In SFHAs or floodplains, where no floodways have been identified and no base flood or 100-year frequency flood elevations have been established by FEMA, and draining more than a square mile, no development shall be permitted unless the cumulative effect of the proposals, when combined with all other existing and anticipated uses and structures, shall not significantly impede or increase the flow and passage of the floodwaters nor significantly increase the base flood or 100-year frequency flood elevation.
A. Development Permit: No person, firm, corporation, or governmental body, not exempted by State law, shall commence any development in an SFHA or floodplain without first obtaining a development permit from the Village. Application for a development permit shall be made on a form provided by the Village.
The application shall be accompanied by drawings of the site, drawn to scale showing property line dimensions; and existing grade elevations and all changes in grade resulting from excavation or filling, sealed by a licensed engineer, architect or surveyor; the location and dimensions of all buildings and additions to buildings; and the elevation of the lowest floor (including basement) of all proposed buildings subject to the requirements of section 10-11-12 of this chapter.
The application for a development permit shall also include the following information:
1. A detailed description of the proposed activity, its purpose, and intended use.
2. Site location (including legal description) of the property, drawn to scale, on the designated floodway maps, indicating whether it is proposed to be in an incorporated or unincorporated area.
3. Anticipated dates of initiation and completion of activity.
4. Plans of the proposed activity shall be provided which include as a minimum:
a. A vicinity map showing the site of the activity, name of the waterway, boundary lines, names of roads in the vicinity of the site, graphic or numerical scale, and north arrow;
b. A plan view of the project and engineering study reach showing existing and proposed conditions including principal dimensions of the structure or work, elevations in mean sea level (1929 adjustment) datum or NGVD, adjacent property lines and ownership, drainage and flood control easements, distance between proposed activity and navigation channel (when the proposed construction is near a commercially navigable body of water), floodplain limit, location and orientation of cross sections, north arrow, and a graphical or numerical scale;
c. Cross section views of the project and engineering study research showing existing and proposed conditions including principal dimensions of the work as shown in plan view, existing and proposed elevations, normal water elevation, 10-year frequency flood elevation, 100-year frequency flood elevation, and graphical or numerical scales (horizontal and vertical); and
d. A soil erosion and sedimentation control plan for disturbed areas. This plan shall include a description of the sequence of grading activities and the temporary sediment and erosion control measures to be implemented to mitigate their effects. This plan shall also include a description of final stabilization and revegetation measures, and the identification of a responsible party to ensure postconstruction maintenance.
5. Engineering calculations and supporting data shall be submitted showing that the proposed work will meet the criteria of subsection D of this section.
6. Any and all other local, State and Federal permits or approvals that may be required for this type of development.
B. Development Site Elevation: Based on the best available existing data according to the Illinois State Water Survey's floodplain information repository, the Village Engineer shall compare the elevation of the site to the base flood or 100-year frequency flood elevation. Should no elevation information exist for the site, the developer's engineer shall calculate the elevation according to subsection 10-11-6D of this chapter. Any development located on land that can be shown to have been higher than the base flood elevation as of the site's first flood insurance rate map identification is not in the SFHA and, therefore, not subject to the requirements of this chapter. The Department of Code Enforcement shall maintain documentation of the existing ground elevation at the development site and certification that this ground elevation existed prior to the date of the site's first flood insurance rate map identification.
C. Copies Of Other Required Permits: The Department of Code Enforcement shall be responsible for obtaining from the applicant copies of all other local, State, and Federal permits, approvals or permit-not-required letters that may be required for this type of activity. The Village shall not issue the development permit unless all required local, State and Federal permits have been obtained.
D. Preventing Increased Damages: No development in the SFHA, where a floodway has not been determined shall create a damaging or potentially damaging increase in flood heights or velocity or threat to public health, safety and welfare or impair the natural hydrologic and hydraulic functions of the floodway or channel, or impair existing water quality or aquatic habitat. Construction impacts shall be minimized by appropriate mitigation methods as called for in this chapter.
