For the purposes of this chapter, the following definitions are hereby adopted:
ACT: An act in relation to the regulation of the rivers lakes and streams of the state of Illinois, 615 Illinois Compiled Statutes 5/4.9 et seq.
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 section 14-1-4 of this chapter.
BASE FLOOD: The flood having a one percent (1%) 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 defined in section 14-1-4 of this chapter.
BUILDING: A structure that is principally aboveground and is enclosed by walls and a roof. This term includes a gas or liquid storage tank, manufactured home, mobile home, and prefabricated building. This term also includes recreational vehicles and travel trailers to be installed at the site for more than one hundred eighty (180) days, unless fully licensed and ready for highway use.
CHANNEL: Any river, stream, creek, brook, branch, natural or artificial depression, pond 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 water or ground water flows either perennially or intermittently.
CHANNEL MODIFICATION: Alteration of a channel by changing the physical dimension material of its bed or banks. "Channel modification" includes damming, riprapping 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 (commonly known as "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 IDNR/OWR and FEMA, or their successor agencies, of a proposed change to the floodway map. This preconstruction approval, pursuant hereto, gives assurances to the property owner that once an appropriate use is constructed according to permitting plans, the floodway map can be changed, as previously agreed, upon review and acceptance of as built plans.
CONDITIONAL LETTER OF MAP REVISIONS (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. An underground water storage tank is not a "dam" as that term is defined herein.
DESIGNATED FLOODWAY: The channel, including on stream lakes, and that portion of the floodplain adjacent to a stream or watercourse as designated by IDNR/OWR, or their successor agencies, 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 ten percent (10%) increase in velocities.
A. The floodways are designed for the Des Plaines River and/or Salt Creek on map number 17031C and panels 0479F, 0483F, 0487F, 0491F, dated November 6, 2000, respectively, of the countywide flood insurance rate map for Cook County prepared by the federal emergency management agency (FEMA) and for the Des Plaines River and/or Salt Creek on the regulatory floodplain map prepared by IDNR/OWR and dated November 6, 2000. When two (2) floodway maps exist for a waterway, the more restrictive floodway limit shall prevail.
B. The floodways for those parts of unincorporated Cook County that are within the one and one-half (11/2) mile extraterritorial jurisdiction of the village that may be annexed into the village are designed for the Des Plaines River and/or Salt Creek on map number 17031C and panels 0479F and 0483F, dated November 6, 2000, respectively, of the countywide flood insurance rate map for Cook County prepared by the federal emergency management agency and for the Des Plaines River and/or Salt Creek on the regulatory floodplain map prepared by IDNR/OWR and dated November 6, 2000.
C. The maps and panels adopted by this chapter shall, without further legislation, be the same as the most current adopted by FEMA, or its successor agency, for the village corporate limits and those parts of unincorporated Cook County that are within the extraterritorial jurisdiction of the village or that may be annexed into the village.
D. To locate the designated floodway boundary on any site, the designed floodway boundary should be scaled off the designated floodway map and located on a site plan, using reference marks common to both maps. Where interpretation is needed to determine the exact location of the designated floodway boundary, IDNR/OWR should be contacted for the interpretation.
DEVELOPMENT:
A. Any manmade change to real estate, including:
1. Construction, reconstruction, repair, placement or replacement of a building or addition to a building.
2. 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 one hundred eighty (180) days. If the travel trailer or recreational vehicle is on site for less than one hundred eighty (180) days, it must be fully licensed and ready for highway use.
3. Drilling, mining, installing utilities and the construction of roads, bridges or similar projects.
4. Demolition of a structure or redevelopment of a site.
5. Clearing of land as an adjunct to construction.
6. Construction or erection of levees, walls, fences, dams, or culverts; channel modification; filling, dredging, grading, excavating, paving or other nonagricultural alterations of the ground surface; storage of materials; or deposit of solid or liquid waste.
7. Any other activity of a person or persons that might change the direction, height or velocity of floodwater or surface water, including extensive removal of vegetation.
B. "Development" does not include maintenance of existing buildings and facilities such as reroofing or resurfacing of roads when there is no increase in elevation; or gardening, plowing and similar agricultural practices which do not involve filling, grading or construction of levees.
ELEVATION CERTIFICATES: A form published by FEMA 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: Any organization which is exempt from the requirements of this chapter pursuant to Illinois law, including state, federal or local units of government.
FEMA: Federal emergency management agency and its regulations (44 CFR 59-79, effective as of September 29, 1989, but not including 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 waters 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 INSURANCE RATE MAP (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.
FLOOD PROTECTION ELEVATION (FPE): The elevation of the base flood or 100-year frequency flood, plus one foot (1') of freeboard, at any given location in the SFHA.
FLOODPLAIN:
A. The 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. "Floodplain" is also known as the "special flood hazard area (SFHA)".
B. "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 SFHAs of the village are generally identified as such on map number 17031C and panels 0479F, 0483F, 0487F, 0491F, dated November 6, 2000, respectively, of the countywide flood insurance rate map for Cook County prepared by the federal emergency management agency (FEMA).
