Isolated Waters of Lake County

Updated National Wetland Plant List (April 28, 2016)

Wetland delineations performed in Lake County, IL, after June 1, 2012, shall use the updated NWPL for the Midwest Region (PDF).

About the IWLC

The Lake County Watershed Development Ordinance (WDO) includes provisions for the protection of isolated waters and wetlands that are not under the jurisdiction of the federal Clean Water Act administered by the U.S Army Corps of Engineers (Corps) - Chicago District.
Wetlands Do Not Enter Sign
SMC regulates IWLC under the WDO, while the Corps regulates Waters of the U.S (WOUS) impacts (i.e., navigable waters and their tributaries and adjacent wetlands).

For projects that will impact WOUS, the applicant must obtain a Section 404 permit from the Corps. In addition, a wetland delineation and permit submittal must be performed under supervision of a Lake County Certified Wetland Specialist (PDF). This requirement is discussed in more detail below.

Jurisdictional Determinations (JD)

The WDO requires the applicant to obtain a written Jurisdictional Determination (JD) for all wetlands and waters identified on a development site by submitting a request to SMC (PB&D in unincorporated areas) or to the Corps. This JD is required to determine whether the wetlands and waters are regulated by the Corps or SMC (or PB&D in unincorporated areas). The JD can be obtained from SMC within 30 days, field conditions permitting and for a nominal review fee, by submitting a Jurisdictional Determination Request Form (PDF).

Wetland Delineations (Non-Agricultural Land)

The presence and extent of wetlands/waters on non-agricultural lands is to be determined by a Lake County Certified Wetland Specialist (PDF) using the current Federal wetland delineation methodology as described in the Corps Manual or approved supplement to the Corps Manual (Regional Supplement: Midwest Region).
The WDO requires that delineations utilize an on-site determination method described in the Corps Manual (or approved supplement to the Corps Manual: Midwest Region) to determine if indicators of wetland hydrology, hydrophytic vegetation, and hydric soils are present. The delineated boundaries of wetlands/waters are to be flagged/staked and surveyed for permitting purposes.

Wetland delineations are usually valid for 3 years, unless substantial changes have occurred on the property.

Agricultural Land Wetland Determinations

If the proposed development site contains agricultural land (i.e., land that has been farmed at least 1 year in the last 5), an agricultural land wetland determination needs to be performed by or under the supervision of a CWS to determine if “farmed wetlands” are present on the site. Refer to the SMC guidance document below for the procedures to be followed.

Updated SMC Guidance for Agricultural Land Wetland Determinations (March 20, 2012) (PDF)

McHenry County Form for FSA Aerial Slides

Digital imagery (JPEG) of the SAM aerial slides for your Lake County farmed wetland determinations can be ordered from the McHenry County Soil and Water Conservation District. Cost is $10 per slide image. See the online order form. For more information, contact Ed Weskerna, MCSWCD, 815-338-0099, ext. 3

Refer to Section B in the Updated SMC Guidance for Agricultural Land Wetland Determinations (PDF) for the designated slide years to be reviewed (depends on which NWS recording station is closest to your project site - Antioch, Barrington or Waukegan). It is recommended you order 9 years or aerial slides for each project site to facilitate the farmed wetland review, including the 2 SET indicator years, 5 PRIMARY normal precipitation years, and 2 SECONDARY normal precipitation years for the closest NWS recording station. Note: The online order form indicates that 2002 aerial slides are not available; however, that only applies to McHenry County slides. The 2002 aerial slides are available for Lake County.

In order to facilitate SMC's review of your farmed wetland determination reports, please provide copies of all aerial slides reviewed with your report. Slides copies provided in digital format (JPEG) are preferred, but we will also accept color photocopies.

IWLC Submittal & Guidance Documents

See IWLC Forms.

Projects with IWLC will be evaluated under the following categories:
  • Category-I: Wetland impacts less than or equal to 1 acre to non-High Quality Aquatic Resources (HQAR) (Basic requirements); Note: Project sites under SMC's jurisdiction with minor impacts to less than 0.1 acre of non-HQAR and less than 1,000 square feet of HQAR may be reviewed under SMC's General Permit No. 2 (PDF)
  • Category-II: Wetland impacts greater than 1 acre and less than 2 acres to non-HQAR (Basic requirements plus applicant must provide a narrative that shows either avoidance, minimization, or mitigation)
  • Category-III: Wetland impacts greater than 2 acres or impacts any acreage of HQAR (Basic requirements plus applicant must show, in sequence, avoidance and minimization before mitigation is considered)
  • Category-IV: Wetland impacts for wetland restoration, creation and enhancement

Mitigation Requirements

The WDO requires compensatory mitigation (wetland replacement) for impacts greater than or equal to 0.1 acre to IWLC including those that are HQAR. For single lot, single-family residences (provided the activity is a single and complete project) mitigation is required for wetland impacts greater than 0.25 acre of IWLC or 0.1 acre of IWLC that are HQAR . Wetland impacts must be replaced at a minimum ratio of 1.5:1 (one and one-half acres mitigation for each acre impacted), 3:1 for HQAR, and 6:1 for forested HQAR. For wetland impacts to open waters that are not HQAR under Categories I, II, and III, a minimum of 1:1 mitigation ratio is required.

All mitigation must take place within Lake County to achieve no net wetland loss in the county.

Mitigation may be achieved in several ways: (1) creating new wetlands or enhancing degraded wetlands on the project site or on an off-site property within the same watershed as the wetland impacts, (2) purchasing credits from a mitigation bank; or (3) using the SMC Wetland Restoration Fund (WRF), which provides for fee-in-lieu of mitigation. The WRF can only be used for IWLC impacts when no mitigation bank credits are available in the watershed.

The Review Process - Community Certification

Projects will be reviewed for conformance with the isolated wetland provisions. The provisions require that a Certified Wetland Specialist review the application materials. Communities desiring to be certified for Isolated Wetland Review will be required to have a Lake County Certified Wetland Specialist (PDF) on staff, or retain a Lake County Certified Wetland specialist consultant. SMC will act as the Certified Wetland Specialist for non-certified communities.

See Certified Communities for those communities certified for IWLC review.

Certified Wetland Specialist

The WDO includes a Lake County Certified Wetland Specialist (PDF) requirement. A CWS is a wetland professional that meets minimum levels of experience and training. To become a CWS, an application and supporting information is required. In addition, the CWS must pass the CWS Exam offered by SMC. See Certified Wetland Specialist for more information.

See CWS for the application form.

Advanced Identification (ADID) Wetland Study 1992