E. Riverine SFHAs; Standards: Within all riverine SFHAs where the floodway has not been determined, the following standards shall apply:
1. Engineering Requirements: The developer shall have a registered professional engineer state in writing and show through supporting plans, calculations, and data that the project meets the engineering requirements of subsections 10-11-9E1 through E13 of this chapter, for the entire floodplain as calculated under the provisions of subsection 10-11-6D of this chapter. As an alternative, the developer should have an engineering study performed to determine a floodway and submit that engineering study to IDNR/OWR for acceptance as a designated floodway. Upon acceptance of their floodway by the department, the developer shall then demonstrate that the project meets the requirements of section 10-11-9 of this chapter for the designated floodway. The "floodway" shall be defined according to the definition in section 10-11-3 of this chapter.
2. IDNR/OWR Permit: A development permit shall not be issued unless the applicant first obtains a permit from IDNR/OWR or written documentation that a permit is not required from IDNR/OWR.
3. IDNR/OWR Permit Requirement Exception: No permit from IDNR/OWR shall be required if the division has delegated permit responsibility to the Village per 92 Illinois Administrative Code, part 708 or as otherwise recodified for designated floodways, per IDNR/OWR Statewide permit entitled "construction in floodplains with no designated floodways in northeastern Illinois".
4. Dam Safety Permits: Any work involving the construction, modification or removal of a "dam" as defined in section 10-11-3 of this chapter shall obtain an IDNR/OWR permit prior to the start of construction of a dam. If the Village finds a dam that does not have an IDNR/OWR permit, the Village shall immediately notify the IDNR/OWR Bartlett Office. If the Village finds a dam which is believed to be in unsafe condition, the Village shall immediately notify the owner of the dam, the IDNR/OWR Bartlett Office, and the Illinois Emergency Management Agency (IEMA).
5. Activities Allowed Without Engineer Review: The following activities may be permitted without a licensed professional engineer's review or calculation of base flood elevation and designated floodway. Such activities shall still meet the other requirements of this chapter.
a. Bridge and culvert crossings of streams in rural areas meeting conditions of IDNR/OWR Statewide permit number 2.
b. Barge fleeting facilities meeting conditions of IDNR/OWR Statewide permit number 3.
c. Aerial utility crossings meeting conditions of IDNR/OWR Statewide permit number 4.
d. Minor boat docks meeting conditions of IDNR/OWR Statewide permit number 5.
e. Minor, nonobstructive activities meeting conditions of IDNR/OWR Statewide permit number 6; activities (not involving fill or positive change in grade) are covered by this permit.
f. Outfall structures and drainage ditch outlets meeting conditions of IDNR/OWR Statewide permit number 7.
g. Underground pipeline and utility crossings meeting the conditions of IDNR/OWR Statewide permit number 8.
h. Bank stabilization projects meeting the conditions of IDNR/OWR Statewide permit number 9.
i. Accessory structures and additions to existing residential buildings meeting the conditions of IDNR/OWR Statewide permit number 10.
j. Minor maintenance dredging activities meeting conditions of IDNR/OWR Statewide permit number 11.
k. Bridge and culvert replacement structures and bridge widenings meeting conditions of IDNR/OWR Statewide permit number 12.
l. Temporary construction activities meeting conditions of IDNR/OWR Statewide permit number 13.
m. Special uses of public waters meeting conditions of IDNR/OWR Statewide permit number 14.
n. Any development determined by IDNR/OWR to be located entirely within a flood fringe area shall be exempt from State floodway permit requirements.
o. The flood carrying capacity of any altered or relocated watercourse shall be maintained.
F. Compensatory Storage: 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 or 100-year frequency flood elevation shall be compensated for and balanced by a hydraulically equivalent volume of excavation taken from below the base flood or 100-year frequency flood elevation. The excavation volume shall be at least equal to one and one-fourth (1.25) 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. All floodplain storage lost below the existing 10-year flood elevation shall be replaced below the proposed 10-year flood elevation. All floodplain storage lost above the existing 10-year flood elevation shall be replaced above the proposed 10-year flood elevation. All such excavations shall be constructed to drain freely and openly to the watercourse. (Ord. 17-2866, 1-23-2017)