11-1-6: PREVENTING INCREASED DAMAGES:
   A.   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.
   B.   Within all 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, division of water resources, issued pursuant to 615 Illinois Compiled Statutes 5/5 et seq.
      2.   The following activities may be constructed without the individual permit required in subsection B1 of this section:
         a.   The construction of wells, 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 (i.e., animal shelters and tool sheds).
         f.   The construction of additions to an existing building which does not increase the first floor area by more than twenty percent (20%), which additions 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 floodwater.
      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 damage or potential flood damage.
   C.   Public health standards in an SFHA:
      1.   No development in an 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 11-1-7B4 of this chapter.
      2.   New and replacement sanitary sewer lines and on site waste disposal systems may be permitted, provided all manholes or other aboveground openings located below the FPE are watertight. (1999 Code § 12.14)