(A) General.
(1) Applicability.
(a) Floodplains, wetlands, linear and nonlinear water bodies. All development shall comply with the natural resource protection standards for regulatory floodplains (subsection (B) below), wetlands (subsection (C)), and nonlinear and linear water bodies (subsections (E) and (G)) regardless of whether they are subject to the site capacity calculation and site plan procedures of § 151.070.
(b) Buffers, woodlands, and significant trees. All development that is subject to the site capacity calculation and site plan procedures of § 151.070 shall comply with the natural resource protection standards for water body buffers (subsections (D), (F), and (H) of this section) woodlands, and significant trees (§ 151.071(I)).
(2) Open space. The natural resource protection areas requiring protection in accordance with subsections (B) through (I) below shall be designated “open space for natural resource protection” and shall be permanently maintained as open space. Those areas lying within existing nonlinear water bodies and those wetlands that are determined by the Army Corps of Engineers or the Planning, Building and Development Director to be non-mitigatable shall not be counted toward meeting minimum open space requirements.
COMMENTARY: Unified Development Ordinance, Appendix N entitled “High-Quality Aquatic Resources” provides guidance in determining non-mitigatable wetlands. |
(3) Responsibility for protection. The land owner shall be responsible for protection of all required natural resource protection areas.
(4) Overlapping resource protection areas. When two or more natural resource protection areas overlap, the stricter standards shall control. Only the natural resource that has the higher protection ratio shall be counted. (See Figure 151.071(A).)
(5) Natural resource protection plan. Where applicable, a plan labeled “Natural Resource Protection Plan” shall be submitted and shall be prepared as an overlay of the grading and drainage plan. The natural resource protection plan shall include the following information:
(a) The location and extent of all natural resource protection areas and location, type and nature of all temporary and permanent measures and practices to be utilized to protect natural resource protection areas from development activities, as required by this chapter; and
(b) A table indicating the gross area (predevelopment area) of each identified natural resource, the net area (post-development area) of each identified natural resource and the percentage protection of each identified natural resource.
(B) Regulatory floodplains.
(1) Calculation of natural resource area. The location and extent of floodplain boundaries shall be determined in accordance with the standards of § 151.147(B)(1). Flood-prone areas with 100 acres or more tributary drainage area shall be considered regulatory floodplains for purposes of this section.
(2) Protection ratio. All regulatory floodplain areas (100%) shall be protected and maintained as permanent open space unless otherwise expressly provided in this chapter.
(3) Protected areas. Top-dressing and shallow-filling uses and other uses that are expressly permitted by § 151.148 shall be permitted within regulatory floodplains only when they comply with all applicable floodplain development performance standards of § 151.149. Deep-filling and other uses allowed by the underlying zoning district shall be allowed in regulatory floodplains only if reviewed and approved in accordance with the regulatory floodplain development standards of § 151.148(B).
(4) Resource protection measures. All required protection measures for regulatory floodplains located on the development site shall be installed prior to the commencement of any site development activity and shall remain in place and in working, functional order until all site development activities have ceased and the surrounding area has been permanently stabilized.
(a) Construction fences. Construction fencing (fluorescent polyethylene laminar safety netting or approved equivalent) with a minimum height of three feet shall be installed around the outer limits of all regulatory floodplain areas. The fencing shall be entrenched, secured to ground-mounted metal or wood posts spaced a maximum of ten feet apart and maintained to prevent clearing, grading, and development activities from encroaching into regulatory floodplain areas.
(b) Soil erosion/sediment control. Soil erosion/sediment control measures shall be designed, installed and maintained in accordance § 151.146(J) and practices described in the Illinois Environmental Protection Agency/Natural Resource Conservation Service’s Illinois Urban Manual.
COMMENTARY: For additional guidance with soil erosion/ sediment control matters, applicants are encouraged to refer to the Technical Reference Manual developed by the Lake County Stormwater Management Commission. |
(c) Restricted activities within protected areas. The storage of trash and the dumping of liquids shall be prohibited within protected areas. Unless otherwise expressly allowed by the provisions of this chapter, all grading and filling shall be prohibited within protected areas. The Planning, Building and Development Director shall be authorized to prohibit other activities within protected areas (such as construction material/equipment storage and vehicle parking) as a condition of site development permit/site plan approval if the Planning, Building and Development Director determines that other reasonably feasible storage alternatives exist on the subject site.
(d) Designation, use, maintenance, and ownership of protected areas. Protected regulatory floodplain areas shall be designated, owned, and maintained in accordance with the provisions of § 151.072. Only those passive uses permitted by § 151.072(C)(1) shall be allowed within protected regulatory floodplain areas.
(C) Wetlands.
(1) Calculation of natural resource area. Wetland areas include any area that meets the definition of a “wetland” as defined in § 151.271. If the Planning, Building and Development Director determines that site conditions warrant, a wetland delineation shall be required. Furthermore, if wetlands are determined to be present, provisions of § 151.146(M) shall apply. Wetland delineations shall be conducted in accordance with the methodology adopted by the U.S. Army Corps of Engineers, the Lake County Stormwater Management Commission, and the USDA Natural Resource Conservation Service.
