(A) The only development in a floodway which will be allowed are appropriate uses, which will not cause a rise in the BFE, and which will not create a damaging or potentially damaging increase in flood heights or velocity or be a threat to public health and safety and welfare or impair the natural hydrologic and hydraulic functions of the floodway or channel, or permanently impair existing water quality or aquatic habitat. Construction impacts shall be minimized by appropriate mitigation methods as called for in this chapter. All buildable residential and nonresidential lots must be outside the SFHA and floodway for new development to minimize flood risk associated with base flood and higher-magnitude floods. Subdivisions and planned unit developments are required to obtain a Letter of Map Revision from FEMA in accordance with § 152.091.
(B) Only those appropriate uses listed in 17 Ill. Adm. Code, Chapter I, IDNR Part 3708 (Floodway Construction in Northeastern Illinois) will be allowed. Appropriate uses do not include the construction or placement of any new structures, fill, buildings, building additions, buildings on stilts, excavation or channel modifications done to accommodate otherwise nonappropriate uses in the floodway, fencing (including landscaping or planting designed to act as a fence) and storage of materials except as specifically defined below as an appropriate use. The approved appropriate uses are as follows:
(1) Flood control structures, dikes, dams and other public works or private improvements relating to the control of drainage, flooding, erosion, or water quality or habitat for fish and wildlife;
(2) Structures or facilities relating to the functionally water dependent uses of, or requiring access to, the water or shoreline, such as existing pumping and treatment facilities, and facilities and improvements related to recreational boating, commercial shipping and other functionally water dependent uses (except for additions to habitable structures on the site);
(3) Storm sewer and treated sanitary treatment plant outfalls;
(4) Underground and overhead utilities;
(5) Recreational facilities such as playing fields and trail systems including any related fencing (at least 50% open when viewed from any one direction) built parallel to the direction of flood flows, and including open air pavilions and toilet facilities (four stall maximum) that will not block flood flows nor reduce floodway storage;
(6) Sheds, boat houses or other non-habitable accessory structures without toilet facilities to existing buildings that will not block flood flows, nor reduce floodway storage. Storage of hazardous material is further prohibited in these structures;
(7) Bridges, culverts, roadways, driveways, sidewalks, railways, runways and taxiway required for crossing the floodway or for access to other appropriate uses in the floodway and any modification thereto;
(8) Parking lots and any modifications thereto and aircraft parking aprons built at or below ground elevation provided that:
(a) The depth of flooding at the 100-year frequency flood event will not exceed one foot, or
(b) The parking lot is accessory to short-term outdoor recreational facilities and the owner agrees to restrict access during periods of inundation and agrees to accept liability for all damage caused by vehicular access during flooding events;
(9) Regulatory floodway regrading, without fill, to create a positive non-erosive slope toward a watercourse;
(10) Floodproofing activities to protect previously existing lawful structures including the construction of water tight window wells, elevating structures, or construction of floodwalls around residential, commercial or industrial principal structures where the outside toe of the floodwall or berm shall be no more than ten feet away from the exterior wall of the existing structure, and, which are not considered substantial improvements to the structure;
(11) Aircraft parking aprons built at or below ground elevation where the depth of flooding at the 100-year frequency flood event will not exceed one foot;
(12) Modifications to existing buildings above the BFE that do not increase the building’s footprint, and which will not block flood flows. These modifications include fireplaces, bay windows, decks, patios and second story addition. No enclosed floor areas may be built on stilts. If the building is improved to 50% or more of the market value before the modification occurred (i.e., a substantial improvement), the building will be protected from flooding to the flood protection elevation.
(13) The replacement, reconstruction or repair of a damaged building, provided that the outside dimensions of the building are not increased and, provided that, if the building is damaged to 50% or more of the building’s market value before it was damaged, the building will be protected from flooding to or above the 100-year frequency flood elevation.
(Ord. 3187, passed 1-22-19) Penalty, see § 152.999