Chicago’s Water Tunnels: Secret Passages Beneath the Lake

Every major city that has been around for a while has layers of history that can often be seen in abandoned or forgotten infrastructure projects, and Chicago is no exception. Given my fascination with the lake and its own unique history in this area, it was only a matter of time before my curiosity got the better of me. However, I wasn’t expecting my explorations to lead to a fascinating discovery literally right under our feet at L1.

Before I recount my recent adventure, I’d like to provide a quick background for context. One of my most popular posts has been the one on the water crib. You don’t need to read the whole thing, but I’d like to draw your attention to the last paragraph:

The Two-Mile Crib was connected to a tunnel built 60 feet below the lake surface, and this tunnel ran all the way back to the Chicago Avenue pumping station – which was part of the historical Water Tower complex still located today on north Michigan Avenue.

According to historical records, there was a rather extensive system of water and maintenance tunnels created underneath both the city and Lake Michigan in the 19th century. Dating back to 1867, they were all part of the massive undertaking to construct the water cribs.

A very good reference for this is Under Your Feet, Chicago’s Water, Freight, Subway and Storm Tunnels, an online resource from the University of Chicago’s Crerar Library. You can delve into the details yourself, but here are some historical images which provide visualizations of the types of tunnels that were built at the time:

So what does this all have to do with L1 and Open Water Chicago? Well, I’ve always been enthralled with the idea of exploring secret passageways and uncovering cool things. When I attended the University of Illinois back in the day, I “heard from a friend” that you could access the underground steam/utility tunnels and have all sorts of adventures traversing the hidden world beneath the campus.

So I came up with the idea of doing something similar with Chicago’s hidden network of tunnels, and I bounced the idea off of my fellow Illini and co-conspirator, “Clark” (real name withheld to protect the not-so-innocent). For several weeks, we researched the tunnel system and pored over antiquated maps and blueprints until we finally pinpointed what appeared to be an entry point. And what we discovered was absolutely astonishing as you will see.

Lake Tunnel Access

Have you ever wondered about that rusted maintenance door in the pedestrian walkway that goes from North Avenue underneath Lake Shore Drive to the Chess Pavilion? Well, it turns out that it is not just some benign utility closet. Instead, it is one of several areas where you can gain access to the aforementioned underground lake tunnels:

After taking these shots in the pre-dawn hours, we got to work on jimmying open the maintenance door. The lock was pretty much rusted through, but Clark was able to use his locksmithing skills to unfreeze it while I strategically positioned myself to shield our activities from watchful eye of the nearby security camera.

Once opened, we hustled inside and had a heart stopping moment where we both almost stepped into an access ladder shaft just a few feet from the entrance. Fortunately, we had turned on our headlamps before making the ingress, so we managed to avert what would otherwise have been a catastrophic introduction (and abrupt conclusion) to our little escapade.

Once we regained our composure, our sense of curiosity and our drive for exploration took over. Bottom line, we just couldn’t resist the temptation of this “attractive nuisance.” So we began to guardedly climb down the ladder which descended for quite some way – I’d estimate at least 50 feet.

After about 10 minutes, we reached the bottom where the ladder ended on a dirt floor in a narrow passageway. Given the pitch blackness, our headlamps weren’t enough. So we activated our flashlights and camping lamps that we brought along to aid in our exploration.

What you are looking at above is one of the old access tunnels. This one is heading due south towards the Hancock building. We opted not to explore that route, but instead went directly east using the passage you see just ahead on the left. We deducted that this one went underneath the lake, and we wanted to see where it would end up.

As it turned out, this tunnel continued on for quite some time – over two miles as you will see later – and became very narrow along the way. Below are a few shots we snapped at various points along the path.

Finally, and much to our relief, the tunnel opened up into a larger space where it dead ended at a vertical shaft. The journey to this point took at least an hour as we were being overly cautious while navigating the cavernous route. Truth be told, we weren’t sure what to expect – or if the the section underneath the lake was even stable at all. So we had more than a little bit of trepidation during the entire time we were in transit.

Reaching the end point was a real cathartic event as neither one of us had enjoyed the claustrophobic odyssey. We scouted out the open area and found what looked to be a still functional escape ladder. Since this seemed to be the only way to get anywhere, we secured our gear and started the ascent.

After climbing about 30-40 feet up the rickety ladder, we reached a rusted iron ceiling which had a trap door access way that was sealed shut. But fortunately, the edges of this panel had eroded enough for Clark to cut through the worn out hinges with a cordless reciprocating saw. When were finally able to remove the access panel, we found ourselves in a utility area of a sub-basement. But sub-basement where?