(2) Protection ratio. All wetlands (100%) with a surface area of one-fourth acre or more, situated wholly or partially on-site, shall be protected and maintained as permanent open space unless otherwise expressly provided in this chapter. This provision applies to all wetland areas that are a part of one-fourth acre or larger wetland areas, regardless of the size of the wetland area located on the development site.
(3) Protected areas. Mitigation shall be allowed in accordance with § 151.146(M), provided there is no net loss of protected wetlands and the mitigation occurs in the county. Existing isolated protected wetlands on or adjacent to a development site shall not be excavated, unless the activity is part of an approved U.S. Army Corps of Engineers or watershed development permit. Development or disturbance of a cumulative total of more than one acre of wetlands shall be allowed only if reviewed and approved in accordance with the wetland development standards of § 151.146(M).
(4) Resource protection measures. All required protection measures for wetlands located on the development site shall be installed prior to the commencement of any site development activity and shall remain in place and in working, functional order until all site development activities have ceased and the surrounding area has been permanently stabilized. All required resource protection measures for wetlands shall be installed around the outer limits of all wetland buffers, unless any development activity is proposed within the buffers, in which case the resource protection measures shall be installed around the outer limits of the wetland.
COMMENTARY: The Lake County Wetland Inventory maps and the aerial photographs available on the Lake County web page or in the Department of Planning, Building and Development may be referenced to determine if the wetland present on the property extends beyond the limits of the property boundary. |
(a) Construction fences. Construction fencing (fluorescent polyethylene laminar safety netting or approved equivalent) with a minimum height of three feet shall be installed around the outer limits of all wetland areas. The fencing shall be entrenched, secured to ground-mounted metal or wood posts spaced a maximum of ten feet apart and maintained to prevent clearing, grading, and development activities from encroaching into wetland areas.
(b) Soil erosion/sediment control. Soil erosion/sediment control measures shall be designed, installed and maintained in accordance with § 151.146(J) and practices described in the Illinois Environmental Protection Agency/Natural Resource Conservation Service’s Illinois Urban Manual.
COMMENTARY: For additional guidance with soil erosion/sediment control matters, applicants are encouraged to refer to the Technical Reference Manual developed by the Lake County Stormwater Management Commission. |
(c) Restricted activities within protected areas. The storage of trash and the dumping of liquids shall be prohibited within protected areas. Unless otherwise expressly allowed by this chapter, all grading and filling shall be prohibited within protected areas. The Planning, Building and Development Director shall be authorized to prohibit other activities within protected areas (such as construction material/equipment storage and vehicle parking) as a condition of site development permit/site plan approval if the Planning, Building and Development Director determines that other reasonably feasible storage alternatives exist on the subject site.
(D) Wetland buffers.
(1) Calculation of natural resource area. A wetland buffer shall extend from the edge of the delineated wetland. A property may contain a wetland buffer that originates from wetlands on adjacent property. The natural resource protection area shall be calculated in the following manner.
(a) For wetlands with a total surface area of one-third acre or greater but less than one acre, a minimum wetland buffer width of 30 feet shall be required.
(b) For wetlands with a total surface area of one acre or greater, but less than two and one-half acres, a minimum wetland buffer width of 40 feet shall be required.
(c) For wetlands with a total surface area of two and one-half acres or greater, a minimum wetland buffer width of 50 feet shall be required.
(d) High-quality aquatic resources shall have a minimum wetland buffer width of 100 feet.
(2) Protection ratio. A minimum of 80% of all wetland buffer areas shall be protected and maintained as permanent open space unless otherwise expressly provided in this chapter.
(3) Buffer averaging. The wetland buffer width for a development site may be reduced to a minimum of one-half of the wetland buffer width required, upon approval of the Planning, Building and Development Director, provided that the total wetland buffer area required is achieved adjacent to the wetland being buffered. The consultation process of the Illinois Department of Natural Resources or U.S. Fish and Wildlife Service may override the ability to average wetland buffer areas upon approval of the Planning, Building and Development Director.
(4) Protected areas.
(a) Areas having state or federal threatened and endangered species present or for Illinois Natural Area Inventory sites, wetland buffer widths may be modified upon approval of the Planning, Building and Development Director, to meet the terms and conditions specified during consultation with the Illinois Department of Natural Resources or U.S. Fish and Wildlife Service pursuant to state and federal laws and regulations. However, any additional wetland buffer required pursuant to this provision shall not affect the site capacity calculation. The Planning, Building and Development Director shall support efforts to protect threatened and endangered species whenever the efforts are consistent with the stated purposes of this chapter.
(b) Areas located within 100 feet from the edge of the delineated wetlands with slopes exceeding 12% grade shall also be protected and maintained as permanent open space unless otherwise expressly provided in this chapter. The Planning, Building and Development Director shall be authorized to allow improvements such as retaining walls to prevent soil erosion and protect public safety within protected steep slope areas. Any additional wetland buffer required pursuant to this provision shall not affect the site capacity calculation.
