(A) Abbreviations. For the purpose of this chapter, the following abbreviations shall apply.
BMP. Best management practice.
COE. United States Army Corps of Engineers.
CWA. Clean Water Act.
EPA. Environmental Protection Agency.
GIS. Geographical information system.
IDEM. Indiana Department of Environmental Management.
MS4. Municipal separate storm sewers.
NRCS. USDA-Natural Resources Conservation Service.
NPDES. National Pollution Discharge Elimination System.
POTW. Publicly owned treatment works.
SWCD. Soil and Water Conservation District.
SWPPP. Storm Water Pollution Prevention Plan.
USDA. United States Department of Agriculture.
USFWS. United States Fish and Wildlife Service.
(B) Definitions. For the purpose of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
AGRICULTURAL LAND-DISTURBING ACTIVITY. Tillage, planting, cultivation or harvesting operations for the production of agricultural or nursery vegetative crops. The term also includes pasture renovation and establishment, the construction of agricultural conservation practices and the installation and maintenance of agricultural drainage pipe. For purposes of this rule, the term does not include land-disturbing activities for the construction of agricultural related facilities, such as barns, buildings to house livestock, roads associated with infrastructure, agricultural waste lagoons and facilities, lakes and ponds, wetlands and other infrastructure.
BASE FLOW. Stream discharge derived from ground water sources as differentiated from surface runoff. Sometimes considered to include flows from regulated lakes or reservoirs.
BEST MANAGEMENT PRACTICES. Design, construction and maintenance practices and criteria for storm water facilities that minimize the impact of storm water runoff rates and volumes, prevent erosion and capture pollutants.
BUFFER STRIP. An existing, variable width strip of vegetated land intended to protect water quality and habitat.
CAPACITY (OF A STORM DRAINAGE FACILITY). The maximum flow that can be conveyed or stored by a storm drainage facility without causing damage to public or private property.
CATCH BASIN. A chamber usually built at the curb line of a street for the admission of surface water to a storm drain or subdrain, having at its base a sediment sump designed to retain grit and detritus below the point of overflow.
CHANNEL. A portion of a natural or artificial watercourse which periodically or continuously contains moving water, or which forms a connecting link between two bodies of water. It has a defined bed and banks which serve to confine the water.
COMPREHENSIVE STORM WATER MANAGEMENT. A comprehensive storm water program for effective management of storm water quantity and quality throughout the community.
CONSTRUCTED WETLAND. A human-made shallow pool that creates growing conditions suitable for wetland vegetation and is designed to maximize pollutant removal.
CONSTRUCTION ACTIVITY. Land-disturbing activities and land-disturbing activities associated with the construction of infrastructure and structures. This term does not include routine ditch or road maintenance or minor landscaping projects.
CONSTRUCTION SITE ACCESS. A stabilized stone surface at all points of ingress or egress to a project site, for the purpose of capturing and detaining sediment carried by tires of vehicles or other equipment entering or exiting the project site.
CONTIGUOUS. Adjoining or in actual contact with.
CONTOUR. An imaginary line on the surface of the earth connecting points of the same elevation.
CONTOUR LINE. Line on a map which represents a contour or points of equal elevation.
CONTRACTOR or SUBCONTRACTOR. An individual or company hired by the project site or individual lot owner, his, her or their agent or the individual lot operator to perform services on the project site.
CONVEYANCE. Any structural method for transferring storm water between at least two points. The term includes piping, ditches, swales, curbs, gutters, catch basins, channels, storm drains and roadways.
CROSS-SECTION. A graph or plot of ground elevation across a stream valley or a portion of it, usually along a line perpendicular to the stream or direction of flow.
CULVERT. A closed conduit used for the conveyance of surface drainage water under a roadway, railroad, canal or other impediment.
DECHLORINATED SWIMMING POOL DISCHARGE. Chlorinated water that has either sat idle for seven days following chlorination prior to discharge to the MS4 conveyance or, by analysis, does not contain detectable concentrations (less than five-hundredths milligram per liter) of chlorinated residual.
