The Chicago River is the only river in the world that permanently flows backwards. This is because of a man-made project. The city got its drinking water from Lake Michigan and the river was sending pollutants into the lake.
No one wants polluted drinking water so the city decided to reverse its course and send the pollution from the lake to the Mississippi River instead. They built a 28 mile canal between the Chicago River and rivers that drain into the Mississippi. In January 1900 when the canal was complete the river reversed course and started to pull water from the lake instead of drain into it.
Take that people down river of the Mississippi!