(615 ILCS 5/18g) (from Ch. 19, par. 65g)
    Sec. 18g. (a) The Department of Natural Resources shall define the 100-year floodway within metropolitan counties located in the area served by the Northeastern Illinois Planning Commission, except for the part of that area which is within any city with a population exceeding 1,500,000. In defining the 100-year floodway, the Department may rely on published data and maps which have been prepared by the Department itself, by the Illinois State Water Survey of the University of Illinois, by federal, State or local governmental agencies, or by any other private or public source which it determines to be reliable and appropriate.
    (b) The Department may issue permits for construction that is an appropriate use of the designated 100-year floodway in such metropolitan counties. If a unit of local government has adopted an ordinance that establishes minimum standards for appropriate use of the floodway that are at least as restrictive as those established by the Department and this Section, and the unit of local government has adequate staff to enforce the ordinance, the Department may delegate to such unit of local government the authority to issue permits for construction that is an appropriate use of the floodway within its jurisdiction.
    (c) No person may engage in any new construction within the 100-year floodway as designated by the Department in such metropolitan counties, unless such construction relates to an appropriate use of the floodway. No unit of local government, including home rule units, in such metropolitan counties may issue any building permit or other apparent authorization for any prohibited new construction within the 100-year floodway.
    (d) For the purpose of this Section, including for the purposes of granting permit and license applications filed or pending prior to the effective date of this amendatory Act of the 96th General Assembly:
        (1) "100-year floodway" means the channel and that
portion of the 100-year floodplain adjacent to a stream or watercourse which is needed to store and convey the 100-year frequency flood discharge without a significant increase in stage.
        (1.5) "100-year floodplain" means the lowland and
relatively flat areas adjoining inland and coastal waters, including flood-prone areas of offshore islands, that are inundated by a flood that has a 1% or greater chance of recurring in any given year or a flood of a magnitude equalled or exceeded once in 100 years on the average over a significantly long period.
        (2) "New construction" means the construction of any
new building or structure or the placement of any fill or material, but does not include the repair, remodeling or maintenance of buildings or structures in existence on the effective date of this amendatory Act of 1987.
        (3) "Appropriate use of the floodway" means use for
(i) flood control structures, dikes, dams and other public works or private improvements relating to the control of drainage, flooding or erosion; (ii) structures or facilities relating to the use of, or requiring access to, the water or shoreline, including pumping and treatment facilities, and facilities and improvements related to recreational boats, commercial shipping and other functionally dependent uses; and (iii) any other purposes which the Department determines, by rule, to be appropriate to the 100-year floodway, and the periodic inundation of which will not pose a danger to the general health and welfare of the user, or require the expenditure of public funds or the provision of public resources or disaster relief services. Appropriate use of the floodway does not include construction of a new building unless such building is a garage, storage shed or other structure accessory to an existing building and such building does not increase flood stages.
        (4) "Person" includes natural persons, corporations,
associations, governmental entities, and all other legal entities.
    (e) All construction undertaken on a designated 100-year floodway in such metropolitan counties, without benefit of a permit from the Department of Natural Resources, shall be unlawful and the Department or any affected unit of local government may, in its discretion, proceed to obtain injunctive relief for abatement or removal of such unlawful construction. The Department, in its discretion, may make such investigations and conduct such hearings and adopt such rules as may be necessary to the performance of its duties under this Section.
    (f) This Section does not limit any power granted to the Department by any other Act.
    (g) This Section does not limit the concurrent exercise by any unit of local government of any power consistent herewith.
    (h) This Section does not apply to any city with a population exceeding 1,500,000.
(Source: P.A. 95-728, eff. 7-1-08 - See Sec. 999; 96-1395, eff. 7-29-10.)