The Cause for the CAWS PART II: The New Canal System
BY HEATHER GARRISON, COLUMBIA FWCO
In Part I, we explored the life of the Illinois & Michigan (I&M) Canal - from its first realization in the 1600’s, to construction centuries later in the mid 1800’s, through its 30 years of operation, on to its all-but-demise by the 1880’s and finally its current preservation as the I&M Heritage Corridor used for recreation. Where the I&M Canal’s story ends (in terms of its traditional use), another story begins.
The I&M Canal was originally built for transportation, i.e., ships and barges. It was only after sanitation issues rose in the rapidly growing city that it began to transport something more - sewage and storm water runoff. Realizing the critical need for managing sanitation in Chicago, engineers began developing plans for the Chicago Sanitary and Ship Canal or CSSC (then called the Chicago Drainage Canal) where this time sanitation was the primary consideration and transportation was secondary. Construction led by the Sanitary District of Chicago (now the Metropolitan Water Reclamation District of Greater Chicago) started in 1892 and was opened eight years later thanks in part to dynamite, steam shovels and many other innovative earth-moving machines. It wasn’t for several more years, and the construction of the Main Channel Extension, that it was completely connected to the Des Plaines River. This new canal, although only two-thirds the length of the I&M canal, was on average over three times as wide and four times as deep as its predecessor. It reversed the flow of the Chicago River “permanently.” This engineering feat removed more than 26 million cubic yards of earth and 12.9 million cubic yards of solid rock (more than for the Panama Canal!). As part of the project, the Lockport Controlling Works and then the Lockport Powerhouse were built at the downstream end of the canal to regulate the flow, mitigate the forty foot elevation drop to the Des Plaines River below and utilize the flowing water for power generation.
As the CSSC started flowing into the Des Plaines River, construction began on another channel farther north and closer to Lake Michigan. The North Shore Channel (Wilmette Channel) was completed in 1910, diverting even more lake water into the Chicago River. Previously known as the “North Branch” of the Chicago River, this tributary became stagnant once the river was reversed. To flush this fetid water downstream, the channel was extended northward to the lake and a pumping station was built at the uppermost portion. The Wilmette Pumping Station provided enough flow to push water down the nearly eight mile channel to the main branch of the Chicago River. Not long after the North Shore Channel was operational, work began on the Calumet-Saganashkee Channel (Cal-Sag Channel) to the south. This channel also reversed flow that historically went into Lake Michigan, forcing it down the Des Plaines River. Starting in 1911, it took 11 years to construct the 16 mile-long channel between the Calumet River and the CSSC.
The Cal-Sag was the last channel built in this system. In 1938 the Chicago Lock was opened. It prevented the Chicago River from back flowing into Lake Michigan at the Chicago Harbor, while still allowing some flow from the lake and vessels to pass through. The T.J. O’Brien Lock & Dam was in operation by the mid-1960’s and served a similar purpose but on the Calumet River south of Chicago proper. It took more than 70 years planning, digging, funding and innovation and the entire series of connected canals, channels and pumping structures joined together to form what we know as the Chicago Area Waterway System (CAWS).