§ 54.20 AUTHORITY AND TITLE.

   (A)   This subchapter is adopted in accordance with statutory authority granted to the Common Council under its home rule powers, and further is required by Phase II of the National Pollution Discharge Elimination System program (FR Doc. 99-29181) authorized by the 1972 amendments to the Clean Water Act, the State Department of Environmental Management’s Rule 13 (327 IAC 15-6), and the State Department of Environmental Management’s Rule 5 (327 IAC 15-2-2). Based on this authority and these requirements, this subchapter regulates:

      (1)   Discharges of prohibited non- stormwater flows into the stormwater drainage system;

      (2)   Stormwater drainage improvements related to development of lands located within the city;

      (3)   Drainage control systems installed during new construction and grading of lots and other parcels of land;

      (4)   Erosion and sediment control systems installed during new construction and grading of lots and other parcels of land;

      (5)   The design, construction, and maintenance of stormwater drainage facilities and systems;

      (6)   The design, construction, and maintenance of stormwater quality facilities and systems; and

      (7)   Land-disturbing activities affecting wetlands.

   (B)   This subchapter shall be known and may be cited as the city’s Stormwater Management Ordinance.

(Ord. 2006-13, passed 10-26-2006; Ord. 2019-25, passed on 5-13-2020)

§ 54.21 APPLICABILITY AND EXEMPTIONS.

   (A)   This subchapter shall be applicable to all development and redevelopment occurring within the city. No permit shall be issued and no land disturbance started for any construction in a development, as defined in § 54.24, until the plans required by this subchapter for such construction have been accepted, in writing, by the city. With the exception of the requirements of §§ 54.28 and 54.32(D), single-family dwelling houses in approved subdivisions, new buildings (or cumulative building additions) with less than 500 square feet of area, and land-disturbing activities affecting less than 10,000 square feet of area shall be exempt from the permitting requirements of this subchapter.

   (B)   In addition to the requirements of this subchapter, compliance with all applicable city ordinances as well as with applicable federal, state, and other local statutes and regulations shall also be required. Unless otherwise stated, all other specifications referred to in this subchapter shall be the most recent edition available. City government public works projects shall also be subject to the requirements of this subchapter. However, the city is exempt from paying any applicable permit and review fees. If the project site is located within a county regulated drain watershed, the applicant will need to check with the County Surveyor’s office to learn if additional Surveyor’s office requirements specific to that regulated drain would apply to the site.

   (C)   Any construction project which has had its final drainage plan approved by the city within a two-year period prior to the effective date of this subchapter shall be exempt from all requirements of this subchapter that are in excess of the requirements of ordinances in effect at the time of approval. Such an exemption is not applicable to the requirements detailed in § 54.28.

(Ord. 2006-13, passed 10-26-2006)

§ 54.22 PURPOSE.

   (A)   The purpose of this subchapter is to provide for the health, safety, and general welfare of the citizens of the city through the regulation of stormwater and non-stormwater discharges to the storm drainage system and to protect, conserve, and promote the orderly development of land and water resources within the city. This subchapter establishes methods for managing the quantity and quality of stormwater entering into the stormwater drainage system in order to comply with state and federal requirements. The objectives of this subchapter are:

      (1)   To reduce the hazard to public health and safety caused by excessive stormwater runoff;

      (2)   To regulate the contribution of pollutants to the stormwater drainage system from construction site runoff;

      (3)   To regulate the contribution of pollutants to the stormwater drainage system from runoff from new development and re-development;

      (4)   To prohibit illicit discharges into the stormwater drainage system; and

      (5)   To establish legal authority to carry out all inspection, monitoring, and enforcement procedures necessary to ensure compliance with this subchapter.

   (B)   As required by Rule 13 (327 IAC 15-6), the requirements of this subchapter are formulated in such a way to promote maximization of open space and minimization of land disturbance and surface imperviousness, where practical, in order to minimize the potential for introduction of pollutants to the city’s drainage conveyance system. The requirements of this subchapter are meant to guide the development within the city so that such development does not negatively impact the quality of stormwater.

(Ord. 2006-13, passed 10-26-2006)

§ 54.23 ABBREVIATIONS.

   For the purposes of this subchapter, 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 sewer system
NOI	Notice of intent
NOT	Notice of termination
NPDES	National pollution discharge elimination system
NRCS	USDA- Natural Resources Conservation Service
POTW	Publicly owned treatment works
SWCD	Soil and water conservation district
SWPPP	Stormwater pollution prevention plan
USDA	United States Department of Agriculture
USFWS	United States Fish and Wildlife Service

 

(Ord. 2006-13, passed 10-26-2006)

§ 54.24 DEFINITIONS.

   For the purpose of this subchapter, 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 tile. For purposes of this subchapter or standards, 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 groundwater 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 stormwater facilities that minimize the impact of stormwater 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 STORMWATER MANAGEMENT. A comprehensive stormwater program for effective management of stormwater 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, their agent, or the individual lot operator to perform services on the project site.

   CONVEYANCE. Any structural method for transferring stormwater 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 0.05 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 stormwater runoff by temporary holding and controlled release.

   DETENTION BASIN. A facility constructed or modified to restrict the flow of stormwater 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 stormwater 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 stormwater 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. 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)   Installing a manufactured home on a site, preparing a site for a manufactured home, or installing a recreational vehicle on a site;

      (3)   For more than 180 days;

      (4)   Installing utilities, construction of walls, construction of roads, or similar projects;

      (5)   Construction of flood control structures such as levees, dikes, dams, or channel improvements;

      (6)   Mining, dredging, filling, grading, excavation, clearing, deforestation, or drilling operations;

      (7)   Construction or reconstruction of bridges or culverts;

      (8)   Storage of materials; or

      (9)   Any other activity that might change the direction, height, or velocity of flood or surface waters.

   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 groundwater drained from land, stormwater runoff, or floodwaters 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 groundwater or surface water.

   DRAINAGE. The removal of excess surface water or groundwater 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 stormwater 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 wind speed 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:

      (1)   ACCELERATED EROSION. Erosion much more rapid than normal or geologic erosion, primarily as a result of the activities of humans;

      (2)   CHANNEL EROSION. An erosion process whereby the volume and velocity of flow wears away the bed and/or banks of a well-defined channel;

      (3)   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;

      (4)   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);

      (5)   SHEET EROSION. The gradual removal of a fairly uniform layer of soil from the land surface by runoff water; and

      (6)   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.

