This Appendix contains the minimum requirements and guidelines for preparation of a Project Mitigation Document (PMD) related to the creation or enhancement of wetlands on a development site, or on an offsite property, to meet the mitigation provisions in§ 151.146(M)(4). These provisions do not apply for Category IV impacts to Isolated Waters of Lake County. The PMD shall provide at a minimum, information needed by Lake County Planning Building & Development (PB&D) to evaluate the appropriateness and enforceability of a proposed mitigation plan. Additional requirements may apply for impacts to Waters of the United States, as determined by the U.S. Army Corps of Engineers. For the purposes of this Appendix, the term mitigation site refers to the ownership parcel where the mitigation is to occur. Mitigation area refers to the location within the mitigation site where the actual mitigation will occur.

   Each PMD shall include specific information in a standard format as outlined in Table 1 and described in Sections A-K below.

 

      1.   Discuss how the wetland mitigation shall duplicate or improve the hydrologic and biologic features of the impacted wetlands. Describe the specific functions of the wetlands to be created or enhanced versus the functions of the wetlands to be impacted.

      2.   Describe the acreage and vegetative community type of wetlands and wetland buffers to be created or enhanced to meet the minimum mitigation ratios required in § 151.146(M)(4)(b). Mitigation acreage shall be credited on the following basis:

         a.   100% for each acre of wetland created or restored. For the purposes of this Appendix, wetland creation includes restoration of historic wetlands which have been filled, drained, or otherwise manipulated to the extent the areas no longer exhibit wetland characteristics. Open water creation shall be credited at 100% for in-kind mitigation (e.g., one acre of open water created for one acre of open water impacted). No mitigation credit shall be given for open water creation to compensate for non-open water impacts.

         b.   25% for each acre of non-farmed wetland enhanced after a minimum ratio of 1:1 for wetland creation to wetland impact is achieved.

         c.   Enhancement of farmed wetlands meeting the size criterion in§ 151.146(M)(5)(a) may be used for up to 80% of the total mitigation requirement (e.g., if 2.0 acres of mitigation are required, up to 1.6 acres may be credited for farmed wetland enhancement, as long as the size criterion above is met).

         d.   Enhanced upland areas or enhanced wetland edges used to meet the buffer requirements in § 151.146(H)(5) shall be credited at 25% for each acre enhanced. Created or restored wetland edges used to meet the buffer requirements of this Ordinance shall be credited at 75% for each acre created or restored. All high-quality aquatic resources existing on the mitigation site shall, at a minimum, meet the buffer requirements for high-quality aquatic resources; all other existing enhanced, created or restored wetland areas shall, at a minimum, meet the non-high-quality aquatic resource buffer requirements of this Ordinance.

      1.   Site Location. Identify the mitigation site on a general location map (USGS quadrangle map preferred), plat of survey, and major watershed map (e.g., Fox River Watershed).

      3.   Land Use. Describe the past and current land use(s) of the mitigation site parcel. Submit a plan at a minimum scale of 1 in.=100 ft. showing the existing land use(s) and pertinent features, such as buildings, roads, utility lines, drain tiles, culverts, landscaping, lot lines, etc. Include on the plan or provide a narrative of any adjacent land uses that could conflict with the mitigation proposal and any zoning restrictions. Discuss potential adverse impacts to the mitigation site, including stormwater runoff from adjacent properties or nearby development in the watershed. Include a copy of the current zoning map and comprehensive land plan showing proposed land use(s), roads and trail systems.

      4.   Ownership. Identify the current owner(s) of the mitigation site property. If the owner is different from the permittee, provide PB&D with a copy of an executed agreement between the owner(s) and permittee that grants permission by the owner(s) for the permittee to use the property for mitigation and specifies the responsibilities of each party for establishment of the mitigation site. Once mitigation is in place, the permittee shall notify PB&D of any change in ownership. The new owner(s) shall provide written assurance to the issuer of the SDP of the transfer of the permit and intent to comply with the terms and conditions of the permit, specifically the mitigation plan.

      5.   Significant Biological Resources. The permittee shall consult with the Illinois Department of Natural Resources (IDNR) and the U.S. Fish & Wildlife Service (USFWS) regarding the possible presence of threatened or endangered species or critical habitat on the mitigation site. PB&D shall not approve the mitigation area until documentation is provided confirming the proposed mitigation area is in compliance with the IDNR’s Endangered Species Consultation Program and the Illinois Natural Areas Preservation Act [520 ILCS 10/11 and 525 ILCS 30/17] and the USFWS’ consultation program under the federal Endangered Species Act.

