For the purpose of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
   80TH PERCENTILE RAINFALL EVENT. The rainfall event, based on historical rainfall records, that represents an event that is equal to or greater than 80% of the rainfall events that would be expected to occur in a typical year. Based on an analysis of precipitation records, it has been determined that for the City of Madisonville, this event corresponds to the runoff volume from a 0.61 inch rainfall event.
   BEST MANAGEMENT PRACTICES or BMPS. Schedules of activities, prohibitions of practices, maintenance procedures, and other management practices to prevent or reduce the pollution of waters of the Commonwealth. BMPs also include treatment requirements, operating procedures, and practices to control stormwater runoff.
   CITY PLAN REVIEW STAFF. The City Engineer and/or other designated officials.
   CONTROLLED RELEASE STRUCTURE. A facility constructed to regulate the volume of stormwater runoff that is conveyed during a specific length of time.
   CONVEYANCE STRUCTURES. Water-carrying devices or improvements such as channels, ditches, storm sewers, culverts, inlets, and the like.
   DETENTION or RETENTION. Restraining the rate of stormwater runoff with some natural or manmade devices.
   DEVELOPED. Conditions after construction or other manmade change to improved or unimproved land, including, but not limited to, buildings or other structures, mining, dredging, filling, grading, paving, excavation, or drilling operations.
   EXCESS STORMWATER. The calculated runoff produced under a natural or pre-developed condition versus the calculated runoff produced under an altered or post-developed condition, or that portion of stormwater runoff which exceeds the capacity of the storm sewers or natural drainage channels serving a specific watershed.
   GREEN INFRASTRUCTURE. An adaptable term used to describe an array of products, technologies, and practices that use natural systems or engineered systems that mimic natural processes to enhance overall environmental quality and provide utility services. As a general principal, green infrastructure techniques use soils and vegetation infiltrate, evapotranspirate, and/or recycle stormwater runoff. When used as components of a stormwater management system, green infrastructure practices such as green roofs, porous pavement, rain gardens, and vegetated swales can produce a variety of environmental benefits. In addition to effectively retaining and infiltrating rainfall, these technologies can simultaneously help filter air pollutants, reduce energy demands, mitigate urban heat islands, and sequester carbon while also providing communities with aesthetic and natural resource benefits.
   HIGH QUALITY WATERS or HQW. Those "Waters of the Commonwealth" that have been categorized by the Kentucky Division of Water as high quality pursuant to the requirements of 401 KAR 10:030, Section 1(3).
   IMPAIRED WATERS or IW. Those "Waters of the Commonwealth" that have been categorized by the Kentucky Division of Water as impaired for applicable designated uses and have been identified pursuant to 33 U.S.C. 1315 (b) and listed in the most recent 305 (b) report.
   IMPERVIOUS SURFACE. Asphalt, concrete or any other surface which does not allow measurable infiltration of stormwater.
   KENTUCKY POLLUTANT DISCHARGE ELIMINATION SYSTEM or KPDES. The Kentucky program for issuing, modifying, revoking and reissuing, revoking, monitoring and enforcing permits to discharge, and imposing and enforcing pretreatment requirements.
   KPDES SMS4 PERMIT. The general permit issued by the Kentucky Division of Water (KDOW) that authorizes small Municipal Separate Storm Sewer Systems (sMS4) to discharge stormwater runoff from a small Municipal Separate Storm Sewer System (MS4) to the receiving waters of the Commonwealth in accordance with effluent limitations, monitoring requirements, and other conditions set forth in the permit authorizing the MS4 to discharge under the Kentucky Pollutant Discharge Elimination System.
   LAND DISTURBANCE ACTIVITY or LAND DISTURBING ACTIVITY. Any clearing, grubbing, grading, excavating, filling, or other alteration of the earth's surface where natural or manmade ground cover is destroyed. Land disturbance activity does not include the following:
      (1)   Minor land disturbance activities including, but not limited to, activities specific to underground utility repairs, replacement of existing utilities, home gardens, minor repairs, and maintenance work;
      (2)   Installation of fence, sign, telephone, and electric poles and other kinds of posts or poles; and
      (3)   Emergency work to protect life, limb, or property and emergency repairs.
   LARGER COMMON PLAN OF DEVELOPMENT OR SALE. A contiguous area where multiple separate and distinct construction activities are planned to occur at different times on different schedules under one plan, e.g., a housing development of 5 1/4-acre lots.
   MS4. An acronym for a "municipal separate storm sewer system."
   MUNICIPAL SEPARATE STORM SEWER SYSTEM. A conveyance, or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, and storm drains) owned or operated by a state, city, town, county, district, association, or other public body (created by or pursuant to state law) having jurisdiction over disposal of sewage, industrial water, stormwater, or other wastes, that discharges to waters of the United States:
      (1)   Designed or used for collecting or conveying stormwater;
      (2)   Which is not a combined sewer; and
      (3)   Which is not part of a Publically Owned Treatment Works (POTW) as defined at 40 CFR 122.2.
   NATURAL DRAINAGE. Water which flows by gravity in channels formed by the surface topography of the earth prior to changes made by the efforts of humans.
   NPDES. An acronym for "National Pollutant Discharge Elimination System," the effluent permitting program for point source discharges that is administered by the United States Environmental Protection Agency (USEPA).
   OFF-SITE. External to the boundary of a development.
   ON-SITE. Internal to the boundary of a development.
   POINT DISCHARGE. Release of stormwater at a specific location.
   RUNOFF. Rainfall excess after natural losses from infiltration, evaporation, transportation or incidental poundage.
   SMS4. An acronym for a "small municipal separate storm sewer system."
   STORMWATER. Stormwater runoff, snowmelt runoff, surface runoff and drainage.
   STORMWATER RUNOFF RELEASE RATE. The rate at which stormwater runoff is released from dominant to servient land.
   STORMWATER STORAGE AREA. An area designed to temporarily accumulate excess stormwater.
   SWALE. Surface-type conveyance for stormwater, usually designated to carry incidental, localized runoff.
   TMDL. An acronym for "Total Maximum Daily Load", a federally mandated program for impaired waters of the Commonwealth to determine the maximum assimilative capacity of a water for a specified pollutant and to allocate allowable pollutant loads to sources in the watershed.
   WATERS OF THE COMMONWEALTH. Means and includes any and all rivers, streams, creeks, lakes, ponds, impounding reservoirs, springs, wells, marshes, and all other bodies of surface or underground water, natural or artificial, situated wholly or partly within or bordering upon the Commonwealth or within its jurisdiction.
   WATERS OF THE UNITED STATES. As defined by the Clean Water Act, applies only to surface waters, rivers, lakes, estuaries, coastal waters and wetlands. Not all surface waters are legally "Waters of the United States". Generally those waters include the following:
      (1)   All interstate waters;
      (2)   Intrastate waters used in interstate and/or foreign commerce;
      (3)   Tributaries of the above;
      (4)   Territorial seas at the cyclical high tide mark; and
      (5)   Wetlands adjacent to all of the above.
   WATER-QUALITY CONTROL STRUCTURE. The structures (e.g. grass swales, filter strips, infiltration basins, detention ponds, stormwater wetlands, natural filtration areas, sand filters, and rain gardens, etc.), used to slow runoff, promote infiltration, and reduce sediments and other pollutants in stormwater runoff.
   WATER QUALITY RUNOFF VOLUME (WQV). The stormwater volume to be treated through a water quality control structure based on the surface runoff produced by an 80th percentile rainfall event.
(Ord. O-2019-20, passed 12-16-19)