Unmatched in size throughout the world, the MWRD’s Tunnel and Reservoir Plan (TARP) works to protect and improve area waterways and reduce flooding throughout Cook County. TARP is one of the country’s largest public works projects for pollution and flood control.
Thornton Composite Reservoir Blast
This video from 2013 shows the blasting of a huge section of rock during excavation and construction of the MWRD's Thornton Composite Reservoir, a major part of the Tunnel and Reservoir Plan (TARP or "Deep Tunnel").
Thornton Composite Reservoir First Fill
November 26, 2015
A stormy Thanksgiving holiday resulted in 400 million gallons of combined sewage and stormwater flowing into the reservoir where the water level reached 17 feet. Though this is a lot of water, it's only five percent of the reservoir's 7.9 billion gallon capacity. The water will remain in the reservoir until it is pumped up to the MWRD's Calumet Water Reclamation Plant to be cleaned.
Thornton Composite Reservoir
Ribbon Cutting Ceremony, September 1, 2015
The MWRD hosted a ribbon cutting to celebrate the completion of the Thornton Composite Reservoir. A major part of the Tunnel and Reservoir Plan (TARP, or “Deep Tunnel”), the 7.9 billion gallon capacity reservoir will provide flood protection benefits for 556,000 people in 14 communities throughout the south side of Chicago and south suburbs. It will protect 182,000 homes, businesses and other facilities and improve water quality in the Calumet Rivers and Calumet-Sag Channel by preventing combined sewer overflows.
MWRD-USACE partnership sets stage for critical reservoir completion
Signing ceremony initiates pilot program to allocate $33.8 million in federal funds to complete second stage of McCook Reservoir, add 6.5 billion gallons of storage. A pilot program by the United States Army Corps of Engineers (Corps), which has never been used by the Corps before, will grant the Metropolitan Water Reclamation District of Greater Chicago (MWRD) the critical funds it needs to complete the final chapter of the famed Tunnel and Reservoir Plan (TARP) that protects and improves the quality of area waterways and reduces flooding.
McCook Reservoir Phase I
Ribbon Cutting Ceremony, December 4, 2017
On December 4 we marked a historic milestone as we celebrated the completion of Stage I of the McCook Reservoir, one of the biggest achievements to date in the MWRD's Tunnel and Reservoir Plan (TARP). The McCook Reservoir will mitigate flooding and prevent pollution from entering our waterways by serving as a holding place to allow our treatment plants more time to keep up with significant rain events.
McCook Reservoir and TARP Tunnel Connection
This video from November 2015 shows a portion of rock blasted away to connect the MWRD's McCook Reservoir to a tunnel. The McCook Reservoir is a part of the MWRD's Tunnel and Reservoir Plan (TARP, or "Deep Tunnel").
McCook Reservoir Time-Lapse February 2018 Fill
McCook Reservoir Time-Lapse February 2018 Fill
8 Minute