      1.   Topography. If grading is proposed, submit a grading plan at a minimum scale of 1 in.=100 ft. showing existing and proposed grades with a minimum of 1-foot contour lines. Identify elevation and location of reference benchmarks. Include cross-sections for the mitigation wetlands with normal water level (NWL) and high water level (HWL) depicted, if applicable.

      2.   Hydrology.

      Identify the source(s) of water for the mitigation wetlands, both surface and subsurface. Describe any water control structures to be used and identify these structures on the grading plan, with invert elevations. Control structures with adjustable inverts are recommended to facilitate management of desired water levels in the mitigation wetlands. Describe the expected hydrologic regime of the mitigation wetlands.

      Provide hydrologic modeling results in both summary table and hydrograph form for the 2-year and 100-year, 24 hour storm events, at a minimum, to support the expected hydrologic regime of the mitigation wetlands. Verify that the mitigation design will not adversely impact the hydrology of existing on-site or nearby wetlands.

      Discuss factors influencing the quality of stormwater runoff from on-site and off-site sources (e.g., roads, lawns, parking lots, etc.) and incorporate best management practices (BMPs) into the design to treat runoff before it discharges into the wetlands. Identify the BMPs on the grading plan.

      Stormwater detention basins shall not be used for creation of wetlands to meet the wetland mitigation requirements of this Ordinance in§ 151.146(M)(4).

      3.   Soils.

      A minimum of twelve (12) inches of suitable rooting medium shall be provided on the mitigation wetlands and wetland buffer areas. Use low ground pressure equipment to minimize soil compaction, include information about whether topsoil will be imported from off-site.

      If the mitigation site contains a drained hydric soil, include the NRCS soil map unit description and describe the drainage system (e.g., drain tile, ditches, channels, etc.). The drainage system shall be shown on the grading plan. Verify the hydric soil map unit by digging a 30-inch deep soil pit in a representative location of the map unit and write a detailed profile description of the soil, including horizons, soil colors using Munsell color charts, and soil texture and structure. Examine the soil profile for the presence of redoximorphic features such as iron/manganese accumulations, oxidized rhizospheres, mottles, and depleted zones. Record the type, relative abundance, location, and color of these features. Record other evidence of soil wetness such as the accumulation of partially decomposed organic matter at the soil surface.

      4.   Planting Plan. Submit a plan at a minimum scale of 1 in.=100 ft. depicting the location and acreage of each wetland and wetland buffer community type to be established. This plan shall also be used as the base map to show the locations of the vegetation monitoring transects and hydrology sampling points discussed in Appendix S, Section I. Provide the list of plants to be established in community by common and scientific name, along with the seeding or planting rate for each species. Seed and plant stock source(s) shall originate from within 150 miles of the mitigation site to maintain local genotypes.

   All mitigation wetlands, as well as other preserved wetlands or waters and wetland buffers on the mitigation site, shall be protected in perpetuity by a deed or plat restriction. The permittee shall provide PB&D with a draft copy of the proposed deed or plat restriction document and associated exhibit(s) showing the restricted areas for approval. Contact PB&D for example wetland and wetland buffer restrictive language.

   Provide a schedule with anticipated start date and duration for each phase of the mitigation site construction, including installation of soil erosion and sediment control measures, earthwork, and planting.

   The permittee shall provide PB&D with a financial surety for 110% of the total estimated cost for construction, monitoring, and management of the mitigation wetlands and wetland buffers. The amount of the financial surety shall be based upon the wetland consultant’s detailed cost estimate for completing the approved mitigation plan, including earthwork, planting, and monitoring and management for a minimum of five (5) full growing seasons after planting is completed. The cost estimate shall be provided to PB&D for approval prior to obtaining the financial surety. The financial surety may be in the form of a performance bond, irrevocable letter of credit, irrevocable trust, escrow account, casualty insurance, or other approved surety.

   The financial surety shall be held by PB&D until the mitigation site meets the performance standards in Section H. Such surety may be phased out or reduced by PB&D once it has been demonstrated that the mitigation site is functionally mature and/or self-sustaining in accordance with the performance standards in Section H.

