Lockport Gates, Illinois

When these gates on the Chicago River (a component of what was then known as the Chicago Drainage Canal), were opened with much fanfare in 1900, the course of the river reversed direction: the culmination of an eight year engineering project. The river was reversed to move the sewage then being dumped into it by the booming city of Chicago, into a river system that led away from the city, and eventually, to the Mississippi River and the Gulf of Mexico (instead of to Lake Michigan, as naturally occurred). One of several rivers that have been reversed in the USA, this project was among the first and the largest. A total of 56 miles of canals were dug by the city in the early part of the 1900's to keep the waste out of the lake, in a network that is said to have involved more earth-moving than digging the Panama Canal. The effect changed the position of Chicago's watershed on a continental scale: from the Great Lakes and the Gulf of the St. Lawrence River, to the Mississippi and the Gulf of Mexico.