Durbin, MWRD seek to secure federal reimbursement for Thornton Reservoir construction
U.S. Senate Democratic Whip Dick Durbin (D-Illinois) and Metropolitan Water Reclamation District of Greater Chicago President Kari Steele met Wednesday to talk about securing federal funding owed to the district for the Thornton Composite Reservoir.
The reservoir was built to reduce chronic flooding in the Great Lakes area, and has been in service since 2015. Located in Chicago's south suburbs, it is the largest combined sewer reservoir in the world and is known as the Grand Canyon of Chicago's South Suburbs.
It has a capacity of 7.9 billion gallons and is connected to Chicago's Deep Tunnel network to prevent flooding — both in the form of basement backups and in the form of overflow of the banks of Thorn Creek. The reservoir is also intended to protect the quality of Calumet River system waterways.
Six Soldier Fields could fit inside the reservoir, and it could fill 144 million rain barrels — enough to circle the Earth more than three times when laid end-to-end, the MWRD said.
The vast size of the reservoir has nearly eliminated combined sewer overflows by collecting stormwater and sewage before it makes its way to the Calumet Water Reclamation Plant to be cleaned up and released into the Calumet River.
The reservoir is a section of the Thornton Quarry, which has been used to mine limestone for nearly two centuries.
The construction of the reservoir was guaranteed through a project cooperation agreement between the MWRD and the U.S. Army Corps of Engineers. During their meeting Wednesday, Durbin and Steele talked about securing federal reimbursement from the Army Corps.
Durbin's office said the reservoir has provided about $660 million in flood reduction benefits for 14 communities, but the Army Corps is still on the hook for $200 million in reimbursements.
Durbin wrote a letter to the Army Corps last month, asking its leaders to include $25 million in construction funds in its Fiscal Year 2026 Work Plan toward reimbursement for the reservoir construction. Durbin also filed an amendment to the FY26 Energy and Water Development Appropriations Act that would direct the Army Corps to make reimbursement money like what's owned to MWRD available.
"MWRD is assigned the critical task of keeping our water supply safe while also ensuring our water infrastructure is in working order. Despite the critical nature of this work, MWRD is still waiting for its reimbursement for the construction of Thornton Reservoir," Durbin said in a news release. "As I told MWRD leadership in our meeting today, I will continue to push for this reimbursement and to offer the resources MWRD needs to keep our state's water infrastructure up and running."
Durbin's office said in Fiscal Year 2024, the senator secured $20 million for the MWRD to address flooding in south suburban communities such as Harvey, South Holland, and Blue Island.