      1.   Upon the completion of earthwork, but prior to planting, the permittee shall provide an as-built topographic map to PB&D for approval. The as-built map shall depict the constructed grades at a minimum of 2-ft contour intervals, along with spot elevations, and the invert elevations of all water control structures. The bench mark(s) used to establish the grades shall also be indicated on the plan. If the constructed grades and invert elevations are not in conformance with the approved grading and utility plan, the permittee shall be responsible for regrading or reinstalling the water control structures at the designed elevations to comply with the approved plan. If the as-built plan and site inspection are determined to be in conformance with the approved design, PB&D shall issue a written approval of the as-built plan and planting activities may commence.

      2.   Upon the completion of planting activities, the permittee shall provide PB&D with lists of the species actually planted in the mitigation wetlands and wetland buffers, including the common and scientific name of each species, the quantity of each species planted (e.g., weight of seeds/acre, number of plugged plants/acre), the source of the seeds/plants, the planting method(s) used, and the date(s) seeding or planting occurred.

   Performance standards are predetermined goals for guiding and measuring mitigation success.

      1.   Performance Period. The performance period shall consist of a minimum five (5) years at which time the vegetation performance standards are met, unless the vegetation performance standards can be met earlier for two (2) consecutive growing seasons, at which time the performance period shall be considered complete. Conversely, the performance period may be required to be longer than five (5) years in order to meet the vegetation performance standards if they haven’t been met after the standard five-year time frame.

      2.   Wetland Vegetation Performance Standards. The performance standards below apply to emergent, wet prairie and sedge meadow communities. If other community types are proposed (e.g., aquatic, forest, etc.), the permittee shall submit proposed performance standards for each community to PB&D for approval.

 

 

         d.   Invasive Species Dominance. By the end of the performance period, none of the three dominant plant species in the emergent, wet prairie, or sedge meadow communities shall be non-native or weedy species, including, but not limited to, the following species: Typha spp., Phragmites australis, Poa compressa, Poa pratensis, Lythrum salicaria, Salix interior, Echinochloa crusgalli, or Phalaris arundinacea. Dominance shall be based on the relative importance value (RIV) of each species, which is calculated by the following equation: Invasive Species Dominance:

         RIVs = [RFs + RCs] / 2 x 100, where:

         RIVs is the relative importance value of the individual species in the community,

         RFs is the frequency of the individual species occurring in all quadrats/the total frequency of all species (adventive and native) occurring in all quadrats, and

         RCs is the coverage of the individual species occurring in all quadrats/the total coverage of all species (adventive and native) occurring in all quadrats.

      3.   Wetland Buffer Vegetation Performance Standards. The performance standards below apply to the prairie community to achieve mitigation credit. If other community types are proposed for the wetland buffers (e.g., forest, savanna, etc.), the permittee shall submit proposed performance standards for each community to PB&D for approval.

         c.   Invasive Species Dominance. By the end of the performance period, none of the three dominant plant species in the mesic prairie buffer community shall be non-native or weedy species, including, but not limited to, the following species: Cirsium arvense, Melilotus spp., Aliiaria petiolata, Poa compressa, Poa pratensis, Ambrosia artemisiifolia, or Rhamnus cathartica and R. franguia. Dominance shall be based on the relative importance value (RIV) of each species, which is calculated using the equation in Section H.2.d.

      1.   Monitoring.

         a.   Monitoring Plan. The PMD shall contain a proposed five-year monitoring plan. Such plan shall include, at a minimum, a description of the sampling methodologies to be followed for evaluating hydrology in the mitigation wetlands and assessing vegetation in the mitigation wetlands and buffers, the frequency of sampling, and the report(s) to be generated.

         b.   Vegetation Monitoring. A sufficient number of straight-line sampling transects shall be established in the mitigation wetlands and wetland buffers to achieve a representative amount of plant frequency and coverage data. The beginning and end points of each transect shall be monumented in the field with a metal stake. The location of each transect and the number of proposed quadrats per transect shall be accurately identified on the Planting Plan (Section C.4.), which shall be included in the annual monitoring reports. Each transect shall consist of a series of sample quadrats either 0.25 or 1.0 square meter in size. Vegetation sampling shall be conducted by, or under the supervision of, a Certified Wetland Specialist twice during the growing season with at least one month between sampling dates (e.g., May/June and August/September). Vegetation sampling shall include the following, at a minimum:

            (1)   Record the number and estimated percent areal coverage of each vascular plant species in each quadrant, including all non-native (adventive) taxa and native taxa. Use this data to perform the calculations in (2)-(4) below, Photograph each end of the transect at the time of sampling,

            (2)   Calculate the native mean C value, FQI, and mean wetness coefficient for each quadrat,

            (3)   Calculate native mean C value, and native FQI and mean wetness coefficient for each transect,

