Peoria, IL Environmental Rules: Stormwater Management (2026)

Peoria's stormwater program is driven by the federal Clean Water Act's NPDES Phase II permit for small Municipal Separate Storm Sewer Systems, administered statewide by the Illinois EPA under the Illinois Pollution Control Board's water-pollution regulations (35 IL Adm. Code Subtitle C). The Illinois EPA's general NPDES permit for MS4s (ILR40) at https://epa.illinois.gov/topics/water-quality/watershed-management/stormwater-mgmt-program/npds-permit.html requires Peoria to implement six minimum control measures: (1) public education; (2) public participation; (3) illicit-discharge detection and elimination (IDDE); (4) construction-site runoff control; (5) post-construction stormwater management; and (6) pollution prevention/good housekeeping for municipal operations. Locally, Peoria Code Chapter 28 (Stormwater Management) — coordinated with the Public Works Engineering Division — implements these requirements. Construction sites disturbing one or more acres must obtain coverage under the Illinois EPA Construction Site General Permit (NPDES ILR10) and prepare a Stormwater Pollution Prevention Plan (SWPPP). Post-construction BMPs typically include detention basins, bio-swales, permeable pavement, and rain gardens designed to capture and treat the first 1 inch of runoff. Illegal discharges — washing paint, motor oil, concrete slurry, or chemicals into a storm drain — are prohibited and reportable to Public Works.