Unless specifically defined below, the words or phrases used in this chapter shall have the same meaning as they have in the "Minnesota Stormwater Manual" and if not defined there, as they are defined in common usage. When not inconsistent with the context, words used in the present tense include the future tense, words in the plural number include the singular number, and words in the singular number include the plural number. The words "shall" and "must" are always mandatory and not merely directive.
APPLICANT: | Any person or entity that applies for any permit for a project that includes a land disturbing activity. Applicant also means that person's agents, employees, and others acting under that person's direction. |
BEST MANAGEMENT PRACTICES (BMPs): | Erosion and sediment control and stormwater management practices that are the most effective and practicable means of controlling, preventing, and minimizing the degradation of surface water, including construction phasing, minimizing the length of time soil areas are exposed, and other management practices published by state or designated area wide planning agencies. BMPs include integrated management practices (IMP), which are small scale, distributed, on site stormwater management devices. Examples of BMPs can be found in the current versions of the "Inver Grove Heights Stormwater Manual - Northwest Area" (2006), the Minnesota pollution control agency's "Minnesota Stormwater Manual". |
BUFFER: | A protective vegetated zone located adjacent to a natural resource, such as a lake, stream or wetland, which is subject to direct or indirect human alteration. Such a buffer strip is an integral part of protecting an aquatic ecosystem through filtering pollutants and providing adjacent habitat. For a stream, the width of a buffer strip is the width along each bank of the stream. Therefore, a thirty foot (30') wide stream with one hundred foot (100') wide buffer strips has a total width of two hundred thirty feet (230'). Buffer vegetation may include preserving existing predevelopment vegetation and/or planting locally distributed native Minnesota trees, shrubs and herbaceous vegetation. |
CITY PLAN: | Any city adopted or approved planning document such as the comprehensive plan, water resources management plan, "Inver Grove Heights Stormwater Manual - Northwest Area" (2006), land use plan, or other. |
CONSTRUCTION ACTIVITY: | A disturbance to the land that results in a change in the topography, existing soil cover (both vegetative and nonvegetative), or the existing soil topography that may result in accelerated stormwater runoff, leading to soil erosion and movement of sediment into surface waters or drainage systems. Examples of construction activity may include clearing, grading, filling and excavating. |
CONVEYANCE: | A structure or feature used for transferring water from one location to another. |
DESIGN STORM: | A rainfall event of specified size and return frequency that is used to calculate the runoff volume and peak discharge rate and is used to measure the performance of stormwater management practices. |
DISCHARGE: | The release, conveyance, channeling, runoff, or drainage of stormwater, including snowmelt, into a receiving water resource. |
DRAINAGEWAYS: | Any natural or constructed channel which provides a course for water flowing either continuously or intermittently. |
EMERGENCY RESPONSE AREA (ERA): | The part of the wellhead protection area that is defined by a one-year time of travel within the aquifer that is used by the public water supply well (as defined by Minnesota Rules, Part 4720.5250, Subpart 3). |
EROSION: | Any process that wears away the surface of the land by the action of water, wind, ice, or gravity. Erosion can be accelerated by the activities of people and nature. |
EROSION AND SEDIMENT CONTROL PRACTICE (ESC): | The management procedures, techniques, and methods to control soil erosion and sedimentation. |
EROSION AND SEDIMENT CONTROL TECHNICIAN (ESC TECH): | For the purposes of construction site erosion and sediment control, the person or persons designated by the contractor who have successfully completed ESC training from the University Of Minnesota; Minnesota department of transportation certification; Minnesota Erosion Control Association training; or other training recognized by the MPCA as meeting the requirements of the NPDES construction stormwater permit. |
EROSION CONTROL: | Refers to methods employed to prevent erosion. Examples include soil stabilization practices, horizontal slope grading, temporary or permanent cover, and construction phasing. |
EXPOSED SOIL AREAS: | All areas of the construction site where the vegetation (trees, shrubs, brush, grasses, etc.) or impervious surface has been removed, thus rendering the soil more prone to erosion. This includes topsoil stockpile areas, borrow areas and disposal areas within the construction site. It does not include stockpiles or surcharge areas of gravel, concrete or bituminous. Once soil is exposed it is considered "exposed soil", until it meets the definition of "final stabilization". |
FINAL STABILIZATION: | That: A. All soil disturbing activities at the site have been completed; and B. A uniform perennial vegetative cover with a density of seventy five percent (75%) of the native background vegetative cover for unpaved areas has been established, or equivalent permanent stabilization measures have been employed. Simply sowing grass seed is not considered final stabilization. |
FLOOD EVENT (100-YEAR): | The precipitation or snowmelt runoff event which has a one percent (1%) chance of occurring at a given location within any one year time period. |
FLOOD FRINGE: | The portion of the floodplain outside of the floodway. |
FLOOD LEVEL (100-YEAR): | The peak water surface elevation of an inundation area or basin resulting from a 100-year flood event. |
