In a January night, in complete darkness, workers removed the final dam that held back the waters. This quiet, almost clandestine act would reverse the course of a river and redraw the hydrographic map of the North American continent. The canal was completed in January 1900, but due to legal challenges and political opposition, the nervous authorities in Chicago chose to open it in secret, during the night of January 2, 1900. In just a few days, the water began to flow in the opposite direction.
Key Takeaways
- Why did Chicago choose to reverse its river instead of cleaning its waters?
- Which U.S. state filed a lawsuit with the Supreme Court against this decision?
- How does a canal from 1900 still curb invasive species with electricity?
A Titanic Project to Save a City from Its Own Sewers
By the end of the 19th century, Chicago found itself trapped by its own dilemma. Before the canal opened in 1900, the city’s sewage flowed into the Chicago River and then into Lake Michigan, even as the potable-water intake lay offshore, with the risk that the sewers could reach that intake and trigger epidemics. The lake that feeds the city was also the place where it emptied its toilets. An untenable equation that cost many lives: repeated outbreaks of typhoid and cholera in the decades leading up to the grand undertaking.
The chosen solution rests on a maxim that would have made several engineers of the era cringe: since we cannot prevent the sewers from draining into the lake, let the river flow in the opposite direction. This project required the construction of the Chicago Sanitary and Ship Canal, a 28‑mile navigable waterway that remains one of the largest earthworks ever undertaken, roughly 45 kilometers carved through bedrock and glacial moraines. This 51‑kilometer canal connects the Chicago River to the Des Plaines River in northeastern Illinois, while the Calumet-Sag Channel, joining the main canal midway, does the same for the Calumet River, ten miles further south.
Between 1885 and 1900, Chicago endured several epidemics that killed thousands, pushing engineers to act quickly despite the enormity of the challenge. The construction of this $31 million project began in 1892 and is regarded by some historians as the largest excavation effort ever undertaken up to that point. The project’s chief engineer, Isham Randolph, would take lessons from this experience and apply them later to another titanic project: the Panama Canal.
The Displaced Problem, Not Solved: Missouri v. Illinois before the Supreme Court
Sending wastewater inland works well if you live along a lake shared by millions. But someone downstream inevitably bears the burden. This time, the state of Missouri pays the price: St. Louis draws its drinking water from the Mississippi, precisely where Chicago’s diverted waters end up via the Illinois River.
The state took the case directly to the nation’s highest court. The remedy sought was an injunction preventing the defendants from receiving or permitting the discharge of wastewater into the artificial canal built by the Sanitary District so that it would flow into the Mississippi, instead of being discharged into Lake Michigan. Missouri charged that Chicago had simply changed the delivery address of its waste. The complaint argued that the construction and maintenance of the project would create a continuing nuisance, dangerous to the health of a neighboring state, by transporting large quantities of untreated sewage daily through an artificial and non-natural canal.
The case, Missouri v. Illinois, was decided in 1901 and again in 1906 by the Supreme Court. The verdict was bittersweet for Missouri: the Court acknowledged that an state can sue another state for a sanitary nuisance, but ultimately refused to order a halt to the discharge, due to insufficient evidence that the canal’s waters actually worsened the Mississippi’s sanitary conditions relative to other pollution sources. Chicago won its legal battle. The river, for its part, kept bearing the burden.
An Invasive-Species Highway, Still Active 125 Years Later
What was meant to be a one-way conduit to evacuate wastewater gradually became something far more troublesome: a biological bridge between two watershed basins that nature had carefully kept apart. There remains a single permanent junction between the two main eastern North American drainage basins—the Chicago Sanitary and Ship Canal—which opened a route allowing invasive species like the carp to colonize vast new territories.
The threat bears a name that makes Great Lakes managers shudder: the Asian carp. These fish have the potential to damage the Great Lakes and the connected riverine ecosystems. To stop them, the U.S. Army Corps of Engineers (USACE) had to adopt a radical solution: electrifying the water. The dispersive electric barrier system, located on the canal at Romeoville, serves as a critical line of defense against the movement of invasive fish between the Mississippi basin and the Great Lakes, generating an underwater electric field that discourages invasive fish from advancing.
The device is far from trivial. Its installation requires ongoing maintenance to sustain two electric barriers sending direct-current pulses across a canal nearly 30 feet deep and 160 feet wide, all for the sole purpose of containing one of the United States’ most stubborn invasive species. The Corps goes even further: at Brandon Road, south of Joliet, a project mobilizes about $1.2 billion in public funds to build an additional barrier intended to prevent carp from reaching the Great Lakes.
A River Still on Life Support, More Than a Century Later
The amount of water diverted remains, to this day, a source of friction among Great Lakes states. Chicago has been limited by the Supreme Court to drawing 2.1 billion gallons of water per day from the lake, a volume that must be shared between human consumption and wastewater disposal. The city has, more than a century after the reversal, continued to live under a judicial cap that governs how much Lake Michigan water it may siphon toward the Mississippi.
The canal carried for long the reputation of being a long open-air sewer. But since 1972 and the adoption of the Clean Water Act, discharges are largely treated before release, and today’s residents, in Lemont or Summit, even campaign to rename the structure and give it a more palatable image. Yet the 1900 engineering, brilliant as it was in saving Chicago from cholera, has created an ecological debt that remains unsettled: a canal linking two aquatic worlds that should never have touched.
Sources: chanrobles.com | supreme.justia.com
