[Ord. No. 10-2022, 7/20/2022]
These definitions do not necessarily reflect the definitions contained in pertinent regulations or statutes, and are intended for this chapter only. 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, 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, builder, and/or other persons, including his/her heirs, successors, agents and assigns, who has filed an application to the municipality for approval to engage in any regulated activity at a project site in the municipality.
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.
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."
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 partial or complete inundation during a 100-year flood, or any area subject to the unusual and rapid accumulation of surface water from any source, as 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). Also referred to as flood-prone 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. 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.
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, all buildings; and all forms of impervious paving materials used for roads, driveways, parking, loading, walks, courts, patio, etc. Nonpermanent, aboveground swimming pools are exempt from this definition, provided that there is a minimum of two feet between the pool and any property line or other structure on the property.
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 DEVELOPMENT (DEVELOPMENT)1. Any of the following activities:
A. The conversion of any existing building or site that involves a change of land use, except as noted below in Subsection 2A.
Development as herein defined.
The improvement of one lot or two or more contiguous lots, tracts or parcels of land for any purposed involving:
(1) A group of two or more residential or nonresidential buildings, whether proposed initially or cumulatively, or single nonresidential building on lot or lots regardless of the number of occupants or tenure.
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.
Except that the following activities shall not be considered land developments:
A. The conversion of an existing single-family detached dwelling or single-family semidetached dwelling into not more than three residential units, unless such units are intended to be a condominium.
The addition of an accessory building, on a lot or lots subordinate to an existing principal building.
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.
MUNICIPALITYBorough of Conshohocken, Montgomery County, Pennsylvania.
NRCSUSDA Natural Resources Conservation Service (previously SCS).
PEAK DISCHARGEThe maximum rate of stormwater runoff from a specific storm event.
PROJECT SITEThe specific parcel(s) of land where any regulated activities in the municipality are planned, conducted, or maintained.
QUALIFIED PROFESSIONALAny person licensed by the Pennsylvania Department of State or otherwise qualified by 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.
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 four-percent chance).
RIPARIAN BUFFERA permanent 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 PLAN (SWM SITE PLAN)The plan prepared by the applicant or his 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.
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.
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 area drained by a river, watercourse, or other surface water of this commonwealth.
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. Development in wetlands is regulated by the U.S. Army Corps of Engineers and the Pennsylvania Department of Environmental Resources. Identification of wetlands should be based upon the Federal Manual for Identifying and Delineating Wetlands, an interagency publication of the Corps of Engineers, EPA, Fish and Wildlife Service, and Soil Conservation Service, dated January 1989.