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(A) Sections 160.087 through 160.100 of this chapter applies to development in or near streams, lakes, ponds and wetlands within the village. Streams, lakes, and ponds (including intermittent streams) are those which are shown on the United States Department of the Interior Geological Survey (USGS) 7.5 minute quadrangle National Wetlands Inventory Maps and those additional streams, lakes, and ponds delineated on the village Water Resources Management Plan map adopted as part of §§ 160.087 through 160.100 of this chapter. Those are hereby made a part of §§ 160.087 through 160.100 of this chapter, and two copies thereof shall remain on file at the village administrative building for public inspection. Wetlands are those designated by the most recent version of the U.S. Army Corps of Engineers Manual of Wetland Delineation. At the discretion of the Stormwater Administrator, a Letter of No Objection (LONO) may be required for any development adjacent to wetlands.
(B) If new drainage courses, lakes, ponds or wetlands are created as part of a development, the requirements for setbacks and uses within setbacks, and the criteria for watercourse relocation and minor modification shall apply. The District shall be amended as appropriate to include these areas.
(1) The Lowland Conservancy Overlay District. The Lowland Conservancy Overlay District shall be considered as an overlay to the zoning districts created by the village zoning ordinance as amended in addition to the requirements of §§ 160.087 through 160.100 of this chapter, applicants for a site development permit within the District shall meet all requirements of the underlying zoning districts. In the event of a conflict between the overlay district requirements and the underlying zoning district requirements, the most restrictive requirements prevail.
(a) Within the Special Flood Hazard Area (SFHA) designated by the Federal Emergency Management Agency (FEMA); or
(b) Within 100 feet of the ordinary high water mark (OHWM) of a perennial stream or intermittent stream, the ordinary high water mark of a lake or pond, or the edge of a wetland; or
(c) Within depressional areas serving as floodplain or stormwater storage areas, as designated on the Lowland Conservancy District Map.
(3) Minimum setback of development activity from streams, lakes, depressional storage, ponds, and wetlands.
(a) Absolutely no development activity (except as provided below) may occur within the minimum setback. The minimum setback, should be a vegetated buffer strip, preferable planted with native plant species, shall be maintained or restored around the periphery of the area in question. The width of the buffer strip shall be as follows:
1. Twenty-five feet for a tributary length of 250 feet or less.
2. Fifty feet for a tributary length greater than 250 feet and less than 500 feet.
3. Seventy-five feet for a tributary length over 500 feet.
Note: the tributary length is the maximum length (measured prior to subdividing the parcel) of the project limits to the sensitive area or the length from a drainage divide to the sensitive area.
(b) The minimum setback shall be measured between the ordinary high water mark of streams, lakes and ponds, or the edge of wetlands, or within a designated depressional areas. In no case shall the setback be less than the boundary of the 100-year floodway as defined by FEMA. These setback requirements do not apply to a stream in a culvert unless the stream is taken out of the culvert as part of development activity. If a culvert functions as a low-flow culvert, where water is intended to periodically flow over it, the setback requirements apply.
(c) The following development activities may be permitted, subject to issuance of a site development permit, within the minimum setback areas only if, as a practical matter, they cannot be located outside the setback area. Such development activities will only be approved based upon a report, prepared by a qualified professional, which demonstrates that they will not adversely affect water quality; destroy, damage or disrupt significant habitat area; adversely affect drainage and/or stormwater retention capabilities; adversely affect flood conveyance and storage; lead to unstable earth conditions, create erosion hazards, or be materially detrimental to any other property in the area of the subject property or to the village as a whole, including the loss of open space or scenic vistas:
1. Minor improvements such as walkways, benches, comfort stations, informational displays, directional signs, footbridges, observation decks, and docks;
2. The maintenance, repair, replacement, and reconstruction of existing utilities, highways and bridges, electrical transmission and telecommunication lines, poles, and towers; and
3. The establishment and development of public and private parks and recreation areas, outdoor education areas, historic natural and scientific areas, game refuges, fish and wildlife improvement projects, game bird and animal farms, wildlife preserves and public boat launching ramps.
(d) Review of proposed development activity within the minimum setback area will consider the following:
1. Only limited filling and excavating necessary for the development of public boat launching ramps, swimming beaches, or the development of park shelters or similar structures is allowed. The development and maintenance of roads, parking lots and other impervious surfaces necessary for permitted uses are allowed only on a very limited basis, and where no alternate location outside of the setback area is available.
