Stormwater Management: Oak Lawn vs Oak Park
How do stormwater management rules compare between Oak Lawn, IL and Oak Park, IL?
Oak Park has fewer restrictions than Oak Lawn.
Oak Lawn, IL
Cook County
Oak Lawn is subject to the Metropolitan Water Reclamation District of Greater Chicago (MWRD) Watershed Management Ordinance (WMO) for stormwater and floodplain management. Development projects disturbing 0.5 acres or more require a WMO permit with detention, water quality, and runoff controls. Smaller residential projects follow Village grading and drainage rules.
View full Oak Lawn 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 | Oak Lawn | Oak Park |
|---|---|---|
| Authority | MWRD WMO | - |
| Permit Threshold | 0.5 acres disturbance | - |
| Volume Control | 1-inch retention | - |
| Detention | Peak rate control | - |
| Local Grading | Oak Lawn Public Works | - |
| Watershed | - | Des Plaines River |
| Sewer System | - | Combined (stormwater + sanitary) |
| Regional Authority | - | MWRD of Greater Chicago |
| Green Infrastructure | - | Rebates may be available |
| Disturbance Threshold | - | 0.5 acres triggers plan requirement |
Highlighted rows indicate differences between cities.
Oak Lawn FAQ
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.
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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