For purposes of this Part
1, the following terms shall be given the following meanings:
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 ACTIVITIESThe 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
1, construction of new buildings or impervious area is not considered an agricultural activity.
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.
APPLICANTA person, entity, land owner and/or developer who has filed an application for approval to engage in any regulated activities as defined in this Part
1.
The Township-approved plans as 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 at the completion of the project.
AS-BUILT SURVEYA plan of the stormwater management improvements as constructed on a lot or right-of-way. Said survey must be prepared by a Pennsylvania registered land surveyor.
BANKFULLThe channel at the top-of-bank or point where water begins to overflow onto a floodplain.
BASE FLOWThe portion of stream flow that is sustained by groundwater discharge.
BIORETENTIONA stormwater retention area which utilizes woody and herbaceous plants and soils to remove pollutants before infiltration occurs.
BMP (best management practice)Stormwater structures, facilities and techniques to control, maintain or improve the quantity and quality of surface runoff and groundwater recharge.
BUFFERThe area of land immediately adjacent to any wetland, lake, pond, or stream, measured perpendicular to and horizontally from the delineated edge of the wetland, lake, pond, or the top-of-bank on both sides of a stream.
CHANNEL EROSIONThe widening, deepening, and headward cutting of small channels and waterways caused by stormwater runoff or bankfull flows.
CISTERNAn underground reservoir or tank for storing rainwater.
CONSUMPTIVE WATER USEThat part of water removed from the immediate water environment not available for other purposes such as water supply, maintenance of stream flows, water quality, fisheries and recreation, as opposed to water that is used nonconsumptively, which is returned to surface water, where practicable, and groundwater.
CULVERTA structure with appurtenant works, which carries water 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.
DEPARTMENTThe Pennsylvania Department of Environmental Protection.
DESIGNEEThe agent of the Township of Tobyhanna involved with the administration, review or enforcement of any provisions of this Part
1. An agent may be of Monroe County Planning Commission, Monroe County Conservation District if by contract or memorandum of understanding with the Township of Tobyhanna.
A Pennsylvania registered professional engineer, registered landscape architect or a registered professional land surveyor trained and experienced in the design of stormwater management plans.
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.
DETENTION BASINAn impoundment structure designed to manage stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate.
DETENTION DISTRICTThose subareas in which some type of detention is required to meet the plan requirements and the goals of Act 167.
DEVELOPERA person or persons, partnership, association, corporation or other entity, or any responsible person therein or agent thereof, that undertakes the activities covered by this Part
1.
The specific tract of land for which a regulated activity is proposed.
DIFFUSED DRAINAGE DISCHARGEDrainage discharge not confined to a single point location or channel, such as sheet flow or shallow concentrated flow.
DISTURBED AREASLand area where an earth disturbance activity is occurring or has occurred.
DIVERSIONTo collect and divert runoff away from an earth disturbance area.
DOWNSLOPE PROPERTY LINEThat 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 FACILITYA stormwater management facility designed to transmit stormwater runoff and shall include channels, swales, pipes, conduits, culverts, storm sewers, etc.
DRAINAGE EASEMENTA right granted by a grantor to a grantee, allowing the use of private land for stormwater management purposes.
DRAINAGE PERMITA permit issued by the municipality after the drainage plan has been approved.
DRAINAGE PLANThe documentation of the stormwater management system, if any, to be used for a given development site, the contents of which are established in §
124-19.
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 SPILLWAYA conveyance area (e.g., a depression in the embankment of a pond or basin) that is used to safely convey peak discharge greater than the maximum design storm controlled by the stormwater facility. The principal outfall structure may not serve as an emergency spillway.
ENCROACHMENTA structure or activity that changes, expands or diminishes the course, current or cross section of a watercourse, floodway or body of water.
EROSIONThe movement of soil particles by the action of water, wind, ice, or other natural forces.
EROSION AND SEDIMENT CONTROL PLANA 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.
ERSAM (Existing Resource and Site Analysis Map)A map showing environmentally sensitive areas, including, but not limited to, steep slopes, ponds, lakes, streams, wetlands, hydric soils, floodplains, buffer areas, hydrologic soil groups A and B (areas conducive to infiltration), any existing recharge areas, compliance with the map preparation criteria denoted in §
124-19B and any other plan preparation criteria outlined in the municipal Subdivision and Land Development Ordinance as may be required by the municipality.
