CHICAGO RIVER

navigable stream that originally flowed into Lake Michigan after being formed by the north and south branches about 1 mi (1.6 km) west of the lake, in Chicago, northeastern Illinois, U.S. After a severe storm in 1885 caused the river to empty large amounts of sewage-polluted water into the lake, plans were begun to reverse its flow through the construction of a canal, which was completed in 1900. The river now flows inland, through the south branch, into the Illinois Waterway (Sanitary and Ship Canal and the Des Plaines and Illinois rivers), to connect with the Mississippi River. The reversal of the river's flow is considered to be one of the greatest feats of modern engineering.