DESIGN STORM. A selected storm event, described in terms of the probability of occurring once within a given number of years, for which drainage or flood control improvements are designed and built.
DETENTION. Managing storm water runoff by temporary holding and controlled release.
DETENTION BASIN. A facility constructed or modified to restrict the flow of storm water to a prescribed maximum rate, and to detain concurrently the excess waters that accumulate behind the outlet.
DETENTION STORAGE. The temporary detaining of storage of storm water in storage facilities, on rooftops, in streets, parking lots, school yards, parks, open spaces or other areas under predetermined and controlled conditions, with the rate of release regulated by appropriately installed devices.
DETENTION TIME. The theoretical time required to displace the contents of a tank or unit at a given rate of discharge (volume divided by rate of discharge).
DETRITUS. Dead or decaying organic matter; generally contributed to storm water as fallen leaves and sticks or as dead aquatic organisms.
DEVELOPER. Any person financially responsible for construction activity, or an owner of property who sells or leases, or offers for sale or lease, any lots in a subdivision.
DEVELOPMENT.
(a) Any human-made change to improved or unimproved real estate including, but not limited to:
1. Construction, reconstruction or placement of a building or any addition to a building;
2. Construction of flood control structures such as levees, dikes, dams or channel improvements;
3. Construction or reconstruction of bridges or culverts;
4. Installing a manufactured home on a site, preparing a site for a manufactured home or installing a recreational vehicle on a site for more than 180 days;
5. Installing utilities, erection of walls, construction of roads or similar projects;
6. Mining, dredging, filling, grading, excavation or drilling operations;
7. Storage of materials; or
8. Any other activity that might change the direction, height or velocity of flood or surface waters.
(b) DEVELOPMENT does not include activities such as the maintenance of existing buildings and facilities such as painting, re-roofing, resurfacing roads or gardening, plowing and similar agricultural practices that do not involve filling, grading, excavation or the construction of permanent buildings.
DISCHARGE. Usually the rate of water flow. A volume of fluid passing a point per unit time commonly expressed as cubic feet per second, cubic meters per second, gallons per minute or millions of gallons per day.
DISPOSAL. The discharge, deposit, injection, spilling, leaking or placing of any solid waste or hazardous waste into or on any land or water so that the solid waste or hazardous waste, or any constituent of the waste, may enter the environment, be emitted into the air or be discharged into any waters, including ground waters.
DITCH. A human-made, open watercourse in or into which excess surface water or ground water drained from land, storm water runoff or flood waters flow either continuously or intermittently.
DRAIN. A buried slotted or perforated pipe or other conduit (subsurface drain) or a ditch (open drain) for carrying off surplus ground water or surface water.
DRAINAGE. The removal of excess surface water or ground water from land by means of ditches or subsurface drains. Also see NATURAL DRAINAGE.
DRAINAGE AREA. The area draining into a stream at a given point. It may be of different sizes for surface runoff, subsurface flow and base flow, but generally the surface runoff area is considered as the DRAINAGE AREA.
DRY WELL. A type of infiltration practice that allows storm water runoff to flow directly into the ground, via a bored or otherwise excavated opening in the ground surface.
DURATION. The time period of a rainfall event.
ENVIRONMENT. The sum total of all the external conditions that may act upon a living organism or community to influence its development or existence.
ERODIBILITY INDEX (EI). The soil erodibility index (EI) provides a numerical expression of the potential for a soil to erode considering the physical and chemical properties of the soil and the climatic conditions where it is located. The higher the index, the greater the investment needed to maintain the sustainability of the soil resource base if intensively cropped. It is defined to be the maximum of (RxKxLS)/T (from the Universal Soil Loss Equation) and (CxI)/T (from the Wind Erosion Equation), where R is a measure of rainfall and runoff, K is a factor of the susceptibility of the soil to water erosion, LS is a measure of the combined effects of slope length and steepness, C is a climatic characterization of windspeed and surface soil moisture and I is a measure of the susceptibility of the soil to wind erosion. ERODIBILITY INDEX scores equal to or greater than eight are considered highly erodible land.
