§ 151.02 DEFINITIONS.
   For the purposes of this Chapter, the following definitions are adopted:
   ACT. "An act in relation to the regulation of the rivers, lakes and streams of the State of Illinois", ILCS Ch. 615, Act 5, §§ 5 et seq.
   ADVERSE IMPACT. Any deleterious impact on water resources or wetlands affecting their beneficial uses including recreation, aesthetics, aquatic habitat, quality, and quantity.
   APPLICANT. Any person, firm, corporation or agency which submits an application.
   APPROPRIATE USE. Only uses of the designated floodway that are permissible and will be considered for permit issuance. The only uses that will be allowed are as specified in § 151.07(D).
   BASE FLOOD. The flood having a one-percent probability of being equaled or exceeded in any given year. The base flood is also known as the 100-year frequency flood event. Application of the base flood elevation at any location is as defined in § 151.05 of this Chapter.
   BUILDING. A structure that is principally above ground and is enclosed by walls and a roof. The term includes a gas or liquid storage tank, a manufactured home, mobile home or a prefabricated building. This term also includes recreational vehicles and travel trailers to be installed on a site for more than 180 days, unless fully licensed and ready for highway use.
   BUILDING PERMIT. A permit issued by the Village for the construction, erection or alteration of a structure or building.
   BYPASS FLOW. Stormwater runoff from upstream properties tributary to a property's drainage system, but not under its control.
   CHANNEL. Any river, stream, creek, brook, branch, natural or artificial depression, ponded area, flowage, slough, ditch, conduit, culvert, gully, ravine, wash, or natural or manmade drainageway, which has a definite bed and banks or shoreline, in or into which surface or groundwater flows, either perennially or intermittently.
   CHANNEL MODIFICATION. Alteration of a channel by changing the physical dimensions or materials of its bed or banks. Channel modification includes damming, rip-rapping (or other armoring), widening, deepening, straightening, relocating, lining and significant removal of native vegetation from the bottom or banks. Channel modification does not include the clearing of dead or dying vegetation, debris, or trash from the channel. Channelization is a severe form of channel modification involving a significant change in the channel cross-section and typically involving relocation of the existing channel (e.g. straightening).
   COMPENSATORY STORAGE. An artificially excavated, hydraulically equivalent volume of storage within the SFHA used to balance the loss of natural flood storage capacity when artificial fill or structures are placed within the floodplain. The uncompensated loss of natural floodplain storage can increase off-site floodwater elevations and flows.
   CONDITIONAL APPROVAL OF A DESIGNATED FLOODWAY MAP CHANGE. Preconstruction approval by DNR/OWR and FEMA of a proposed change to the floodway map. This preconstruction approval, pursuant to this Part, gives assurances to the property owner that once an Appropriate Use is constructed according to permitted plans, the floodway map can be changed, as previously agreed, upon review and acceptance of as-built plans.
   CONDITIONAL LETTER OF MAP REVISION (CLOMR). A letter which indicates that FEMA will revise base flood elevations, flood insurance rate zones, flood boundaries or floodway as shown on an effective Flood Hazard Boundary Map or Flood Insurance Rate Map, once the as-built plans are submitted and approved.
   CONTROL STRUCTURE. A structure designed to control the rate of flow that passes through the structure, given a specific upstream and downstream water surface elevation.
   DAM. All obstructions, wall embankments or barriers, together with their abutments and appurtenant works, if any, constructed for the purpose of storing or diverting water or creating a pool. Underground water storage tanks are not included.
   DESIGNATED FLOODWAY. The channel, including on-stream lakes, and that portion of the floodplain adjacent to a stream or watercourse as designated by DNR/OWR, which is needed to store and convey the existing 100-year frequency flood discharge with no more than a 0.1 foot increase in stage due to the loss of flood conveyance or storage, and no more than a 10 percent increase in velocities.
      (1)   The floodways are designated for Crystal Creek, Crystal Creek Tributary, and the Des Plaines River, dated August 19, 2008, respectively, of the countywide Flood Insurance Rate Map for Cook County prepared by the Federal Emergency Management Agency.
      (2)   The floodways for those parts of unincorporated Cook County that are within the one and one-half mile jurisdiction of the Village and may be annexed into the Village are designated for Crystal Creek, Crystal Creek Tributary, and the Des Plaines River, dated August 19, 2008, respectively, of the countywide Flood Insurance Rate Map for Cook County prepared by the Federal Emergency Management Agency.
      (3)   To locate the designated floodway boundary on any site, the designated floodway boundary should be scaled off the designated floodway map and located in a site plan, using reference marks common to both maps. Where interpretation is needed to determine the exact location of the designated floodway boundary, Illinois Department of Natural Resources, Office of Water Resources should be contacted for the interpretation.
