Page "Chicago" Paragraph 9

To accommodate rapid population growth and demand for better sanitation, the city implemented various infrastructural improvements.

In February 1856, the Chesbrough plan for the building of the United States ' first comprehensive sewerage system was approved by the Common Council.

The project raised much of central Chicago to a new grade.

While raising Chicago, and at first improving the health of the city, the untreated sewage and industrial waste now flowed into the Chicago River, then into Lake Michigan, polluting the primary source of fresh water for the city.

The city responded by tunneling two miles ( 3 km ) out into Lake Michigan to newly built water cribs.

In 1900, the problem of sewage contamination was largely resolved when the city reversed the flow of the Chicago River so that it flowed away from Lake Michigan, rather than into it.

This project began with the construction and improvement of the Illinois and Michigan Canal, and was completed with the Chicago Sanitary and Ship Canal that connects to the Illinois River, which flows into the Mississippi River.