The Metropolitan Water Reclamation District of Greater Chicago (MWRD) has been working around the clock to provide flood protection for Cook County, Ill.. It monitors the weather, and prior to major storms, draws down the waterways to provide maximum capacity for storm water. MWRD’s goal is to provide maximum capacity in the area waterways, tunnels and reservoir system to provide as much protection from flooding as possible.
When the Chicago Area Waterway levels are higher than Lake Michigan and predetermined elevations are reached, the MWRD opens control structures to move as much water as possible out of the system. This provides overbank flooding protection as well as more capacity for storm water.
On Thursday, April 18, MWRD opened the gates at the locks at the following times: 1:25am at Wilmette Lock; 3:47 a.m. at Chicago River Controlling Works; and 6:15 a.m. at O’Brien Controlling Works and Lock. The locks will remain open until the situation is stabilized.
Currently, the Tunnel and Reservoir system, which is comprised of 109 miles of tunnel and two reservoirs, is 100% full. The Mainstream Tunnel was 100% full at 12:31 a.m. Thursday morning and the Des Plaines Tunnel was 100% full at 3:30 a.m. Thursday morning. The entire tunnel system holds 2.3 billion gal.
MWRD encourages the public to minimize their use of water in their homes to reduce the amount of water flowing into the sewer system during extraordinary rain events such as what occurred. This will provide maximum capacity for combined storm water flows.
Source: MWRD