   DETENTION FACILITY. A detention facility stores stormwater runoff, and provides a controlled release of this runoff during, and after a flood or storm.
   DEVELOPMENT. Any man-made change to real estate, including:
      (1)   Construction, reconstruction, repair, 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 travel trailer or recreational vehicle on a site for more than 180 days. If the travel trailer or recreational vehicle is on site for less than 180 days, it must be fully licensed and ready for highway use.
      (3)   Drilling, mining, installing utilities, construction of roads, bridges, or similar projects.
      (4)   Demolition of a structure or redevelopment of a site.
      (5)   Clearing of land as an adjunct of construction.
      (6)   Construction or erection of levees, walls, fences, dams, or culverts; channel modification; filling, dredging, grading, excavating, paving, or other non-agricultural alterations of the ground surface; storage of materials; deposit of solid or liquid waste.
      (7)   Any other activity of man that might change the direction, height, or velocity of flood or surface water, including extensive vegetation removal.
   DEVELOPMENT does not include maintenance of existing buildings and facilities such as re-roofing or re-surfacing of roads when there is no increase in elevation, or gardening, plowing, and similar agricultural practices that do not involve filling, grading, or construction of levees.
   DNR/OWR. The Illinois Department of Natural Resources, Office of Water Resources.
   DRY BASIN. A detention basin designed to drain completely after temporary storage of stormwater runoff, and to normally be dry over the majority of its bottom area.
   ELEVATION CERTIFICATES. A form published by FEMA that is used to certify the elevation to which a building has been elevated.
   EROSION. The general process whereby soils are moved by flowing water or wave action.
   EXEMPT ORGANIZATIONS. Organizations which are exempt from this Chapter per Illinois Compiled Statutes (ILCS) including state, federal or local units of government.
   EXISTING MANUFACTURED HOME PARK OR SUBDIVISION. A manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) has been completed before April 1, 1990.
   EXPANSION TO AN EXISTING MANUFACTURED HOME PARK OR SUBDIVISION. The preparation of additional sites by the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads).
   FEMA. Federal Emergency Management Agency and its regulations at 44 CFR 59-79 effective as of September 29, 1989. This incorporation does not include any later editions or amendments.
   FLOOD. A general and temporary condition of partial or complete inundation of normally dry land areas from overflow of inland or tidal waves, or the unusual and rapid accumulation or runoff of surface waters from any source.
   FLOOD FREQUENCY. A period of years, based on a statistical analysis, during which a flood of a stated magnitude may be expected to be equaled or exceeded.
   FLOOD FRINGE. That portion of the floodplain outside of the designated floodway.
   FLOOD PROFILE. The graphical representations of the elevations of the water surface of the 100-year flood along the watercourses of the Village.
   FLOOD INSURANCE RATE MAPS (FIRM). A map prepared by FEMA that depicts the Special Flood Hazard Area (SFHA) within a community. This map includes insurance rate zones and floodplains and may or may not depict floodways.
   FLOODPLAIN. That land typically adjacent to a body of water with ground surface elevations at or below the base flood or the 100-year frequency flood elevation. FLOODPLAINS may also include detached special Flood Hazard Areas, ponding areas, etc. The FLOODPLAIN is also known as the Special Flood Hazard Area (SFHA).
      (1)   The floodplains are those lands within the jurisdiction of the Village that are subject to inundation by the base flood or 100-year frequency flood. The SFHA's of the Village are generally identified as such on the countywide Flood Insurance Rate Map for Cook County prepared by the Federal Emergency Management Agency and dated August 19, 2008.
      (2)   The SFHA's for those parts of unincorporated Cook County that are within the one and one-half mile extraterritorial jurisdiction of the Village and may be annexed into the Village are designated for Crystal Creek, Crystal Creek Tributary, and for Des Plaines River on the countywide Flood Insurance Rate Map for Cook County prepared by the Federal Emergency Management Agency and dated August 19, 2008.
   FLOODPROOFING. Any combination of structural and non-structural additions, changes or adjustments to structures which reduce or eliminate flood damage to real estate or improved real property, water and sanitary facilities, structures and their contents.
   FLOODPROOFING CERTIFICATE. A form published by FEMA that is used to certify that a building has been designed and constructed to be structurally dry floodproofed to the flood protection elevation.
   FLOOD PROTECTION ELEVATION (FPE). The elevation of the base flood or 100-year frequency flood plus one foot of freeboard at any given location in the SFHA.
