Mile 109.8: Lockport, Illinois
First visit: Feb. 19, 2023 Public trail? Mostly not Private land? Surely Distance walked: 2.75 miles
Like Chicago, Lockport is only barely a Des Plaines River community, in that the river flows through it for only a few miles on the outskirts of town. Lockport is instead about the canals. And the locks, of course. The town rose during construction of the Illinois & Michigan Canal in the 1850’s and was the headquarters of the canal before it closed permanently in 1933. It would assume somewhat reduced importance when the I&M was replaced by the Sanitary and Ship Canal in 1900, yet it is home to the only lock and dam on the San Ship today, the latter in service of the Lockport Powerhouse, which generates over $1 million in electricity revenue yearly for the Metropolitan Water Reclamation District (MWRD).
Despite – and because of – its association with the canals, Lockport is arguably the most consequential point of all for the Des Plaines River, because it is here that it meets the Chicago Sanitary and Ship Canal.
The San Ship Canal was built in the latter half of the 1800’s, both to replace the obsolete Illinois & Michigan (I&M) Canal, and to reverse the flow of the Chicago River. This redirected all the city’s wastewater away from Lake Michigan, which supplies the city’s drinking water, while at the same time creating the most significant inland shipping channel in the history of North America. The San Ship additionally connects to the Cal Sag Channel, which allows part of the Calumet River to also flow to the Des Plaines. What all of this did, in effect, was turn both the Chicago River and the Calumet River into tributaries for the Des Plaines River.
These developments were life-changing for the river, well beyond the artificial rerouting it underwent during the canal’s construction. Water levels, volumes, quality and navigation have all undergone dramatic transformation as a result of this merger. For a spring-fed river that never had a natural connection to Lake Michigan, and whose only other water source was precipitation, the Des Plaines River now drains the lake both directly and indirectly, receiving virtually every drop of the metro area’s wastewater – most of which originates as tap water pumped from the lake. The MWRD alone operates seven water treatment plants in the Chicago metro area, whose discharge ultimately joins the Des Plaines River. And I was able to identify at least five more upstream sources of processed wastewater besides, all in Illinois. (Wisconsin communities no longer discharge into the Des Plaines, routing their wastewater instead to Lake Michigan.) That’s all before the San Ship merger. After the merger there are at least nine more wastewater plants discharging directly into the river, in DuPage and Will Counties, bringing the total that I could find to 21. And none of that includes the wastewater from the many industries and power generators that also gets discharged into the river and/or the San Ship. (To learn more about this, see my Gurnee article.)
How life-changing has this been for the humble little river that “rises” from the Wisconsin prairie? A 2007 article in Water Environment Research, titled “A River is Reborn”, states that the lower Des Plaines River is the largest effluent-dominated stream in the U.S.
By using the San Ship to open commerce and reverse the flow of the Chicago River, not only was the Des Plaines forced to accommodate substantially increased water volumes, but it continues to take on still more, as the metropolitan area continues to grow. It’s why the river south of Lockport is wide enough and deep enough to carry barge traffic.
A desperate last stand
The thing about canals is that they facilitate all kinds of marine traffic, not just boats. Because the Des Plaines connects to the Illinois River, which in turn connects to the Mississippi, it has always been a route for marine life to get into the Des Plaines, and certain species are undoubtedly present who originally came upstream from the Mississippi. But a similar egress to Lake Michigan did not exist until the completion of the San Ship Canal. Between the San Ship Canal, the Erie Canal (both from roughly the same era), and the St. Lawrence Seaway, the Great Lakes were subjected to a largely invisible yet profound foreign invasion.
On my walks along many trails in many preserve areas I’ve seen many signs meant to enlighten and warn visitors about invasive plants and fish – alternately referred to as exotic or nuisance species. Humans bear a disproportionate responsibility for the introduction of non-native species, not just here, but all over the world. I write about invasive plants in my Mettawa section, and they are indeed a scourge to the Des Plaines River basin from top to bottom. Here I want to talk fish, and the larger family of marine life that doesn’t belong around these parts, and the breadth of the threat they represent.
A vivid childhood memory for me is the sight and smell of millions of dead alewives washed onto Chicago beaches during the 1960s and 70s. These were my first introduction to invasive species, though I wouldn’t have understood what that meant, and were a vanguard of sorts for a coming onslaught of invaders that would plague the Great Lakes for generations: spiny water fleas, lamprey eels, zebra mussels and round gobies, to name a small fraction, all of whom are still wreaking destruction in the lakes. Decades of debate about how to keep these invaders out of the Mississippi River, including proposals to simply close down the Canal, resulted in a measure that sounds almost laughable out of context: the installation of electric grids in the canal, collectively called the Fish Dispersal Barrier, an ostensibly lethal roadblock for any round goby foolish enough to swim downstream. (The gobies are now routinely found in the Des Plaines River, by the way.)
It turns out those same grids would become an integral part of a last-stand strategy to halt a different threat, coming from the other direction: Asian Flying Carp, which have inundated the Mississippi River and a long line of its tributaries, including the Illinois River – which connects to the Des Plaines River, which connects to the Sanitary and Ship Canal, which connects to Lake Michigan. The Canal represents an entirely logical migration route into the Great Lakes for all marine life, and the weakest link in the fight against the Asian Carp, who as of early 2023 had still somehow managed to not get to the lake. (I am tempted to add the word “yet” but can already hear a friend of mine accusing me of being negative.)
