Debra Shore

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My Mission Debra Shore

Want to Get to the Bottom?

June 30, 2015
the limestone quarry near interstate 80 that will become The Thornton Reservoir

Photo courtesy Metropolitan Water Reclamation District of Greater Chicago

Since 1998, the Metropolitan Water Reclamation District of Greater Chicago (MWRD) has been working to convert a limestone quarry visible from Interstate 80 into a reservoir to capture stormwater overflows and provide flood water storage from Thorn Creek. After years of mining, tunnel construction, and $400 million expended, the Thornton Reservoir will be dedicated sometime in August.

Before then, however, the MWRD is offering tours of the nearly–completed reservoir to the public on Sunday, July 12 and Sunday, July 26. The Thornton Reservoir is in a limestone quarry located south of Interstate 80/Interstate 294 between Halsted Street and Indiana Avenue, in Thornton, IL. Tours are 30 minutes long and participants will be driven on a bus to the floor of the reservoir, 300 feet below surface level (you'll have to stay on the bus, however). There are approximately 30–40 openings on these tours still available but slots are filling up fast. If you want to get to the bottom of this and sign up for a tour, call the MWRD Office of Public Affairs at (312) 751-6633 or email to make a reservation.

When completed later this summer, the Thornton Reservoir will be one of the largest quarries devoted to stormwater capture and flood relief in the world. It will hold nearly eight billion gallons of water, provide annual benefits (in avoided flooding) of $40 million to approximately 556,000 people by protecting 182,000 structures in 15 communities in Cook County's south suburbs.

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