Stormwater Management: Chicago vs Evanston
How do stormwater management rules compare between Chicago, IL and Evanston, IL?
Evanston has fewer restrictions than Chicago.
Chicago, IL
Cook County
Chicago's Stormwater Management Ordinance (MCC 11-18) requires regulated developments to capture and manage stormwater runoff, including capturing the first half-inch from impervious surfaces. The 2024 Stormwater Manual provides detailed BMP guidelines.
View full Chicago rules →Evanston, IL
Cook County
Evanston requires stormwater management for new development and substantial improvements. Projects disturbing more than 5,000 square feet of land or adding significant impervious surface must provide on-site stormwater detention. The city follows Metropolitan Water Reclamation District of Greater Chicago (MWRD) watershed management ordinance standards.
View full Evanston rules →Key Facts Comparison
| Fact | Chicago | Evanston |
|---|---|---|
| Code Section | MCC 11-18 | - |
| Volume Capture | First 0.5 inch from impervious surfaces | - |
| Alternative | 15% impervious surface reduction | - |
| Authority | Dept. of Water Management | - |
| Manual | 2024 Stormwater Management Ordinance Manual | - |
| Disturbance Threshold | - | 5,000 sq ft triggers requirements |
| Detention Standard | - | MWRD WMO standards |
| Green Infrastructure | - | Encouraged, may offset detention |
| NFIP Participant | - | Yes — SFHA regulations apply |
| Public Works | - | (847) 448-4311 |
Highlighted rows indicate differences between cities.
Chicago FAQ
What triggers stormwater management requirements in Chicago?
Regulated developments as defined in MCC 11-18 must submit a stormwater management plan. This generally applies to new construction and significant redevelopment projects that increase impervious surface area.
What BMPs does Chicago accept for stormwater management?
Approved BMPs include green roofs, rain gardens, permeable pavement, bioswales, cisterns, rain barrels, and native landscaping. The 2024 Stormwater Manual provides detailed design guidance.
Evanston FAQ
When is a stormwater management plan required in Evanston?
Projects disturbing 5,000 square feet or more or increasing impervious surface by more than 2,500 square feet must provide a stormwater management plan prepared by a licensed engineer. The plan must comply with MWRD Watershed Management Ordinance standards.
Can I use rain gardens instead of detention basins?
Yes. Evanston encourages green infrastructure including rain gardens, bioswales, permeable pavers, and green roofs. These may satisfy part of the detention requirement. Contact Public Works for design criteria.
Does Evanston have combined sewer issues?
Yes. Portions of Evanston have combined sewer systems. The city encourages downspout disconnection and green infrastructure to reduce stormwater inflow to combined sewers and minimize basement flooding during heavy rain events.
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