Thornton Quarry

As part of the Chicago Deep Tunnel project, both Thornton Quarry and McCook Quarry will serve as reservoirs to reduce the backflow of stormwater and sewage from Chicago area rivers into Lake Michigan.

It is estimated that the reservoir will help protect 500,000 people who live in the surrounding 14 suburbs it serves, and will save the city around $40 million worth of damages each year.

[2] The quarry contains Silurian reefs which formed when the Michigan Basin was covered in sea water more than 400 million years ago.

Gurdon Saltonstall Hubbard received 160 acres of land from Watseka, his Potawatomi wife.

The Thornton Quarry supplies 7.9 billion gal US of stormwater storage, allowing the water to be treated before release into the waterways.