Stormwater Management: Evanston vs Oak Lawn

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.

Do I need a stormwater permit for my home project?

Most residential lot projects disturb less than 0.5 acres and do not require an MWRD permit, but must comply with Oak Lawn's grading and drainage rules at building permit.

Who regulates stormwater in Oak Lawn?

MWRD administers the Watershed Management Ordinance for larger projects. Oak Lawn enforces lot-level grading, drainage, and downspout rules through its Building Department.

Can I discharge my sump pump to the street?

Sump discharge to the street or alley is typically acceptable where it drains to a storm sewer. Discharge directly onto neighboring property is not permitted. Check Oak Lawn Public Works for specifics.