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Metropolitan Water Reclamation District of Greater Chicago

The July 11-12 storm has ended, and the Metropolitan Water Reclamation District of Greater Chicago’s (MWRD’s) Tunnel and Reservoir Plan (TARP) continues to operate as designed.

The tunnels and reservoirs are holding more than 8.09 billion gallons of water. The current status of all TARP tunnels and reservoirs is as follows:

Kirie TARP Status
The Kirie TARP system is comprised of the Kirie Tunnel and Majewski Reservoir.
Kirie Tunnel is 11% full = 7.8 Million Gallons (MG)
Majewski Reservoir = 0% full

McCook TARP Status
The McCook TARP system is comprised of the Mainstream Tunnel, Des Plaines Tunnel, and McCook Reservoir.
Mainstream Tunnel is 98% full = 1.17 Billion Gallons (BG)
Des Plaines Tunnel is 47% full = 190 MG
McCook Reservoir is 92% full = 3.3 BG

Calumet TARP Status
The Calumet TARP system is comprised of the Calumet Tunnel and Thornton Composite Reservoir.
Calumet Tunnel is 78% full = 490 MG
Thornton Composite Reservoir is 30.5% full = 2.4 BG

Before severe storms, the MWRD lowers the levels of the Chicago Area Waterway System. We work around the clock to manage the excess water coming into our seven water reclamation plants. The Overflow Action Alert has ended, but we still encourage the public to reduce their use of water before and during rain events: wait to run the dishwasher, shower and/or do the laundry.

Learn more about how the MWRD’s infrastructure and waterway system operate.

Information about the Tunnel and Reservoir Plan (TARP)
How the Chicago Area Waterway System works
How to prepare your home for storms
Understand How Sewers Work
We have both a brochure and PowerPoint presentation. Contact us at so that we may present to your community or organization.
Take a virtual or live tour of our facilities

23_07_Storm followup.pdf

Press Release

Established in 1889, the Metropolitan Water Reclamation District of Greater Chicago (MWRD) is an award-winning, special purpose government agency responsible for wastewater treatment and stormwater management in Cook County, Illinois.


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