||The sanitary conditions in
Chicago were getting worse and the I&M Canal, being
strictly a ship canal, did little to help. The
population was expanding. From DuSable and his family in
1779, the population slowly grew to 100 in 1830. After
that growth was rapid; 5000 in 1840, 30,000 in 1850,
reaching 1 million in 1890 and 1.6 million in 1900.
To understand the problems of populating the area, we must picture the topography; the slope of the land from the high point of the portage to the lake is practically dead flat. The high point at the original portage was only seventeen feet above the lake, even flatter than the land east of Oak Park. It was a swampy area, difficult to drain. The sanitary conditions were formidable. All of the sewage system in the area simply dumped into the Chicago River. Attempts to divert the sewage into the I & M Canal were less than successful. Pumps could handle the steadily increasing flow in normal weather but during heavy rains, the Chicago River would revert to its original flow41 carrying untreated sewage into Lake Michigan, from where the City took its water supply.
Front page articles in contemporaneous newspapers note that in August 2, 1885, 6.2 inches of rain fell on the city. Whereas sewage was washed into Lake Michigan, strong northeast winds prevented the waste water from reaching the city’s water intakes. There was no adverse affect on public health and no large number of disease deaths. However, the event brought increased interest in finding a solution for the city’s sewage problem. It was only a few years later before the authorization of a sanitary canal in 1889, and the start of construction in 1892. [See author’s note, page 10]
A permanent solution was sought and in 1889,44 by an incredible margin of 99%,45 the voters approved the formation of The Sanitary District of Chicago, covering the City and a few outside areas including Oak Park. The solution proposed by the District was to create a drainage canal reversing the flow of the Chicago River. Waste and sewage, still totally untreated, would flow away from the lake, over the continental divide and into the Illinois River valley. Chicago called it "disposal by dilution."46
The idea was simple; with such a flat slope, it would only be necessary to cut a channel to a point in the Des Plaines valley below the level of Lake Michigan and the water would flow, positively reversing the direction of flow of the Chicago River.