Deep Tunnel as the wrong solution to water issues (plus alternative uses)

Henry Grabar poses an interesting question: what if the Deep Tunnel project, one of the largest civil engineering feats in the world, does not solve flooding and stormwater issues in the Chicago region?

What if Chicago took a wrong turn in 1972 when, in the spirit of civic grandee Daniel Burnham (“Make no little plans”), it opted to build the world’s largest sewers instead of making all possible efforts to keep rainwater out of them? Scott Bernstein, the founder of the Center for Neighborhood Technology, says that the Deep Tunnel imposed a massive opportunity cost because the city and the district did little else to adapt. The MWRD spent billions on what engineers call “gray infrastructure” (pipes, tanks, pumps) and virtually nothing on “green infrastructure”: rain barrels, detention ponds, green roofs, porous pavements, and other adaptations that would have kept water out of the system…

The project proceeded regardless. Even with downsized reservoirs and a longer time frame, Chicago’s ambition captured the attention of civil engineers around the world. Today, most U.S. cities whose combined sewer overflows are governed by consent decrees with the EPA are working on Chicago-style digs. St. Louis, which has the fourth-largest sewer system in the country, is under a consent decree to commit $4.7 billion to ending its overflows through deep tunnels…

While engineers’ penchant for megaprojects endures, some American cities are preaching deterrence. If Chicago built a bathtub, Philadelphia is trying to transform itself into a sponge with park space, street trees, and permeable pavement. The city is spending $2.4 billion to implement the nation’s largest green infrastructure plan, an experiment that positions it as the anti-Chicago. The city thinks keeping water out of the system will save billions of dollars compared to a rejected tunnel proposal—and that green initiatives will produce positive externalities, like improving air quality and creating verdant streets.

In Chicago, meanwhile, the MWRD has committed to creating just 10 million gallons of green infrastructure capacity under its EPA consent decree. Compare that to neighboring Milwaukee, a deep-tunnel city that now believes its green infrastructure will, by 2035, surpass the capacity of the tunnels and hold up to 740 million gallons of rain where it falls.

Hindsight may always be a little tricky in these cases as we have the advantage now of being able to see the Deep Tunnel project in action. Does it actually accomplish its goals? Was all the spent money worth it? At the same time, a project of this magnitude should have generated plenty of discussion and at least a few alternative options.

If Deep Tunnel does not work as intended or does not solve all of the flooding and stormwater problems, I wonder if it could be used in other ways. I’m thinking of other major infrastructure projects that have been reversed or reused, like urban highways that are torn out (like in Boston or San Francisco) or former railroad lines turned parks or recreation areas (think the High Line). Some other options for the Deep Tunnel:

  1. Underground roads. With Elon Musk’s Boring Company working on underground roads plus Chicago’s legacy of Lower Wacker Drive, perhaps traffic could be rerouted deep underground.
  2. Underground freight movement. Given Chicago’s railroad bottleneck, this could be an interesting solution.
  3. An underground park and recreation area. It would certainly be unique. Think a combination of spelunking, rock climbing, and exploration.
  4. A military installation and testing area.

Teaching kids about Chicago’s Deep Tunnel project

Kids should know about one of the largest civil engineering projects in the world: the Deep Tunnel project in and around Chicago.


This is from the Riverworks exhibit at the Peggy Notebaert Nature Museum in Chicago. While some of the pieces of the exhibit failed to work the day we visited, I think I could see the purpose of the The Deep Tunnel exhibit: the floodwaters would be diverted away from the city.

The concept may appear simple and explainable to kids but the execution in real life is not. The exhibit suggests the flooding the past is now alleviated by Deep Tunnel. Yet, the problems are likely to go on in a region that continues to expand and change. Remediating water and flooding issues is a very difficult task compared to altering development at the beginning.

It is interesting to think how else this engineering feat could be presented to children. I could imagine a scaled model that kids could walk through to help give them a sense of the size of the sewers needed as well as the size of some of the water reservoirs. Deep Tunnel is not intended for minor amounts of water; this is supposed to help protect millions of people on a fairly regular basis. Communicating the sheer size could fascinate kids. Or, perhaps some sort of computer game where kids play the role of an engineer or expert as they make choices about where to divert water. Come to think of it, where is this version of Simcity or Roller Coaster Tycoon – “Infrastructure Builder” or “Sewer Wars” or something catchier.

Considering a new utility tax in DuPage County to help address flooding

These are the sorts of issues sprawl brings: the DuPage County Chairman discussed a new power available to the county to collect tax monies to address flooding.

Cronin told the audience at a Naperville Area Chamber of Commerce luncheon that flooding has long been a serious problem in DuPage.

In order to address it, he said, infrastructure improvements are needed. Right now, money for those projects comes from property taxes.

The proposed utility fee would charge property owners based on use. Those who have more stormwater leaving their land would pay a higher fee. Anyone with land producing less stormwater runoff would pay a lower fee.

Enacting a utility fee would make it possible to have charges for stormwater projects removed from the property tax bill, he said…

However, some residents already are opposing the idea. Last month, protesters demonstrated before a county board meeting and called the proposal a “rain tax.” Objections also are expected to come from schools, churches and other tax-exempt entities that would be required to pay the fee.

At this point, DuPage County is largely built-out (or the land is tied up in Forest Preserves) so dealing with flooding is largely taking place after the development has already happened. Thus, remediation can be quite expensive. I imagine residents and organizations would not like the idea of a new tax but flooding is a serious recurring issue.

On a related note about the cost and length of projects intended to combat flooding: here is a story about progress being made at constructing the world’s “largest reservoir of its kind in the world” in the south suburbs as part of the impressive Deep Tunnel.

A small crowd gathered Monday at the lip of the mammoth Thornton Quarry, all eyes fixed on an outcropping of dolomite nearly 300 feet below the shoulder of the westbound lanes of Interstate 80.

A ripple shot through the two-story rock formation, and it collapsed amid a small, dusty landslide. And so construction of the largest portion to date of the decades-in-the-making Deep Tunnel floodwater control system began with a bang…

When it goes online in 2015, the Thornton Composite Reservoir will hold 7.9 billion gallons of stormwater and sanitary sewer water from more than a dozen south suburban towns…

The 30-story-deep reservoir will fill like a regional bathtub during massive storms that threaten to overwhelm local sewer systems, a problem that has grown worse with more frequent and intense downpours in recent years and as development has replaced open, absorbent land with rooftops and pavement.

Dealing with flooding is not easy