As used in this chapter, the following terms shall have the meanings indicated:
ACCELERATED EROSIONThe 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. Construction of new buildings or impervious area 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; land disturbance.
APPLICANTA landowner or developer who has filed an application for approval to engage in any regulated activities as defined in §
377-4 of this chapter.
Stormwater structures, facilities and techniques intended to maintain or improve the hydrologic regime or improve the water quality of surface runoff.
BOROUGHBorough of Jim Thorpe, Carbon County, Pennsylvania.
CHANNEL EROSIONThe widening, deepening, and headward cutting of small channels and waterways, due to erosion caused by moderate to large floods.
CISTERNAn underground reservoir or tank for storing rainwater.
CULVERTA structure with appurtenant works which carries a stream 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.
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.
DESIGNEEJim Thorpe Borough will be the governing body involved with the administration, review, or enforcement of any provisions of this chapter by contract or memorandum of understanding.
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, partnership, association, corporation, or other entity, or any responsible person therein or agent thereof, that undertakes any regulated activity of this chapter.
DEVELOPMENT SITEThe specific tract of land for which a regulated activity is proposed.
DOWNSLOPE PROPERTY LINEThat portion of the property line of the lot, tract, or parcels of land being developed, located such that all overland or pipe flow from the site would be directed towards it.
DOWNSTREAM HYDRAULIC CAPACITY ANALYSISAny downstream capacity hydraulic analysis conducted in accordance with this chapter shall use the following criteria for determining adequacy for accepting increased peak flow rates:
A. Natural or man-made channels or swales must be able to convey the increased rate of runoff associated with a two-year return period event within their banks at velocities consistent with protection of the channels from erosion. Acceptable velocities shall be based upon criteria included in the DEP Erosion and Sediment Pollution Control Program Manual.
Natural or man-made channels or swales must be able to convey the increased twenty-five-year return period rate of runoff without creating any hazard to persons or property.
Culverts, bridges, storm sewers or any other facilities which must pass or convey flows from the tributary area must be designed in accordance with DEP Chapter 105 regulations (if applicable) and, at a minimum, pass the increased twenty-five-year return period rate of runoff.
No new channels or conveyance facilities shall be authorized by this language.
DRAINAGE CONVEYANCE FACILITYA stormwater management facility designed to transmit stormwater runoff which shall include streams, channels, swales, pipes, conduits, culverts, storm sewers, etc.
DRAINAGE EASEMENTA right granted by a landowner to a grantee, allowing the use of private land for stormwater management purposes.
DRAINAGE PERMITA permit issued by the Borough governing body after the drainage plan has been approved. Said permit is issued prior to or with the final Borough approval.
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 §
377-16.
Any activity including, but not limited to, construction, mining, timber harvesting and grubbing which alters, disturbs, and exposes the existing land surface.
EROSIONThe movement of soil particles by the action of water, wind, ice, or other natural forces.
EXISTING CONDITIONSThe initial condition of a project site prior to the proposed construction. 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.
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.
FLOODPLAINAny 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. Also included are areas that compose Group 13 Soils, as listed in Appendix A of the Pennsylvania Department of Environmental Protection (PA DEP) Technical Manual For Sewage Enforcement Officers (as amended or replaced from time to time by PA DEP).
FLOODWAYThe channel of the watercourse and those portions of the adjoining floodplains that are reasonably required to carry and discharge the 100-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 100-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 forest land. These include timber inventory and preparation of forest management plans, silvicultural treatment, cutting budgets, logging and road design and construction, timber harvesting, site preparation, and reforestation.
FREEBOARDA vertical distance between the elevation of the design high-water and the top of a dam, levee, tank, basin, or diversion ridge. 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.
A. TO GRADETo 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.
IMPERVIOUS SURFACEImpervious surfaces are those surfaces which do not absorb water. All structures, buildings, parking areas, driveways, roads, sidewalks, and any areas of concrete, asphalt, compacted playing field, or packed stone shall be considered impervious surface. In addition, all other areas as determined by the Municipal Engineer to be impervious within the meaning of this definition shall also be considered as impervious surface.
IMPOUNDMENTA retention or detention basin designed to retain stormwater runoff and release it at a controlled rate.
INFILTRATION STRUCTURESA structure or basin designed to direct runoff into the ground (e.g., French drains, seepage pits, seepage trench).
INLETA. A 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.
KARSTA type of topography or landscape characterized by surface depressions, sinkholes, rock pinnacles/uneven bedrock surface, underground drainage, and caves. Karst is formed on carbonate rocks, such as limestone or dolomite.
LAND 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 buildings; or
The division or allocation of land or space 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.