   FREEBOARD. An increment of elevation added to the base flood elevation to provide a factor of safety for uncertainties in calculations, future watershed development, unknown localized conditions, wave actions and unpredictable effects such as those caused by ice or debris jams.
   HISTORIC STRUCTURE. Any structure that is:
      (1)   Listed individually in the National Register of Historic Places or preliminary determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register;
      (2)   Certified or preliminary determined by the Secretary of the Interior as contributing to the historic district or a district preliminary determined by the Secretary to qualify as a registered historic district;
      (3)   Individually listed on the State inventory of historic places by the Illinois Historic Preservation Agency;
      (4)   Individually listed on a local inventory of historic places that has been certified by the Illinois Historic Preservation Agency.
   HYDROGRAPH. A graph showing the flow rate with respect to time at a given location on a stream or in a conduit.
   HYDROLOGIC AND HYDRAULIC CALCULATIONS. Engineering analysis which determine expected flood flows and flood elevations based on land characteristics and rainfall events.
   INFILTRATION. The passage or movement of water into the soil surfaces.
   LETTER OF MAP AMENDMENT (LOMA). That Official determination by FEMA that a specific structure is not in a 100-year flood zone; amends the effective FIRM.
   LETTER OF MAP REVISION (LOMR). That Letter that revises base flood or 100-year frequency flood elevations, flood insurance rate zones, flood boundaries or floodways as shown on an effective FIRM.
   MAJOR DRAINAGE SYSTEM. The portion of a drainage system needed to store and convey flows beyond the capacity of the minor drainage system.
   MANUFACTURED HOME. A structure, transportable in one or more sections, which is built on a permanent chassis and is designated for use with or without a permanent foundation when attached to the required utilities. The term manufactured homes also includes park trailers, travel trailers and other similar vehicles placed on site for more than 180 consecutive days. The term "manufactured home" does not include a "recreational vehicle".
   MANUFACTURED HOME PARK OR SUBDIVISION. A parcel (or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale.
   MINOR DRAINAGE SYSTEM. That portion of a drainage system designed for the convenience of the public. It consists of street gutters, storm sewers, small open channels, and swales, and is usually designed to handle the stormwater runoff from the 10-year frequency storm.
   MITIGATION. Mitigation includes those measures necessary to minimize the negative effects which floodplain development activities might have on the public health, safety and welfare. Examples of mitigation include compensatory storage, soil erosion and sedimentation control, and channel restoration. Mitigation may also include those activities taken to reduce a structure's susceptibility to flooding.
   NEW MANUFACTURED HOME PARK OR SUBDIVISION. Manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) has been completed on or after April 1, 1990.
   NGVD. National Geodetic Vertical Datum of 1929. Reference surface set by the National Geodetic Survey deduced from a continental adjustment of all existing adjustments in 1929.
   NATURAL. When used in reference to channels means those channels formed by the existing surface topography of the earth prior to changes made by man. A natural stream tends to follow a meandering path; its floodplain is not constrained by levees; the area near the bank has not been cleared, mowed or cultivated; the stream flows over soil and geologic materials typical of the area with no substantial alteration of the course or cross-section of the stream caused by filling or excavating. A modified channel may regain some natural characteristics over time as the channel meanders and vegetation is re-established. Similarly, a modified channel may be restored to more natural conditions by man through regrading and revegetation.
   N.F.I.P. The National Flood Insurance Program. The N.F.I.P is a federal program, administered by FEMA, enabling property owners to purchase flood insurance.
   ONE HUNDRED YEAR FLOOD. The rainfall, storm water runoff, and flood having a one percent (1%) probability of being equaled or exceeded in any given year. Also known as the BASE FLOOD.
   ORDINARY HIGH WATER MARK (OHWM). The point on the bank or shore up to which the presence and action of surface water is so continuous so as to leave a distinctive mark such as by erosion, destruction or prevention of terrestrial vegetation, predominance of aquatic vegetation or other easily recognized characteristics.
   PEAK FLOW. The maximum rate of flow of water at a given point in a channel or conduit.
   PUBLIC FLOOD CONTROL PROJECT. A flood control project which will be operated and maintained by a public agency to reduce flood damages to existing buildings and structures which includes a hydrologic and hydraulic study of the existing and proposed conditions of the watershed. Nothing in this definition shall preclude the design, engineering, construction or financing, in whole or in part, of a flood control project by persons or parties who are not public agencies.
