Kankakee Torrent

The Kankakee Torrent was a catastrophic flood that occurred about 19,000 BP calibrated years ago in the Midwestern United States. It resulted from a breach of moraines forming a large glacial lake fed by the melting of the Late Wisconsin Laurentide Ice Sheet. The point of origin of the flood was Lake Chicago. The landscape south of Chicago still shows the effects of the torrent, particularly at Kankakee River State Park and on the Illinois River at Starved Rock State Park.
The Kankakee Torrent was responsible for extensive modification of the Kankakee River and Illinois River river valleys and landforms characteristic of megaflooding. Both the Kankakee River and Illinois River largely follow paths carved out by the torrent, a process that is believed to have taken only days. Most notable today is a region in north-central Illinois known as Starved Rock; while most of Illinois is located on a low-lying plain with little variation in elevation, Starved Rock State Park features several canyons which were created in the Kankakee Torrent. Another, very different, geologic effect left over from the Kankakee Torrent is the existence of "sand prairies". Sand prairies exist where the massive flood waters stopped their movement and deposited large quantities of sand. When European settlers arrived, one remaining sign of these deposits were sand dunes located along parts of the flood's course.

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