   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.

   FILL MATERIAL. Any material used for the primary purpose of replacing a wetland area with dry land or of changing the bottom elevation of a wetland or a waterbody. This definition shall be considered to be automatically amended to conform with the definition of FILL MATERIAL established, from time to time, by the United States of America or United States Army Corps of Engineers.

   FILTER STRIP. Usually a long, relatively narrow area (usually, 20-75 feet wide) of undisturbed or planted vegetation used near disturbed or impervious surfaces to filter stormwater 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 flood plain 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 groundwater 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.

      (1)   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.

      (2)   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.

      (3)   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.

   GROUNDWATER. 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.

   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 stormwater 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, being 33 U.S.C. § 1313(d).

   IMPERVIOUS SURFACE. Surfaces, such as pavement and rooftops, which prevent the infiltration of stormwater into the soil.

   INDIVIDUAL BUILDING LOT. A single parcel of land.

   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 groundwater. Examples include infiltration basins or trenches, dry wells, and porous pavement.

   INLET. An opening into a stormwater drainage system for the entrance of surface stormwater 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 ENGINEER. 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 (abutting) 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. Refers to the lowest of the following:

      (1)   The top of the basement floor;

      (2)   The top of the garage floor, if the garage is the lowest level of the building;

      (3)   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

      (4)   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:

         (a)   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 openings (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; and

         (b)   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 SEWER SYSTEM. An MS4 meets all the following criteria:

      (1)   Is a conveyance or system of conveyances owned by the state, county, city, town, or other public entity;

      (2)   Discharges to waters of the United States;

      (3)   Is designed or used for collecting or conveying stormwater;

      (4)   Is not a combined sewer; and

      (5)   Is not part of a publicly owned treatment works (POTW).

   NATIONAL POLLUTION 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 stormwater quality.

   NATURAL DRAINAGE. The flow patterns of stormwater run-off over the land in its pre-development state.

   NUTRIENT(S).

      (1)   A substance necessary for the growth and reproduction of organisms.

      (2)   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 (PL 92-500, § 502(14), being 33 U.S.C. § 1362).

   POROUS PAVEMENT. A type of infiltration practice to improve the quality and reduce the quantity of stormwater 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 stormwater 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 groundwater reservoirs by infiltration and transmission from the outcrop of an aquifer or from permeable soils.

   REDEVELOPMENT. Alterations of a property that change a site or building in such a way that there is disturbance of 10,000 square feet or more of land. The term does not include such activities as exterior remodeling.

   REFUELING AREA. An operating gasoline or diesel fueling area whose primary function is to provide fuel to equipment or vehicles.

   REGULATORY FLOOD. The discharge or elevation associated with the 100-year flood as calculated by a method and procedure which is acceptable to and accepted 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 stormwater released from a stormwater 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 stormwater 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 stormwater 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 HABITAT. A land area adjacent to a waterbody that supports animal and plant life associated with that waterbody.

   RIPARIAN ZONE. Of, on, or pertaining to the banks of a stream, river, or pond.

   RUNOFF. The portion of precipitation that flows from a drainage area on the land surface, in open channels, or in stormwater conveyance systems.

   RUNOFF COEFFICIENT. A decimal fraction relating the amount of rain which appears as runoff and reaches the stormwater drainage 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 stormwater 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 based on its:

      (1)   Providing habitat for threatened or endangered species;

      (2)   Usage as a public water supply intake;

      (3)   Relevant community value; and

      (4)   Usage for full body contact recreation;

      (5)   Exceptional use classification as found in 327 IAC 2-1-11(b), outstanding state resource water classification as found in 327 IAC 2-1.5-18 and 327 IAC 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 subchapter follow the common presentation of slopes - e.g., 2:1 with the metric presentation shown in parenthesis - 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.

   STABILIZED. The establishment, at a uniform density of 70% across the disturbed area, of vegetative cover or noninvasive material that will ensure the resistance of the soil to erosion, sliding, or other movement.

   STORM DURATION. The length of time that water may be stored in any stormwater 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 10-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 stormwater, while excluding sewage and industrial wastes. Also called a STORM DRAIN.

   STORMWATER. Water resulting from rain, melting or melted snow, hail, or sleet.

   STORMWATER DRAINAGE SYSTEM. All means, natural or human-made, used for conducting stormwater 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.

   STORMWATER POLLUTION PREVENTION PLAN. A plan developed to minimize the impact of stormwater pollutants resulting from construction activities.

   STORMWATER RUNOFF. The water derived from rains falling within a tributary basin, flowing over the surface of the ground or collected in channels or conduits.

   STORMWATER QUALITY MANAGEMENT PLAN. A comprehensive written document that addresses stormwater runoff quality.

   STORMWATER QUALITY MEASURE. A practice, or a combination of practices, to control or minimize pollutants associated with stormwater runoff.

   STORMWATER UTILITY. The city’s stormwater utility, established under this chapter.

   STORMWATER UTILITY COORDINATOR. The Stormwater Coordinator or such other individual appointed by the Board to administer and supervise the operation of the stormwater utility.

   STRIP DEVELOPMENT. A multi-lot project where building lots front on an existing road.

   SUBDIVISION. Any land that is divided or proposed to be divided into 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 groundwater 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 stormwater into primary drainage channels and may provide some groundwater 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.

   TIMBER HARVESTING. Cutting tree branches and trunks for commercial purposes without disturbing the root system.

   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 given 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 stormwater quality, including erosion and sediment control as may be demonstrated by state registration, professional certification, experience, or completion of coursework that enable the individual to make judgments regarding stormwater control or treatment and monitoring.

   URBAN DRAIN. A drain defined as “Urban Drain” in the state’s 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 stormwater 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 groundwater 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 stormwater 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 stormwater 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 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. This definition shall be considered to be automatically amended to conform with the definition of a wetlands established from time to time by the United States of America or United States Army Corps of Engineers.

(Ord. 2006-13, passed 10-26-2006; Ord. 2019-25, passed on 5-13-2020)

§ 54.25 RESPONSIBILITY FOR ADMINISTRATION.

   The city shall administer, implement, and enforce the provisions of this subchapter through the city’s stormwater utility. Any powers granted or duties imposed upon the authorized enforcement agency may be delegated, in writing, by Council, the Board, or the authorized official to qualified persons or entities acting in the beneficial interest of or in the employ of city government.

(Ord. 2006-13, passed 10-26-2006; Ord. 2019-25, passed on 5-13-2020)

§ 54.26 CONFLICTING ORDINANCES.