LAND/EARTH DISTURBANCEAny activity involving grading, tilling, digging, or filling of ground or stripping of vegetation or any other activity that causes an alteration to the natural condition of the land.
MAIN STEM (MAIN CHANNEL)Any stream segment or other runoff conveyance facility used as a reach in the hydrologic model of a watershed.
MANNING EQUATION IN (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 as long as the flow is not under pressure.
MUNICIPALITYBorough of Jim Thorpe, Carbon County, Pennsylvania.
NONPOINT SOURCE POLLUTIONPollution that enters a watery body from diffuse origins in the watershed and does not result from discernible, confined, or discrete conveyances.
NRCSNatural Resources Conservation Service [previously Soil Conservation Service (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 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.
PARKING LOT STORAGEInvolves the use of impervious 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 used for the Act 167 Plan proposed by DEP. 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.
PMF (PROBABLE MAXIMUM FLOOD)The flood that may be expected from the most severe combination of critical meteorological and hydrologic conditions that are reasonably possible in any 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).
RECHARGE VOLUMEA calculated volume of stormwater runoff from impervious areas which is required to be infiltrated at a site and may be achieved through use of structural or nonstructural BMPs.
RELEASE RATEThe percentage of predevelopment of peak rate of runoff from a site or subarea to which the postdevelopment peak rate of runoff must be reduced to protect downstream areas.
RETENTION BASINAn impoundment in which stormwater is stored and not released during the storm event. Stored water may be released 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. For example, the twenty-five-year storm period rainfall would be expected to recur on the average once every 25 years. This is equivalent to this type of rain event having a 4% chance of activity occurring in one year.
RIPARIANA term that relates to an area of land directly influenced by permanent water. It has visible vegetation or physical characteristics reflective of permanent water influence. Lake shores and stream banks are typical riparian areas.
RIPARIAN BUFFERThe natural vegetation from the edge of the stream bank out through the riparian zone. The vegetative zone serves as a buffer to pollutants entering a stream from runoff, controls erosion, and provides habitat and nutrient input into the stream.
RISERA vertical pipe extending from the bottom of a point that 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 surfaces by incorporating controlled-flow roof drains into building designs.
RUNOFFAny part of precipitation that flows over the land surface.
SEDIMENT BASINA barrier, dam, or retention or detention basin located and designed to retain rock, sand, gravel, silt, or other material transported by water.
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 requirement 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 coarse material, into which surface water is directed for infiltration into the ground.
SHEET FLOWRunoff that flows over the ground surface as a thin, even layer, not concentrated in a channel.
SOIL GROUP, HYDROLOGICA classification of soils by the Natural Resource 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.
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 depression in the embankment of a pond or basin which is used to pass peak discharge greater than the maximum design storm controlled by the pond.
STORAGE FACILITYAlso known as a stormwater management storage facility, is any earth impoundment, subsurface basin, pit, trench, chambers, etc., that is designed to store stormwater for any amount of time for the purpose of peak rate reduction. Examples of storage facilities are detention basins, retention basins, wet basins, extended detention basins, infiltration basins, subsurface chambers, subsurface infiltration pits, subsurface stone beds or trenches, etc.
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." Also, the percent likelihood that the storm could occur in a single year.
STORM SEWERA system of pipes and/or open channels that convey intercepted runoff and stormwater from other sources, but excludes domestic sewage and industrial wastes.
STORMWATERThe total amount of 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. 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 stormwater runoff in the watersheds of Jim Thorpe Borough as required by the Act of October 4, 1978, P.L. 864 (Act 167); and the Carbon County plan is known as the "Jim Thorpe Borough Watershed Action 167 Stormwater Management Plan."
STORMWATER MANAGEMENT SITE PLANThe plan prepared by the developer or his representative indicating how stormwater runoff will be managed at the particular site of interest according to this chapter.
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.
SUBAREAThe 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, 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 dwellings, shall be exempt.
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.
WATER QUALITY VOLUMEA calculated volume of stormwater runoff from impervious areas which is required to be captured and treated at a site and may be achieved through use of structural or nonstructural BMPs. Numerically, the water quality volume is a product of the volumetric runoff coefficient, the site area, and a depth of rainfall of one inch (keeping units consistent).
WATERCOURSEAny channel or conveyance of surface waters 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, 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, subject to the regulations of the commonwealth.
WATERSHEDThe area that collects drainage from precipitation into one common watercourse; the watersheds, in part or in total, of the Silk Mill Run, Slaughterhouse Creek, Robertson Run, Mahoning Creek, and Mauch Chunk Creek which are within the boundaries of the Borough of Jim Thorpe, all of which flow into the Lehigh River within the Delaware River Basin.
WETLANDThose 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.