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.
Our ongoing planning and analysis to identify flooding and develop solutions.
Watersheds in Cook County
Learn more about MWRD's work in your area.
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.