(c) All existing native vegetation within protected wetland buffer areas shall be left undisturbed. Protected wetland buffer areas may be regraded if the Planning, Building and Development Director determines that the regrading is necessary to stabilize the area, prevent soil erosion or otherwise protect or enhance the protected wetland buffer area. The protected wetland buffer area may also be regraded to allow storm-water basins. Access through protected wetland buffer areas shall be provided, when necessary, for maintenance purposes. The protected wetland buffer areas shall be restabilized and re-vegetated with native vegetation immediately after any disturbance or modification. All runoff will be directed to enter protected wetland buffer areas as unconcentrated flow or will be treated to remove all silt and sediment prior to entering the adjacent wetland. In those very limited and unique circumstances when no other reasonable alternative exists, the Planning, Building and Development Director shall be authorized to allow direct runoff into the adjacent wetland with the design and implementation of acceptable best management practices (BMPs). The Planning, Building and Development Director shall report that action to the Planning, Building and Zoning Committee within 15 days of the decision or at the next regularly scheduled meeting of the Planning, Building and Zoning Committee.
COMMENTARY: Stormwater basins may be allowed within the protected wetland buffer areas pursuant to § 151.146 of this chapter. These basins, when properly designed, act as sediment basins and improve the quality of water entering the adjacent wetland. For guidance in designing stormwater facilities that meet this intent, refer to the following sources: Illinois Environmental Protection Agency/Natural Resources Conservation Services, Technical Reference Manual (Lake County Stormwater Management Commission), Native Plant Guide for Streams and Stormwater Facilities in Northeastern Illinois (USDA Natural Resources Conservation Service in cooperation with U.S. Fish and Wildlife Service and U.S. Army Corps of Engineers), Urban Stormwater Best Management Practices for Northeastern Illinois Course Notebook (Northeastern Illinois Planning Commission), Reducing the Impact of Urban Run-Off: Advantages of Alternative Site Design Approaches (Northeastern Illinois Planning Commission for Illinois Environmental Protection Agency). |
(5) Non-protected areas. Wetland buffer areas that are not protected (the remaining 20%) may be developed with structures and impervious surfaces including trails and paths.
(6) Resource protection measures. All required protection measures for wetland buffers located on the development site shall be installed prior to the commencement of any site development activity and shall remain in place and in working, functional order until all site development activities have ceased or the surrounding area has been stabilized.
(a) Construction fences.
1. Construction fencing (fluorescent polyethylene laminar safety netting or approved equivalent) with a minimum height of three feet shall be installed around the outer limits of all wetland buffer areas.
2. The fencing shall be secured to ground-mounted metal or wood posts spaced a maximum of ten feet apart and maintained to prevent clearing, grading, and development activities from encroaching into wetland buffer areas.
(b) Soil erosion/sediment control. Soil erosion/sediment control measures shall be designed, installed and maintained in accordance with § 151.146(J) and practices described in the Illinois Environmental Protection Agency/Natural Resource Conservation Service’s Illinois Urban Manual.
(c) Restricted activities within protected areas. The storage of trash and the dumping of liquids shall be prohibited within protected areas. Unless otherwise expressly allowed by this chapter, all grading and filling shall be prohibited within protected areas. The Planning, Building and Development Director shall be authorized to prohibit other activities within protected areas (such as construction material/equipment storage and vehicle parking) as a condition of site development permit/site plan approval if the Planning, Building and Development Director determines that other reasonably feasible storage alternatives exist on the subject site according to BMPs.
COMMENTARY: For additional guidance with soil erosion/ sediment control matters, applicants are encouraged to refer to the Technical Reference Manual developed by the Lake County Stormwater Management Commission. |
(E) Nonlinear water bodies.
(1) Calculation of natural resource area. The extent of a nonlinear water body (not delineated as wetlands) shall be determined based on the ordinary high water mark.
(2) Protection ratio. The entire area of nonlinear water bodies (100%) shall be protected and maintained as permanent open space unless otherwise expressly provided in this chapter.
(3) Protected areas. The Planning, Building and Development Director shall be authorized to allow only minimal development or disturbance of nonlinear water bodies, provided that the development or disturbance complies with the regulatory floodplain development standards of § 151.148(B) and all applicable U.S. Army Corps of Engineers standards.
(4) Resource protection measures. All required protection measures for nonlinear water bodies located on the development site shall be installed prior to the commencement of any site development activity and shall remain in place and in working, functional order until all site development activities have ceased and the surrounding area has been permanently stabilized. All required resource protection measures for nonlinear water bodies shall be installed around the outer limits of all buffer areas, unless any development activity is proposed within the buffer area, in which case the resource protection measures shall be installed around the outer limits of a nonlinear water body.
(a) Construction fences. Construction fencing (fluorescent polyethylene laminar safety netting or approved equivalent) with a minimum height of three feet shall be installed around the outer limits of all nonlinear water bodies. The fencing shall be entrenched, secured to ground-mounted metal or wood posts spaced a maximum of ten feet apart and maintained to prevent clearing, grading, and development activities from encroaching into nonlinear water bodies.
(b) Soil erosion/sediment control. Soil erosion/sediment control measures shall be designed, installed, and maintained in accordance with § 151.146(J) and practices described in the Illinois Environmental Protection Agency/Natural Resource Conservation Service’s Illinois Urban Manual.
