The preparation of soil erosion and sediment control plans shall follow the principles outlined in the “Illinois Procedures and Standards for Urban Soil Erosion and Sedimentation Control”, excepting Chapter Six (6) published by the Urban Committee of the Association of Illinois Soil and Water Conservation Districts. The design criteria, standards, and methods shall be prepared in accordance with the requirements of this Code and the standards and specifications contained in “Illinois Urban Manual” prepared for the Illinois Environmental Protection Agency by the U.S.D.A., Natural Resources Conservation Service, which standards and methods are hereby incorporated into this Code by reference. In the event of conflict between the provisions of said manuals and of this Code, this Code shall govern. The following requirements should also be met:
(A) 
Erosion and sediment control design requirements. New developments or redevelopments shall comply with and meet the following:
(1) 
Control measures shall be constructed to control runoff from the property to such an extent possible that sediment is retained on site.
(2) 
Temporary on-site control measures required shall be constructed and functional prior to initiating clearing, grading, stripping, excavating or fill activities on site.
(3) 
Disturbed areas shall be stabilized with permanent measures within seven (7) calendar days following the end of active disturbance, or re-disturbance consistent with the following criteria:
(a) 
Appropriate permanent stabilization measures shall include seeding, mulching, or sodding, with non-vegetative measures as a last resort.
(b) 
Areas having slopes greater than three to one (3:1) shall be stabilized with sod, mat, or blanket in combination with seeding or equivalent.
(4) 
All temporary and permanent erosion and sediment control practices should be maintained and repaired as needed to assure effective performance of their intended function.
(5) 
All temporary erosion and sediment control measures shall be disposed in a proper manner within thirty (30) days after final site stabilization is achieved with permanent soil stabilization measures. Trapped sediment and other disturbed soils resulting from the disposition of temporary measures shall be permanently stabilized to prevent further erosion and sedimentation.
(6) 
Site development requirements. On site sediment control measures, as specified by the following criteria, shall be constructed as specified in the referenced handbooks, and be functional prior to initiating clearing, grading, stripping, excavating or fill activities on site.
(a) 
For drainage areas less than one (1) acre, filter barriers including filter fences, straw bales, or equivalent control measures shall be constructed to control all onsite runoff. Vegetated filter strips, with a minimum width of twenty-five (25) feet, may be used as an alternative only where runoff in sheet flow is expected.
(b) 
For drainage areas more than one (1) acre but less than five (5) acres, a sediment trap or equivalent control measure shall be constructed at the downslope point of the disturbed area.
(c) 
For drainage areas greater than five (5) acres, a sediment basin or equivalent control measure shall be constructed at the downslope point of the disturbed area.
(d) 
Sediment basin and sediment trap designs shall provide for both dry detention and wet detention sediment storage. The detention storage shall be composed of equal volumes of wet detention storage and dry detention storage and each shall be sized as specified in Section 32-1-5(B). The release rate of the basin shall be that rate as specified in Section 32-1-5(B). The elevation of the outlet structure shall be placed such that it only drains the dry detention storage.
(e) 
The sediment storage shall be sized to store the estimated sediment load generated from the site over the duration of the construction period with a minimum storage equivalent to the volume or sediment generated in one (1) year. For construction periods exceeding one (1) year, the one (1) year sediment load and a sediment removal schedule may be substituted.
(f) 
For erosion and sediment control measures the alteration of sinkholes by filling, grading or excavation is prohibited.
(g) 
To the extent possible or as otherwise regulated in this Code all desirable trees eight (8) inches in diameter and larger shall be protected for their present and future value for erosion protection and other environmental benefits. Trees that have been selected for preservation shall be marked prior to the beginning of any clearing, grading, stripping, excavation, or filling of the site. A “no construction zone” shall be established and marked at the perimeter of the dripline of each tree which is to be preserved.
(7) 
Stormwater conveyance channels, including ditches, swales, and diversions, and the outlets of all channels and pipes shall be designed and constructed as specified in Section 32-1-5(B). All constructed or modified channels shall be stabilized within forty-eight (48) hours, consistent with the following standards and as required in the referenced handbooks:
(a) 
For grades of four to one (4:1) to eight to one (8:1), an erosion blanket or equivalent control measure shall be applied in the channel.
(b) 
For grades greater than eight to one (8:1), rock, riprap, or an equivalent control measure shall be applied over filter fabric or other type of soil protection, or the grade shall be effectively reduced using drop structures.
(8) 
Land disturbance activities in stream channels shall be avoided, where possible, or as specified in Section 32-1-5(B). If disturbance activities are unavoidable, the following requirements shall be met:
(a) 
Construction vehicles shall be kept out of the stream channel to the maximum extent practicable. Where construction crossings are necessary, temporary crossings shall be constructed of nonerosive material, such as riprap or gravel.
(b) 
The time and area of disturbance of stream channels shall be kept to a minimum. The stream channel, including bed and banks, shall be stabilized within forty-eight (48) hours after channel disturbance is completed, interrupted, or stopped.
(c) 
Whenever channel relocation is necessary, the new channel shall be constructed under dry conditions and fully stabilized before flow is diverted, incorporating meanders, pool and riffle sequence, and riparian planting.
(9) 
Storm sewer inlets and culverts shall be protected by sediment traps or filter barriers meeting accepted design standards and specifications.