The electric grid in the Canal is one of two defenses that would seem funny to me if the situation weren’t so desperate. The other can be seen by hikers on the Centennial Trail, part of a much longer trail system that runs between the Des Plaines River and the Sanitary and Ship Canal. This second line of defense is literally (get ready for it): a fence. Called the Des Plaines River Barrier, it’s a metal mesh fence not unlike you might see in someone’s backyard, or in the outfield of a Little League ballpark. It runs for miles along the flood basin between the Des Plaines River and the Sanitary and Ship Canal, just a foot or two off the Centennial Trail, and can first be seen by the public across from Columbia Woods, a Cook County Forest Preserve in Willow Springs.
Where the Des Plaines meets the canal
It turns out that determining where the Des Plaines and the San Ship meet isn’t as straightforward as you might think, because there look to be two places where they possibly could meet, and a third where they definitely do – all in Lockport. None of them are publicly accessible by foot, but I tried.
The first is north of town, a massive structure called the Lockport Controlling Works, built between the San Ship and the Des Plaines. It is partially viewable by foot, but only from a distance, and only with difficulty, and only by possibly (probably) trespassing. These giant gates, I’ve learned, could be opened, mainly for water level control on the San Ship, which would be the first point at which the waters of the two are intentionally mixed. What I did, which I do not recommend, was walk the river’s west bank off the old 9th St. bridge, gingerly stepping among thawing marsh and thorny brush as I stayed well clear of Powerhouse Drive, which was open but posted with No Trespassing signs. I was able to get within a few hundred yards of the Works, but the view, and risk, is not worth it.
The second point where the Des Plaines and the San Ship might merge is a little downriver, and certainly within walking distance of the Works, were the public allowed to walk around here: the iconic Lockport Powerhouse itself, which is physically situated on the San Ship Canal. This doesn’t look like a spot where its water mingles with the nearby Des Plaines, but the MWRD, which owns the Powerhouse, reports at its website the following: “The Powerhouse is located where the Chicago Sanitary and Ship Canal connects with the Des Plaines River.” So that’s what they say. In any case, notwithstanding that it’s technically on the San Ship and not the Des Plaines, you can’t really walk to see the Powerhouse either, though it may be slightly more legal to try. (Note: the MWRD hosted an Open House at the Powerhouse on June 8, 2024, for the first time in at least a decade. I went, of course, and can report here that aside from their physical proximity to one another, the waters of the Des Plaines River do not meet the San Ship here. I think the MWRD should clarify its information.) My strategy was to walk the length of the Lockport Prairie Nature Preserve, across the river from the Powerhouse, all off trail, with increasingly difficult terrain as I got nearer to the dam. I was ultimately forced to abandon my effort less than a quarter-mile from the Power House, tired, dirty and defeated. (I never said it was a good strategy.) I took solace in the fact that the Powerhouse is not, strictly speaking, on the Des Plaines River. Nonetheless, as with the Works, the view and the effort are not worth it.
Finally, just south of Lockport city limits is where the San Ship Canal ends, and all of its water exits to join the Des Plaines River. Regardless of whether the two meet further upstream, they indisputably do so here, and once again, you can’t walk there. Despite this, I did walk to a point where I could see the confluence with the San Ship, just south of a railroad bridge. That point, like some others I’d gained in the course of my many walks, is also very much off trail, and also very much private property. Nonetheless, as I consider this confluence to be among the five most consequential points in the river’s story, I was excited to see it, especially as it was the last one on my list and took two efforts on consecutive Sunday mornings.
As a kind of bonus, by walking just a bit further north here, I could also see the south-facing side of the Power House, not to mention a rocky breakwater ostensibly separating the Des Plaines and San Ship just a few yards north of their ultimate confluence.
I came here thinking I might have been able to walk a couple of Powerhouse roads that run between the Controlling Works and the Powerhouse, but I should have known better. Especially as I’d just taken an MWRD Zoom tour of the Powerhouse a few days earlier, because public visitation is not presently allowed. The Zoom tours are held monthly and are fascinating and well done. And free. I highly recommend signing up for one. Here is a link to more information.
The amazing history in this area
I’d like to say something here for anyone thinking of tackling the Des Plaines by foot, as I’ve been doing: it isn’t easy to do that in this area. And by “this area” I guess I mean the stretch that runs through Lockport and Joliet, two physically large towns that are next door to each other.
There are many reasons for this, almost all of them having to do with the industrialized nature of the river’s environs in the area, but that doesn’t mean you can’t see the river, and it doesn’t mean there aren’t some great trails and amazing sights around there. In terms of gaining a well-rounded perspective on the role the Des Plaines has played in Chicago’s story, it would be negligent to not come down here and walk along the I&M Trail. This is effectively an extension of the Centennial Trail that, as its name says, follows the I&M Canal. Or what remains of it. This trail goes from Romeoville all the way out to LaSalle, and while portions of it do run parallel to the Des Plaines, the only section that’s actually on the river begins where the DuPage merges with the Des Plaines at the Four Rivers Nature Center, which is well south of Lockport. From there you can walk to the river’s confluence with the Illinois (and far beyond).
From the San Ship confluence that you’re not allowed to walk to, it’s about two miles to the I&M trailhead at the amazing Joliet Iron Works site, owned by the Will County Forest Preserve. This stretch of trail offers a look at the canal as it makes its way to the Iron Works, and goes behind the Old Joliet Prison made famous in The Blues Brothers. Afterwards, a quick walk to the Ruby Street bridge from the parking lot offers a view of the I&M Canal’s confluence with the Des Plaines. In the distance I could see the train bridge where I’d trespassed to see the San Ship confluence.