Within all floodplains where a floodway has not been identified on the countywide flood insurance rate map, and within all other floodplains where a floodway has not been delineated, the following standards shall apply.
(A) Except as provided in division (B) below, 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) No fill shall be allowed in a floodway;
(2) Projects involving grading, large excavations, channel improvements or bridge and culvert replacements will require a no-rise certificate completed by an licensed engineer, architect or land surveyor;
(3) Bridge and culvert crossings of streams in rural areas meeting the conditions of IDNR/OWR Statewide Permit No. 2;
(4) Barge fleeting facilities meeting the conditions of IDNR/OWR Statewide Permit No. 3;
(5) Aerial utility crossings meeting the conditions of IDNR/OWR Statewide Permit No. 4;
(6) Minor boat docks meeting the conditions of IDNR/OWR Statewide Permit No. 5;
(7) 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 No. 6;
(8) Outfall structures and drainage ditch outlets meeting the conditions of IDNR/OWR Statewide Permit No. 7;
(9) Underground pipeline and utility crossings meeting the conditions of IDNR/OWR Statewide Permit No. 8;
(10) Accessory structures and additions to existing residential buildings meeting the conditions of IDNR/OWR Statewide Permit No. 10;
(11) Minor maintenance dredging activities meeting the conditions of IDNR/OWR Statewide Permit No. 11;
(12) Bridge and culvert replacement structures and bridge widening meeting the conditions of IDNR/OWR Statewide Permit No. 12;
(13) Temporary construction activities meeting the conditions of IDNR/OWR Statewide Permit No. 13; and
(14) Any development determined by IDNR/OWR to be located entirely within a flood fringe area.
(B) Other development activities not listed in division (A) above may be permitted only if:
(1) Fill is being used in the flood fringe to elevate the site above the base flood elevation, the applicant shall submit sufficient data and obtain a letter of map revision (LOMR) from FEMA for the purpose of removing the site from the floodplain;
(2) Whenever any portion of a floodplain is authorized for use, the volume of space which will be occupied by the authorized fill or structure below the base flood elevation shall be compensated for and balanced by a hydraulically equivalent volume of excavation taken from below the base flood elevation;
(3) The excavation volume shall be at least equal to one and one-half times the volume of storage lost due to the fill or structure. In the case of streams and watercourses, such excavation shall be made opposite or adjacent to the areas so filled or occupied;
(4) All floodplain storage lost below the existing ten-year flood elevation shall be replaced below the proposed ten-year flood elevation. All floodplain storage lost above the existing ten-year flood elevation shall be replaced above the proposed ten-year flood elevation. All such excavations shall be constructed to drain freely and openly to the watercourse;
(5) A permit has been issued for the work by IDNR/OWR (or written documentation is provided that an IDNR/OWR permit is not required); and
(6) 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) In-ground swimming pools located within the floodplain shall be designed as follows:
(1) Anchored to prevent floatation, collapse or lateral movement and ground level;
(2) Be constructed with materials and utility equipment resistant to flood damage and constructed by methods and practices that minimize flood damage per the ASCE 24 Flood Resistant Design and Construction;
(3) Installation of pressure relief valves in the pool floor and all mechanical equipment is to be elevated above the BFE;
(4) Pools shall not be enclosed by walls, roofs or solid fencing;
(5) A plan view of the project and engineering study each showing existing and proposed conditions including principal dimensions of the structure or work, elevations in mean sea level using NAVD 88, adjacent property lines and ownership, drainage and flood control easements, proposed activity and navigation channel (when the proposed construction is near a commercially navigable body of water), designated floodway limit, floodplain limit, location and orientation of cross-sections, north arrow and a graphic or numerical scale;
(6) Cross-section views of the project and engineering study each showing existing and proposed conditions including principal dimensions of the work as shown in a plan view, existing and proposed elevations, normal water elevation, ten-year frequency flood elevation, 100-year frequency flood elevation and graphic or numerical scales (horizontal and vertical);
(7) A copy of the designated floodway map, marked to reflect any proposed change in the designated floodway location;
(8) Any and all other federal, state and local permits or approval letters that may be required for this type of development;
(9) Engineering calculations and supporting data shall be submitted showing that the proposed work will meet the permit criteria of division (B) above; and
(10) If the designated floodway delineation, base flood or 100-year frequency flood elevation will change due to the proposed project, the application will not be considered complete until IDNR/OWR has indicated conditional approval of the designated floodway map change. No structures may be built until a letter of map revision has been approved by FEMA;
(Ord. 21-4, passed 11-9-2021)