   The provisions of this subchapter shall be deemed as additional requirements to minimum standards required by other city ordinances, and as supplemental requirements to the state’s Rule 5 regarding Stormwater Discharge Associated with Construction Activity (327 IAC 15-2-2) and the state’s Rule 13 regarding Stormwater Runoff Associated with Municipal Separate Storm Sewer System Conveyances (327 IAC 15-6). In case of conflicting requirements, the most restrictive shall apply.

(Ord. 2006-13, passed 10-26-2006)

§ 54.27 DISCLAIMER OF LIABILITY.

   (A)   The degree of protection required by this subchapter is considered reasonable for regulatory purposes and is based on historical records, engineering, and scientific methods of study. Larger storms may occur or stormwater runoff amounts or stormwater quality may be altered by human-made or natural causes.

   (B)   This subchapter does not imply that land uses permitted will be free from stormwater damage. This subchapter shall not create liability on the part of Council, the Board, the city stormwater utility, the Stormwater Utility Coordinator, or any officer, representative, or employee thereof, for any damage which may result from reliance on this subchapter or on any administrative decision lawfully made there under.

(Ord. 2006-13, passed 10-26-2006; Ord. 2019-25, passed on 5-13-2020)

§ 54.28 PROHIBITED DISCHARGES AND CONNECTIONS.

   (A)   Applicability and exemptions.

      (1)   This section shall apply to all discharges, including illegal dumping, entering the stormwater drainage system regulated by the city, regardless of whether the discharge originates from developed or undeveloped lands, and regardless of whether the discharge is generated from an active construction site or a stabilized site. These discharges include flows from direct connections to the stormwater drainage system, illegal dumping, and contaminated runoff.

      (2)   Stormwater runoff from agricultural, timber harvesting, and coal mining activities is exempted from the requirements of this section unless determined to contain pollutants not associated with such activities or in excess of standard practices. Farm residences are not included in this exemption.

      (3)   Any non-stormwater discharge permitted under an NPDES permit, waiver, or waste discharge order issued to the discharger and administered under the authority of the federal Environmental Protection Agency, provided that the discharger is in full compliance with all requirements of the permit, waiver, or order and other applicable laws and regulations, and provided that IDEM issues written acceptance for the subject discharge to the stormwater drainage system, is also exempted from this section.

   (B)   Prohibited discharges and connections.

      (1)   No person shall discharge to a MS4 conveyance, watercourse, or waterbody, directly or indirectly, any substance other than stormwater or an exempted discharge. Any person discharging stormwater shall effectively minimize pollutants from also being discharged with the stormwater, through the use of best management practices (BMPs) referred to in the city’s “Stormwater Technical Standards Manual”.

      (2)   The city is authorized to require dischargers to implement pollution prevention measures, utilizing BMPs, necessary to prevent or reduce the discharge of pollutants into the city stormwater drainage system.

   (C)   Exempted discharges and connections. Notwithstanding other requirements in this subchapter, the following categories of non-stormwater discharges or flows are exempted from the requirements of this section:

      (1)   Water line flushing;

      (2)   Landscape irrigation;

      (3)   Diverted streamflows;

      (4)   Rising ground waters;

      (5)   Uncontaminated groundwater infiltration;

      (6)   Uncontaminated pumped ground water;

      (7)   Discharges from potable water sources;

      (8)   Foundation drains;

      (9)   Air conditioning condensation;

      (10)   Irrigation water;

      (11)   Springs;

      (12)   Water from crawl space pumps;

      (13)   Footing drains;

      (14)   Lawn watering;

      (15)   Individual residential car washing;

      (16)   Flows from riparian habitats and wetlands;

      (17)   Dechlorinated swimming pool discharges;

      (18)   Street wash water;

      (19)   Discharges from firefighting activities; and

      (20)   Naturally introduced detritus (e.g., leaves and twigs).

   (D)   Storage of hazardous or toxic material. Storage or stockpiling of hazardous or toxic material within any watercourse, or in its associated floodway or floodplain, is strictly prohibited. Storage or stockpiling of hazardous or toxic material on active construction sites must include adequate protection or containment so as to prevent any such materials from entering any temporary or permanent stormwater conveyance or watercourse.

   (E)   Private property maintenance duties. Every person owning property through which a watercourse passes, or such person’s lessee, shall keep and maintain that part of the watercourse located within their property boundaries, free of trash, debris, excessive vegetation, and other obstacles that would pollute, contaminate, or significantly retard the flow of water through the watercourse. In addition, the owner or lessee shall maintain existing privately owned structures within or adjacent to a watercourse, so that such structures will not become a hazard to the use, function, or physical integrity of the watercourse.

   (F)   Spill reporting.

      (1)   Any discharger who accidentally discharges into a waterbody any substance other than stormwater or an exempted discharge shall immediately inform the County Health Department and the City Fire Department concerning the discharge. A written report concerning the discharge shall be filed with the city and IDEM, by the dischargers, within five days. The written report shall specify:

         (a)   The composition of the discharge and the cause thereof;

         (b)   The date, time, and estimated volume of the discharge;

         (c)   All measures taken to clean up the accidental discharge, and all measures proposed to be taken to prevent any recurrence; and

         (d)   The name and telephone number of the person making the report, and the name and telephone number of a person who may be contacted for additional information on the matter.

      (2)   A properly reported accidental discharge shall be an affirmative defense to a civil infraction proceeding brought under this subchapter against a discharger for such discharge. It shall not, however, be a defense to a legal action brought to obtain an injunction, to obtain recovery of costs, or to obtain other relief because of or arising out of the discharge. A discharge shall be considered properly reported only if the discharger complies with all the requirements of this section. This requirement does not relieve the discharger from notifying other entities as required by other local, state, and federal regulations.

   (G)   Inspections and monitoring.

      (1)   Storm drainage system. The city has the authority to periodically inspect any portion of the storm drainage system, whether publicly or privately owned, in an effort to detect and eliminate illicit connections and discharges into the system. This inspection may include a screening of discharges from outfalls connected to the system in order to determine if prohibited flows are being conveyed into the storm drainage system. It could also include spot testing of waters contained in the storm drainage system itself to detect the introduction of pollutants into the system by means other than a defined outfall, such as dumping or contaminated sheet runoff.

