Jurisdictional Determinations, Boundary Verifications & Exclusions

Jurisdictional DeterminationsJDs icon

Section 1001 of the Lake County Watershed Development Ordinance (WDO) requires that permit applicants provide a valid, written Jurisdictional Determination (JD) from the U.S. Army Corps of Engineers, Chicago District (Corps), or a Corps-approved agency such as the SMC (or Lake County PBD in unincorporated areas) to determine whether wetlands and waters on a development site are Waters of the U.S (WOTUS) or Isolated Waters of Lake County (IWLC). 

A JD can be obtained from the Corps; however, the turnaround time is indefinite (see: USACE JD Request Form (PDF)). Alternatively, a preliminary jurisdictional determination (PJD) can be obtained from the SMC within 30 days (field conditions permitting) for a nominal review fee by submitting a Jurisdictional Determination Request Form (PDF). Either a JD from the Corps or a PJD from SMC satisfies the WDO requirement for a written jurisdictional determination.

WOTUS are defined in 33 CFR Part 328.3.(a) and generally include navigable waters and their tributaries, adjacent/abutting wetlands, and certain other waters included under the definition. The Corps regulates WOTUS under Section 404 of the federal Clean Water Act (CWA) and under the Rivers and Harbors Act (RHA).

Appendix A of the WDO defines IWLC as “All waters such as lakes, ponds, streams, farmed wetlands, and wetlands that are not under U.S. Army Corps of Engineers’ (Corps) jurisdiction. The limits of the Isolated Waters of Lake County extend to the ordinary high water mark or the delineated wetland boundary.” IWLC are regulated by the SMC or by an Isolated Wetland Certified Community (IWCC – see Certified Communities Webpage for the current list of IWCC). 

Boundary Verifications (BVs)SMC_DpLkRd Storm Swr_wtl boundary flags_IMG_1762 cropped

Sometimes wetland boundaries can be straightforward. Other times they can be obscure. Field boundary verifications (BVs) of the delineated wetland-water body boundaries are strongly recommended before the boundaries are surveyed to avoid the possible need for re-survey, if adjustments are requested by the regulatory agencies (SMC, PBD, and/or Corps) or the IWLC-certified community, based on field observations. 

The Corps may verify WOTUS boundaries during the JD/PJD field review if the boundaries are clearly staked or flagged. Alternately, the Corps may perform the WOTUS BV at a later time (but prior to permit application) upon submission of a completed request form to the Corps by an applicant – see: USACE JD Request Form (PDF). The Corps does not charge a fee for BVs of WOTUS.

SMC (or PBD, as applicable) may verify boundaries of IWLC during the JD/PJD visit for areas under their jurisdiction, provided the applicant has requested IWLC BV, sufficient time is available, and the boundaries are clearly staked or flagged. Alternately, the SMC/PBD may perform a requested IWLC BV for areas under their jurisdiction at a later time (but prior to permit application). SMC and PBD charge a nominal review fee for IWLC BVs. To request a BV of delineated IWLC from the SMC, the applicant should submit a completed request form, along with required documentation (e.g., wetland delineation aerial photograph exhibit) – see: PJD/BV Request Form (PDF).

Verification of IWLC boundaries in IWLC-certified communities is done via request to the community’s CWS after the JD/PJD is performed. See Certified Communities Webpage for the current list of IWCC. 


The Corps may exclude certain water features from WOTUS based on the current definition in CFR 33 Part 328.3, along with any supporting information provided by the applicant with a JD/PJD request (e.g., approved plans or permits for constructed stormwater management features, etc.).

Features excluded from WOTUS automatically default to being IWLC. However, such areas may qualify for exclusion under the definition Isolated Waters of Lake County in WDO Appendix A if they meet one or more of the following criteria:

  1. Excavations and impoundments that have received a permit from the appropriate jurisdictional authority.
  2. Excavations and impoundments permitted by right, prior to being a regulated activity, within 40% or more non-hydric soils. Areas designated as ‘water’ as depicted on the Soil Survey of Lake County, SCS, 1970 are determined as either hydric or non-hydric soils by connecting adjoining soil boundaries to create complete polygons of the depicted soil type.
  3. Wetlands created incidental to construction grading on development sites.
  4. Roadside ditches (as defined in WDO Appendix A).

Note that the following shall not be considered as meeting the IWLC exclusion criteria above:PinClipart.com_clip-art-reminder_873407

  1. All areas meeting the definition of high-quality aquatic resources (HQAR) in WDO Appendix L.
  2. Wetland mitigation areas created to meet the requirements of the WDO or Section 404 of the Clean Water Act.
  3. Wetland areas created or restored using public funds.

IWLC exclusion determinations are made by the Enforcement Officer (EO) in certified communities (see Certified Communities Webpage) or by the SMC’s Chief Engineer in areas under SMC’s permitting authority. To request an IWLC exclusion determination, the applicant should submit a completed IWLC Exclusion Worksheet with supporting documentation to the EO or SMC.