Title
Ordinance amending the Lake County Watershed Development Ordinance (WDO) to adopt the updated rainfall standards published by the Illinois State Water Survey and additional minor technical and administrative enhancements.
Staff Summary
• On March 13, 2019, the Illinois State Water Survey published updated statewide rainfall statistics based on recorded precipitation observations. The intensity and frequency of heavy rainfall events in Lake County have significantly increased, up to 45 percent compared to current outdated standards.
• Over the past 18 months, the Stormwater Management Commission (SMC) and its advisory committees held 25 public meetings to develop, discuss, and approve 28 total amendments.
• The proposed amendments pertain to increased rainfall, stormwater detention options including incentives for green infrastructure, hydrologic soil groups, wetlands, sediments and erosion control, and administrative items.
• SMC approved a fee-in-lieu program for a portion of the detention storage above the new 50-year volume requirement. This optional program allows Certified Communities to collect development fees and expend funds for in-the-ground projects to resolve local, inter-jurisdictional, and regional drainage and flooding related problems.