These definitions do not necessarily reflect the definitions contained in pertinent regulations or statutes and are intended for this chapter only.
ACT 167The Borough is empowered to regulate land use activities that affect runoff and surface and groundwater quality and quantity by the authority of the Act of October 4, 1978, P.L. 864 (Act 167), 32 P.S. § 680.1 et seq., as amended, the "Storm Water Management Act."
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, land clearing, plowing, disking, harrowing, planting, 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 Borough for approval to engage in any regulated activity at a project site in the Borough.
BEST MANAGEMENT PRACTICE (BMP)Activities, facilities, designs, measures, or procedures used to manage stormwater impacts from regulated activities, to meet state water quality requirements, 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 refer to operational and/or behavior-related practices that attempt to minimize the contact of pollutants with stormwater runoff, whereas structural BMPs or measures are those that consist of a physical device or practice that is installed 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, low impact design, bioretention, wet ponds, permeable paving, grassed swales, riparian or forested buffers, sand filters, detention basins, and manufactured devices. Structural stormwater BMPs are permanent appurtenances to the project site.
BOROUGHBorough of Crafton, Allegheny County, Pennsylvania.
CONSERVATION DISTRICTA conservation district, as defined in Section 3(c) of the Conservation District Law [3 P.S. § 851(c)] that has the authority under a delegation agreement executed with DEP to administer and enforce all or a portion of the regulations promulgated under 25 Pa. Code Chapter 102.
DEPThe Pennsylvania Department of Environmental Protection.
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."
DESIGNATED PLAN REVIEWERA qualified professional as defined herein, or organization such as the Allegheny County Conservation District, that has been designated by the Borough to be the reviewer of SWM site plans for the Borough and shall be understood to be the reviewer where indicated as the Borough within this chapter.
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 in a designed period after a rainfall event, and to become dry until the next rainfall event.
DETENTION VOLUMEThe volume of runoff that is captured and released into the waters of the commonwealth at a controlled rate.
DISTURBED AREAAn unstabilized land area where an earth disturbance activity is occurring or has occurred.
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; road maintenance; building construction; and the moving, depositing, stockpiling, or storing of soil, rock, or earth materials.
EROSIONThe natural process by which the surface of the land is worn away by water, wind, or chemical action.
EXISTING CONDITIONThe dominant land cover during the five-year period immediately preceding a proposed regulated activity.
FEMAFederal Emergency Management Agency.
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. Also includes areas that comprise Group 13 Soils, as listed in
Appendix A of the Pennsylvania DEP Technical Manual for Sewage Enforcement Officers (as amended or replaced from time to time by DEP).
The channel of the watercourse and those portions of the adjoining floodplains that are reasonably required to carry and discharge the 100-year 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 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. These include conducting a timber inventory, preparation of forest management plans, silvicultural treatment, cutting budgets, logging road design and construction, timber harvesting, site preparation, and reforestation.
GREEN INFRASTRUCTURESystems and practices that use or mimic natural processes to infiltrate, evapotranspire, or reuse stormwater on the site where it is generated.
GROUNDWATERWater beneath the earth's surface that supplies wells and springs and is within the saturated zone of soil and rock.
GROUNDWATER RECHARGEThe replenishment of existing natural underground water supplies from precipitation or overland flow.
HYDROLOGIC SOIL GROUP (HSG)Infiltration rates of soils vary widely and are affected by subsurface permeability as well as surface intake rates. Soils are classified into four HSGs (A, B, C, and D) according to their minimum infiltration rate, which is obtained for bare soil after prolonged wetting. The NRCS defines the four groups and provides a list of most of the soils in the United States and their group classification. The soils in the area of the development site may be identified from a soil survey report that can be obtained from local NRCS offices or conservation district offices. Soils become less pervious as the HSG varies from A to D (NRCS1,2).
IMPERVIOUS SURFACE (IMPERVIOUS AREA)A surface that prevents the infiltration of water into the ground. Impervious surfaces (or areas) shall include, but not be limited to: roofs; additional indoor living spaces, patios, garages, storage sheds and similar structures; and any new streets or sidewalks. Decks, parking areas, and driveway areas are counted as impervious areas if they directly prevent infiltration.
INFILTRATIONMovement of surface water into the soil, where it is absorbed by plant roots, evaporated into the atmosphere, or percolated downward to recharge groundwater.
INVASIVE SPECIESDCNR defines invasive plants as those species that are not native to the state, grow aggressively, and spread and displace native vegetation (see http://www.dcnr.state.pa.us/cs/groups/public/documents/document/dcnr_010314.pdf for a list of invasive species).
LAND DEVELOPMENT (DEVELOPMENT)Inclusive of any or all of the following meanings: (i) the improvement of one lot or two or more contiguous lots, tracts, or parcels of land for any purpose involving (a) a group of two or more buildings or (b) 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; (ii) any subdivision of land; (iii) development in accordance with § 503(1.1) of the Pennsylvania Municipalities Planning Code.
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, evaporate, 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.
NATIVE VEGETATIONPlant species that have historically grown in Pennsylvania and are not invasive species as defined herein.
NRCSUSDA Natural Resources Conservation Service (previously SCS).
PEAK DISCHARGEThe maximum rate of stormwater runoff from a specific storm event.
PROJECT SITEThe specific area of land where any regulated activities in the Borough are planned, conducted, or maintained.
QUALIFIED PROFESSIONALAny person licensed by the Pennsylvania Department of State or otherwise qualified under Pennsylvania law to perform the work required by this chapter.
REGULATED ACTIVITIESAny earth disturbance activities or any activities that involve the alteration or development of land in a manner that may affect stormwater runoff.
RELEASE RATEThe percentage of existing conditions peak rate of runoff from a site or subarea to which the proposed conditions peak rate of runoff must be reduced to protect downstream areas.
RELEASE RATE DISTRICTA watershed or portion of a watershed for which a release rate has been established by an adopted Act 167 Stormwater Management Plan.
RETENTION VOLUME/REMOVED RUNOFFThe volume of runoff that is captured and not released directly into the surface waters of this 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).
RIPARIAN BUFFERA permanent vegetated area of trees and shrubs located adjacent to streams, lakes, ponds and wetlands.
RUNOFFAny part of precipitation that flows over the land.
SEDIMENTSoils or other materials transported by surface water as a product of erosion.
STATE WATER QUALITY REQUIREMENTSThe regulatory requirements to protect, maintain, reclaim, and restore water quality under Title 25 of the Pennsylvania Code and the Clean Streams Law.
STORMWATERDrainage runoff from the surface of the land resulting from precipitation or snow or ice melt.
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 facilities.
STORMWATER MANAGEMENT SITE PLANThe plan prepared by the developer or the developer's representative indicating how stormwater runoff will be managed at the development site in accordance with this chapter. "Stormwater management site plan" will be designated as "SWM site plan" throughout this chapter.
STREAMA channel or conveyance of surface water having a defined bed and banks, whether natural or artificial, with perennial or intermittent flow.
SUBDIVISIONAs defined in The Pennsylvania Municipalities Planning Code, Act of July 31, 1968, P.L. 805, No. 247.
USDAUnited States Department of Agriculture.
WATERS OF THIS 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 and underground water, or parts thereof, whether natural or artificial, within or on the boundaries of this commonwealth.
WATERSHEDRegion or land area drained by a river, watercourse, or other surface water of this commonwealth to a downstream point.
WETLANDAreas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions, including swamps, marshes, bogs, and similar areas.