A.
For the purposes of this Part 1, certain terms and words used herein shall be interpreted as follows:
(1)
Words used in the present tense include the future tense; the singular number includes the plural, and the plural number includes the singular; words of masculine gender include feminine gender; and words of feminine gender include masculine gender.
(2)
The word "includes" or "including" shall not limit the term to the specific example but is intended to extend its meaning to all other instances of like kind and character.
(3)
The word "person" includes an individual, firm, association, organization, partnership, trust, company, corporation, or any other similar entity.
(4)
The words "shall" and "must" refers to items which are mandatory; the words "may" and "should" refer to items which are permissive.
(5)
The words "used or occupied" include the words "intended, designed, maintained, or arranged to be used, occupied, or maintained."
B.
These definitions do not necessarily reflect the definitions contained in pertinent regulations or statutes and are intended for this Part 1 only.
C. ACCELERATED EROSION AGRICULTURAL ACTIVITIES ALTERATION APPLICANT AS-BUILT DRAWINGS BANKFULL BASE FLOW BEST MANAGEMENT PRACTICE (BMP) BIORETENTION CHANNEL EROSION CISTERN CONSERVATION DISTRICT CULVERT DAM DEP DEPARTMENT DESIGN PROFESSIONAL (QUALIFIED) DESIGN STORM DESIGNEE DETENTION BASIN DETENTION DISTRICT DETENTION VOLUME DEVELOPMENT SITE (SITE) DIFFUSED DRAINAGE DISCHARGE DISTURBED AREAS DOWNSLOPE PROPERTY LINE DRAINAGE CONVEYANCE FACILITY DRAINAGE EASEMENT DRAINAGE PERMIT DRAINAGE PLAN EARTH DISTURBANCE ACTIVITY EMERGENCY SPILLWAY ENCROACHMENT EROSION EROSION AND SEDIMENT POLLUTION CONTROL PLAN ERSAM EXCEPTIONAL VALUE WATERS EXISTING CONDITION FEMA FLOOD FLOODPLAIN FLOODWAY 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 FOREST MANAGEMENT/TIMBER OPERATIONS FREEBOARD GRADE GRASSED WATERWAY GREEN INFRASTRUCTURE GROUNDWATER RECHARGE HEC-HMS — The U.S. Army Corps of Engineers, Hydrologic Engineering Center (HEC) HIGH QUALITY WATERS HYDROLOGIC REGIME (NATURAL) HYDROLOGIC SOIL GROUP (HSG) HYETOGRAPH IMPERVIOUS SURFACE (IMPERVIOUS AREA) IMPOUNDMENT INFILL INFILTRATION INFILTRATION STRUCTURES INLET KARST LAND DEVELOPMENT (DEVELOPMENT) LAND EARTH DISTURBANCE LIMITING ZONE(1) (2) (3) LOW-IMPACT DEVELOPMENT (LID) MAIN STEM (MAIN CHANNEL) MANNING EQUATION (MANNING FORMULA) MUNICIPALITY NATURAL HYDROLOGIC REGIME NONPOINT SOURCE POLLUTION NPDES NRCS OPEN CHANNEL OUTFALL OUTLET PARENT TRACT PARKING LOT STORAGE PEAK DISCHARGE PENN STATE RUNOFF MODEL (CALIBRATED) PERVIOUS AREA PIPE PLANNING COMMISSION PMF (PROBABLE MAXIMUM FLOOD) POINT SOURCE PREDEVELOPMENT PRETREATMENT PROJECT SITE QUALIFIED PROFESSIONAL RATIONAL METHOD RECHARGE AREA RECONSTRUCTION RECORD DRAWINGS REDEVELOPMENT REGULATED ACTIVITIES REGULATED EARTH DISTURBANCE ACTIVITY RELEASE RATE RETENTION BASIN RETENTION VOLUME/REMOVED RUNOFF RETURN PERIOD RIPARIAN BUFFER RISER ROAD MAINTENANCE ROOFTOP DETENTION RUNOFF SALDO SEDIMENT SEDIMENT BASIN SEDIMENT POLLUTION SEDIMENTATION SEEPAGE PIT/SEEPAGE TRENCH SEPARATE STORM SEWER SYSTEM SHEET FLOW SOIL COVER COMPLEX METHOD SOURCE WATER PROTECTION AREAS (SWPA) SPECIAL PROTECTION SUBWATERSHEDS SPILLWAY STATE WATER QUALITY REQUIREMENTS STORAGE INDICATION METHOD STORM FREQUENCY STORM SEWER STORMWATER STORMWATER MANAGEMENT FACILITY STORMWATER MANAGEMENT PLAN STORMWATER MANAGEMENT SITE PLAN STREAM STREAM BUFFER STREAM ENCLOSURE SUBAREA SUBDIVISION SWALE TIMBER OPERATIONS TIME-OF-CONCENTRATION (Tc) USDA WATERCOURSE WATERS OF THIS COMMONWEALTH WATERSHED WELLHEAD WELLHEAD PROTECTION AREA WETLAND
As used in this Part 1, the following terms shall have the meanings indicated:
The removal of the surface of the land through the combined action of man's activity and the natural processes at a rate greater than would occur because of the natural process alone.