2. Land surface modification within the minimum setback shall be permitted for the development of stormwater drainage swales between the developed area of the site (including a stormwater detention facility on the site) and a stream, lake or pond, or wetland. Detention basins within the setback are generally discouraged, unless it can be shown that resultant modifications will not impair water quality, habitat, or flood storage functions.
3. No filling or excavating within wetlands is permitted except to install piers for the limited development of walkways and observation decks. Walkways and observation decks should avoid high quality wetland areas, and should not adversely affect natural areas designated in the Illinois Natural Areas Inventory or the habitat of rare or endangered species.
4. Wetland area occupied by the development of decks and walkways must be mitigated by an equal area of wetland habitat improvement.
5. a. Modification of degraded wetlands for purposes of stormwater management is permitted where the quality of the wetland is improved and total wetland acreage is preserved. Where such modification is permitted, wetlands shall be protected from the effects of increased stormwater runoff by measures such as detention or sedimentation basins, vegetated swales and buffer strips, and sediment and erosion control measures on adjacent developments. The direct entry of storm sewers into wetlands shall be avoided. Environmental impact analysis of wetland modification may be required in accordance with § 160.093 of this chapter.
b. An applicant for a site development permit (see § 160.090 of this chapter) must stabilize areas left exposed after land surface modification with vegetation normally associated with that stream or wetland. The planting of native riparian vegetation is recommended as the preferred stabilization measure. Other techniques should be used only when and where vegetation fails to control erosion. The preferred alternative is riprap, using natural rock materials where practicable, installed on eroding bank areas in a manner that provides interstitial space for vegetative growth and habitat for macro invertebrates and other stream organisms. Lining of the stream channel bottom is not permitted.
c. The applicant shall minimize access to the applicant's proposed development activity within all or part of the Lowland Conservancy Overlay District where such access could adversely affect the stream, lake, pond, wetland, or related environmentally sensitive areas.
(4) Site development plan.
(a) A site development plan must be prepared for any proposed development within, or partly within, the Lowland Conservancy Overlay District and must indicate:
1. Dimension and area of parcel, showing also the vicinity of the site in sufficient detail to enable easy location, in the field, of the site for which the site development permit is sought, and including the boundary line, underlying zoning, a legend, a scale, and a north arrow. This requirement may be satisfied by the submission of a separate vicinity map;
2. Location of any existing and proposed structures;
3. Location of existing or proposed on-site sewage systems or private water supply systems;
4. Location of any perennial or intermittent stream, lake or pond, and its ordinary high water mark;
5. Location and landward limit of all wetlands;
7. Location of the 100-year floodway and floodplain limits;
8. Location of existing or future access roads;
9. Specifications and dimensions of stream, wetland or other water areas proposed for alterations;
10. Cross-sections and calculations indicating any changes in flood storage volumes; and
11. Such other information as reasonably requested by the village.
(b) The applicant shall present evidence, prepared by a qualified professional engineer, that demonstrates that the proposed development activity will not endanger health and safety, including danger from the obstruction or diversion of flood flow. The developer shall also show, by submitting appropriate calculations and resource inventories, that the proposed development activity will not substantially reduce natural floodwater storage capacity, destroy valuable habitat for aquatic or other flora and fauna, adversely affect water quality or ground water resources, increase stormwater runoff velocity so that water levels on other lands are substantially raised or the danger from flooding increased, or adversely impact any other natural stream, floodplain, or wetland functions, and is otherwise consistent with the intent of §§ 160.087 through 160.100 of this chapter.
(5) Geologic and soil report. The site proposed for development shall be investigated to determine the soil and geologic characteristics, including soil erosion potential. A report, prepared by a licensed professional engineer, geoscientist, or soil scientist experienced in the practice of geologic and soil mechanics, shall be submitted with every application for land development within the Lowland Conservancy Overlay District. This report shall include a description of soil type and stability of surface and subsurface conditions. Any area that the investigation indicates as being subject to geologic or soil hazards shall not be subjected to development, unless the engineer or soil scientist can demonstrate conclusively that these hazards can be overcome.
(6) Hydrologic controls/drainage control plan.
(a) A drainage control plan that describes the hydraulic characteristics of on-site and nearby watercourses as well as the proposed drainage plan, prepared by a registered professional engineer experienced in hydrology and hydraulics, shall be submitted with each application for land development within the Lowland Conservancy Overlay District. Unless otherwise noted, the following restrictions, requirements and standards shall apply to all development within the Lowland Conservancy Overlay District:
1. Natural open-channel drainageways shall be preserved; and
2. Runoff from areas of concentrated impervious cover (e.g., roofs, driveways, streets, patios, etc. shall be collected and transported to a drainageway (preferably a natural drainageway) with sufficient capacity to accept the discharge without undue erosion or detrimental impact. Vegetated drainage swales are preferred over conveyances constructed of concrete or other manufactured materials.