      (2)   Potential polluters. If, as a result of the storm drainage system inspection, a discharger is suspected of an illicit discharge, the city may inspect or obtain stormwater samples from stormwater runoff facilities of the subject discharger, to determine compliance with the requirements of this subchapter. Upon request, the discharger shall allow the city’s properly identified representative to enter upon the premises of the discharger at all hours necessary for the purposes of such inspection or sampling. The city’s properly identified representative may place on the discharger’s property the equipment or devices used for such sampling or inspection. Identified illicit connections or discharges shall be subject to enforcement action as described in § 54.33.

      (3)   New development and re-development. Following the final completion of construction and the receipt of as-built drawings, the city has the authority to inspect new development and re-development sites to verify that all on-site stormwater conveyances and connections to the storm drainage system are in compliance with this section.

(Ord. 2006-13, passed 10-26-2006)

§ 54.29 STORMWATER QUANTITY MANAGEMENT.

   (A)   Applicability and exemptions. The storage and controlled release rate of excess stormwater runoff shall be required for all new business, commercial, and industrial developments; residential subdivisions; planned development; rural estate subdivisions; and any redevelopment or other new construction located within the city. The city, after thorough investigation and evaluation, may waive the requirement of controlled runoff for minor subdivisions and parcelization.

   (B)   Policy on stormwater quantity management.

      (1)   Detention policy. It is recognized that most streams and drainage channels serving the city do not have sufficient capacity to receive and convey stormwater runoff resulting from continued urbanization. Accordingly, the storage and controlled release of excess stormwater runoff shall be required for all developments and redevelopments (as defined in § 54.24) located within the city.

         (a)   General release rates.

            1.   In general, the post- development release rates for developments up to and including the ten-year return period storm may not exceed 0.1 cfs per acre of development. The post-development release rate for developments for the 11- to 100-year return period storms shall not exceed 0.3 cfs per acre of development. The above fixed general release rates may be set at a lower value by the city for certain watersheds if more detailed data becomes available as a result of comprehensive watershed studies conducted or formally approved and adopted by the City Council. The applicant shall confirm the applicable release rates with the city prior to initiating the design calculations to determine whether a basin-specific rate has been established for the watershed.

            2.   The release rate for pre- developed areas that have more than one outlet must be computed based on pre-developed drainage area tributary to each outlet point. The computed release rate at each outlet point shall not be exceeded at the respective outlet point, even if the post-developed conditions would involve a different arrangement of outlet points. Also, if an outlet control structure includes an orifice to restrict the flow rate, such orifice shall be no less than four inches in diameter, even if the four-inch diameter orifice results in a discharge that exceeds the above-noted general release rates.

         (b)   Site-specific release rates for sites with depressional storage.

            1.   For sites where depressional storage exists, the general release rates provided above may have to be further reduced. If depressional storage exists at the site, site-specific release rates must be calculated according to methodology described in the city’s “Stormwater Technical Standards Manual”, accounting for the depressional storage by modeling it as a pond whose outlet is a weir at an elevation that stormwater can currently overflow the depressional storage area. Post developed release rate for sites with depressional storage shall be the two-year pre-developed peak runoff rate for the post-developed ten-year storm and ten-year pre-developed peak runoff rate for the post-developed 100-year storm. In no case shall the calculated site-specific release rates be larger than general release rates provided above.

            2.   Also note that, for determining the post-developed peak runoff rate, the depressional storage must be assumed to be filled unless the city can be assured, through dedicated easement, that the noted storage will be preserved in perpetuity.

         (c)   Management of off-site runoff. 

            1.   Runoff from all upstream tributary areas (off-site land areas) may be bypassed around the detention/retention facility without attenuation. Such runoff may also be bypassed through the detention/retention facility without attenuation, provided that a separate secondary outlet system is incorporated for the safe passage of such flows, i.e., not through the primary outlet of a detention facility. Unless the pond is being designed as a regional detention facility and therefore all off-site runoff to the pond detained, the primary outlet structure shall be sized and the invert elevation of the secondary outlet for bypassing off-site runoff determined according to the on-site runoff only. To accomplish this, the 100-year on-site runoff must be determined by temporarily ignoring the off-site runoff and routed through the pond and through the primary outlet pipe. The resulting pond elevation would be the invert elevation of the secondary outlet. Once the size and location of primary outlet structure and the invert elevation of the secondary outlet for bypassing off-site runoff are determined by considering on-site runoff only, the size of the secondary outlet and the 100-year pond elevation is determined by routing the entire inflow, on-site and off-site, through the pond. Once the 100-year pond elevation is determined in this manner, the crest elevation of the open emergency weir is set at that elevation.

            2.   Note that the efficiency of the detention/retention facility in controlling the on-site runoff may be severely affected if the off-site area is considerably larger than the on-site area. As a general guidance, on-line detention may not be effective in controlling on-site runoff where the ratio of off-site area to on-site area is larger than 5:1. Additional detention (above and beyond that required for on-site area) may be required by the city when the ratio of off-site area to on-site area is larger than 5:1.

         (d)   Downstream restrictions.

            1.   In the event the downstream receiving channel or storm sewer system is inadequate to accommodate the post-developed release rate provided above, then the allowable release rate shall be reduced to that rate permitted by the capacity of the receiving downstream channel or storm sewer system. Additional detention, as determined by the city, shall be required to store that portion of the runoff exceeding the capacity of the receiving storm sewers or watercourses. When such downstream restrictions are suspected, the city may require additional analysis to determine the receiving system’s limiting downstream capacity.

            2.   If the proposed development makes up only a portion of the undeveloped watershed upstream of the limiting restriction, the allowable release rate for the development shall be in direct proportion to the ratio of its drainage area to the drainage area of the entire watershed upstream of the restriction.

   (C)   Grading and building pad elevations.

      (1)   Maximum yard slopes are 3:1 where soil has been disturbed during construction processes. Finished floor elevation or the lowest building entry elevation must be no less than six inches above finished grade around the building. The building’s lowest entry elevation that is adjacent to and facing a road should be a minimum of 15 inches above the road elevation or top of curb.

      (2)   All buildings shall have a minimum flood protection grade shown on the secondary plat. Minimum flood protection grade of all structures fronting a pond or open ditch shall be no less than two feet above any adjacent 100-year local or regional flood elevations, whichever is greater, for all windows, doors, unsealed pipe entrances, window well rim elevations, and any other structure member where floodwaters can enter a building.

