The Metropolitan Water Reclamation District of Greater Chicago (MWRD) is currently investigating damage that occurred to a structure connected to the Deep Tunnel at Veterans Park in Calumet City, Ill.
At approximately 8 p.m. May 11, a cover blew off of the structure, and the surrounding earth was displaced, creating a sinkhole around the structure. The MWRD has secured the area and has started repairs. No injuries have been reported.
Approximately 1.8 in. of rain fell in an hour on the county’s south side—an extreme amount of water in a very short period of time. An additional 0.2 in. of rain was expected at 6 p.m. May 12.
The Calumet Tunnel system was full as of 10 p.m. May 11; this tunnel holds 620 million gal of water and is part of the Deep Tunnel system which can hold a total of 2.3 billion gal of water. Currently, the Mainstream Tunnel is 77% full, the Des Plaines Tunnel is 51% full, and the Kirie Tunnel is empty.
Source: MWRD