   PUBLIC BODIES OF WATERS. All open public streams and lakes capable of being navigated by watercraft, in whole or in part, for commercial uses and purposes, and all lakes, rivers, and streams which in their natural condition were capable of being improved and made navigable, or that are connected with or discharge their waters into navigable lakes or rivers within, or upon the borders of the State of Illinois, together with all bayous, sloughs, backwaters, and submerged lands that are open to the main channel or body of water directly accessible thereto.
   RECREATIONAL VEHICLE or TRAVEL TRAILER. A vehicle which is:
      (1)   Built on a single chassis;
      (2)   400 square feet or less when measured at the largest horizontal projection;
      (3)   Designed to be self-propelled or permanently towable by a light duty truck; and
      (4)   Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use.
   REGISTERED LAND SURVEYOR. A land surveyor registered in the State of Illinois, under The Illinois Land Surveyors Act. (ILCS Ch. 225, Act 330, §§ 1 et seq.)
   REGISTERED PROFESSIONAL ENGINEER. An engineer registered in the State of Illinois, under The Illinois Professional Engineering Practice Act. (ILCS Ch. 225, Act 325, §§ 1 et seq.)
   REPAIR, REMODELING OR MAINTENANCE. Development activities which do not result in any increases in the outside dimensions of a building or any changes to the dimensions of a structure.
   RETENTION FACILITY. A retention facility stores stormwater runoff without a gravity release.
   RIVERINE SFHA. Any SFHA subject to flooding from a river, creek, intermittent stream, ditch, on stream lake system or any other identified channel. This term does not include areas subject to flooding from lakes, ponding areas, areas of sheet flow, or other areas not subject to overbank flooding.
   RUNOFF. The water derived from melting snow or rain falling on the land surface, flowing over the surface of the ground or collected in channels or conduits.
   SEDIMENTATION. The processes that deposit soils, debris, and other materials either on other ground surfaces or in bodies of water or watercourses.
   SCS. The United States Soil Conservation Service.
   SPECIAL FLOOD HAZARD AREA (SFHA). Any base flood area subject to flooding from a river, creek, intermittent stream, ditch, or any other identified channel or ponding and shown on a Flood Insurance Rate Map as Zone A, AO, A1-30, AE, A99, AH, VO, V30, VE, V, M, E, D, or X.
   STRUCTURE. The results of a man-made change to the land constructed on or below the ground, including the construction, reconstruction or placement of a building or any addition to a building; installing a manufactured home on a site; preparing a site for a manufactured home or installing a travel trailer on a site for more than 180 days unless they are fully licensed and ready for highway use.
   SUBSTANTIAL IMPROVEMENT:
      (1)   Any repair, reconstruction or improvement of a structure, the cost of which equals or exceeds fifty percent (50%) of the market value of the structure either,
         (a)   Before the improvement or repair is started, or
         (b)   If the structure has been damaged, and is being restored, before the damage occurred. This term also includes structures which have incurred "repetitive loss".
      (2)   For the purposes of this definition "substantial improvement" is considered to occur when the first alteration of any wall, ceiling, floor, or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure regardless of the actual work performed.
      (3)   The term does not, however, include either,
         (a)   Any project for improvement of a structure to comply with existing state or local health, sanitary, or safety code specifications which are solely necessary to assure safe living conditions or
         (b)   Any alteration of a "historic structure", provided that the alteration will not preclude the structure's continued designation as an historic structure.
   SWALE. A low-lying, natural or graded depressed land area which acts as a drainageway, but has no definite bed, banks or shorelines, and intermittently conveys only smaller quantities of water, thus permitting growth of maintainable sod or other low vegetation.
   TEN YEAR FLOOD. The rainfall, storm water runoff, and flood having a ten percent (10%) probability of being equaled or exceeded in any given year.
   TIME OF CONCENTRATION. The elapsed time for stormwater to flow from the most hydraulically remote point in a drainage basin to a particular point of interest in that watershed.
   TWO YEAR FLOOD. The rainfall, storm water runoff, and flood having a fifty percent (50%) probability of being equaled or exceeded in any given year.
   TRANSITION SECTION. Reaches of the stream or floodway where water flows from a narrow cross-section to a wide cross-section or vice versa.
   WET BASIN. A detention basin designed to maintain a permanent pool of water after the temporary storage of stormwater runoff.
   WETLAND. Land that has a predominance of hydric soils (soils that are usually wet, and where there is little or no free oxygen) and that is inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and under normal circumstances does support, a prevalence of hydrophytic vegetation typically adapted for life in saturated soil conditions. Areas that are restored or created as a result of mitigation or planned construction projects, and that function as wetlands are included within this definition, even when all three parameters are not present.
(Ord. 05-2528, passed 7-26-05; Am. Ord. 08-2680, passed 5-27-08)