      (3)   The lowest floor elevation of all residential, commercial, or industrial structures, located within the special flood hazards area (SFHA), as shown on the FEMA maps, shall be at the flood protection grade and therefore have two feet of freeboard above the 100-year flood elevation.

      (4)   The lowest adjacent grade for residential, commercial, or industrial buildings outside a FEMA or IDNR designated floodplain shall have two feet of freeboard above the flooding source’s 100-year flood elevation under proposed conditions, unless the flooding source is a rear-yard swale. When the flooding source is a rear-yard swale, the lowest adjacent grade for residential, commercial, or industrial buildings shall have two feet of freeboard above the 100-year flood elevation under proposed conditions.

      (5)   The lowest adjacent grade to ponds for all residential, commercial, or industrial buildings (including walkout basement floor elevation) shall be set a minimum of two feet above the 100-year pond elevation or two feet above the emergency overflow weir elevation, whichever is higher. In addition to the lowest adjacent grade requirements, any basement floor must be at least a foot above the permanent water level (normal pool elevation).

      (6)   The 100-year overflow paths throughout the development, whether shown on FEMA maps or not, must be shown as hatched area on the plans. A minimum of 20 feet along the centerline of the 100- year overflow path must be contained within permanent drainage easements. A statement shall be added to the plat that would refer the viewer to the construction plans to see the entire extent of overflow path as hatched areas. No fences or landscaping can be constructed within the easement areas that may impede the free flow of stormwater. These areas are to be maintained by the property owners or be designated as common areas that are to be maintained by the homeowners association. The lowest adjacent grade for all residential, commercial, or industrial buildings shall be set a minimum of one foot above the noted overflow path/ponding elevation, calculated based on all contributing drainage areas, on-site and off-site, in their proposed or reasonably anticipated land use and with storm pipe system assumed completely plugged.

      (7)   It shall be the property owners’ responsibility to maintain the natural features and the natural flow of drainage on their lots and to take preventive measures against any and all erosion or deterioration of natural or human-made features on their lots.

   (D)   Acceptable outlet and adjoining property impact policies.

      (1)   Design and construction of the stormwater facility shall provide for the discharge of the stormwater runoff from off-site land areas as well as the stormwater from the area being developed (on-site land areas) to an acceptable outlet(s) (as determined by the city) having capacity to receive upstream (off-site) and on-site drainage. The flow path from the development outfall(s) to a regulated drain or natural watercourse (as determined by the city) shall be provided on an exhibit that includes topographic information. Any existing field tile encountered during the construction shall also be incorporated into the proposed stormwater drainage system or tied to an acceptable outlet. In addition, no activities conducted as part of the development shall be allowed to obstruct the free flow of flood waters from an upstream property.

      (2)   Where the outfall from the stormwater drainage system of any development flows through real estate owned by others prior to reaching a regulated drain or watercourse, no acceptance shall be granted for such drainage system until all owners of real estate and/or tenants crossed by the outfall consent in writing to the use of their real estate through a recorded easement.

      (3)   If an adequate outlet is not located on-site, then further reduction in allowable release rates or off-site drainage improvements may be required. Those improvements may include, but are not limited to, extending storm sewers, clearing, dredging, or removal of obstructions to open drains or natural water courses, and the removal or replacement of undersized culvert pipes as required by the city.

   (E)   No net loss floodplain storage policy.

      (1)   Floodplains exist adjacent to all natural and human-made streams, regardless of contributing drainage area or whether they have been previously identified or mapped. Due to potential impacts of floodplain loss on peak flows in streams and on the environment, disturbance to floodplains must be avoided. When the avoidance of floodplain disturbance is not practical, the natural functions of floodplain must be preserved to the extent possible.

      (2)   In an attempt to strike a balance between the legitimate need for economic development within the city and the need to preserve the natural functions of floodplains to the extent possible, compensatory excavation equivalent to the floodplain storage lost shall be required for all activities within floodplain of streams located in the city where drainage area of the stream is equal or larger than one square mile. This requirement shall be considered to be above and beyond the minimum requirements provided in the applicable flood hazard areas ordinance currently in effect in the city. The city may alter the compensation ratio, based on extenuating circumstances, for a specific project.

      (3)   Note that, by definition, COMPENSATORY STORAGE is the replacement of the existing floodplain and, in rare exceptions, the floodway storage lost due to fill. Compensatory storage is required when a portion of the floodplain is filled, occupied by a structure, or when as a result of a project a change in the channel hydraulics occurs that reduces the existing available floodplain storage. The compensatory storage must be located adjacent or opposite the placement of the fill and maintain an unimpeded connection to an adjoining floodplain area.

      (4)   Computations must show the provision of compensatory floodplain storage for 10-year, 50-year, and 100-year storm events. That is, the post-development 10-year floodplain storage along a stream shall be equivalent to the 10-year pre-development floodplain storage along the stream within the property limits, the post-development 50-year floodplain storage along a stream shall be equivalent to the 50-year pre-development floodplain storage along the stream within the property limits, and the post-development 100-year floodplain storage along a stream shall be equivalent to the 100-year pre-development floodplain storage along the stream within the property limits.

      (5)   Calculations for floodplain volume shall be submitted in tabular form showing calculations by cross-section. The volume of floodplain storage under the without-project conditions and the with-project conditions must be determined using the average-end-area method with plotted cross-sections at a horizontal to vertical ratio of between 5:1 and 10:1, with 10- through 100-year flood elevations noted on each cross-section. The scale chosen must be large enough to show the intent of proposed grading. Cross-sections must reflect both the existing and proposed conditions on the same plot. The location and extent of the compensatory storage area as well as the location and orientation of cross-sections must be shown on the grading plan.

   (F)   Calculations and design standards and specifications. The calculation methods as well as the type, sizing, and placement of all stormwater facilities shall meet the design criteria, standards, and specifications outlined in the city’s “Stormwater Technical Standards Manual”. The methods and procedures in the “Stormwater Technical Standards Manual” are consistent with the policy stated above.

   (G)   Drainage easement requirements. There shall be no trees or shrubs planted, nor any structures or fences erected, in any drainage easement, unless otherwise allowed by the city.

      (1)   All new channels, drain tiles equal to or greater than 12 inches in diameter, inlet and outlet structures of detention and retention ponds, and appurtenances thereto as required by this section, that are installed in subdivisions requiring a stormwater management permit from the city shall be contained within a minimum of 20 feet of drainage easement (ten feet from centerline on each side) and shown on the recorded plat. New drain tiles refer to all sub-surface stormwater piping, tubing, tiles, manholes, inlets, catch basins, risers, and the like.