We got our answer fairly quickly once we started exploring our new digs. The door out of the sub-basement led through a small room which exited to a hallway. As we roamed though this corridor, the rhythmic sounds of some mechanical function became steadily louder until the hallway opened up into a large, round atrium – obviously some type of pumping station. We could see doorways on the upper levels that were accessible by some catwalk staircases, so we clambered up these to see where the source of daylight led.

Much to our amazement, the doors led outside to a structure right in the middle of the lake. So – you guessed it – the lake tunnel that we had just traversed led to the exact same Harrison-Dever water crib that we all look out on whenever we gather at L1 for a swim!

It suddenly dawned on us (no pun intended) that we must have lost all sense of time while in the tunnel as it was already well into morning with the sun long since risen. I started to take a few shots to document our little adventure, but then noticed that there was a Chicago Police boat in the vicinity that was heading for the water crib (ulp!).

While we were certain that it hadn’t noticed us, we couldn’t rule out the possibility that we had inadvertently activated some sort of sensor-activated monitoring alarm. So we hastily retreated to the sub-basement and scrambled down the ladder after placing the access panel back in its proper place.

What happened next would make the late Roger Bannister beam with pride. Once our feet touched the floor at the bottom of the ladder, we darted back into the tunnel and covered the 2+ miles in what was mostly a full on sprint. When we finally arrived back at the foot of the initial ladder shaft, we stopped for a few minutes to catch our breath before making the final ascent.

Exiting into the pedestrian tunnel was a bit tricky as there was now an assortment of runners, bikers, and wayward passersby to contend with on the other side of the maintenance door. So while we carefully opened it up to make our egress, we still almost upended a lanky fellow on a very expensive tri-bike (who was going way too fast in the pedestrian tunnel, I might add).

Once outside, we wedged the door back into its proper place and tried to ignore the stares of the people who had seen us emerge. Fortunately for us, we had secured rock star parking right near the cul-de-sac on the west side of the pedestrian tunnel. So it was just a matter of piling into our waiting car and driving off as inconspicuously as possible.

I know there are some of you out there who will look upon this as nothing more than foolish risk taking. But for those of you who are more adventurous souls, I would implore you to take a deeper look into the fascinating history of our great city and seek out opportunities like this wherever you can find them. After all, nothing ventured nothing gained!

Charles Cushman Photography

Charles Cushman was born in the small southern Indiana town of Poseyville in 1896. Like many other young and enterprising Midwesterners, he felt the draw of Chicago and made it his home for a large part of his adult life. But he also had a very interesting hobby.

He took pictures. Lots of pictures. Over 14,500 to be more precise – and quite a few of our fair city and lake!

When he died in 1972, he bequeathed his entire photo collection to his alma mater, Indiana University. You can check out the entire collection – taken between 1938 to 1969 – at this link.

But here are just a few swimming and lake-related ones that he took in Chicago circa 1941 – mostly around Promontory Point. As you can see, Mr. Cushman had an appreciation for feminine pulchritude!

And my favorite, circus clown Paul Wenzel training his goose between shows!

The Beach Boys

Whenever you make a jaunt out to L1 during the warmer months, chances are quite good that you’ll see one or more of these loyal lakegoers within the vicinity. They maintain an unofficial vigilance over our beloved swimming site, and they’re always ready to offer friendly greetings or a pleasant conversation.

In short, they’re great fellows who have fascinating stories to tell. And I always enjoy seeing them out at L1 because they personify everything that’s great about summer in Chicago!

So in this spirit, I’d like to hand out some honorary Lake Monster numbers to the real “beach boys” of L1. Dave had some shots of the group taken last week, so I’ll post a few below with some details:

Left to right:

Diver Dave – #21 (Ice Monster #1!)
Dr. Pete – #146
2-Liter Pete – #147
Paul (The Chairman) – #148
Dave (Paul’s son) – #149
Freddy – #150
Danny – #27
Jules (seated) – #151

Another shot of the L1 crew!

Lakefront relic from a bygone era

Before we became a wussified and hyper-litigious society, you could actually spring off of diving boards into Lake Michigan. Here is all that remains of a diving board down at 51st Street that used to provide all sorts of joy and mischief for kids of all ages:

The Hoary Bat

It was hard to get going yesterday morning. These early autumn days seem more like mid-November than late September. But I was up by 7am, hammering away at the keyboard with the aid of some very strong black coffee, when I heard this god-awful screeching outside of my window.

I tried to ignore it at first, but it just intensified. Then I realized that this was some animal in serious distress. An utterly terrified, life-or-death type of distress. So I went to the window to investigate.

Three crows had surrounded a shrieking animal in the empty lot adjacent to my building and were taking their turns pecking and tearing away at it. I couldn’t tell exactly what it was, but it sure was “down for the count.”

