Skip to main content

Overflow Action Alert

The MWRD has issued an Overflow Action Day alert. Please limit water usage to absolute necessities. Visit our Overflow Action page for more information.


Metropolitan Water Reclamation District of Greater Chicago


Additional Resources

Program mission and achievements
Overview of our goals and work across Cook County.

Stormwater plans and reports
Information on completed projects, regulatory reporting, and technical plans for Cook County watersheds.

Stormwater planning
Our ongoing planning and analysis to identify flooding and develop solutions.

Watersheds in Cook County
Learn more about MWRD's work in your area.

A flooded street

What is runoff?

Stormwater runoff occurs when rain or melting snow flows off rooftops, streets, and parking lots. Instead of being naturally absorbed into the ground, much of the stormwater in Cook County flows into combined sewers.

During heavy rainstorms, these local sewers can become overwhelmed, causing back ups that lead to flooded homes and combined sewer overflows that carry pollution into our rivers.

A blue rain barrel being placed on a stand

How you can help

As we work to manage stormwater across the county, the MWRD can not do it alone. 

You can help reduce stormwater runoff and improve the quality of our waterways. Click on the links below to learn more.