      (2)   A minimum of 25 feet from top of the bank on each side of a new channel shall be designated on the recorded plat as a drainage easement. If the top of the bank is not vegetated according to the development’s landscape plan, a minimum 25-foot width of filter strip shall be installed within the drainage easement.

      (3)   Rear-yard swales and emergency overflow paths associated with detention ponds shall be contained within a minimum of 20 feet width (ten feet from centerline on each side) of drainage easement.

      (4)   A minimum of 20 feet beyond the actual footprint (top of the bank) of stormwater detention facilities shall be designated as drainage easement. A minimum of 20-foot width easement shall also be required as access easement from a public right-of-way to the facility, unless the pond is immediately next to a public right-of-way.

   (H)   Placement of utilities. No utility company may disturb existing storm management facilities without the consent of the city. All existing drainage facilities shall have senior rights and damage to said facilities shall result in penalties, as prescribed in § 54.33.

   (I)   Inspection, maintenance, record keeping, and reporting.

      (1)   After the approval of the stormwater management permit by the city and the commencement of construction activities, the city has the authority to conduct inspections of the work being done to ensure full compliance with the provisions of this section, the “Stormwater Technical Standards Manual”, and the terms and conditions of the approved permit.

      (2)   The city also has the authority to perform long-term, post-construction inspection of all public or privately owned stormwater quantity facilities. The inspection will cover physical conditions, available storage capacity, and the operational condition of key facility elements. Stormwater quantity facilities shall be maintained in good condition, in accordance with the terms and conditions of the approved stormwater management permit, and shall not be subsequently altered, revised, or replaced except in accordance with the approved stormwater permit, or in accordance with approved amendments or revisions to the permit. If deficiencies are found during the inspection, the owner of the facility will be notified by the city and will be required to take all necessary measures to correct such deficiencies. If the owner fails to correct the deficiencies within the allowed time period, as specified in the notification letter, the city will undertake the work and collect from the owner using lien rights if necessary.

(Ord. 2006-13, passed 10-26-2006)

§ 54.30 STORMWATER POLLUTION PREVENTION FOR CONSTRUCTION SITES.

   (A)   Applicability and exemptions.

      (1)   The city requires that a stormwater pollution prevention plan (SWPPP), which includes erosion and sediment control measures and materials handling procedures, to be submitted as part of the construction plans and specifications. Once approved, the developer must comply with the approved plan and abide by all the requirements of the permit. Any project located within the city that includes clearing, grading, excavation, or other land-disturbing activities, resulting in the disturbance of or impact on one acre or more of total land area, is subject to the requirements of this section. This includes both new development and redevelopment. This section also applies to disturbances of less than one acre of land that are part of a larger common plan of development or sale if the larger common plan will ultimately disturb one or more acres of land, within the MS4 area. For sites with a total disturbance less than one acre that are not part of a larger common plan or development, the applicant shall provide an erosion and sediment control plan, as noted in § 54.32. Division (C) provides guidelines for calculating land disturbance.

      (2)   The requirements under this section do not apply to the following activities:

         (a)   Agricultural land-disturbing activities; and

         (b)   Timber harvesting activities.

      (3)   The requirements under this section do not apply to the following activities, provided other applicable state permits contain provisions requiring immediate implementation of soil erosion control measures:

         (a)   Landfills that have been issued a certification of closure under 329 IAC 10;

         (b)   Coal mining activities permitted under I.C. 14-34; and

         (c)   Municipal solid waste landfills that are accepting waste pursuant to a permit issued by the State Department of Environmental Management under 329 IAC 10 that contains equivalent stormwater requirements, including the expansion of landfill boundaries and construction of new cells either within or outside the original solid waste permit boundary.

      (4)   The owner or operator of each individual lot where land disturbance is expected to be one acre or more must complete their own notice of intent letter, apply for an improvement location permit (ILP) from the city, and ensure that a sufficient construction and stormwater pollution prevention plan is completed and submitted in accordance with § 54.32, regardless of whether the individual lot is part of a larger permitted project site.

      (5)   An individual lot with land disturbance or impact less than one acre, located within a larger permitted project site, is considered part of the larger permitted project site and the individual lot operator must, at a minimum, comply with the terms and conditions of the stormwater pollution prevention plan approved for the larger project site. The development plans for the larger project site must include detailed erosion and sediment control and material handling measures for individual lots. In addition, the owner or operator of these individual lots are required to submit as part of their improvement location permit (ILP), a stormwater pollution prevention plan in the form of an individual lot plot plan detailing erosion and sediment control measures and material handling procedures that will be followed for the duration of construction. Details of the permitting process are contained in § 54.32.

      (6)   An individual lot with land disturbance or impact of greater than 10,000 square feet but less than one acre must include, as part of the improvement location permit (ILP), a stormwater pollution prevention plan in the form of an individual lot plot plan detailing erosion and sediment control and material handling procedures.

      (7)   It is the responsibility of the project site owner to complete an improvement location permit application and ensure that a sufficient construction plan is completed and submitted to the city in accordance with § 54.32. It is the responsibility of the project site owner and permit holder to ensure compliance with this subchapter during the construction activity and implementation of the construction plan, and in following and implementing all best management practices, and to notify the city with a sufficient notice of termination letter upon completion of the project and stabilization of the site. However, all persons engaging in construction and land-disturbing activities on a permitted project site meeting the applicability requirements must comply with the requirements of this section and this subchapter.

   (B)   Policy on stormwater pollution prevention. Effective stormwater pollution prevention on construction sites is dependent on a combination of preventing movement of soil from its original position (erosion control), intercepting displaced soil prior to entering a waterbody (sediment control), and proper on-site materials handling. The developer must submit to the city a SWPPP with detailed erosion and sediment control plans as well as a narrative describing materials type and specification, handling and storage, and construction sequencing. The following principles apply to all land-disturbing activities and must be considered in the preparation of a stormwater pollution prevention plan within the city.

