Skokie, IL Environmental Rules: Grading & Drainage (2026)

Skokie Public Works and Community Development review grading and drainage for new construction, substantial additions, and landscaping projects that alter site grades. The Village follows the Cook County Watershed Management Ordinance (WMO) and local rules requiring that positive drainage be maintained away from structures and that runoff be conveyed to acceptable discharge points (street, alley, curb inlet, or approved storm sewer connection). Runoff from one lot may not be concentrated or redirected onto adjacent lots in a way that was not the historical drainage pattern. Grading plans typically require a foundation elevation certificate and as-built verification for new construction. Retaining walls over 4 feet may require engineered design and a permit. Sump pump discharges must daylight onto the owner's property or discharge to an approved location, not concentrated onto neighbors. Downspouts must not connect to the sanitary sewer. Compacted clay soils typical of Skokie create challenging drainage conditions, and proper grading with 2% minimum slope away from foundations is critical to prevent basement seepage.