Illinois Administrative Code
Title 17 - CONSERVATION
Part 3708 - FLOODWAY CONSTRUCTION IN NORTHEASTERN ILLINOIS
Section 3708.20 - Definitions

Unless specifically defined in this Section, words and phrases used in this Part shall be interpreted so as to give them the meaning they have in common usage.

"Act" - The Rivers, Lakes and Streams Act [615 ILCS 5 ].

"Application" - An application for a permit to authorize new construction in a regulatory floodway as required by this Part.

"Appropriate Use" - See Section 3708.70.

"Building" - A structure that is principally above ground and is enclosed by walls and a roof. This term includes a gas or liquid storage tank, a manufactured 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.

"Conditional Approval of a Regulatory Floodway Map Change" - Preconstruction approval by the Department 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. The Department will accept as-built plans which show the project was built in accordance with the permitted plans.

"Department" - The Illinois Department of Natural Resources.

"FEMA" - Federal Emergency Management Agency and its regulations at 44 CFR 65 effective as of October 1, 1988. This incorporation does not include any later editions or amendments.

"Flood Fringe" - That portion of the flood plain outside the regulatory floodway.

"Flood Plain" - That land adjacent to a body of water with ground surface elevations at or below the 100-year frequency flood elevation.

"Hydraulically Significant" - The length of a hydraulically significant portion of a watershed is determined by three factors; the drainage area of the watershed, the amount of flood plain storage in the regulatory floodway of the stream, and the impact flood plain storage has on reducing downstream flood heights. For example, on a stream with a small drainage area, with little flood plain storage, and little downstream impact, only one municipality may have to require effective compensatory storage. On larger streams, several communities may be involved.

"New Construction" - The construction of any new building or structure or the placement of any fill, material, or structure or regrading but does not include the repair, remodeling, or maintenance of buildings or structures in existence on November 18, 1987 (Section 18g of the Act).

"Office" - The Illinois Department of Natural Resources, Office of Water Resources.

"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 or this Part shall preclude the design, engineering, construction or financing, in whole or in part, of a flood control project under this Part by persons or parties who are not public agencies.

"Registered Land Surveyor" - A land surveyor registered in the State of Illinois, under the Illinois Professional Land Surveyor Act [225 ILCS 330 ].

"Registered Professional Engineer" - An engineer registered in the State of Illinois, under the Illinois Professional Engineering Practice Act [225 ILCS 325 ].

"Regulatory Floodway" - The channel and that portion of the floodplain adjacent to a stream or watercourse as designated by the Department pursuant to Section 18g of the Act, which is needed to store and convey the100-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% increase in velocities (Section 18g of the Act).

"Repair, Remodeling or Maintenance" - Construction activities which do not result in any increases in the outside dimensions of a building or any changes to the dimensions of a structure.

"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; installing utilities, construction of roads or similar projects; construction or erection of levees, walls, fences, bridges or culverts; drilling, mining, filling, dredging, grading, excavating; and the storage of materials.

"Transition Sections" - are reaches of the stream or floodplain where water flows from a narrow cross-section to a wide cross-section or vice versa.