COMMENTARY: For additional guidance with soil erosion/ sediment control matters, applicants are encouraged to refer to the Technical Reference Manual developed by the Lake County Stormwater Management Commission. |
(c) Restricted activities within protected areas. The storage of trash and the dumping of liquids shall be prohibited within protected areas. Unless otherwise expressly allowed by this chapter, all grading and filling shall be prohibited within protected areas. The Planning, Building and Development Director shall be authorized to prohibit other activities within protected areas (such as construction material/equipment storage and vehicle parking) as a condition of site development permit/site plan approval if the Planning, Building and Development Director determines that other reasonably feasible storage alternatives exist on the subject site. The Planning, Building and Development Director shall report the action to the Planning, Building and Zoning Committee within 15 days of the decision or at the next regularly scheduled meeting of the Planning, Building and Zoning Committee.
(d) Designation, use, maintenance, and ownership of protected areas. Protected nonlinear water bodies areas shall be designated, owned, and maintained in accordance with the provisions of § 151.072. Only those passive uses permitted by § 151.072(C)(1) shall be allowed within protected nonlinear water body areas.
(F) Nonlinear water body buffers.
(1) Calculation of natural resource area. Nonlinear water body buffers (that are not delineated as wetlands) shall extend from the ordinary high water mark. A property may contain a buffer that originates from a water body on an adjacent property. The natural resource protection area for nonlinear water body buffers shall be calculated in the following manner.
(a) For nonlinear water bodies with a total surface area of one-third acre or greater but less than one acre, a minimum buffer width of 30 feet shall be required.
(b) For nonlinear water bodies with a total surface area of one acre or greater but less than two and one-half, a minimum buffer width of 40 feet shall be required.
(c) For nonlinear water bodies with a total surface area of two and one-half acres or greater, a minimum buffer width of 50 feet shall be required.
(2) Protection ratio. A minimum of 80% of all nonlinear water body buffer areas shall be protected and maintained as permanent open space unless otherwise expressly provided in this chapter.
(3) Buffer averaging. The nonlinear water body buffer width for a development site may be reduced to a minimum of one-half of the buffer width otherwise required, upon approval of the Planning, Building and Development Director, provided that the total buffer area required is achieved adjacent to the resource being buffered. The consultation process of the Illinois Department of Natural Resources or U.S. Fish and Wildlife Service may override the ability to average buffer areas upon approval of the Planning, Building and Development Director.
(4) Protected areas.
(a) Areas having state or federal threatened and endangered species present or for Illinois Natural Area Inventory sites, nonlinear water body buffer widths may be modified upon approval of the Planning, Building and Development Director, to meet the terms and conditions specified during consultation with the Illinois Department of Natural Resources or U.S. Fish and Wildlife Service pursuant to state and federal laws and regulations. However, any additional nonlinear water body buffer required pursuant to this provision shall not affect the site capacity calculation.
(b) Areas located within 100 feet from the ordinary high water mark of a nonlinear water body with slopes exceeding 12% grade shall also be protected and maintained as permanent open space unless otherwise expressly provided in this chapter. The Planning, Building and Development Director shall be authorized to allow improvements such as retaining walls to prevent soil erosion and protect public safety within protected steep slope areas. Any additional nonlinear water body buffer required pursuant to this provision, shall not affect the site capacity calculation.
(c) All existing native vegetation within protected nonlinear water body buffer areas shall be left undisturbed. Protected nonlinear water body buffer areas may be re-graded if the Planning, Building and Development Director determines that the regrading is necessary to stabilize the area, prevent soil erosion, or otherwise protect or enhance the protected nonlinear water body buffer areas. The protected nonlinear water body buffer areas may also be regraded to allow stormwater basins. Access through protected nonlinear water body buffer areas shall be provided, when necessary, for maintenance purposes. The protected nonlinear water body buffer areas shall be re-stabilized and re-vegetated with native vegetation immediately after any disturbance or modification. All runoff will be directed to enter protected nonlinear water body buffer areas as unconcentrated flow or will be treated to remove all silt and sediment prior to entering the adjacent water body. Only in those very limited and unique circumstances where no other reasonable alternative exists, the Planning, Building and Development Director may allow a direct runoff into the adjacent water body with the design and implementation of acceptable best management practices (BMPs). The Planning, Building and Development Director shall report that action to the Planning, Building and Zoning Committee within 15 days of the decision or at the next regularly scheduled meeting of the Planning, Building and Zoning Committee.
COMMENTARY: Stormwater basins are allowed within protected nonlinear water body buffer areas. These basins, when properly designed, act as sediment basins and improve the quality of water entering the adjacent water body. For guidance in designing stormwater facilities that meet this intent, please refer to the following sources: Illinois Environmental Protection Agency/Natural Resources Conservation Services Illinois Urban Manual, Technical Reference Manual developed by the Lake County Stormwater Management Commission, Native Plant Guide for Streams and Stormwater Facilities in Northeastern Illinois prepared by USDA Natural Resources Conservation Service in cooperation with U.S. Fish and Wildlife Service and U.S. Army Corps of Engineers, Urban Stormwater Best Management Practices for Northeastern Illinois Course Notebook prepared by the Northeastern Illinois Planning Commission, Reducing the Impact of Urban Run-Off: Advantages of Alternative Site Design Approaches, prepared by Northeastern Illinois Planning Commission for Illinois Environmental Protection Agency. |
(5) Non-protected areas. Nonlinear water body buffer areas that are not protected (the remaining 20%) may be developed with structures and impervious surfaces including trails and paths. This provision is intended to allow boat ramps, walkways, and other similar features.
