Chicago’s Incredible Engineering Feat

Over Labor Day weekend I accomplished another item on my Great Lakes summer intentions list. We were in Chicago for a family event but had a gap in the schedule Saturday afternoon and I made it to a Chicago area beach. We were in the northern suburbs so the closest beach was Tower Road Park and Beach in Winnetka. It was a beauty for sure. Colorful umbrellas and shade coverings dotted the wide swath of sand while boats puttered out into Lake Michigan from a nearby marina. There was a generous swimming area and playground on the beach.

Chicago’s size and expanse always impresses me whenever I visit. So much highway. So many surface roads. So many diners. There are just a heck of a lot of people living in and around the city (2.6 million in the city; 8.9 million in the metro area). All these people require a lot of built infrastructure to live, including clean water and sanitation systems. 

How Chicago managed to develop both of these for its growing population at the turn of the 20th century is one of the greatest engineering feats of its time. The flow of the Chicago River was fully reversed to prevent water polluted by industry and sewage from moving into Lake Michigan, which has always been Chicago’s drinking water source. I’m going to share the story this week because it’s incredible – but it also sets up my next post, which will be about one of the most important recent developments for the Great Lakes.

river between trees and city skyscrapers
Photo by Heather B on Pexels.com

Prior to white settlers in the Chicago area, the Chicago River was a slow, somewhat unremarkable river that flowed through a soggy wetland. Two branches merged about a mile from Lake Michigan before flowing into the lake. In a twist of geographical fate, there is a ridge running north and south through what is now the Chicago metro area that created a subtle but crucial divide. Waters on the east side flowed east into the Chicago River and out into the lake and on the west side down into the Des Plaines River and eventually out to the Mississippi River and down into the Gulf of Mexico.

Starting in 1840 and extending through the Civil War, Chicago grew rapidly. Growing in parallel was Chicago’s enormous meat-packing industry. This industry contributed substantially to the pollution flowing into the river and out into Lake Michigan. By the 1880s, the situation was horrific. The river’s stench, drinking water contamination, and epidemics were constantly present. In 1886 a Citizen’s Association formed the Commission on Drainage and Water Supply. Eventually the Commission made several proposals to improve the situation, one of which was approved by the Illinois Legislature in 1889.

The proposal centered on building the Chicago Sanitary and Ship Canal. The canal would pull large amounts of water from Lake Michigan and, using a series of locks and dams, would shift the direction of the Chicago River, sending sewage out towards the Mississippi watershed while also creating a wider and deeper shipping channel that the Commission hoped might appease those downstream who were likely to be unhappy with the project.

The engineering required to build the canal throughout the 1890s is  beyond the scope of this post but it would not be too much to say that it was transformational. Equipment, tools and techniques developed in the process were replicated the world over, including in the construction of the Panama Canal. But the manpower required was also astronomical, and without question exploitative of recent immigrants and Blacks who were recruited or lured from the South to do the dangerous work. 

On January 2, 1900, a new century had dawned and with it came the initial intentional breach of a small dam holding water between the Chicago River and the new canal. It took two weeks for the canal to fill. On January 17, 1900, the controlling gates at Lockport, IL were opened, the Bear Trap Dam was lowered, and the river changed its course. The project had taken eight years from first shovel and had removed over 42 million cubic yards of soil and rock.

Technology can enable amazing things, like preserving drinking water for millions. But man-made solutions are not without environmental impacts, including sometimes wildly unexpected ones. Stay tuned for the next post to explore one directly related to the Chicago Sanitary and Ship Canal and the health of all of the Great Lakes.

Much of the content of today’s post came from a terrifically informative six-page write-up on the Chicago River’s history from the Metropolitan Water Reclamation District of the City of Chicago.

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