Activities 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.
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; landdisturbance.
Those 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 the same, are turned over to the Engineer at the completion of the project.
The channel at the top of bank or point where water begins to overflow onto a floodplain.
The portion of stream flow that is sustained by groundwater discharge.
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 Part 1. Stormwater BMPs are commonly grouped into one of two broad categories or measures: "structural" or "nonstructural." In this Part 1, 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.
A stormwater management facility which utilizes woody and herbaceous plants and soils to remove pollutants before infiltration occurs.
The widening, deepening, and headward cutting of small channels and waterways caused by moderate to large floods.
An underground reservoir or tank for storing rainwater.
A structure with appurtenant works which carries a stream under or through an embankment or fill.
An 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 that does or may impound water or another fluid or semifluid.
The Pennsylvania Department of Environmental Protection.
Pennsylvania Department of Environmental Protection.
A Pennsylvania registered professional engineer, registered landscape architect, or a registered professional land surveyor trained to develop stormwater management plans.
The 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."
The agent of the Morrisville Borough Planning Commission and/or agent of the governing body involved with the administration, review, or enforcement of any provisions of this Part 1 by contract or memorandum of understanding.
An impoundment structure designed to manage stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate.
Those subareas in which some type of detention is required to meet the plan requirements and the goals of Act 167.[1]
The volume of runoff that is captured and released into the waters of the commonwealth at a controlled rate.
See "project site."
Drainage discharge not confined to a single point location or channel, such as sheet flow or shallow concentrated flow.
An unstabilized land area where an earth disturbance activity is occurring or has occurred.
That 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.
A stormwater management facility designed to transmit stormwater runoff and shall include streams, channels, swales, pipes, conduits, culverts, storm sewers, etc.
A right granted by a landowner to a grantee, allowing the use of private land for stormwater management purposes.
A permit issued by the municipal governing body after the drainage plan has been approved. Said permit is issued prior to or with the final Municipal approval.
The documentation of the stormwater management system, to be used for a given development site, the contents of which are established in § 370-26.
A construction or other human activity which disturbs the surface of 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.
A conveyance area that is used to pass peak discharge greater than the maximum design storm controlled by the stormwater facility.
A structure or activity that changes, expands or diminishes the course, current or cross section of a watercourse, floodway or body of water.
The natural process by which the surface of the land is worn away by water, wind, or chemical action.
A plan that is designed to minimize accelerated erosion and sedimentation.
Existing Resource and Site Analysis Map.
Surface waters of high quality which satisfy Pennsylvania Code Title 25, Environmental Protection, Chapter 93, Water Quality Standards, § 93.4b(b) (relating to antidegradation).
The dominant land cover during the five-year period immediately preceding a proposed regulated activity.
Federal Emergency Management Agency.
A 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.
Any 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 Department of Environmental Protection (DEP) Technical Manual for Sewage Enforcement Officers (as amended or replaced from time to time by DEP).
that the floodway extends from the stream to 50 feet from the top of the bank of the stream.
Planning 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.
A 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.
A natural or constructed waterway, usually broad and shallow, covered with erosion-resistant grasses, used to conduct surface water.
Systems and practices that use or mimic natural processes to infiltrate, evapotranspire, or reuse stormwater on the site where it is generated.
Replenishment of existing natural underground water supplies.
Hydrologic Modeling System (HMS) adapted to the Delaware River South Watershed.
Surface waters having quality which exceeds levels necessary to support propagation of fish, shellfish, and wildlife and recreation in and on the water by satisfying Pennsylvania Code Title 25, Environmental Protection, Chapter 93, Water Quality Standards, § 93.4b(a).
The hydrologic cycle or balance that sustains quality and quantity of stormwater, baseflow, storage, and groundwater supplies under natural conditions.
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).
A graphical representation of average rainfall, rainfall excess rates, or volumes over specified areas during successive units of time during a storm.
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 not counted as impervious areas if they do not prevent infiltration.
A retention or detention basin designed to retain stormwater runoff and release it at a controlled rate.
Development 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.
The passing of stormwater through the soil from the surface.
A structure designed to direct runoff into the ground (e.g., french drains, seepage pits, seepage trench).
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.
A 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.
Inclusive of any or all of the following meanings:
Any 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.
A soil horizon or condition in the soil profile or underlying strata which includes one of the following:
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 effluent.
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.
Any stream segment or other runoff conveyance facility used as a reach in the Delaware River South Creek hydrologic model.
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.
Borough of Morrisville, Bucks County, Pennsylvania.
(See "hydrologic regime.")
Pollution that enters a body of water from diffuse origins in the watershed and does not result from confined or discrete conveyances.
National Pollutant Discharge Elimination System, the federal government's system for issuance of permits under the Clean Water Act, which is delegated to DEP in Pennsylvania.