EROSION. The wearing away of the land surface by water, wind, ice, gravity or other geological agents. The following terms are used to describe different types of WATER EROSION.
(a) ACCELERATED EROSION. Erosion much more rapid than normal or geologic erosion, primarily as a result of the activities of humans.
(b) CHANNEL EROSION. An erosion process whereby the volume and velocity of flow wears away the bed and/or banks of a well-defined channel.
(c) GULLY EROSION. An erosion process whereby runoff water accumulates in narrow channels and, over relatively short periods, removes the soil to considerable depths, ranging from one to two feet to as much as 75 to 100 feet.
(d) RILL EROSION. An erosion process in which numerous small channels only several inches deep are formed; occurs mainly on recently disturbed and exposed soils. (See RILL.)
(e) SPLASH EROSION. The spattering of small soil particles caused by the impact of raindrops on wet soils; the loosened and spattered particles may or may not be subsequently removed by surface runoff.
(f) SHEET EROSION. The gradual removal of a fairly uniform layer of soil from the land surface by runoff water.
EROSION AND SEDIMENT CONTROL. A practice, or a combination of practices, to minimize sedimentation by first reducing or eliminating erosion at the source and then as necessary, trapping sediment to prevent it from being discharged from or within a project site.
FILTER STRIP. Usually a long, relatively narrow area (usually, 20 to 75 feet wide) of undisturbed or planted vegetation used near disturbed or impervious surfaces to filter storm water pollutants for the protection of watercourses, reservoirs or adjacent properties.
FLOATABLE. Any solid waste that will float on the surface of the water.
FLOOD or FLOOD WATERS. A general and temporary condition of partial or complete inundation of normally dry land areas from the overflow, the unusual and rapid accumulation or the runoff of surface waters from any source.
FLOODPLAIN. The channel proper and the areas adjoining the channel which have been or hereafter may be covered by the regulatory or 100-year flood. Any normally dry land area that is susceptible to being inundated by water from any natural source. The FLOODPLAIN includes both the floodway and the floodway fringe districts.
FLOODWAY. The channel of a river or stream and those portions of the floodplains adjoining the channel which are reasonably required to efficiently carry and discharge the peak flow of the regulatory flood of any river or stream.
FLOODWAY FRINGE. The portion of the floodplain lying outside the floodway, which is inundated by the regulatory flood.
FOOTING DRAIN. A drain pipe installed around the exterior of a basement wall foundation to relieve water pressure caused by high ground water elevation.
GARBAGE. All putrescible animal solid, vegetable solid and semisolid wastes resulting from the processing, handling, preparation, cooking, serving or consumption of food or food materials.
GASOLINE OUTLET. An operating gasoline or diesel fueling facility whose primary function is the resale of fuels. The term applies to facilities that create 5,000 or more square feet of impervious surfaces, or generate an average daily traffic count of 100 vehicles per 1,000 square feet of land area.
GEOGRAPHICAL INFORMATION SYSTEM. A computer system capable of assembling, storing, manipulation and displaying geographically referenced information. This technology can be used for resource management and development planning.
GRADE.
(a) The inclination or slope of a channel, canal, conduit and the like, or natural ground surface usually expressed in terms of the percentage the vertical rise (or fall) bears to the corresponding horizontal distance;
(b) The finished surface of a canal bed, roadbed, top of embankment or bottom of excavation; any surface prepared to a design elevation for the support of construction, such as paving or the laying of a conduit; and
(c) To finish the surface of a canal bed, roadbed, top of embankment or bottom of excavation or other land area to a smooth, even condition.
GRADING. The cutting and filling of the land surface to a desired slope or elevation.
GRASS. A member of the botanical family Graminae, characterized by blade-like leaves that originate as a sheath wrapped around the stem.
GROUND WATER. Accumulation of underground water, natural or artificial. The term does not include human-made underground storage or conveyance structures.
HABITAT. The environment in which the life needs of a plant or animal are supplied.
HIGHLY ERODIBLE LAND (HEL). Land that has an erodibility index of eight or more.
