It was another year of progress and protection in 2025 for the agency tasked with treating wastewater, protecting area waterways and Lake Michigan, and managing stormwater. In 2025, the Metropolitan Water Reclamation District of Greater Chicago (MWRD) served approximately 5.19 million people in Chicago and 128 suburban municipalities within an 882.1-square-mile service area across Cook County.

“We thank Cook County residents for bestowing their trust in our service and our partners for making water a priority in 2025,” said MWRD President Kari Steele. “We look forward to another year of protecting our water environment through innovation, sustainability and an open dialogue with the communities we serve.” 

The MWRD is in the final year of a five-year strategic plan while also developing the groundwork for a new plan that will again supply a blueprint of which to follow in meeting the MWRD’s mission, emerging trends, changing environments, new industry standards and expanding capabilities. 

Each day, the MWRD treats the region’s wastewater and transforms it into clean water in a matter of hours to be returned to the environment. Through November, the MWRD treated approximately 359 billion gallons of water, averaging about 1.1 billion gallons per day at its seven water reclamation plants. In its labs, the MWRD performed an estimated 397,594 lab tests through October to ensure the quality of local waterways and that the biosolids soil amendments recovered meet strict regulations.

The MWRD also continues to manage a robust stormwater management program. Since being granted stormwater management authority for Cook County in 2004, the MWRD has worked with communities and other agencies to identify, develop, fund and build projects to mitigate regional and localized flooding. Since receiving authority to work on local projects in 2014, the MWRD has worked on more than 289 stormwater management projects designed to protect nearly 19,000 homes, businesses and buildings. The MWRD also established and manages the Watershed Management Ordinance to regulate development by managing stormwater onsite. 

Through the Small Streams Maintenance Program, the MWRD also maintains over 500 miles of streams and rivers, removing obstructions that limit drainage. In 2025, the MWRD also joined Space to Grow™ partners to open seven new permeable schoolyards at Chicago Public Schools that capture 2,220,960 gallons of rainwater during each rain event, while giving students and their families a vibrant new place to play and an education in green infrastructure.

In addition, the MWRD owns and operates the Tunnel and Reservoir Plan (TARP). The “Deep Tunnel,” as it is famously known, continues to serve as one of the world’s civil engineering and public works projects for water quality and stormwater management. TARP reduces flooding, improves water quality in Chicago area waterways and protects Lake Michigan from pollution caused by sewer overflows across a 360-square-mile area serviced by combined sewers. Through the first nine months of 2025, the MWRD captured over 14 billion gallons of combined stormwater and sewage that previously would have overflowed into waterways or flooded communities without the TARP system in place.

“Our dedicated staff and innovative systems safeguard the quality of life for millions while protecting Lake Michigan and the Chicago Area Waterway System—our region’s most treasured natural resources,” said MWRD Vice President Patricia Theresa Flynn. “From the North Shore Channel to the Des Plaines and Calumet Rivers, we are committed to preserving and enhancing our water environment for generations to come.”

In 2025, the MWRD: 

--Engaged with over 391,435 people at tours of MWRD water reclamation plants, at community events and presentations throughout Cook County. 

--Delivered 7,632 rain barrels to Cook County residents. 

--Distributed over 17,000 free milkweed and other native wildflower seed packets to capture more stormwater and support monarch butterflies and other pollinators. 

 --Provided 11,500 free native tree saplings through its “Restore the Canopy, Plant a Tree” program to capture more stormwater.

 --Collected more than 390 pounds of medications through its medication disposal program and community outreach.  

--Removed an estimated 6,983 cubic yards of debris from small streams and 1,584 cubic yards of debris from rivers in 2025.

--Conducted 22 fish surveys across area waterways from June to October 2025, collecting, identifying, weighing, and measuring 8,011 fish, nearly all of which were released back into their habitats.

--Carried out 686,784 hourly measurements at 20 different locations in area waterways to monitor dissolved oxygen levels, which are essential for aquatic life and continued steady improvement in water quality.