A surface water that meets one or more of the conditions as defined by the Pennsylvania Code Title
25, Environmental Protection, Chapter
93, Water Quality Standards, Section 93.4b(b).
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.
FEMAThe Federal Emergency Management Agency.
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.
FLOODPLAINThe lands adjoining a river or stream that have been or may be expected to be inundated by floodwaters in the one-hundred-year-frequency flood.
FLOODWAYThe 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 the bank of the stream.
FOREST MANAGEMENT/TIMBER OPERATIONSPlanning and activities necessary for the management of forestland 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.
FREEBOARDA 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.
GRADEA slope, usually of a road, channel or natural ground, specified in percent and shown on plans as specified herein.
GRADE, TOTo 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 convey surface water.
HAZARDOUS MATERIALSThose chemicals or substances that are physical hazards or health hazards as defined and classified in the International Fire Code and the International Building Code, whether the materials are in usable or waste condition.
HEC-HMSThe U.S. Army Corps of Engineers, Hydrologic Engineering Center (HEC) - Hydrologic Modeling System (HMS) computer program.
HIGH-QUALITY WATERSA surface water that meets one or more of the conditions as defined by the Pennsylvania Code Title
25, Environmental Protection, Chapter
93, Water Quality Standards, Section 93.4b(a), as amended.
In general terms, the hydrologic cycle or balance that sustains quality and quantity of stormwater, base flow, storage, and groundwater supplies under natural conditions.
HYDROLOGIC SOIL GROUPA 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 SURFACEA surface that prevents the percolation of water into the ground such as rooftops, pavement, sidewalks, driveways, gravel drives, roads and parking, and compacted fill, earth or turf to be used as such.
IMPOUNDMENTA retention basin or detention basin designed to retain stormwater runoff and release it at a controlled rate.
INFILLDevelopment that occurs on smaller parcels that remain undeveloped but are within or in 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.
INFILTRATIONMovement of surface water into soil, where it is absorbed by plant roots, evaporated into the atmosphere, or percolates downward to recharge groundwater.
INFILTRATION STRUCTURESA structure designed to direct runoff into the underground water (e.g., french drains, seepage pits, seepage trench).
INLETA surface connection to a closed drain; a structure at the diversion end of a conduit; the upstream end of any structure through which water may flow.
LAND DEVELOPMENTA. 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.
LIMITING ZONEA 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.
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 which is so slowly permeable that it effectively limits downward passage of water.
LOTA 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 Brodhead/McMichaels 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.
MUNICIPALITYTownship of Tobyhanna, Monroe County, Pennsylvania.
NONPOINT SOURCE POLLUTIONPollution that enters a water body from diffuse origins in the watershed and does not result from discernible, confined, or discrete conveyances.
NONSTRUCTURAL BMPsMethods 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.
NRCSNatural Resource Conservation Service (previously SCS).
OPEN CHANNELA drainage element in which stormwater flows within 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.
OUTFALLPoint where water flows from a conduit, stream, or drain.
OUTLETPoints of water disposal from a stream, river, lake, tidewater or artificial drain.
PARENT TRACTThe parcel of land from which a land development or subdivision originates existing as of the date of municipal adoption of the original Brodhead or McMichaels Creek Ordinance.
PARKING LOT STORAGEInvolves the use of parking areas as temporary impoundments with controlled release rates during rainstorms.
PEAK DISCHARGEThe maximum rate of stormwater runoff from a specific storm event.
PENN STATE RUNOFF MODEL (CALIBRATED)The computer-based hydrologic modeling technique adapted to the Brodhead/McMichaels Watershed for the Act 167 plan. The model has been "calibrated" to reflect actual recorded flow values by adjoining key model input parameters.
PIPEA culvert, closed conduit, or similar structure (including appurtenances) that conveys stormwater.
PLANNED RESIDENTIAL DEVELOPMENTAn area of land, controlled by a landowner, to be developed as a single entity for a number of dwelling units, or a combination of residential and nonresidential uses, the development plan for which may not correspond in lot size, bulk, type of dwelling or use, density, or intensity, lot coverage and required open space to the regulations established in any one district created, from time to time, under the provisions of the municipality's ordinances.
