A Century Later, the Expensive Lesson of Reversing the Chicago River

Way back in 1673, the French Canadian explorer Louis Jolliet noticed that the land around present-day Chicago had “a very great and important advantage, which perhaps will hardly be believed.” The area, he foresaw, could become the great node of a huge continent, with the Great Lakes on one side and, just a few miles to the southwest, the Illinois River and the entire Mississippi Basin. Jolliet envisioned, rather hopefully, that connecting the two — and creating a water route from Lake Erie all the way to the Gulf of Mexico – would be as simple as building a canal through just “half a league of prairie.”

The reality, of course, turned out to be far more complicated and expensive. It would be nearly 200 years before the first, 96-mile connection — the Illinois and Michigan Canal — was completed, and another 50 before the current connection — the Chicago Sanitary and Ship Canal — opened its locks for the first time. Finished in 1900, the latter canal created a shorter, 28-mile route linking the two waterways. Even more significantly, it was engineered to reverse the flow of the Chicago River and instead carry the growing city’s wastewater away from its drinking supply in Lake Michigan. By moving then-untreated waste away from the crown jewel of the lake, Chicago was able to put off dealing with many of the consequences of man-made intervention in the Midwest's ecosystem.