FLOODPLAIN: | The areas adjoining a watercourse or water basin that have been or may be covered by a regional flood. |
FLOODWAY: | The channel of the watercourse, the bed of water basins, and those portions of the adjoining floodplain that are reasonably required to carry and discharge floodwater and provide water storage during a regional flood. |
FULLY RECONSTRUCTED: | Any areas of preexisting impervious surface where reconstruction activities disturb below the top of subgrade. The top of subgrade is considered the grade at which a typical pavement section begins with select granular material or, in absence of select granular material, class 5 aggregate base. Roadway reconstruction projects that do not replace the entirety of the typical roadway section throughout a project area to the top of subgrade are not considered fully reconstructed, including mill and overlay, pavement replacement, partial reconstruction, or full depth reclamation projects. Maintenance activities such as catch basin repair/replacement, utility repair/replacement, lighting, pedestrian ramp improvements, or performing spot correction of deficient subgrade to bring a portion of a project area into conformance with the typical roadway section are not considered fully reconstructed activities. |
ILLEGAL DISCHARGE: | Any direct or indirect nonstormwater discharge to the storm drain system. |
ILLICIT CONNECTIONS: | An illicit connection is defined as either of the following: A. Any drain or conveyance, whether on the surface or subsurface, which allows an illegal discharge to enter the storm drain system including, but not limited to, any conveyance which allows any nonstormwater discharge including sewage, process wastewater, and wash water to enter the storm drain system and any connections to the storm drain system from indoor drains and sinks, regardless of whether said drain or connection had been previously allowed, permitted, or approved by an authorized enforcement agency; or B. Any drain or conveyance connected from a commercial or industrial land use to the storm drain system which has not been documented in plans, maps, or equivalent records and approved by an authorized enforcement agency. |
IMPERVIOUS SURFACE: | A constructed hard surface that either prevents or retards the entry of water into the soil, and causes water to run off the surface in greater quantities and at an increased rate of flow than existed prior to development. Examples include rooftops, sidewalks, patios, driveways, parking lots, storage areas, and concrete, asphalt, or gravel roads. |
INFILTRATION: | Flow of water from the land surface into the subsurface. |
INLET PROTECTION: | Preservation of the integrity and protection from erosion of the area where water enters into a treatment area usually by vegetation or armoring. |
INUNDATION AREA OR BASIN: | A low lying area that is subject to periodic flooding. Examples include wetlands, ponds, lakes, streams, open channels, or any low lying area or basin. |
LID (LOW IMPACT DEVELOPMENT): | An innovative stormwater management approach with a basic principle that is modeled after nature by managing rainfall at the source. |
LAND DISTURBING ACTIVITY: | Any land change that may result in soil erosion from water or wind and the movement of sediments into or upon waters or lands within the city's jurisdiction or into an adjacent jurisdiction. This may include, but is not limited to: A. A disturbance to the land that results in a change in the topography. B. Disturbance of the existing soil cover (both vegetative and nonvegetative cover). C. A disturbance of the existing soil topography that may result in accelerated stormwater runoff. D. A pavement rehabilitation project that removes the pavement and aggregate base, exposing the subgrade base material (a reclamation or partial depth mill and overlay project is not considered a land disturbing activity). Land disturbing activity includes clearing and grubbing, grading, excavating, transporting and filling of land for all new construction and redevelopment. Ongoing operations and maintenance activities for existing facilities such that any single activity does not exceed project sizes specified in section 9-5-5 of this chapter are not considered land disturbing activity. |
LANDLOCKED BASIN: | A basin that does not discharge under back to back 100-year, 24-hour rainfall events. |
LINEAR PROJECTS: | Construction or reconstruction of roads, trails, sidewalks, and rail lines that are not part of a common plan of development or sale; or any project consisting of the construction or reconstruction of roads, trails, sidewalk, and rail lines performed by the city or any other government agency within the city. |
MPCA: | Minnesota pollution control agency. |
NRCS: | Natural resources conservation service. |
NATURAL OVERFLOW ELEVATION: | The low point on the landscape where water will leave a depression or basin. |
NORMAL WATER LEVEL (NWL): | The water level in a natural water body or constructed pond having an outlet or overflow control structure that is the lowest water level held by the outlet or overflow structure, or for landlocked basins, the elevation that may be attained naturally by infiltration, evaporation, or transpiration often demarked by a change in vegetation from terrestrial to aquatic. For basins with piped outlets, the NWL is the invert elevation of the outlet pipe. |
OPERATOR: | The person (usually the general contractor), designated by the owner, who has day to day operational control and/or the ability to modify project plans and specifications related to the stormwater management plan. |