USDA Natural Resources Conservation Service (previously SCS).
A 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.
Point where water flows from a conduit, stream, or drain.
Points of water disposal from a stream, river, lake, tidewater or artificial drain.
The parcel of land from which a land development or subdivision originates as of the date of the original Delaware River South Creek stormwater ordinance adoption.
Involves the use of impervious parking areas as temporary impoundments with controlled release rates during rainstorms.
The maximum rate of stormwater runoff from a specific storm event.
The computer-based hydrologic modeling technique adapted to the Delaware River South Watershed for the Act 167 plan. The model has been "calibrated" to reflect actual recorded flow values by adjoining key model input parameters.
Any area not defined as impervious.
A culvert, closed conduit, or similar structure (including appurtenances) that conveys stormwater.
The Planning Commission of the municipality.
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 based on data obtained from the National Oceanographic and Atmospheric Administration (NOAA).
Undeveloped/natural condition.
Techniques employed in stormwater BMPs to provide storage or filtering to help trap coarse materials and other pollutants before they enter the system.
The specific area of land where any regulated activities in the municipality are planned, conducted or maintained.
Any person licensed by the Pennsylvania Department of State or otherwise qualified by law to perform the work required by this Part 1.
A rainfall-runoff relation used to estimate peak flow.
Undisturbed surface area or depression where stormwater collects, and a portion of which infiltrates and replenishes the underground and groundwater.
The process by which existing developed area is adaptively reused, rehabilitated, restored, renovated, and/or expanded. The development relies on existing infrastructure and does not require an extension of water, sewer, or other public utilities.
Original 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.
The construction, alteration, or improvement exceeding 5,000 square feet of land disturbance performed on sites where existing land use is commercial, industrial, institutional, or multifamily residential.
Any earth disturbance activities or any activities that involve the alteration or development of land in a manner that may affect stormwater runoff.
The 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.
An 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.
The volume of runoff that is captured and not released directly into the surface waters of this commonwealth during or after a storm event.
The 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 of 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).
A permanent area of trees and shrubs located adjacent to streams, lakes, ponds and wetlands.
A vertical pipe extending from the bottom of a pond that is used to control the discharge rate from the pond for a specified design storm.
Earth disturbance activities within the existing road cross-section, such as grading and repairing existing unpaved road surfaces, cutting road banks, cleaning or clearing drainage ditches and other similar activities.
Temporary ponding and gradual release of stormwater falling directly onto flat roof surfaces by incorporating controlled-flow roof drains into building designs.
Any part of precipitation that flows over the land.
Subdivision and Land Development Ordinance.[6]
Soils or other materials transported by surface water as a product of erosion.
A barrier, dam, or retention or detention basin located and designed to retain rock, sand, gravel, silt, or other material transported by water.
The 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 requirements of the DEP Erosion and Sediment Pollution Control Program Manual.
The process by which mineral or organic matter is accumulated or deposited by the movement of water.
An area of excavated earth filled with loose stone or similar coarse material, into which surface water is directed for infiltration into the ground.
A 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.
Runoff that flows over the ground surface as a thin, even layer, not concentrated in a channel.
A 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).
The zone through which contaminants are likely to migrate and reach a drinking water well or surface water intake.
Watersheds for which the receiving waters are exceptional value (EV) or high quality (HQ) waters.
A conveyance that is used to pass the peak discharge of the maximum design storm controlled by the stormwater facility.
The regulatory requirements to protect, maintain, reclaim, and restore water quality under Title 25 of the Pennsylvania Code and the Clean Streams Law.
A 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.
The number of times that a given storm "event" occurs or is exceeded on the average in a stated period of years. See "return period."
A system of pipes and/or open channels that convey intercepted runoff and stormwater from other sources, but excludes domestic sewage and industrial wastes.
Drainage runoff from the surface of the land resulting from precipitation or snow or ice melt.
Any 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.
The plan for managing stormwater runoff in the Delaware River South Watershed adopted by Bucks County as required by the Act of October 4, 1978, P.L. 864 (Act 167),[7] and known as the Delaware River South Watershed Act 167 Stormwater Management Plan.
A natural watercourse.
The land area adjacent to each side of a stream, essential to maintaining water quality measured 150 feet from the top of the bank.
A bridge, culvert, or other structure in excess of 100 feet in length upstream to downstream which encloses a regulated water of this commonwealth.
The smallest drainage unit of a watershed for which stormwater management criteria have been established in the stormwater management plan.
As defined in the Pennsylvania Municipalities Planning Code, Act of July 31, 1968, P.L. 805, No. 247.[8]
A low-lying stretch of land which gathers or carries surface water runoff.
See "forest management."
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.
United States Department of Agriculture.
River, brook, creek, or a channel or ditch for water, whether natural or man-made with perennial or intermittent flow.
Any 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.
Region or area drained by a river, watercourse, or other surface water of this commonwealth.
The 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 towards and reach the water source.
Those 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, including swamps, marshes, bogs, ferns, and similar areas.