Go back you are going the wrong way

At the start of our the Architectural River Cruise we had to pass through locks and into the Chicago River. The Chicago river used to flow into the Lake Michigan ... But in 1900, they decided to reverse the flow of the river and now Chicago River originates from Lake Michigan and empties into the Mississippi River System ... It's an engineering marvel - A 28-mile canal that controls the flow of water now going from Lake Michigan into the Chicago River, through the Sanitary and Ship Canal, and into the Des Plaines River.

But why ???

As the population of chicago grew there were problems of water pollution ... most waste was simply drained into the river. The residents of the city collected their drinking water from collection facilities just offshore in Lake Michigan. With the influx of waste in the river and in their drinking water, outbreaks of cholera, typhoid and other water-borne diseases were common. In 1854, a cholera epidemic took the lives of 5 ½ percent of the population - so this was the solution.
Why didn't anyone tell me you can't take a movie sideways!