ORDINARY HIGH WATER LEVEL (OHW): | Minnesota statute 103G.005, subd. 14 states that the ordinary high water level means the boundary of water basins, watercourses, public waters, and public waters wetlands, and: A. The ordinary high water level is an elevation delineating the highest water level that has been maintained for a sufficient period of time to leave evidence upon the landscape, commonly the point where the natural vegetation changes from predominantly aquatic to predominantly terrestrial; B. For watercourses, the ordinary high water level is the elevation of the top of the bank of the channel; and C. For reservoirs and flowages, the ordinary high water level is the operating elevation of the normal summer pool. The term ordinary high water mark is further defined in Minnesota rule 6120.2500, subpart 11, as amended from time to time. Ordinary high water marks are determined by the Minnesota department of natural resources' area hydrologist. |
OWNER: | The person or party possessing the title of the land on which the construction activities will occur; or if the construction activity is for a leaseholder, the party or individual identified as the leaseholder; or the contracting government agency responsible for the construction activity. |
PERMANENT COVER: | "Final stabilization". Examples include vegetative cover composed primarily of grasses, and hard surfaces, such as gravel, asphalt, and concrete. See also the definition of Final Stabilization. |
PERMIT: | Where not otherwise defined within this ordinance, the term "permit" shall include any form of permit issued by the city, including but not limited to building permits, demolition permits, land alteration permits, right of way excavation permits, or right of way utility permits. |
PLANNED UNIT DEVELOPMENT: | A development of land that is under unified control and is planned and developed as a whole in a single development operation or programmed series of development stages. The development may include streets, circulationways, utilities, buildings, open spaces, and other site features and improvements. |
RATE CONTROL: | Controlling the rate that stormwater is released from localized holding areas into larger conveyance systems. |
RECHARGE: | The addition of water to an aquifer by natural infiltration or artificial means. |
REDEVELOPMENT: | Any land disturbing activity that occurs following a rezoning of a property within the city; any land disturbing activity that occurs on a previously developed site; or any structure development (construction, installation, or expansion of a building or other impervious surface feature, including roads, trails, sidewalks, and parking lots) resulting in the creation or addition of impervious surfaces. |
REGIONAL FLOOD: | A flood that is representative of large floods known to have occurred generally in the state and reasonably characteristic of what can be expected to occur on an average frequency in the magnitude of a 100-year recurrence interval. |
SWCD: | Soil and water conservation district. |
SEDIMENT CONTROL: | The methods employed to prevent sediment from leaving the development site. Sediment control practices include silt fences, sediment traps, earth dikes, drainage swales, check dams, subsurface drains, pipe slope drains, storm drain inlet protection, other appropriate measures, and temporary or permanent sedimentation basins. |
SHORELAND DISTRICT OR SHORELAND: | All lands located within the following distance from the ordinary high water level of a public water: A. One thousand feet (1,000') from a lake pond or reservoir; B. Three hundred feet (300') from a river or stream. |
STABILIZED: | The exposed ground surface after it has been covered by sod, erosion control blanket, riprap, or other material that prevents erosion. Simply sowing grass seed is not considered stabilization. |
STEEP SLOPE: | Land where agricultural activity or development is either not recommended or described as poorly suited due to slope steepness and the site's soil characteristics, as mapped and described in available county soil surveys or other technical reports, unless appropriate design and construction techniques and farming practices are used in accordance with the provisions of this chapter. Where specific information is not available, steep slopes are lands having average slopes over eighteen percent (18%), as measured over horizontal distances of fifty feet (50') or more, that are not bluffs. |
STORMWATER MANAGEMENT PLAN: | A joint stormwater management and erosion and sediment control plan that when implemented will provide for both temporary and permanent control of soil erosion on a parcel of land, prevent off site nonpoint source pollution, and control stormwater rates and volumes. |
STORMWATER POLLUTION PREVENTION PLAN (SWPPP): | A plan for stormwater discharge that includes erosion prevention measures and sediment controls that, when implemented, will decrease soil erosion on a parcel of land and decrease off site nonpoint pollution. |
STRUCTURE: | Anything manufactured, constructed or erected which is normally attached to or positioned on land, including portable structures, earthen structures, roads, parking lots, and paved storage areas. |
SUBDIVISION: | Any tract of land divided into building lots for private, public, commercial, industrial, etc., development. Minnesota rule 6120.2500, subpart 17 defines subdivision as, "...land that is divided for the purpose of sale, rent, or lease, including planned unit development." |
TOTAL MAXIMUM DAILY LOAD (TMDL): | The amount of a pollutant from both point and nonpoint sources that a water body can receive and still meet water quality standards. |
WETLANDS: | Defined in Minnesota rules 7050.0130, subp. F and includes 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. Wetlands generally include swamps, marshes, bogs, and similar areas. Constructed wetlands designed for wastewater treatment are not waters of the state; to be a wetland the area must meet wetland criteria for soils, vegetation, and hydrology as outlined in the 1987 U.S. army corps of engineers "Wetland Delineation Manual". (Ord. 1326, 11-28-2016; amd. Ord. 1435, - -2022) |