About the Watershed Development Ordinance (WDO)

The goal of the Lake County Watershed Development Ordinance (July 11, 2023) (PDF) is to ensure that new development does not increase existing stormwater problems or create new ones. The WDO establishes minimum countywide standards for stormwater management, including floodplains, detention, soil erosion/sediment control, water quality treatment, and wetlands.

The WDO is implemented at the local level. Forty of the 52 municipalities in the county are standard Certified Communities (PDF). The designation allows those communities to enforce WDO standards within their own jurisdictions, except for isolated wetlands. SMC reviews isolated wetlands unless a community becomes "Wetland Certified."

For unincorporated areas, the Lake County Planning, Building and Development Department (PB&D) is the permitting agency. Contact Lizeth Zuniga, PB&D, 847-377-2114.

2023 Ordinance Amendments

SMC will be opening a public comment period for our Ordinance Amendments on May 1, 2023. Click to view the 2023 WDO Amendments Packet (PDF) - 4/20/2023 TAC Approved. 

Approved 2023 WDO Amendments Packet (PDF) - 6/1/2023 Final Version

Pending FEMA Floodplain – Draft Map Changes

Non-Certified Communities

SMC is the permitting agency for Non-Certified Communities (PDF). Even in Certified Communities, however, certain floodway and floodplain development applications are forwarded to SMC for review and approval. A Watershed Development Permit is required for major and minor development, and public road construction.

Jurisdictional Determination

The WDO provide standards for the isolated wetlands no longer under the jurisdiction of the U.S. Army Corps of Engineers (Corps). If your project may impact a wetland, you are required to submit a Jurisdictional Determination to determine if the wetland is an Isolated Waters of Lake County (IWLC) or a Water of the U.S. (WOUS). See IWLC for more information.

SMC, Corps, USDA - Natural Resources Conservation Service, and the Lake County Soil and Water Conservation District have intergovernmental agreements in place to ensure proper and appropriate soil erosion and sediment control measures are installed and maintained on development sites. The four agencies meet quarterly to coordinate on potential site violations.

Erosion Control

The Designated Erosion Control Inspector (DECI) program, per the WDO, requires a DECI be part of the site inspection process for:

• All development with 10 acres or more of hydrologic disturbance
• All development with 1 acre or more of hydrologic disturbance and regulatory floodplain or wetlands on site or on adjoining properties