HOT SPOT DEVELOPMENT. Projects involving land uses considered to be high pollutant producers such as vehicle service and maintenance facilities, vehicle salvage yards and recycling facilities, vehicle and equipment cleaning facilities, fleet storage areas for buses, trucks and the like, industrial/commercial or any hazardous waste storage areas or areas that generate such wastes, industrial sites, restaurants and convenience stores, any activity involving chemical mixing or loading/unloading, outdoor liquid container storage, public works storage areas, commercial container nurseries and some high traffic retail uses characterized by frequent vehicle turnover.
HYDROLOGIC UNIT CODE. A numeric United States Geologic Survey code that corresponds to a watershed area. Each area also has a text description associated with the numeric code.
HYDROLOGY. The science of the behavior of water in the atmosphere, on the surface of the earth and underground. A typical hydrologic study is undertaken to compute flow rates associated with specified flood events.
ILLICIT DISCHARGE. Any discharge to a conveyance that is not composed entirely of storm water, except naturally occurring floatables, such as leaves or tree limbs.
IMPAIRED WATERS. Waters that do not or are not expected to meet applicable water quality standards, as included on IDEM’s CWA § 303(d), List of Impaired Waters.
IMPERVIOUS SURFACE. Surfaces, such as pavement and rooftops, which prevent the infiltration of storm water into the soil.
INDIVIDUAL BUILDING LOT. A single parcel of land within a multi-parcel development.
INDIVIDUAL LOT OPERATOR. A contractor or subcontractor working on an individual lot.
INDIVIDUAL LOT OWNER. A person who has financial control of construction activities for an individual lot.
INFILTRATION. Passage or movement of water into the soil. INFILTRATION practices include any structural BMP designed to facilitate the percolation of run-off through the soil to ground water. Examples include INFILTRATION basins or trenches, dry wells and porous pavement.
INLET. An opening into a storm drain system for the entrance of surface storm water runoff, more completely described as a storm drain inlet.
LAND-DISTURBING ACTIVITY. Any human-made change of the land surface, including removing vegetative cover that exposes the underlying soil, excavating, filling, transporting and grading.
LAND SURVEYOR. A person licensed under the laws of the state to practice land surveying.
LARGER COMMON PLAN OF DEVELOPMENT OR SALE. A plan, undertaken by a single project site owner or a group of project site owners acting in concert, to offer lots for sale or lease; where such land is contiguous, or is known, designated, purchased or advertised as a common unit or by a common name, such land shall be presumed as being offered for sale or lease as part of a larger common plan. The term also includes phased or other construction activity by a single entity for its own use.
LOWEST ADJACENT GRADE. The elevation of the lowest grade adjacent to a structure, where the soil meets the foundation around the outside of the structure (including structural members, such as basement walkout, patios, decks, porches, support posts or piers, and rim of the window well).
LOWEST FLOOR. The lowest of the following:
(a) The top of the basement floor;
(b) The top of the garage floor, if the garage is the lowest level of the building;
(c) The top of the first floor of buildings constructed on a slab or of buildings elevated on pilings or constructed on a crawl space with permanent openings; or
(d) The top of the floor level of any enclosure below an elevated building where the walls of the enclosure provide any resistance to the flow of flood waters unless:
1. The walls are designed to automatically equalize the hydrostatic flood forces on the walls by allowing for the entry and exit of flood waters, by providing a minimum of two opening (in addition to doorways and windows) having a total area of one square foot for every two square feet of enclosed area subject to flooding. The bottom of all such openings shall be no higher than one foot above grade; or
2. Such enclosed space shall be usable only for the parking of vehicles or building access.
MANHOLE. Storm drain structure through which a person may enter to gain access to an underground storm drain or enclosed structure.
MEASURABLE STORM EVENT. A precipitation event that results in a total measured precipitation accumulation equal to, or greater than, one-half inch of rainfall.
MULCH. A natural or artificial layer of plant residue or other materials covering the land surface which conserves moisture, holds soil in place, aids in establishing plant cover and minimizes temperature fluctuations.