      (1)   Minimize the potential for soil erosion by designing a development that fits the topography and soils of the site. Deep cuts and fills in areas with steep slopes must be avoided wherever possible, and natural contours must be followed as closely as possible;

      (2)   Existing natural vegetation must be retained and protected wherever possible. Areas immediately adjacent (within 30 feet of top of bank) to watercourses and lakes also must be left undisturbed wherever possible. Unvegetated or vegetated areas with less than 70% cover that are scheduled or likely to be left inactive for 15 days or more must be temporarily or permanently stabilized with measures appropriate for the season to reduce erosion potential. Alternative measures to site stabilization may be acceptable if the project site owner or their representative can demonstrate they have implemented and maintained erosion and sediment control measures adequate to prevent sediment discharge from the inactive area;

      (3)   All activities on a site must be conducted in a logical sequence so that the smallest practical area of land will be exposed for the shortest practical period of time during development;

      (4)   The length and steepness of designed slopes must be minimized to reduce erosion potential. Drainage channels and swales must be designed and adequately protected so that their final gradients and resultant velocities will not cause erosion in the receiving channel or at the outlet. Methods for determining acceptable velocities are included in the “Stormwater Technical Standards Manual”;

      (5)   Sediment-laden water which otherwise would flow from the project site shall be treated by erosion and sediment control measures appropriate to minimize sedimentation. A stable and erosion resistant construction site access point (i.e., crushed stone, slag, aggregate, and the like) shall be provided at all points of construction traffic ingress and egress to the project site;

      (6)   Appropriate measures shall be implemented to prevent wastes or unused building materials, including garbage, debris, packaging material, fuels and petroleum products, hazardous materials or wastes, cleaning wastes, wastewater, concrete truck washout, and other substances from being carried from a project site by runoff or wind. Identification of areas where concrete truck washout is permissible must be clearly posted at appropriate areas of the site. Wastes and unused building materials shall be managed and disposed of in accordance with all applicable state statutes and regulations. Proper storage and handling of materials such as fuels or hazardous wastes, and spill prevention and cleanup measures shall be implemented to minimize the potential for pollutants to contaminate surface or ground water or degrade soil quality;

      (7)   Public or private roadways shall be kept cleared of accumulated sediment that is a result of runoff or tracking. Bulk clearing of accumulated sediment shall not include flushing the area with water. Cleared sediment shall be redistributed or disposed of in a manner that is in accordance with all applicable statutes and regulations;

      (8)   Collected runoff leaving a project site must be either discharged directly into a well-defined, stable receiving channel, or diffused and released to adjacent property without causing an erosion or pollutant problem to the adjacent property owner; and

      (9)   Natural features, including wetlands, shall be protected from pollutants associated with stormwater runoff.

   (C)   Calculations and design standards and specifications.

      (1)   In calculating the total area of land disturbance, for the purposes of determining applicability of this section to the project, the following guidelines must be used.

         (a)   Off-site construction activities that provide services (for example, road extensions, sewer, water, and other utilities) to a land-disturbing project site must be considered as a part of the total land disturbance calculation for the project site, when the activity is under the control of the project site owner.

         (b)   Strip developments will be considered as one project site and must comply with this section unless the total combined disturbance on all individual lots is less than one acre and is not part of a larger common plan of development or sale.

         (c)   To determine if multi-lot project sites are regulated by this rule, the area of land disturbance shall be calculated by adding the total area of land disturbance for improvements, such as roads, utilities, or common areas, and the expected total disturbance on each individual lot, as determined by the following:

            1.   Construction of a single-family residential project site where the lots are one-half acre or more, one-half acre of land disturbance must be used as the expected lot disturbance;

            2.   Construction of a single-family residential project site where the lots are less than one-half acre in size, the total lot must be calculated as being disturbed; and

            3.   To calculate lot disturbance on all other types of projects sites, such as industrial and commercial projects project sites, a minimum of one acre of land disturbance must be used as the expected lot disturbance, unless the lots are less than one acre in size, in which case the total lot must be calculated as being disturbed.

      (2)   The calculation methods as well as the type, sizing, and placement of all stormwater pollution prevention measures for construction sites shall meet the design criteria, standards, and specifications outlined in the latest editions of the state’s “Stormwater Quality Manual” and the city’s “Stormwater Technical Standards Manual”. The methods and procedures included in these two references are in keeping with the above stated policy and meet the requirements of IDEM’s Rule 5. A copy of the state’s “Stormwater Quality Manual” may be obtained through IDEM.

   (D)   Inspection, maintenance, record keeping, and reporting.

      (1)   Following approval of the development plan or improvement location permit, the city will have the authority to conduct inspections of the site to ensure full compliance with the provisions of this section, the latest edition of the state’s “Stormwater Quality Manual”, and the terms and conditions of the approved permit.

      (2)   A self-monitoring program must be implemented by the project site owner or permit holder to ensure the stormwater pollution prevention plan is working effectively. A trained individual, acceptable to the city, shall perform a written evaluation of the project site by the end of the next business day following each measurable storm event. If there are no measurable storm events within a given week, the site must be monitored at least once in that week. Weekly inspections by the trained individual shall continue until the entire site has been stabilized and a notice of termination has been issued. The trained individual must look at the maintenance of existing stormwater pollution prevention measures, including erosion and sediment control measures, drainage structures, and construction materials storage/containment facilities, to ensure they are functioning properly and that they are not dismantled or tampered with by others. The trained individual must also identify additional measures, beyond those originally identified in the stormwater pollution prevention plan, necessary to remain in compliance with all applicable statutes and regulations.

      (3)   The resulting evaluation reports must include the name of the individual performing the evaluation, the date of the evaluation, problems identified at the project site, and details of maintenance, additional measures, and corrective actions recommended and completed.

      (4)   The stormwater pollution prevention plan shall serve as a guideline for stormwater quality, but shall not be interpreted to be the only basis for implementation of stormwater quality measures for a project site. The project site owner and permit holder is responsible for implementing, in accordance with this section, all measures necessary to adequately prevent polluted stormwater runoff. Recommendations by the trained individual for modified stormwater quality measures must be implemented.

      (5)   Although self-monitoring reports do not need to be submitted, the city has the right to request complete records of maintenance and monitoring activities involving stormwater pollution prevention measures. All evaluation reports for the project site must be made available to the city in an organized fashion within 48 hours upon request.

(Ord. 2006-13, passed 10-26-2006; Ord. 2019-25, passed on 5-13-2020)

§ 54.31 STORMWATER QUALITY MANAGEMENT FOR POST-CONSTRUCTION.

   (A)   Applicability and exemptions.