(6) Resource protection measures. All required protection measures for nonlinear water body buffer areas located on the development site shall be installed prior to the commencement of any site development activity and shall remain in place and in working, functional order until all site development activities have ceased or the surrounding area has been stabilized.
(a) Construction fences. Construction fencing (fluorescent polyethylene laminar safety netting or approved equivalent) with a minimum height of three feet shall be installed around the outer limits of all nonlinear water body buffer areas. The fencing shall be secured to ground-mounted metal or wood posts spaced a maximum of ten feet apart and maintained to prevent clearing, grading, and development activities from encroaching into nonlinear water body buffer areas.
(b) Soil erosion/sediment control. Soil erosion/sediment control measures shall be designed, installed and maintained in accordance § 151.146(J) and practices described in the Illinois Environmental Protection Agency/Natural Resource Conservation Service’s Illinois Urban Manual.
COMMENTARY: For additional guidance with soil erosion/ sediment control matters, applicants are encouraged to refer to the Technical Reference Manual developed by the Lake County Stormwater Management Commission. |
(c) Restricted activities within protected areas. The storage of trash and the dumping of liquids shall be prohibited within protected areas. Unless otherwise expressly allowed by this chapter, all grading and filling shall be prohibited within protected areas. The Planning, Building and Development Director shall be authorized to prohibit other activities within protected areas (such as construction material/equipment storage and vehicle parking) as a condition of site development permit/site plan approval if the Planning, Building and Development Director determines that other reasonably feasible storage alternatives exist on the subject site. The Planning, Building and Development Director shall report that action to the Planning, Building and Zoning Committee within 15 days of the decision or at the next regularly scheduled meeting of the Planning, Building and Zoning Committee.
(d) Designation, use, maintenance, and ownership of protected areas. Protected nonlinear water body buffer areas shall be designated, owned, and maintained in accordance with the provisions of § 151.072. Only those passive uses permitted by § 151.072(C)(1) shall be allowed within protected nonlinear water body buffer areas.
(G) Linear water bodies.
(1) Calculation of natural resource area. The extent of a linear water body (not delineated as wetlands) shall be determined based on the ordinary high water mark.
(2) Protection ratio. The entire area (100%) of linear water bodies shall be protected and maintained as permanent open space unless otherwise expressly provided in this chapter.
(3) Protected areas. Protected linear water bodies may be modified for stormwater conveyance or detention purposes only in accordance with the site development regulations of §§ 151.145 through 151.154 and all other applicable regulations of this chapter. Protected linear water bodies may be modified for restoration purposes, provided that a restoration plan has been prepared, submitted, and approved by all of the appropriate federal, state, and county regulatory agencies (IDNR/OWR, ACOE, LCSMC) and is consistent with the site development regulations of §§ 151.145 through 151.154. Restoration of protected linear water bodies may include but is not limited to regrading and re-vegetating banks with native plant species, placement of appropriate in-stream habitat structures (subject to consultation with IDNR), or re-meandering a straightened linear water body to increase habitat diversity.
(4) Resource protection measures. All required protection measures for linear water bodies located on the development site shall be installed prior to the commencement of any site development activity and shall remain in place and in working, functional order until all site development activities have ceased or the surrounding area has been stabilized. All required resource protection measures for linear water bodies shall be installed around the outer limits of all buffer areas, unless any development activity is proposed within the buffer areas, in which case the resource protection measures shall be installed around the outer limits of a water body.
(a) Construction fences. Construction fencing (fluorescent polyethylene laminar safety netting or approved equivalent) with a minimum height of three feet shall be installed around the outer limits of all linear water bodies. The fencing shall be secured to ground-mounted metal or wood posts spaced a maximum of ten feet apart and maintained to prevent clearing, grading, and development activities from encroaching into linear water body areas.
(b) Soil erosion/sediment control. Soil erosion/sediment control measures shall be designed, installed and maintained in accordance § 151.146(J) and practices described in the Illinois Environmental Protection Agency/Natural Resource Conservation Service’s Illinois Urban Manual.
COMMENTARY: For additional guidance with soil erosion/sediment control matters, applicants are encouraged to refer to the Technical Reference Manual developed by the Lake County Stormwater Management Commission. |
(c) Restricted activities within protected areas. The storage of trash and the dumping of liquids shall be prohibited within protected areas. Unless otherwise expressly allowed by this chapter, all grading and filling shall be prohibited within protected areas. The Planning, Building and Development Director shall be authorized to prohibit other activities within protected areas (such as construction material/equipment storage and vehicle parking) as a condition of site development permit/site plan approval if the Planning, Building and Development Director determines that other reasonably feasible storage alternatives exist on the subject site. The Planning, Building and Development Director shall notify the Planning, Building and Zoning Committee of all these decisions within 15 days of action or at the next regularly scheduled meeting of the Planning, Building and Zoning Committee.
(d) Designation, use, maintenance, and ownership of protected areas. Protected linear water body areas shall be designated, owned, and maintained in accordance with the provisions of § 151.072. Only those passive uses permitted by § 151.072(C)(1) shall be allowed within protected linear water body areas.