MUNICIPAL SEPARATE STORM SEWERS. An MS4 meets all the following criteria:
(a) Is a conveyance or system of conveyances owned by the state, county, city, town or other public entity;
(b) Discharges to waters of the United States;
(c) Is designed or used for collecting or conveying storm water;
(d) Is not a combined sewer; and
(e) Is not part of a publicly owned treatment works (POTW).
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM. A permit developed by the U.S. EPA through the Clean Water Act. In the state, the permitting process has been delegated to IDEM. This permit covers aspects of municipal storm water quality.
NATURAL DRAINAGE. The flow patterns of storm water run-off over the land in its pre- development state.
NUTRIENT(S).
(a) A substance necessary for the growth and reproduction of organisms; and
(b) In water, those substances (chiefly nitrates and phosphates) that promote growth of algae and bacteria.
OPEN DRAIN. A natural watercourse or constructed open channel that conveys drainage water.
OPEN SPACE. Any land area devoid of any disturbed or impervious surfaces created by industrial, commercial, residential, agricultural or other human-made activities.
OUTFALL. The point, location or structure where a pipe or open drain discharges to a receiving body of water.
OUTLET. The point of water disposal from a stream, river, lake, tidewater or artificial drain.
PEAK DISCHARGE or PEAK FLOW. The maximum instantaneous flow from a given storm condition at a specific location.
PERCOLATION. The movement of water through soil.
PERMANENT STABILIZATION. The establishment, at a uniform density of 70% across the disturbed area, of vegetative cover or permanent non-erosive material that will ensure the resistance of the soil to erosion, sliding or other movement.
PERVIOUS. Allowing movement of water.
POINT SOURCE. Any discernible, confined and discrete conveyance including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure or container from which pollutants are or may be discharged (Pub. Law No. 92-500, § 502(14)).
POROUS PAVEMENT. A type of infiltration practice to improve the quality and reduce the quantity of storm water run-off via the use of human-made, pervious pavement which allows run-off to percolate through the pavement and into underlying soils.
PROFESSIONAL ENGINEER. A person licensed under the laws of the state to practice professional engineering.
PROJECT SITE. The entire area on which construction activity is to be performed.
PROJECT SITE OWNER. The person required to submit a storm water permit application, and required to comply with the terms of this chapter, including a developer or a person who has financial and operational control of construction activities, and project plans and specifications, including the ability to make modifications to those plans and specifications.
RAIN GARDEN. A vegetative practice used to alter impervious surfaces, such as roofs, into pervious surfaces for absorption and treatment of rainfall.
RECEIVING STREAM, RECEIVING CHANNEL or RECEIVING WATER. The body of water into which runoff or effluent is discharged. The term does not include private drains, unnamed conveyances, retention and detention basins or constructed wetlands used as treatment.
RECHARGE. Replenishment of ground water reservoirs by infiltration and transmission from the outcrop of an aquifer or from permeable soils.
RE-DEVELOPMENT. Development occurring on a previously developed site.
REFUELING AREA. An operating gasoline or diesel fueling area whose primary function is to provide fuel to equipment or vehicles.
REGIONAL POND. A detention/retention basin sized to detain/retain the runoff from the entire watershed, on-site and off-site, tributary to the pond’s outlet.
REGULATORY FLOOD. The discharge or elevation associated with the 100-year flood as calculated by a method and procedure which is acceptable to and approved by the State Department of Natural Resources and the Federal Emergency Management Agency. The REGULATORY FLOOD is also known as the BASE FLOOD.
REGULATORY FLOODWAY. See FLOODWAY.
RELEASE RATE. The amount of storm water release from a storm water control facility per unit of time.
RESERVOIR. A natural or artificially created pond, lake or other space used for storage, regulation or control of water. May be either permanent or temporary. The term is also used in the hydrologic modeling of storage facilities.
RETENTION. The storage of storm water to prevent it from leaving the development site. May be temporary or permanent.
RETENTION BASIN. A type of storage practice, that has no positive outlet, used to retain storm water run-off for an indefinite amount of time. Runoff from this type of basin is removed only by infiltration through a porous bottom or by evaporation.