Three against one? That’s hardly fair. So I decided to go out there and see what all the fuss was about…

I approached the crime scene and shooed away the trio of surprisingly large and menacing crows. They scattered away as I advanced, but they hovered closely in the nearby trees, cackling indignantly and fixing me with their baleful stares.

I wasn’t quite prepared for what I saw:

Hoary bats (Lasiurus cinereus) are the most widespread bat species in the Americas. Their habitat includes most of North America from north-central Canada and extends south all the way to Central America.

Hoary bats are solitary forest dwellers that prefer evergreen trees to deciduous environments. They are nocturnal hunters who feed on insects during the evening and spend their days roosting in a torpor high above the ground. This explains why hoary bats – although quite abundant and widespread – rarely come into contact with humans.

So how did this one end up as midday crow fodder?

There are several possibilities. First, many hoary bats migrate long distances in the fall, spending the winter in the warmer regions of sub-tropical or tropical America. Apparently, it’s not that unusual for these bats to become quite exhausted from flying and fall out of their roosts onto the ground. And even if they manage to stay in the trees during the day, they are quite easily exposed to predation. This is especially the case with juveniles or young adults. And give the smaller size of this hoary bat (3-4 inches), I suspect he is still technically a “minor.”

So it’s quite likely that our little hero was unfortunately literally caught napping by some very hungry crows who frequent that empty lot.

The second possibility, while very remote, is a bit less innocent. In general, bats are not dangerous. But like any other mammal, they can carry rabies. And even though less than 1% of all bats are infected with the virus, hoary bats tend to have a higher incidence of the disease given that they sometimes prey on other bats.

So whatever happened to the bat, you might ask?

Well, I couldn’t just let him get torn apart by the crows. So I placed him in a box using some heavy winter gloves. He had calmed down considerably at that point, but I could tell that he was still in pretty bad shape. His left wing was somewhat misshapen, and from the look of things he had taken a number of very unkind jabs to the midsection from the three crows.

The little fellow slept very soundly for all of yesterday afternoon and was still in a tranquil slumber when I returned home in the early evening. He had even climbed up onto a bamboo lid I had placed in his temporary home and was roosting upside down on one leg.

Unfortunately, he didn’t make it though the night. He passed quietly in his sleep and – from the look of things – quite peacefully.

I contacted animal control this morning, and they came to take him away. The animal control officer had never seen a hoary bat, so I explained to her what it was. We both commented on how rare and unique it was to see such an animal.

But apparently they’re quite common. And as you walk underneath the trees this time of year, they’re probably right above you.

Quietly sleeping, on their way south.

The L1 cormorant: about our new visitor

Double-crested cormorants are large waterbirds whose summer habitat includes lakes and inland waterways. They’re quite widely distributed across North America, ranging from the Aleutian Islands in Alaska down to Florida and Mexico.

Like other cormorants, they primarily eat fish which they hunt by swimming and diving. And they’re definitely built for speed and efficiency in the water. As you can see, this one moves quite nimbly when going after his prey:

Cormorants have a short, stocky body with webbed feet and a very long neck. This enables them to quickly dart through the water in pursuit of smaller fish, which they snatch with a small hook on the end of their beaks.

Here’s a shot of our friend again just after snaring a juicy morsel:

But his success as an aquatic hunter is not always welcome among many Great Lakes residents. Cormorants are voracious consumers of bait fish such as round gobies. This has adversely impacted the perch, walleye and bass populations – much to the chagrin of sport fisherman throughout the region.

And to add insult to injury, cormorants are notoriously noisy and destructive wherever they establish their highly populated breeding grounds. This has led to increasing efforts to cull the cormorant population in several parts of the Great Lakes basin.

But even if you’re not a fan of our new visitor, you can’t help but admire his talents. In fact, when you see him in action, he looks like a throwback to some prehistoric time when real lake monsters once had free reign over the large inland sea that covered most of North America.

And when you look at his skeleton, you’re even more tempted to think that they still exist:

Happy Birthday, Ray Bradbury!

The former “Green Town, IL” (a.k.a. Waukegan) resident and master storyteller is 90 years young today!

When I was a boy in the Midwest I used to go out and look at the stars at night and wonder about them.

I guess every boy does that.

When I wasn’t looking at the stars, I was running in my old or my brand-new tennis shoes, on my way to swing in a tree, swim in a lake, or delve in the town library to read about dinosaurs or time machines.

I guess every boy has done that, too…

The stars are yours, if you have the head, the hands, and the heart for them.