(H) Linear water body buffers.
(1) Calculation of natural resource area. Linear water body buffers (that are not delineated as wetlands) shall extend from the ordinary high water mark. A property may contain a linear water body buffer that originates from a linear water body on an adjacent property. The natural resource protection area shall be calculated in the following manner.
(a) Linear water bodies with a watershed of more than 20 acres, but less one square mile, shall have a water body buffer of at least 50 feet on each side of the water body.
(b) When the linear water body has a watershed greater than one square mile, the minimum linear water body buffer width shall be 30 feet on each side of the water body.
(c) Linear water bodies with an index of biotic integrity (IBI) greater than 40 shall have a minimum linear water body buffer width of 100 feet on each side. (Initial IBI based on Illinois Environmental Protection Agency Illinois Water Quality Report, biannual. A site-specific IBI assessment may override this report.)
(d) Linear water body buffers shall not be required for water bodies enclosed in an underground conduit or culvert.
(2) Protection ratio. A minimum of 80% of all linear water body buffer areas shall be protected and maintained as permanent open space unless otherwise expressly provided in this chapter.
(3) Buffer averaging. The linear water body buffer width for a development site may be reduced to a minimum of one-half of the linear water body buffer width required, upon approval of the Planning, Building and Development Director, provided that the total linear water body buffer area required is achieved adjacent to the resource being buffered. The consultation process of the Illinois Department of Natural Resources or U.S. Fish and Wildlife Service may override the ability to average linear water body buffer areas upon approval of the Planning, Building and Development Director.
(4) Protected areas.
(a) Areas having state or federal threatened and endangered species present or for Illinois Natural Area Inventory sites, linear water body buffer widths may be modified upon approval of the Planning, Building and Development Director, to meet the terms and conditions specified during consultation with the Illinois Department of Natural Resources or U.S. Fish and Wildlife Service pursuant to state and federal laws and regulations. However, any additional linear water body buffer required pursuant to this provision shall not affect the site capacity calculation.
(b) Areas located within 100 feet from the ordinary high water mark of a water body with slopes exceeding 12% grade shall also be protected and maintained as permanent open space unless otherwise expressly provided in this chapter. The Planning, Building and Development Director shall be authorized to allow improvements such as retaining walls to prevent soil erosion and protect public safety within protected steep slope areas. Any additional linear water body buffer required pursuant to this provision shall not affect the site capacity calculation.
(c) All existing native vegetation within protected linear water body buffer areas shall be left undisturbed. Protected linear water body buffer areas may be re-graded if the Planning, Building and Development Director determines that the regrading is necessary to stabilize the area, prevent soil erosion, or otherwise protect or enhance the protected linear water body buffer areas. The protected linear water body buffer areas may also be regraded to allow stormwater basins. Access through protected linear water body buffer areas shall be provided, when necessary, for maintenance purposes. The linear water body buffer areas shall be re-stabilized and re-vegetated with native vegetation immediately after any disturbance or modification. All runoff will be directed to enter protected linear water body buffer areas as unconcentrated flow or will be treated to remove all silt and sediment prior to entering the adjacent water body. Only in those very limited and unique circumstances where no other reasonable alternative exists, the Planning, Building and Development Director may allow a direct runoff into the adjacent water body with the design and implementation of acceptable best management practices (BMPs). The Planning, Building and Development Director shall report that action to the Planning, Building and Zoning Committee within 15 days of the decision or at the next regularly scheduled meeting of the Planning, Building and Zoning Committee.
(5) Non-protected areas.
(a) Linear water body buffer areas that are not protected (the remaining 20%) may be developed with structures and impervious surfaces including paths and trails.
(b) This provision is intended to allow boat ramps, walkways and other similar features.
COMMENTARY: Stormwater basins are allowed within protected linear water body buffer areas. These basins, when properly designed, act as sediment basins and improve the quality of water entering the adjacent water body. For guidance in designing stormwater facilities that meet this intent, please refer to the following sources: Illinois Environmental Protection Agency/Natural Resources Conservation Services Illinois Urban Manual, Technical Reference Manual developed by the Lake County Stormwater Management Commission, Native Plant Guide for Streams and Stormwater Facilities in Northeastern Illinois prepared by USDA Natural Resources Conservation Service in cooperation with U.S. Fish and Wildlife Service and U.S. Army Corps of Engineers, Urban Stormwater Best Management Practices for Northeastern Illinois Course Notebook prepared by the Northeastern Illinois Planning Commission, Reducing the Impact of Urban Run-Off: Advantages of Alternative Site Design Approaches, prepared by Northeastern Illinois Planning Commission for Illinois Environmental Protection Agency. |
(6) Resource protection measures. All required protection measures for linear water body buffers located on the development site shall be installed prior to the commencement of any site development activity and shall remain in place and in working functional order until all site development activities have ceased or the surrounding area has been stabilized.
(a) Construction fences. Construction fencing (fluorescent polyethylene laminar safety netting or approved equivalent) with a minimum height of three feet shall be installed around the outer limits of all linear water body buffer areas. The fencing shall be secured to ground-mounted metal or wood posts spaced a maximum of ten feet apart and maintained to clearing, grading, and development activities from encroaching into buffer areas.
