where such trees existed at any time within three years of the time of land development application submission of the proposed project. The land area to be considered woods shall be measured from the outer driplines of the outer trees.