The lock that helps limit the amount … Chicago River, navigable stream that originally flowed into Lake Michigan after being formed by the north and south branches about 1 mile (1.6 km) west of the lake, in Chicago, northeastern Illinois, U.S.

The River is also noteworthy for its natural and human-engineered history. The History of the Chicago River. The Chicago River was reversed in order to send pollution away from the Lake, the City’s primary source of drinking water. Though not especially long, the river is notable because it is one of the reasons for Chicago's geographic importance: the related Chicago Portage is a link between the Great Lakes and the Mississippi River Basin, and ultimately the Gulf of Mexico. The Chicago River system flows 156 miles (251 km) from Park City (north) to Lockport (south); some 45 bridges span the river. Chicago plans to eliminate the system’s overflows through green infrastructure and completing the Tunnel and Reservoir Plan, known as the Deep Tunnel project, which started in 1975 and the city hopes to complete by 2029. According to The Chicago Tribune, 18.2 billion gallons of pollution entered the river last year. For centuries, the Chicago River has drawn intrepid explorers, immigrant laborers, and industrial giants to its shores, lured by the promise of its opportunities. In 1887, the Illinois Genera St. Louis filed an injunction against the reversal on January 17.

A few days later, according to the Chicago Record, “Water that was actually blue in color and had blocks of ice of a transparent green hue floating in it…caused people who crossed bridges over the Chicago River…to stop and stare in amazement.”. Yet as much as the river has been Chicago’s raison d’être, it has … By the 1870s the dumping of waste from industrial and commercial development led to visible signs of pollution and increased concern about threats the river posed to public health.Between 1889 and 1910 the Metropolitan Sanitary District of Greater Chicago completed two major engineering projects to direct the flow of the river into the Des Plaines River and divert wastes away from Lake Michigan. Cleaning up the Chicago River, a waterway engineered to flow backward and lined with dozens of sewage pipes, has always been a tough fight.

The Chicago River is a system of rivers and canals with a combined length of 156 miles that runs through the city of Chicago, including its center.