(b) Soil erosion/sediment control. Soil erosion/sediment control measures shall be designed, installed and maintained in accordance § 151.146(J) and practices described in the Illinois Environmental Protection Agency/Natural Resource Conservation Service’s Illinois Urban Manual.
COMMENTARY: For additional guidance with soil erosion/ sediment control matters, applicants are encouraged to refer to the Technical Reference Manual developed by the Lake County Stormwater Management Commission. |
(c) Restricted activities within protected areas. The storage of trash and the dumping of liquids shall be prohibited within protected areas. Unless otherwise expressly allowed by this chapter, all grading and filling shall be prohibited within protected areas. The Planning, Building and Development Director shall be authorized to prohibit other activities within protected areas (such as construction material/equipment storage and vehicle parking) as a condition of site development permit/site plan approval if the Planning, Building and Development Director determines that other reasonably feasible storage alternatives exist on the subject site.
(d) Designation, use, maintenance, and ownership of protected areas. Protected linear water body areas shall be designated, owned, and maintained in accordance with the provisions of § 151.072. Only those passive uses permitted by § 151.072(C)(1) shall be allowed within protected linear water body areas.
(I) Woodlands and significant trees.
(1) Calculation of natural resource area.
(a) Mature woodlands. A mature woodland is an area or stand of trees whose total combined canopy covers an area of 20,000 square feet or more, at least 50% of which is composed of trees having a diameter breast height of 16 inches or more.
(b) Groves. A grove is a stand of five or more individual trees whose total combined canopy covers an area of less than 20,000 square feet, at least 50% of which is composed of trees having a diameter breast height of 16 inches or more.
(c) Young woodlands. A young woodland is an area or stand of trees whose total combined canopy covers an area of 20,000 square feet or more, at least 50% of which is composed of trees having a diameter breast height of at least three inches and less than 16 inches.
(d) Significant trees. Significant trees are trees having a diameter breast height (four and one-half feet above average ground elevation) of 24 inches or greater for deciduous trees and 12 inches or greater for evergreen trees.
(e) Trees planted for commercial purposes.
1. Active commercial nurseries and Christmas tree operations shall be exempt from the woodland protection standards of this subchapter. If a commercial nursery operation has been abandoned, the areas shall be subject to the woodland protection standards of this subchapter.
2. In determining whether the areas qualify for protection, the Planning, Building and Development Director shall be authorized to require the submission of an assessment of the areas that identifies: the canopy and understory vegetation; the estimated canopy area; the general health condition of the trees; and relevant site conditions such as soils or drainage conditions that may promote or prohibit maturity of the vegetation.
(f) Noxious species. Undesirable or non-native tree species such as Acer negundo (box elder), Robinia pseudoacacia (black locust), Rhamnus cathartica (common buckthorn), Rhamnus frangula (smooth buckthorn), Ailanthus altissima (tree of heaven), Morus alba (white or common mulberry), Eleagnus angustifolia (Russian olive), Eleagnus umbellata (autumn olive), Populus alba (white poplar) and Ulmus pumila (siberian elm) shall not be considered a natural resource and shall not require protection under this section.
(2) Tree surveys. Tree surveys shall be required for all parcels that contain mature woodlands, groves, young woodlands, or significant trees. Tree surveys shall identify the location, size (caliper), species and condition health rating of all trees having a diameter breast height of 12 inches or more. Property line and hedge row trees shall be included in the tree survey. Required tree surveys and inventories shall be conducted by a certified arborist, professional forester, or by a registered professional in a related field. The Planning, Building and Development Director may waive all or a portion of the tree survey requirements if it is determined that no development will take place within a protected woodland area. A condition health rating categorizes trees in one of the following health categories: 5) excellent, 4) very good, 3) good, 2) fair, or 1) poor. The Planning, Building and Development Director may authorize removal of trees identified as “fair” or “poor” by a certified arborist or professional forester.
(3) Protection ratios. See Figure 151.071(I).
(a) Mature woodlands. A minimum of 70% of mature woodland areas shall be protected and maintained as permanent open space unless otherwise expressly provided in this chapter.
(b) Groves. A minimum of 70% of grove areas shall be protected and maintained as permanent open space unless otherwise expressly provided in this chapter.
(c) Young woodlands. A minimum of 50% of young woodland areas shall be protected and maintained as permanent open space unless otherwise expressly provided in this chapter.
(d) Significant trees. At least 70% of all significant trees shall be protected and maintained as permanent open space except those trees that are located within the ultimate rights-of-way of existing roads and existing drainage and utility easements which may be disturbed during construction. All care and effort shall be applied to locate buildings and improvements in a way that reduces the need for removal of significant trees.
(e) Mixed (mature-young) woodland areas. In woodland areas containing a combination of young and mature woodlands, the minimum area that must be protected may be determined by calculating the weighted average protection ratio applicable to the woodland as a whole, in accordance with the following formula:
Weighted average woodland protection ratio | = | (Mature woodland area x .70) + (Young woodland area x 0.50) |
Total woodland area |
(4) Protected areas. Areas located within 100 feet from the edge of the woodlands with slopes exceeding 12% grade shall be protected and maintained as permanent open space unless otherwise expressly provided in this chapter. The Planning, Building and Development Director shall be authorized to allow improvements such as retaining walls to prevent soil erosion and protect public safety within protected steep slope areas. Any additional buffer required pursuant to this provision shall not affect the site capacity calculation.
