No development in the SFHA shall create a damaging or potentially damaging increase in flood heights or velocity or threat to public health and safety.
A. Within the floodway identified on the flood boundary floodway map, the following standards shall apply:
1. Except as provided in subsection A2 of this section, no development shall be allowed which, acting in combination with existing or future similar works, will cause any increase in the base flood elevation. The specific development activities identified in subsection B2 of this section shall be considered as meeting this requirement.
2. No increase in the base flood elevation may be permitted unless:
a. The total cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the base flood elevation more than one foot (1') for the affected hydraulic reach of the stream and will not increase flood damages or potential flood damages;
b. A permit has been issued by the Illinois department of transportation, office of water resources as required in subsection B1 of this section; and
c. For all projects involving channel modifications or fill (including levees), the city shall submit sufficient data to the federal emergency management agency to revise the regulatory flood data.
B. Within all other riverine SFHAs, the following standards shall apply:
1. In addition to the other requirements of this chapter, a development permit for a site located in a floodway (or in a riverine SFHA where no floodway has been identified) shall not be issued unless the applicant first obtains a permit or written documentation that a permit is not required from the Illinois department of transportation, office of water resources, issued pursuant to 20 Illinois Compiled Statutes 801/5-5.
2. The following activities may be constructed without the individual permit required in subsection B1 of this section in accordance with statewide permits issued by the Illinois department of transportation, office of water resources provided the activities do not involve placement of fill, change of grade or construction in the normal channel. Such activities must still meet the other requirements of this chapter:
a. The construction of walls, septic tanks and underground utility lines not crossing a lake or stream;
b. The construction of light poles, signposts and similar structures;
c. The construction of sidewalks, driveways, athletic fields (excluding fences), patios and similar surfaces which are built at grade;
d. The construction of properly anchored, unwalled, open structures such as playground equipment pavilions and carports;
e. The placement of properly anchored buildings not exceeding seventy (70) square feet in size, nor ten feet (10') in any dimension (e.g., animal shelters and tool sheds); and
f. The construction of additions to existing buildings which do not increase the first floor area by more than twenty percent (20%), which are located on the upstream or downstream side of the existing building, and which do not extend beyond the sides of the existing building that are parallel to the flow of floodwaters.
3. The total cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the base flood elevation more than one foot (1') for the affected hydraulic reach of the stream and will not increase flood damages or potential flood damages.
C. Public health standards in all SFHAs:
1. No development in the SFHA shall include locating or storing chemicals, explosives, buoyant materials, flammable liquids, pollutants or other hazardous or toxic materials below the FPE unless such materials are stored in a storage tank or floodproofed building constructed according to the requirements of subsection 9-3-7B5 of this chapter.
2. New and replacement sanitary sewer lines and on site waste disposal systems may be permitted providing all manholes or other aboveground openings located below the FPE are watertight. (Ord. 6675, 9-25-2002)