Lake County, IL Environmental Rules: Erosion Control (2026)
Key Facts
- Stabilization deadline
- 7 calendar days after disturbance ends
- 1-5 acre disturbance
- Sediment trap required
- Over 5 acres
- Sediment basin with filtered riser
- Inspector required
- Over 10 acres of disturbance
- Applies to
- Unincorporated Lake County only
Summary
Unincorporated Lake County requires soil erosion and sediment control measures on any regulated land disturbance, with specific stabilization timelines and sediment-trapping standards by disturbed acreage.
Soil erosion and sediment control related measures are required to be constructed and maintained for any regulated land disturbance activity, in accordance with the standards of this section. All temporary measures and permanent erosion and sediment control shall be maintained continuously in an effective, working condition. ... Disturbed areas shall be stabilized with temporary or permanent measures within seven calendar days following the end of active hydrologic disturbance, or redisturbance...
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-15: Supplement contains: Local legislation current through Ord. 26-0618, passed 6-9-2026 | State legislation current through ILCS Pamphlet 2025 #5).
Full Breakdown
Lake County Code § 151.146(J) requires erosion and sediment control measures for any regulated land disturbance activity in unincorporated Lake County, maintained continuously in effective working condition. Disturbed areas must be stabilized with temporary or permanent measures within 7 calendar days after active disturbance ends. Control requirements scale with tributary area: sites disturbing 1,000 sq ft to 1 acre need a filter barrier or equivalent; 1 to 5 acres need a sediment trap; over 5 acres need a sediment basin with filtered riser pipe. Projects over 10 acres (or smaller with floodplain/waters exposure) must retain a Designated Erosion Control Inspector who logs conditions and reports noncompliance to the Planning, Building and Development Director within 24 hours. This chapter (the Unified Development Ordinance) applies only to unincorporated county land per § 151.003. Waukegan, North Chicago, Highland Park, Gurnee, Libertyville, Mundelein and other municipalities enforce their own separate erosion control rules.
Violations & Fines
Enforced by the Planning, Building and Development Director; noncompliant sites can be denied site development permits or certificates of occupancy, and required temporary controls must be removed within 30 days of final stabilization or as no longer needed.
Frequently Asked Questions
Does this rule apply inside Waukegan or Highland Park?
How fast must a construction site be stabilized after grading stops?
Sources & Official References
Other rules in Lake County
Compare Lake County to another location·View the Illinois environmental rules overview
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