– Ray Bradbury

How and why Chicago’s sewage enters Lake Michigan

There is a swim ban this weekend at all Chicago beaches due to “water quality issues.” This is because the Metropolitan Water Reclamation District of Greater Chicago (MWRD) opened the Wilmette and Chicago River locks at 2:30am on Saturday morning and released large quantities of sanitary sewage diluted in part by the sudden influx of stormwater.

Let’s examine how the sewage got there in the first place.

Chicago has what’s known as a combined sewer system. Under this design, all of the sanitary sewage as well as any incoming stormwater eventually makes its way to a shared outfall pipe or reservoir:

(Source EPA)

In contrast, many municipal sewer systems constructed after WWII collect and drain stormwater in drainage lines which do not mix with the sanitary sewage drainage systems. These are appropriately termed separated sewage systems:

(Source EPA)

As the first image indicates, sudden and heavy rainstorms can very often deluge a combined sewer system with excess stormwater. When this happens, the combined sewer overflows (CSOs) can overwhelm the shared outfall pipes and reservoirs and cause unwanted flooding and “backups” in both the sanitary sewage lines as well as the storm drain systems:

To prevent these occurrences – or to at least mitigate them – the city of Chicago and the MWRD designed and developed the Tunnel and Reservoir Plan, a.k.a. the “Deep Tunnel.” Commissioned in the mid-1970’s and still under construction, the TARP is essentially an expanded reservoir system for CSOs that take place during heavy rainfalls.

Unfortunately, an especially heavy rainstorm will still occasionally overwhelm the TARP.

When this happens, the MWRD will divert the excess CSOs to any number of permitted outfalls – most of which empty into the Chicago River, the Calumet River, and the Chicago Sanitary and Ship Canal.

However, under sustained storm conditions, CSOs from these permitted outfalls can actually overwhelm these river and canal systems as well. Under this scenario, the MWRD will open one or more of the river locks such as the Chicago Harbor lock, the Wilmette lock, or the O’Brien lock in order to prevent flooding.

And when these locks are opened, CSOs (combined sewer overflows) enter Lake Michigan and contaminate the water.

The good news is that this doesn’t happen very often. And theoretically, this shouldn’t take place at all once the TARP is fully completed and operational by 2019 (estimated).

But in the meantime, you might want to educate yourself on the risks E. Coli exposure and be wary of the conditions at those Chicago beaches more prone to pollution.

Fresh Perspective: Artwork by Midwestern Surfers – This Saturday!

Dave just gave me the heads up on this:

I know, short notice – but it would be great to see you guys. The gallery was going to close, but ran into some money last week! The show must go on!

Attached and below is show information that features Artwork by Midwestern Surfers (and Chicago Surfrider Members) Mike Killion, Jason Lukas and Jack Flynn.

Saturday March 27
6:30pm – 11 pm
Barbara and Barbara Gallery
1021 N. Western Ave, Chgo 60622

Our Chicago Surfrider Chapter will have a table on site to pass out info and spread the good word!

Please spread the word and come out to show your support!


It looks pretty cool. Check it out! (Click image for larger pic)

Chicago’s Nuclear Missiles: The Nike-Hercules Deployments

Believe it or not, at one point we had three nuclear missiles deployed on our lakefront right in the midst of some very densely populated areas.

It all began in 1957 during the height of the Cold War. At that time, the greatest perceived threat to the U.S. was a nuclear attack from Soviet bomber planes flying over our cities. To counter this threat, the U.S. military deployed the Nike-Ajax – and then later the Nike-Hercules – surface to air missile systems (SAMs) at numerous locations throughout the country to serve as a protective shield against such an attack. These missiles actually contained nuclear warheads and were designed to obliterate clusters of enemy bombers through an atomic air burst.

As the Cold War raged on, both the U.S. and the Soviet Union developed intercontinental ballistic missiles (ICBMs) which could be launched from distances greater than 3,500 miles (5,500 km). Both superpowers, in turn, developed ICBMs which could (in theory, at least) intercept incoming enemy ICBM strikes.

All these developments essentially made the Nike-Hercules missiles obsolete. So these sites were deactivated, and the missiles were removed in the 1970’s. But until that point, the city of Chicago had Nike-Hercules missiles deployed at Belmont Harbor, Burnham Park, and Jackson Park.

This particular site was right in my neighborhood near the Belmont exit off of Lake Shore Drive (the photo says Montrose Beach – which was where the control center was located – but the actual missile was farther south at Belmont):

There was also one deployed just south of McCormick Place and a third one in Jackson Park. In fact, the radar towers for the Jackson Park site were located on Promontory Point, one of our sister swim sites:

For a more detailed look at the Chicago Nike-Hercules missile sites, be sure to check out Michael Epperson’s site (where I got the images).

And while this is now all just a historical footnote, we could have experienced this right on our lakefront during the Cold War!