Chicago, IL Environmental Rules: Stormwater Management (2026)
Key Facts
- Trigger threshold
- 15,000 sq ft disturbed or 7,500 sq ft impervious
- Volume control
- Capture 0.5 in. runoff or 15% reduction
- Enforcing agency
- Dept. of Water Management
- Penalty for no plan
- $5,000-$10,000 civil penalty
- Residential subdivisions
- Exempt from plan requirement
Summary
Chicago requires a City-approved Stormwater Management Plan for regulated developments disturbing 15,000+ sq ft or creating 7,500+ sq ft of impervious surface.
Except as provided in subsection (2), every Regulated Development shall at all times have in place a Plan approved by the City. ... Stormwater Drainage Systems shall manage the peak rate of discharge from the Regulated Development... Stormwater drainage systems shall reduce the volume of runoff... by... capture one-half inch of runoff from all impervious surfaces in accordance with volume control BMPs.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-74: Current through Council Journal of June 17, 2026).
Full Breakdown
Under the Chicago Stormwater Management Ordinance (MCC Ch. 11-18), any "Regulated Development", construction, excavation or grading that disturbs 15,000 or more square feet, creates 7,500 or more square feet of at-grade impervious surface, or discharges stormwater into waters or a separate sewer system, must have a City-approved Stormwater Management Plan in place at all times. The plan must address rate control (managing peak discharge), volume control (capturing one-half inch of runoff from impervious surfaces or a 15% impervious-surface reduction), sediment and erosion control, and ongoing operations and maintenance. Residential subdivision development and routine maintenance activity are exempt from the plan requirement. The Department of Water Management, under the commissioner, administers approvals, amendments, variances and site inspections.
Violations & Fines
Failure to obtain required plan approval: civil penalty of $5,000-$10,000. Other chapter violations, including violating plan conditions: $100-$1,000 per violation, with each day a separate violation; the City may also recover attorneys' fees and 3x abatement costs.
Frequently Asked Questions
Does every construction project in Chicago need a stormwater plan?
What happens if I build without an approved stormwater plan?
Sources & Official References
Other rules in Chicago
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Stormwater Management in Nearby Cities
How other cities in Cook County handle stormwater management.