PMF (probable maximum flood)The flood that may be expected from the most severe combination of critical meteorologic and hydrologic conditions that are reasonably possible in an area. The PMF is derived from the probable maximum precipitation (PMP) as determined on the basis of data obtained from the National Oceanographic and Atmospheric Administration (NOAA).
PRACTICABLE ALTERNATIVEAn alternative that is available and capable of being done after taking into consideration cost, existing technology and logistics in light of overall project purposes.
PRETREATMENTTechniques employed in structural and nonstructural stormwater BMPs to provide storage or filtering to help trap coarse materials and other pollutants before they enter the system.
RECHARGE AREAUndisturbed surface area or depression where stormwater collects, and a portion of which infiltrates and replenishes the underground and groundwater.
RECORD DRAWINGSOriginal documents revised to suit the as-built conditions and subsequently provided by the engineer to the client. The engineer 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, in both cases for the client's permanent records.
REDEVELOPMENTAny construction, alteration, or improvement exceeding 5,000 square feet of impervious surface on sites where existing land use is commercial, industrial, institutional, or residential.
REGULATED ACTIVITIESActions or proposed actions that have an impact on stormwater runoff quality and quantity and that are specified in this Part
1.
The percentage of the pre-development peak rate of runoff for a development site to which the post-development peak rate of runoff must be controlled to protect downstream areas.
RETENTION BASINAn impoundment in which stormwater is stored and not released during the storm event. Stored water may be released at a controlled rate from the basin at some time after the end of the storm.
RETURN PERIODThe average interval, in years, within which a storm event of a given magnitude can be expected to recur.
RISERA vertical pipe that is typically extended from the bottom of a detention basin and is used to control the discharge rate from the pond for a specified design storm.
ROOFTOP DETENTIONTemporary ponding and gradual release of stormwater falling directly onto flat roof surfaces by incorporating controlled-flow roof drains into building designs.
RUNOFFAny part of precipitation that flows over the land surface.
SALDOSubdivision and Land Development Ordinance.
SEDIMENT BASINA barrier, dam, retention or detention basin located and designed to retain rock, sand, gravel, silt, or other material transported by water during construction.
SEDIMENTATIONThe process by which mineral or organic matter is accumulated or deposited by the movement of water or air.
SEDIMENT POLLUTIONThe placement, discharge or any other introduction of sediment into the waters of the commonwealth.
SEEPAGE PIT/SEEPAGE TRENCHAn area of excavated earth filled with loose stone or similar coarse material, into which surface water is directed for infiltration into the underground water.
SHEET FLOWA flow process associated with broad, shallow water movement on sloping ground surfaces that is not channelized or concentrated.
SOIL-COVER COMPLEX METHODA 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).
SPILLWAYA conveyance that is used to pass the peak discharge of the maximum design storm controlled by the stormwater facility.
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 or other conduits that convey intercepted runoff and stormwater from other sources, but excludes domestic sewage and industrial wastes.
STORMWATERThe surface runoff generated by precipitation reaching the ground surface.
STORMWATER MANAGEMENT FACILITYAny structure, natural or man-made, that, due to its condition, design, or construction, conveys, stores, or otherwise affects stormwater runoff quality and 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 PLANThe plan for managing those land use activities that will influence stormwater runoff quality and quantity and that would impact the Brodhead/McMichaels Watershed as required by the Act of October 4, 1978, P.L. 864 (Act 167), as amended.
STORMWATER MANAGEMENT SITE PLANThe plan prepared by the applicant or his representative indicating how stormwater runoff will be managed at the particular site of interest according to this Part
1.
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.
SUBDIVISIONThe 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.
SWALEA low-lying stretch of land which gathers or carries surface water runoff.
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.
WATERCOURSEA channel or conveyance of surface water having defined bed and banks, whether natural or artificial, with perennial or intermittent flow.
WATERSHEDThe entire region or area drained by a river or other body of water, whether natural or artificial.
WATERS OF THE COMMONWEALTHRivers, streams, creeks, rivulets, impoundments, ditches, watercourses, storm sewers, lakes, dammed water, wetlands, ponds, springs, and 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.
WELLHEADThe point at which a groundwater well bore hole meets the surface of the ground.
WELLHEAD PROTECTION AREAThe 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.
WETLANDAreas that are inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions, including swamps, marshes, bogs, and similar areas.