RETURN PERIOD. The average interval of time within which a given rainfall event will be equaled or exceeded once. A flood having a RETURN PERIOD of 100 years has a 1% probability of being equaled or exceeded in any one year.
RIPARIAN ZONE. Of, on or pertaining to the banks of a stream, river or pond.
RIPARIAN HABITAT. A land area adjacent to a waterbody that supports animal and plant life associated with that waterbody.
RUNOFF. The portion of precipitation that flows from a drainage area on the land surface, in open channels or in storm water conveyance systems.
RUNOFF COEFFICIENT. A decimal fraction relating the amount of rain which appears as runoff and reaches the storm drain system to the total amount of rain falling. A coefficient of 0.5 implies that 50% of the rain falling on a given surface appears as storm water runoff.
SEDIMENT. Solid material (both mineral and organic) that is in suspension, is being transported or has been moved from its site of origin by air, water, gravity or ice and has come to rest on the earth’s surface.
SEDIMENTATION. The process that deposits soils, debris and other unconsolidated materials either on the ground surfaces or in bodies of water or watercourses.
SENSITIVE WATER. A waterbody in need of priority protection or remediation base on its:
(a) Providing habitat for threatened or endangered species;
(b) Usage as a public water supply intake;
(c) Relevant community value;
(d) Usage for full body contact recreation;
(e) Exceptional use classification as found in 327 I.A.C. 2-1-11(b); and
(f) Outstanding state resource water classification as found in 327 I.A.C. 2-1.5-19(b).
SITE. The entire area included in the legal description of the land on which land-disturbing activity is to be performed.
SLOPE. Degree of deviation of a surface from the horizontal, measured as a numerical ratio or percent. Expressed as a ratio, the first number is commonly the horizontal distance (run) and the second is the vertical distance (rise) (e.g., 2:1). However, the preferred method for designation of SLOPES is to clearly identify the horizontal (H) and vertical (V) components (length (L) and Width (W) components for horizontal angles). Also, note that according to international standards (metric), the SLOPES are presented as the vertical or width component shown on the numerator (e.g., 1V:2H). SLOPE expressions in this chapter follow the common presentation of SLOPES (e.g., 2:1) with the metric presentation shown in parentheses (e.g., (1V:2H)). SLOPES can also be expressed in “percents”. SLOPES given in percents are always expressed as (100*V/H) (e.g., a 2:1 (1V:2H) slope is a 50% slope).
SOIL. The unconsolidated mineral and organic material on the immediate surface of the earth that serves as a natural medium for the growth of land plants.
SOIL AND WATER CONSERVATION DISTRICT. A public organization created under state law as a special-purpose district to develop and carry out a program of soil, water and related resource conservation, use and development within its boundaries. A subdivision of state government with a local governing body, established under I.C. 14-32.
SOLID WASTE. Any garbage, refuse, debris or other discarded material.
SPILL. The unexpected, unintended, abnormal or unapproved dumping, leakage, drainage, seepage, discharge or other loss of petroleum, hazardous substances, extremely hazardous substances or objectionable substances. The term does not include releases to impervious surfaces when the substance does not migrate off the surface or penetrate the surface and enter the soil.
STORM DURATION. The length of time that water may be stored in any storm water control facility, computed from the time water first begins to be stored.
STORM EVENT. An estimate of the expected amount of precipitation within a given period of time. For example, a ten-year frequency, 24-hour duration STORM EVENT is a storm that has a 10% probability of occurring in any one year. Precipitation is measured over a 24-hour period.
STORM SEWER. A closed conduit for conveying collected storm water, while excluding sewage and industrial wastes. Also called a STORM DRAIN.
STORM WATER. Water resulting from rain, melting or melted snow, hail or sleet.
STORM WATER MANAGEMENT SYSTEM. A collection of structural and non-structural practices and infrastructure designed to manage storm water on a site. This system may include, but is not limited to, erosion control measures, storm drainage infrastructure, detention/retention facilities and storm water quality BMPs.
