Featured Projects + Tools
Even With $1B Upgrade, Chicago's Deep Tunnel Swamped by Winter Storm, as Streets and Basements Flooded
Despite a new $1 billion flood-control reservoir more than 20 times bigger than Soldier Field, rain and melting snow swamped the largest section of the Deep Tunnel project in less than a day last month, according to records obtained by the Tribune.
Starting on Feb. 20, more than 2 inches of rain flushed a torrent of sewage mixed with runoff from rooftops, streets and parking lots into stormwater tunnels stretching from Wilmette to Westchester, rapidly filling the McCook Reservoir built to hold wastewater until it can be treated.
After the 5.1 billion-gallon system swelled to capacity, leftovers from the storm surge began backing up in basements and pouring out of overflow pipes into the Chicago River and other area streams during the next two days. Nearly 4 billion gallons of raw sewage, debris and runoff gushed into the waterways, most of it from a pair of pumping stations that convey waste from homes and factories on the North and South sides to the district’s treatment plants, according to a summary compiled by the Metropolitan Water Reclamation District at the Tribune’s request. Another government agency, the Chicago Department of Water Management, fielded 510 reports of basement flooding during and after the storm, and recorded 240 cases of standing water on city streets.
“Before McCook came online, we would start seeing (sewage overflows) almost as soon as it started raining,” St. Pierre said. “This time the system held on for 20 hours, which makes me fairly optimistic that what we saw last month will be relatively rare.”
With the bulk of the project completed, even some of the project’s most ardent backers say the city and county need to start focusing more intensely on neighborhood-focused improvements that allow runoff to soak into the ground before it reaches local sewers. Yet state legislative leaders in Springfield have blocked measures that would authorize the water reclamation district to spend taxpayer funds on the smaller-scale initiatives, which can help prevent sewage from backing up into basements and take pressure off the larger system of sewers and stormwater tunnels.
Meanwhile, staff turnover at the city has slowed progress on a pilot project in the low-lying Chatham neighborhood on the South Side, where the nonprofit Center for Neighborhood Technology has drafted plans to direct downspouts away from homes, seal foundation cracks and install rain gardens and other landscaping improvements to absorb runoff.
“They are good at what they do,” Scott Bernstein, the center’s co-founder, said of the Deep Tunnel’s operators. “But we are seeing more intense storms like what happened in February, and it’s clear we still aren’t ready to deal with all of that rain.”
St. Pierre agrees. “We are not going to be able to solve this with pipes alone,” he said. “Once again, this storm shows why you shouldn’t build a large city in a swamp.”
CNT is engaged by governments, advocates, policy makers, and community groups to apply our expertise to solving problems.