why did they change the flow of the chicago river
Chicago River The River is also noteworthy for its natural and man-made history. In 1887, the Illinois General Assembly, partly in response to concerns arising out of an extreme weather event in 1885 that threatened the city's water supply,[3] decided to reverse the flow of the Chicago River through civil engineering by taking water from Lake Michigan and discharging it into the Mississippi River watershed. In 1889, the Illinois General Assembly created the Chicago Sanitary District (now The Metropolitan Water Reclamation District) to replace the Illinois and Michigan Canal, which had become inadequate to carry the city's increasing sewage and commercial navigation needs, with the Chicago Sanitary and Ship Canal, a much larger waterway.[4] The District completed this man-made hydrologic connection between the Great Lakes and Mississippi watershed in 1900 [5] by reversing the flow of the Main Stem and South Branch of the river using a series of canal locks, and increasing the river's flow from Lake Michigan, causing it to empty into the new Canal. In 1999, this system was named a 'Civil Engineering Monument of the Millennium' by the American Society of Civil Engineers (ASCE).[6]
Wabash River The Wabash River /ˈwɔːbæʃ/ (French: Ouabache) is a 503-mile-long (810 km)[2] river in the Midwestern United States that flows southwest from near the Indiana border in northwest Ohio, across northern and central Indiana to southern Illinois, where it forms the Illinois-Indiana border before draining into the Ohio River, of which it is the largest northern tributary. From the dam near Huntington, Indiana, to its terminus at the Ohio River, the Wabash flows freely for 411 miles (661 km). Its watershed drains most of Indiana.