      (1)   In addition to the requirements of § 54.30, the stormwater pollution prevention plan, which is to be submitted to the city as part of the stormwater management permit application, must also include post-construction stormwater quality measures. These measures are incorporated as a permanent feature into the site plan and are left in place following completion of construction activities to continuously treat stormwater runoff from the stabilized site. Any project located within the city that includes clearing, grading, excavation, or other land-disturbing activities, resulting in the disturbance of or impact on one acre or more of total land area, is subject to the requirements of this section. This includes both new development and redevelopment, and disturbances of less than one acre of land that are part of a larger common plan of development or sale if the larger common plan will ultimately disturb one or more acres of land within the MS4 area.

      (2)   The requirements under this section do not apply to the following activities:

         (a)   Agricultural land-disturbing activities;

         (b)   Timber harvesting activities;

         (c)   Construction activities associated with a single-family residential dwelling disturbing less than five acres, when the dwelling is not part of a larger common plan of development or sale;

         (d)   Single-family residential developments consisting of four or less lots;

         (e)   A single-family residential strip development where the developer offers for sale or lease without land improvements and the project is not part of a larger common plan of development of sale; or

         (f)   Individual building lots within a larger permitted project.

      (3)   The requirements under this section do not apply to the following activities, provided other applicable state permits contain provisions requiring immediate implementation of soil erosion control measures:

         (a)   Landfills that have been issued a certification of closure under 329 IAC 10;

         (b)   Coal mining activities permitted under I.C. 14-34; and

         (c)   Municipal solid waste landfills that are accepting waste pursuant to a permit issued by the State Department of Environmental Management under 329 IAC 10 that contains equivalent stormwater requirements, including the expansion of landfill boundaries and construction of new cells either within or outside the original solid waste permit boundary.

      (4)   It will be the responsibility of the project site owner to complete a stormwater permit application and ensure that a sufficient construction plan is completed and submitted to the city in accordance with § 54.32. It will be the responsibility of the project site owner or permit holder to ensure proper construction and installation of all stormwater BMPs in compliance with this subchapter and with the approved stormwater management permit, and to notify the city with a sufficient notice of termination letter upon completion of the project and stabilization of the site. However, all eventual property owners of stormwater quality management facilities meeting the applicability requirements must comply with the requirements of this section and this subchapter.

   (B)   Policy on stormwater quality management.

      (1)   It is recognized that developed areas, as compared to undeveloped areas, generally have increased imperviousness, decreased infiltration rates, increased runoff rates, and increased concentrations of pollutants such as fertilizers, herbicides, greases, oil, salts, and other pollutants. As new development and re-development continues in the city, measures must be taken to intercept and filter pollutants from stormwater runoff prior to reaching regional creeks, streams, and rivers. It is presumed that through the use of best management practices (BMP), stormwater runoff will be filtered and harmful amounts of sediment, nutrients, and contaminants will be removed. The city has established a minimum standard that the measurement of the effectiveness of the control of stormwater quality will be based on the management of total suspended solids (TSS).

      (2)   The project site owner must submit to the city a stormwater pollution prevention plan (SWPPP) that will show placement of appropriate BMP(s) from a pre-approved list of BMPs specified in the city’s “Stormwater Technical Standards Manual”. The noted BMPs must be designed, constructed, and maintained according to guidelines provided or referenced in the city’s “Stormwater Technical Standards Manual”. Practices other than those specified in the pre-approved list may be utilized. However, the burden of proof, as to whether the performance (minimum 80% TSS removal) and ease of maintenance of such practices will be according to guidelines provided in the city’s “Stormwater Technical Standards Manual”, would be placed with the applicant. Details regarding the procedures and criteria for consideration of acceptance of such BMPs are provided in the city’s “Stormwater Technical Standards Manual”.

      (3)   Gasoline outlets and refueling areas must install appropriate practices to reduce lead, copper, zinc, and hydrocarbons in stormwater runoff. These requirements will apply to all new facilities, any existing facilities that replace storage tanks, or any facility that is contributing to water quality degradation through tank leakage, sheet drainage, or any other conveyance that introduces a pollutant to surface or ground waters.

   (C)   Calculations and design standards and specifications.

      (1)   Calculation of land disturbance must follow the guidelines discussed in § 54.30(C).

      (2)   The calculation methods as well as the type, sizing, and placement of all stormwater quality management measures, or BMPs shall meet the design criteria, standards, and specifications outlined in the latest editions of the state’s “Stormwater Quality Manual” and the city’s “Stormwater Technical Standards Manual”. The methods and procedures included in these two references are in keeping with the above stated policy and meet the requirements of IDEM’s Rule 13.

   (D)   Easement requirements. All stormwater quality management systems, including detention or retention basins, filter strips, pocket wetlands, in-line filters, infiltration systems, conveyance systems, structures, and appurtenances located outside of the right-of-way shall be designated as common areas or incorporated into permanent drainage easements. A 20-foot wide access easement from the public right-of-way shall be provided for each BMP. An adequate easement, as detailed in the city’s “Stormwater Technical Standards Manual”, beyond the actual footprint of the stormwater quality management facility must also be provided for the purposes of monitoring, inspection, and general maintenance activities.

   (E)   Inspection, maintenance, record keeping, and reporting.

      (1)   After the approval of the stormwater management permit, the city has the authority to conduct inspections of the work being done to ensure full compliance with the provisions of this section, the “Stormwater Technical Standards Manual”, and the terms and conditions of the approved permit.

      (2)   Stormwater quality management facilities shall be maintained in good condition, in accordance with the operation and maintenance procedures and schedules listed in the latest editions of the state’s “Stormwater Quality Manual” and the city’s “Stormwater Technical Standards Manual”, and the terms and conditions of the approved stormwater permit, and shall not be subsequently altered, revised, or replaced except in accordance with the approved stormwater permit, or in accordance with approved amendments or revisions in the permit. Following construction completion, maintenance of stormwater quality facilities shall be the long-term responsibility of the facility’s owner.

      (3)   The city has the authority to perform long-term, post-construction inspection of all public or privately owned stormwater quality facilities. The inspections will follow the operation and maintenance procedures included in the “Stormwater Technical Standards Manual” or permit application for each specific BMP. The inspection will cover physical conditions, available water quality storage capacity, and the operational condition of key facility elements. Noted deficiencies and recommended corrective action will be included in an inspection report. If deficiencies are found during the inspection, the owner of the facility will be notified by the city and will be required to take all necessary measures to correct such deficiencies. If the owner fails to correct the deficiencies within the allowed time period, as specified in the notification letter, the city will undertake the work and collect from the owner using lien rights if necessary.

(Ord. 2006-13, passed 10-26-2006)