Stormwater Management: Evanston vs Oak Park
How do stormwater management rules compare between Evanston, IL and Oak Park, IL?
Evanston and Oak Park have similar restriction levels.
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 →Oak Park, IL
Cook County
Oak Park has comprehensive stormwater management regulations to address flooding concerns, particularly related to the Des Plaines River watershed and combined sewer system. Property owners must manage stormwater runoff from new construction and significant improvements. The village participates in the Metropolitan Water Reclamation District's stormwater management program.
View full Oak Park rules →Key Facts Comparison
| Fact | Evanston | Oak Park |
|---|---|---|
| Disturbance Threshold | 5,000 sq ft triggers requirements | 0.5 acres triggers plan requirement |
| Detention Standard | MWRD WMO standards | - |
| Green Infrastructure | Encouraged, may offset detention | Rebates may be available |
| NFIP Participant | Yes — SFHA regulations apply | - |
| Public Works | (847) 448-4311 | - |
| Watershed | - | Des Plaines River |
| Sewer System | - | Combined (stormwater + sanitary) |
| Regional Authority | - | MWRD of Greater Chicago |
Highlighted rows indicate differences between cities.
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.
Oak Park FAQ
Why does Oak Park have stormwater management requirements?
Oak Park is in the Des Plaines River watershed with a combined sewer system prone to overload during heavy rain. Stormwater management reduces flooding risk and sewer backups that have historically affected the village.
Are there rebates for rain barrels or rain gardens?
Yes, the MWRD Green Infrastructure Program may offer rebates for residential stormwater management improvements like rain barrels, downspout disconnection, and rain gardens. Contact the village or MWRD for current program availability.
Where should my sump pump discharge?
Sump pump discharge should be directed to your yard or an appropriate drainage area, not onto neighboring properties or directly into the sanitary sewer. The village can provide guidance on proper discharge locations.
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