The CRAZY Engineering Of Chicago

July second, twenty twenty-three. Chicago, Illinois. At four in the afternoon, after a storm dumped up to eight inches of rain on parts of the city, engineers did something they really, really don’t like doing. They opened the locks at the mouth of the Chicago River, right downtown, and let the river run backward. Into Lake Michigan. The same lake Chicago drinks from. For ten and a half hours, the Chicago River flowed the wrong way. Past the Riverwalk, past the skyscrapers, out into the lake. And here’s what makes that strange. The Chicago River isn’t supposed to be able to flow into the lake at all. Over a hundred years ago, this city turned the whole river around and made it run away from the lake, toward the Mississippi. It took eight years and the biggest earth-moving job North America had ever seen. That’s not even the craziest thing Chicago did to itself. In eighteen fifty, Chicago had about thirty thousand people. By nineteen hundred, it had almost one point seven million. It grew faster than almost any city in history, and it did it on a piece of ground that was barely above the water. Flat, wet, swampy ground, where the sewage had nowhere to go. So the city lifted itself out of the mud. Building by building. Sometimes with the people still inside. This is the crazy engineering of Chicago. Start with the ground, because the ground is the whole problem. Chicago sits on the old bed of a glacial lake. It’s flat. Ridiculously flat. The city grew up only a few feet above Lake Michigan, on land where the water table sat just under your boots. When it rained, the water didn’t drain. It just stayed. Streets turned into mud so deep that, as the old Chicago stories go, people stuck joke signs in the worst holes. No bottom here. Shortest road to China. Funny, until you think about where everything else was going. Privies, stables, slaughterhouse waste. It all soaked into that same wet ground, and into the river, and the river ran into the lake, and the lake was the drinking water. You can guess how that ended.