STORM WATER POLLUTION PREVENTION PLAN. A plan developed to minimize the impact of storm water pollutants resulting from construction activities.
STORM WATER RUNOFF. The water derived from rains falling within a tributary basin, flowing over the surface of the ground or collected in channels or conduits.
STORM WATER QUALITY MANAGEMENT PLAN. A comprehensive written document that addresses storm water runoff quality.
STORM WATER QUALITY MEASURE. A practice, or a combination of practices, to control or minimize pollutants associated with storm water runoff.
STORM WATER DRAINAGE SYSTEM. All means, natural or human-made, used for conducting storm water to, through or from a drainage area to any of the following: conduits and appurtenant features, canals, channels, ditches, storage facilities, swales, streams, culverts, streets and pumping stations.
STRIP DEVELOPMENT. A multi-lot project where building lots front on an existing road.
SUBDIVISION, MAJOR. Any land that is divided or proposed to be divided into four or more lots, whether contiguous or subject to zoning requirements, for the purpose of sale or lease as part of a larger common plan of development or sale.
SUBDIVISION, MINOR. Any land that is divided or proposed to be divided into less than four lots, whether contiguous or subject to zoning requirements, for the purpose of sale or lease as part of a larger common plan of development or sale.
SUBSURFACE DRAIN. A pervious backfield trench, usually containing stone and perforated pipe, for intercepting ground water or seepage.
SURFACE RUNOFF. Precipitation that flows onto the surfaces of roofs, streets, the ground and the like and is not absorbed or retained by that surface, but collects and runs off.
SWALE. An elongated depression in the land surface that is at least seasonally wet, is usually heavily vegetated and is normally without flowing water. SWALES conduct storm water into primary drainage channels and may provide some ground water recharge.
TEMPORARY STABILIZATION. The covering of soil to ensure its resistance to erosion, sliding or other movement. The term includes vegetative cover, anchored mulch or other non-erosive material applied at a uniform density of 70% across the disturbed area.
TILE DRAIN. Pipe made of perforated plastic, burned clay, concrete or similar material, laid to a designed grade and depth, to collect and carry excess water from the soil.
TOPOGRAPHIC MAP. Graphical portrayal of the topographic features of a land area, showing both the horizontal distances between the features and their elevations above a given datum.
TOPOGRAPHY. The representation of a portion of the earth’s surface showing natural and human-made features of a give locality such as rivers, streams, ditches, lakes, roads, buildings and most importantly, variations in ground elevations for the terrain of the area.
TRAINED INDIVIDUAL. An individual who is trained and experienced in the principles of storm water quality, including erosion and sediment control as may be demonstrated by state registration, professional certification (such as CESSWI and/or CPESC certification), or other documented and applicable experience or coursework as deemed sufficient by the town that enable the individual to make judgments regarding storm water control or treatment and monitoring.
URBAN DRAIN. A drain defined as “urban drain” in the State Drainage Code.
URBANIZATION. The development, change or improvement of any parcel of land consisting of one or more lots for residential, commercial, industrial, institutional, recreational or public utility purposes.
VEGETATED SWALE. A type of vegetative practice used to filter storm water runoff via a vegetated, shallow-channel conveyance.
WATER QUALITY. A term used to describe the chemical, physical and biological characteristics of water, usually in respect to its suitability for a particular purpose.
WATER RESOURCES. The supply of ground water and surface water in a given area.
WATERBODY. Any accumulation of water, surface or underground, natural or artificial, excluding water features designed and designated as water pollution control facilities.
WATERCOURSE. Any river, stream, creek, brook, branch, natural or human-made drainageway in or into which storm water runoff or floodwaters flow either continuously or intermittently.
WATERSHED. The region drained by or contributing water to a specific point that could be along a stream, lake or other storm water facilities. WATERSHEDS are often broken down into subareas for the purpose of hydrologic modeling.
WATERSHED AREA. All land and water within the confines of a drainage divide. See also WATERSHED.
WETLANDS. Areas that are inundated or saturated by surface water 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.
(Ord. 2013-17, passed 12-2-2013)