Within any floodway identified on the Flood Insurance Rate Map of St. Clair County, and within all other floodplains of the village where a floodway has not been delineated, the following standards shall apply:
(A) Except as provided in § 152.08(B) of this chapter, no development shall be allowed which, acting in combination with existing and anticipated development, will cause any increase in flood heights or velocities or threat to public health and safety. The following specific development activities shall be considered as meeting this requirement:
(1) Bridge and culvert crossings of streams in rural areas meeting the conditions of the Illinois Department of Natural Resources, Office of Water Resources Statewide Permit Number 2;
(2) Barge fleeting facilities meeting the conditions of IDNR/OWR Statewide Permit Number 3;
(3) Aerial utility crossings meeting the conditions of IDNR/OWR Statewide Permit Number 4;
(4) Minor boat docks meeting the conditions of IDNR/OWR Statewide Permit Number 5:
(5) Minor, non-obstructive activities such as underground utility lines, light poles, sign posts, driveways, athletic fields, patios, playground equipment, minor storage buildings not exceeding 70 square feet and raising buildings on the same footprint which does not involve fill and any other activity meeting the conditions of IDNR/OWR Statewide Permit Number 6;
(6) Outfall structures and drainage ditch outlets meeting the conditions of IDNR/OWR Statewide Permit Number 7;
(7) Underground pipeline and utility crossings meeting the conditions of IDNR/OWR Statewide Permit Number 8;
(8) Bank stabilization projects meeting the conditions of IDNR/OWR Statewide Permit Number 9;
(9) Accessory structures and additions to existing residential buildings meeting the conditions of IDNR/OWR Statewide Permit Number 10;
(10) Minor maintenance dredging activities meeting the conditions of IDNR/OWR Statewide Permit Number 11;
(11) Bridge and culvert replacement structures and bridge widening meeting the conditions of IDNR/OWR statewide Permit Number 12;
(12) Temporary construction activities meeting the conditions of IDNR/OWR statewide Permit Number 13.
(13) Any development determined by IDNR/OWR to be located entirely within a flood fringe area shall be exempt from state floodway permit requirements.
(B) Other development activities not listed in § 152.08(A) may be permitted only if:
(1) Permit has been issued for the work by IDNR/OWR (or written documentation is provided that an IDNR/OWR permit is not required), or
(2) Sufficient data has been provided to FEMA when necessary, and approval obtained from FEMA for a revision of the regulatory map and base flood elevation.
(C) Encroachment into the floodway. The construction of any new building within the mapped floodway of the village is prohibited.
(D) Compensatory storage volume standards.
(1) The placement of fill, structures, or any other material above natural grade in the floodplain shall require compensatory storage equal to at least one and one half times the volume of floodplain storage displaced.
(2) When floodplain storage is lost below the ten-year flood elevation the compensatory storage must be below the ten-year flood elevation.
(3) Grading and any other soil disturbing activities in wetland or riparian buffer areas shall be executed in such a manner that the existing effective floodplain storage is maintained at all times.
(4) Excavation for the purpose of compensatory storage directly adjacent to streams and other watercourses shall be made opposite or directly adjacent to the areas to be filled.
(E) In addition to the above requirements, drainage in AO and AH zones requires that grading of the subject site shall allow for adequate drainage paths around structures on slopes to guide floodwater around and away from the proposed structure. Furthermore, the drainage shall not adversely affect any adjacent property.
(Prior Code, § 17-107) (Ord. 1891, passed 10-5-2020)