            (4)   Calculate the RIVn of total native species by the following equation:

            RIVn = [RFn + RCn] / 2 x 100, where:

            RIVn is the relative importance value of the total native species in the community,

            RFn is the total frequency of the native species occurring in all quadrats/the total frequency of all species (adventive and native) occurring in all quadrats, and

            RCn is the total coverage of the native species occurring in all quadrats/the total coverage of all species (adventive and native) occurring in all quadrats.

         c.   Hydrology Monitoring. A sufficient number of representative sample points shall be established in each mitigation wetland to assess the hydrologic conditions. The sample points shall be monumented in the field with a metal stake. The location of each sample point shall be accurately identified on the Planting Plan (Section C.4.), which shall be included in the annual monitoring reports. At a minimum, hydrology monitoring shall be conducted on a bi-weekly basis during the first growing season and on a monthly basis during each succeeding growing season of the monitoring period. Hydrology sampling shall include the following, at a minimum:

            (1)   Depth of inundation (in. or cm.) based on NAVD 88 datum, which superseded the NGVD 29 datum used prior to September 18, 2013, and

            (2)   Soil moisture condition to a minimum depth of 12 in. (e.g., saturated, moist, dry).

      2.   Management.

         a.   Management Plan. The PMD shall contain a proposed five-year management plan. Such plan shall include a description of the anticipated management practices to be employed each year to meet the performance standards in Section H., and a schedule of all proposed management practices (i.e., a calendar indicating month and year of activity). In addition, the plan shall identify the entity to assume responsibility for long-term management of the mitigation wetlands and wetland buffers after the performance period and the dedicated source of funding for long-term management. At completion of the performance period, PB&D shall require a written agreement between the permittee and the entity identified for long-term management.

         b.   Management Practices. Describe the methods and equipment to be used for each proposed management practice (e.g., prescribed burning, control of invasive plant species by herbicide application or hand removal, mow management, etc.). List all permits or certifications/licenses required for the proposed management practices (e.g., IEPA open burn permit, local fire department permits, IDOA herbicide applicators license, etc.). Personnel who perform the management activities shall have appropriate licenses and qualifications.

   At a minimum, an annual report prepared by, or under the supervision of, a Certified Wetland Specialist summarizing the results of the previous year’s monitoring data shall be submitted to the PB&D by January 31st of the following year. The annual reports shall contain, at a minimum:

      1.   A narrative summary of the vegetation and hydrology monitoring data;

      2.   A discussion of the progress of native vegetation establishment relative to the performance standards in Section H.;

      3.   An appendix containing the monitoring data;

      4.   Photographs of the sample transects and panoramic views of the mitigation wetlands and buffers;

      5.   A narrative summary of the management practices employed during the previous year and photographs documenting these activities;

      6.   Recommendations for proposed management practices to be employed during the following year(s), based on the monitoring results to date; and

      7.   The proposed schedule for management practices in the following year(s).

      1.   Responsible Parties.

      The permittee shall be responsible for establishment of the mitigation wetlands and wetland buffers and all associated monitoring and management activities for the performance period. The permittee shall take corrective measures as necessary to meet the performance standards in Section H., within the performance period.

      After the performance period, the entity identified for long term management shall assume long-term management for the mitigation wetlands and wetland buffers. The permittee’s responsibility for the mitigation wetlands and wetland buffers shall be released in writing by PB&D.

      2.   Notification.

      After the performance period, the permittee shall provide written notification to PB&D, along with following information: 1) A scaled plan (min. 1 in. = 100 ft.) showing the delineated boundaries and actual acreages of the mitigation wetlands and wetland buffers; and 2) A summary of how the performance standards have been met for each wetland and buffer. Upon notification, PB&D shall review the submitted information and perform a site inspection to evaluate the success of the mitigation site. If the mitigation goals and performance standards have been met, PB&D shall notify the permittee in writing that the permittee’s responsibility for the mitigation site is released. A copy of the written release shall be provided to the entity designated for long-term management of the mitigation site.

      If PB&D determines that the mitigation goals or performance standards have not been met based on the information submitted and site inspection, PB&D shall notify the permittee in writing of the specific shortfalls. The permittee shall be granted a specified time limit to respond to the identified shortfalls. Failure to fully respond to the identified shortfalls within the specified time limit may result in PB&D’s use of the mitigation surety to correct the shortfalls.

(Ord. passed 10-9-2012; Ord. 22-1060, passed 8-9-2022; Ord. 23-1056, passed 8-8-2023)