(b) The drainage control plan shall identify appropriate measures, such as recharge basins and detention/retention basins, which will limit the quantitative and qualitative effects of stormwater runoff to pre-development conditions.
(7) Site grading and excavation plan.
(a) Division (B)(7) of this section applies to the extent that grading and excavation and erosion control plans, which satisfy the following requirements, are not already required by a jurisdiction.
(b) A site grading and excavation plan, prepared by a registered professional engineer, trained and experienced in civil engineering, shall be submitted with each application for a site development permit and shall include the following:
1. Details of the existing terrain and drainage pattern with one-foot contours;
2. Proposed site contours at one-foot intervals;
3. Dimensions, elevation and contours of grading, excavation and fill; slopes of all drainage swales shall be a minimum of 2% through the side and rear yard drainage easements;
4. A description of methods to be employed in disposing of soil and other material that is removed from allowable grading and excavation sites, including location of the disposal site if on the property;
5. A schedule showing when each stage of the project will be completed, including the total area of soil surface to be disturbed during each stage, and estimated starting and completion dates. The schedule shall be prepared so as to limit, to the shortest possible period, the time soil is exposed and unprotected. In no case shall the existing natural vegetation be destroyed, removed or disturbed more than 15 days prior to initiation of the improvements; and
6. A detailed description of the revegetation and stabilization methods to be employed, to be prepared in conjunction with the landscape plan per division (B)(8) of this section. This description should include locations of erosion control measures such as sedimentation basins, straw bales, diversion swales, etc.
1. Every effort shall be made to develop the site in such a manner so as to minimize the alteration of the natural topography;
2. No grading, filling, cleaning, clearing, terracing or excavation of any kind shall be initiated until final engineering plans are approved and the site development permit is granted by the village; and
3. The depositing of any excavation, grading or clearing material within a stream, lake, pond or wetland area shall be prohibited.
(e) In addition to locating all site improvements on the subject property to minimize adverse impacts on the stream, lake, pond, or wetland, the applicant shall install a berm, curb, or other physical barrier during construction, and following completion of the project, where necessary, to prevent direct runoff and erosion from any modified land surface into a stream, lake, pond, or wetland. All parking and vehicle circulation areas should be located as far as possible from a stream, lake, pond, or wetland.
(f) The village may limit development activity in or near a stream, lake, pond, or wetland to specific months, and to a maximum number of continuous days or hours, in order to minimize adverse impacts. Also, the village may require that equipment be operated from only one side of a stream, lake, or pond in order to minimize bank disruption. Other development techniques, conditions, and restrictions may be required in order to minimize adverse impacts on streams, lakes, ponds or wetlands, and on any related areas not subject to development activity.
(8) Natural vegetation buffer strip required; vegetation and revegetation/landscape plan.
(a) To minimize erosion, stabilize the streambank, protect water quality, maintain water temperature at natural levels, preserve fish and wildlife habitat, to screen man-made structures, and also to preserve aesthetic values of the natural water course and wetland areas, a natural vegetation strip shall be maintained along the edge of the stream, lake, pond or wetland. The natural vegetation strip shall be as described in division (B)(3) of this section and shall be measured from the ordinary high water mark of a perennial or intermittent stream, lake or pond and the edge of wetland.
(b) Within the natural vegetation strip, trees and shrubs may be selectively pruned or removed for harvest of merchantable timber, to achieve a filtered view of the water body from the principal structure and for reasonable private access to the stream, lake, pond, or wetland. Said pruning and removal activities shall ensure that a live root system stays intact to provide for streambank stabilization and erosion control.
(c) A landscape plan, prepared by a professional, shall be submitted with each site development permit application for development activity within the Lowland Conservancy Overlay District and contain the following:
1. A plan describing the existing vegetative cover of the property and showing those areas where the vegetation will be removed as part of the proposed construction; and
2. A plan describing the proposed revegetation of disturbed areas specifying the materials to be used.
(d) The vegetation must be planned in such a way that access for stream maintenance purposes shall not be prevented.
(Ord. 06-0383, passed 3-15-06; Am. Ord. 19-1532, passed 1-16-19)