C. The SFHAs of those parts of unincorporated Cook County that are within the extraterritorial jurisdiction of the village or that may be annexed into the village are designated for the Des Plaines River and/or Salt Creek on map number 17031C and panels 0479F and 0483F, dated November 6, 2000, respectively, of the countywide flood insurance rate map for Cook County prepared by the federal emergency management agency (FEMA).
FLOODPROOFING: Any combination of structural and nonstructural additions, changes or adjustments to structures which reduces or eliminates flood damage to real estate or improved real property, water and sanitary facilities, structures and their contents.
FLOODPROOFING CERTIFICATE: A form published by FEMA used to certify that a building has been designed and constructed to be structurally dry floodproofed to the flood protection elevation.
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 action and unpredictable effects such as those caused by ice or debris jams.
HISTORIC STRUCTURE: Any structure that is:
A. Listed individually in the National Register of Historic Places or preliminarily determined by the secretary of the interior as meeting the requirements for individual listing on the national register.
B. Certified or preliminarily determined by the secretary of the interior as contributing to the historic district or a district preliminarily determined by the secretary to qualify as a registered historic district.
C. Individually listed on the State Inventory of Historic Places by the Illinois historic preservation agency.
D. Individually listed on a local inventory of historic places that has been certified by the Illinois historic preservation agency.
HYDROLOGIC AND HYDRAULIC CALCULATIONS: Engineering analyses which determine expected flood flows and flood elevations based on land characteristics and rainfall events.
IDNR/OWR: Illinois department of natural resources, office of water resources.
LETTER OF MAP AMENDMENT (LOMA): An official determination by FEMA that a specific structure is not in a 100-year flood zone. Such letter amends the effective flood hazard boundary map (FHBM) or FIRM.
LETTER OF MAP REVISION (LOMR): A letter which revises base flood or 100-year frequency flood elevations, flood insurance rate zones, flood boundaries or floodways as shown on an effective FHBM or FIRM.
MANUFACTURED HOME: A structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when connected to the required utilities. The term "manufactured home" also includes park trailers, travel trailers and other similar vehicles placed on site for more than one hundred eighty (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 (2) or more manufactured home lots for rent or sale. A "new manufactured home park or subdivision" is 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 on or after April 1, 1990.
MITIGATION: Includes those measures necessary to minimize the negative effects which floodplain development activities might have on the public health, safety and welfare including, but not limited to, 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.
NGVD: "National geodetic vertical datum of 1929". "NGVD" is a 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 reestablished. Similarly, a modified channel may be restored to more natural conditions through regrading and revegetation.
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.
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.
PUBLIC FLOOD CONTROL PROJECT: A flood control project that will be operated and maintained by a public agency to reduce flood damages to existing buildings and structures, that includes a hydrologic and hydraulic study of the existing and proposed conditions of the watershed. Nothing in this definition shall or is intended to 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.
RECREATIONAL VEHICLE OR TRAVEL TRAILER: A vehicle that is:
A. Built on a single chassis;
B. Four hundred (400) square feet or less when measured at the largest horizontal projection;
C. Designed to be self-propelled or permanently towable by a light duty truck; and
D. Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, seasonal or similar use(s).
REGISTERED LAND SURVEYOR: A land surveyor registered in the state of Illinois, pursuant to the provision of the Illinois professional land surveyor act, 225 Illinois Compiled Statutes 330/1 et seq.
REGISTERED PROFESSIONAL ENGINEER: An engineer registered in the state of Illinois, pursuant to the provision of the Illinois professional engineering practice act, 225 Illinois Compiled Statutes 325/1 et seq.
REPAIR, REMODELING OR MAINTENANCE: Development activities that do not result in any increases in the outside dimensions of a building or any changes to the dimensions of a structure.
RETENTION/DETENTION FACILITY: A "retention facility" stores stormwater runoff without a gravity release. A "detention facility" provides for storage of stormwater runoff and controlled release of this runoff during and after a flood or storm.
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, pond 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 material either on other ground surfaces or in bodies of water or watercourses.
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 hazard boundary map or flood insurance rate map as zone A, AO, A1-30, AE, A99, AH, V0, V30, VE, V, M, E, D or X.
STRUCTURE: The results of a manmade 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 one hundred eighty (180) days unless it is fully licensed and ready for highway use.
SUBSTANTIAL IMPROVEMENT:
A. Any repair, reconstruction, or improvement of the structure, the cost of which equals or exceeds fifty percent (50%) of the market value of the structure either:
1. Before the improvement or repair is started; or
2. If the structure has been damaged, and is being restored, before the damage occurred.
B. 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 the alteration affects the external dimensions of the structure.
C. The term does not, however, include either:
1. 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
2. Any alteration of a historic structure; provided, that the alteration will not preclude the structure's continued designation as a historic structure.
TRANSITION SECTION: Reaches of a stream or floodway where water flows from a narrow cross section to a wide cross section or vice versa. (1965 Code § 7-18-3; amd. 2009 Code)