The year 2015 marks the 115th anniversary of the Chicago River’s reversal, an incredible engineering feat that turned the Eastern half of the United States into an island. Of course, this monumental project didn’t happen overnight; in fact, the events leading up to the reversal as well as the continued construction it required spanned nearly sixty years. Here’s a look back at the history behind the reversal of the Chicago River and the legacy it’s left since.

Before the river was reversed, Chicago was in the midst of a great period of growth. As the city grew, more water was needed; this water was brought in from further out in the Lake where the Chicago River emptied into it, bringing diseases such as cholera and typhus into the city. Water cribs were built to house and protect the offshore water for the city to drink, but it wasn’t enough to solve the disease problem- which led to the Chicago River Reversal Project. After a huge rainfall in 1885 carried sewage to Lake Michigan, Chicagoans panicked that another such storm could cause widespread disease; this fear of disease helped spur the decision to reverse the river.

In 1871, during a period of particularly low water, the city pumped water from the Chicago River into the Illinois and Michigan Canal to maintain its level, which led Chicago’s sewage to float away from Lake Michigan. This sight would inspire the river’s permanent reversal, a task that the government decided to take on in 1887.

Led by the Sanitary District of Chicago, construction began on the Chicago Sanitary and Ship Canal in the fall of 1892. This canal would connect the Chicago and Des Plaines rivers in a perpetually deepening design that would allow water to flow downhill- and in a new direction.

On January 2, 1900, water from Lake Michigan was first diverted down the newly constructed channel. However, construction didn’t stop there. In the years to follow, several side channels and canals were built to extend the canal, flush waste water, and allow more water into the main channel.

Since its completion, the historic Chicago River reversal has left a mixed legacy of innovation and, unfortunately, environmental damage. The creative techniques and machines used to reverse the river became known as the “Chicago School of Earth Moving,” and the methods used were instrumental in future projects and the construction of the Panama Canal. In 1999, the Chicago Wastewater System was named a “Civil Engineering Monument of the Millennium” by the American Society of Civil Engineers.

However, at the time of the reversal, no one was even thinking about the environmental impact of the waterway. Linking these two separate watersheds created a highway for invasive species. Now, preventing the influx of invasive water species costs the Great Lakes Region $2 billion every year. As a result, the federal government has proposed an $18 billion project to recreate a separation between the waterways.

Today, the Sanitary District (which has been renamed the Metropolitan Water Reclamation District of Greater Chicago) continues to uphold its mission of protecting the quality of Chicago’s water supply source while managing water as a crucial resource for its service area. Whether the waterways will be separated remains to be seen; however, the impact of the Chicago River reversal will never be forgotten.

Creative Commons Images:
Wikipedia – Water Cribs in Chicago
Flickr Gallery – The 1896 Sanitary and Ship Canal Excavation
Wikimedia – 12th Street Bascule Bridge
Wikimedia – Michigan Ave
Wikimedia – Chicago Sanitary and Ship Canal at Willow Springs
Wikipedia – Chicago Drainage Canal Construction 1900
Wikimedia – Chicago Drainage Canal 1899