(5) Non-protected areas. Woodland areas that are not required to be protected may be cleared or developed.
(6) Resource protection measures. All required protection measures for woodlands, groves and significant trees located on the development site shall be installed prior to the commencement of any site development activity and shall remain in place and in working, functional order until all site development activities have ceased and the surrounding area has been permanently stabilized.
(a) Construction fences. Construction fencing (fluorescent polyethylene laminar safety netting or approved equivalent) with a minimum height of three feet shall be installed around the drip lines of all woodlands, groves, and significant trees, prior to pruning. The fencing shall be entrenched, secured to ground-mounted metal or wood posts spaced a maximum of ten feet apart and maintained to prevent clearing, grading, and development activities from encroaching into woodlands, groves, and significant tree areas.
(b) Soil erosion/sediment control. Soil erosion/sediment control measures shall be designed, installed and maintained in accordance § 151.146(J) and practices described in the Illinois Environmental Protection Agency/Natural Resource Conservation Service’s Illinois Urban Manual.
COMMENTARY: For additional guidance with soil erosion/sediment control matters, applicants are encouraged to refer to the Technical Reference Manual developed by the Lake County Stormwater Management Commission. |
(c) Restricted activities within protected areas. The storage of trash and the dumping of liquids shall be prohibited within protected areas. Other activities, such as construction material/equipment storage and vehicle parking, shall also be prohibited within protected areas. Unless otherwise expressly allowed by this chapter, all grading and filling shall be prohibited within protected areas.
(d) Designation, use, maintenance, and ownership of protected areas. Protected woodlands, groves, and significant trees areas shall be designated, owned, and maintained in accordance with the provisions of § 151.072. Only those passive uses permitted by § 151.072(C)(1) shall be allowed within protected areas.
(e) Replacement of woodland credit.
1. If the Planning, Building and Development Director determines that practical difficulties or hardships will result from strict application of the woodland and tree protection standards of this subsection (I)(6), the Planning, Building and Development Director may authorize the clearance of more protected tree or woodland area than is otherwise permitted by this subsection (I)(6), in accordance with the following table. The Planning, Building and Development Director shall notify the Planning, Building and Zoning Committee of all these decisions within 15 days of action or at the next regularly scheduled meeting of the Planning, Building and Zoning Committee.
Zoning District | Minimum Protection Area (%) |
LC, RC, GC | 15 |
LI, II, GO | 30 |
All other | 45 |
2. In order to receive replacement of woodland credit, the following shall be required:
a. The developer shall designate a new woodland area on a part of the site not forested. A reforestation plan, prepared by a certified arborist or registered landscape architect, shall be submitted to the Planning, Building and Development Department showing the location, size, and type of all plant materials to be installed. The materials shall be of a suitable type and compatible with the existing or native vegetation of the site.
b. The new woodland area shall consist of one and one-half times the surface acreage of the woodland area disturbed pursuant to this subsection (I)(6) (the new woodland area shall be subtracted from the net buildable site area calculated under § 151.070).
c. The following amount of plant materials shall be provided per each acre of new woodland to be established. Fractional requirements resulting from fractions of acres to be established shall be rounded up. Types of plant materials shall conform to the list of plant materials found in Appendix A. Either of the following two options may be chosen:
Plant Material Required Per Acre | Minimum Size of Plant Material | |
Option 1 | 10 Canopy trees | 3-inch caliper size |
20 Canopy trees | 2-inch caliper size | |
30 Understory trees | 2-inch caliper size | |
Option 2 | 10 Canopy trees | 3-inch caliper size |
50 Understory trees | 1-1/2-inch caliper size | |
(7) Removal, damage and replacement of significant trees.
(a) Removal. The Planning, Building and Development Director may allow the removal of protected significant trees, when deemed necessary to allow:
1. Work shown on approved construction or engineering plans; or
2. Construction of buildings or improvements.
(b) Reports. Within 15 days of approving the removal of protected significant trees, the Planning, Building and Development Director shall provide a report to the Planning, Building and Zoning Committee. This report shall describe the action taken and the basis for the decision.
(c) Replacement.
1. If the Planning, Building and Development Director allows the removal of protected significant trees, or if the protected trees are damaged during the construction process, high-quality replacement trees of the same species or a species considered native to the area or any other species approved by the Planning, Building and Development Director after consultation with other county departments shall be provided on the development site.
2. The combined total caliper of the replacement trees shall equal at least the combined caliper of the trees to be removed, and all replacement trees shall have a minimum caliper size of three inches.
3. If trees that may have fallen under natural resource protection have been removed prior to site capacity/site plan review approval or in the absence of a tree survey, a licensed arborist must provide an assessment of the impact using all available information. The burden of determining the extent of natural resources shall, in all cases, be upon the property owner and/or developer. In the absence of credible evidence supplied by the applicant, staff shall determine the extent to which protected woodlands or significant trees have been impacted based on all available information.
(Ord., § 4.2, passed 10-13-2009; Ord. passed 8-14-2012; Ord. 19-1378, passed 9-10-2019)