(10) 
Soil storage piles containing more than ten (10) cubic yards of material shall not be located with a downslope drainage length of less than twenty-five (25) feet to a roadway, drainage channel, or sinkhole. Filter barriers, including straw bales, filter fence, or equivalent, shall be installed immediately on the downslope side of the piles.
(11) 
If dewatering devices are used, discharge locations shall be protected from erosion. All pumped discharges shall be routed through appropriately designed sediment traps or basins, or equivalent, and shall not be deposited into a sinkhole.
(12) 
Each site shall have graveled or equivalent entrance roads, access drives, and parking areas of sufficient length and width to prevent sediment from being tracked onto public or private roadways. Any sediment reaching a public or private road shall be removed by shoveling or street cleaning, not flushing, before the end of each workday and transported to a controlled sediment disposal area.
(B) 
Maintenance of control measures. All soil erosion and sediment control measures necessary to meet the requirements of this Code shall be maintained periodically by the applicant or subsequent landowner during the period of land disturbance and development of the site in a satisfactory manner to ensure adequate performance.
CRITICAL STORM EVENT
The critical storm event shall be considered as the one hundred (100) year, twenty-four (24) hour event unless engineering evaluation shows that the rainfall for an event of lesser duration creates more runoff for any specific watershed. The storm event, including, but not limited to, rainfall amount and duration, that the County in consultation with the applicant’s Licensed Professional Engineer during the preliminary plat stage, will be required for calculations pertaining to the development of stormwater and erosion control plans.
DRAINAGE PLAN
A plan, including engineering drawings and supporting calculations, which describes the existing stormwater drainage system and environmental features, including grading, as well as proposed alterations or changes to the drainage system and environment of the property.
DRAINAGEWAY
A watercourse, gully, dry stream, creek or ditch which carries stormwater sewers, or which serves the purpose of draining water from the lands adjacent to such watercourse, gully, dry stream, creek or ditch.
FLOODPLAIN
That land adjacent to a body of water with ground surface elevations at or below the base flood or the one hundred (100) year frequency flood elevation which is subject to inundation. The flood plain as designated by the Federal Emergency Management Agency (FEMA) is also known as the Special Flood Hazard Area (SFHA). This area is the collective combination of the regulatory floodway and the flood fringe. (See Chapter 14 in County Code)
MODIFIED RATIONAL METHOD
As described in the Illinois Department of Transportation’s “Drainage Manual” is based on the principal that the maximum rate of runoff from a given drainage area occurs at that point in time when all parts of the watershed are contributing to the flow. The rainfall generating the peak flow is assumed to be of uniform intensity of the entire watershed with a rainfall duration equal to the time of concentration.
ONE HUNDRED YEAR EVENT
A rainfall, runoff, or flood event having a one percent (1%) chance of occurring in any given year. A twenty-four (24) hour storm duration is assumed unless otherwise noted.
RETENTION
A facility natural or man-made, that provides permanent or long-term storage of surface runoff accompanied by a low release rate.
RETENTION BASIN
A facility, designed to completely retain a specified amount of stormwater runoff without release except by means of evaporation, infiltration, emergency bypass or pumping.
SINKHOLE
Any natural depression formed as a result of subsurface removal of soil or rock materials and causing the formation of a collapse feature that exhibits internal drainage. The existence of a sinkhole shall be indicated by the uppermost closed depression contour lines on the USGS seven and one-half (7½) minute quadrangle topographic maps or as determined by field investigations.
TWO-YEAR EVENT
A runoff, rainfall, or flood event having a fifty percent (50%) chance of occurring in any given year. A twenty-four (24) hour storm duration is assumed unless otherwise noted.
WATERSHED
All land area drained by, or contributing water to, the same stream, creek, ditch, lake, marsh, stormwater facility, groundwater or depressional area.
WET BASIN
A detention basin designed to maintain a permanent pool of water after the temporary storage of stormwater runoff.
WETLANDS
Wetlands are defined by regulation as those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. For general, but inclusive locations of designated wetlands, refer to mapping prepared jointly by the U.S. Department of Interior, Fish and Wildlife Service and the Illinois Department of Natural Resources, Office of Resource Conservation; National Wetlands Inventory Mapping, 1987.
By ordinance, the County Board of Commissioners shall establish (and may periodically amend) a schedule of fees for the various permits and procedures listed in this Code. Said fees are intended to defray the administrative costs connected with the processing/reviewing of such permits or procedures; the fees do not constitute a tax or other revenue-raising device. All such fees shall be paid by the applicant to the County and are non-refundable. A current schedule of filing fees shall be maintained in the Code Official’s office and on file with the County Clerk.
Any person, partnership or corporation violating any of the provisions of this Code shall be deemed guilty of a misdemeanor, and each day during which any violation of any of the provisions of this Code is committed, continued, or permitted shall constitute a separate offense. Upon conviction of any such violation, such person, partnership or corporation shall be punished by a fine of not more than One Thousand Dollars ($1,000.00) for each offense. In addition to any other penalty authorized by this Section, any person, partnership, or corporation convicted of violating any of the provisions of this Code shall be required to restore the site to the condition existing prior to commission of the violation, or to bear the expense of such restoration. Failure on the part of the subdivider to comply forthwith with any order made under the provisions of this Code will result in injunctive action, notwithstanding the penalty provisions of this Section.