Reversing the flow

На відміну від СРСР де довго думали повернути течію сибірських рік на південь чи ні, американці таки зробили розворот течії ріки

Reversing the flow

Originally, the river flowed into Lake Michigan. As Chicago grew, this allowed sewage and other pollution into the clean-water source for the city. This contributed to several public health problems, including some problems with typhoid fever.^[9] Starting in the 1850s, much of the flow was diverted across the Chicago Portage into the Illinois and Michigan Canal.^[10] In 1900, the Sanitary District of Chicago, then headed by Rudolph Hering, completely reversed the flow of the river using a series of canal locks, and caused the river to flow into the newly completed Chicago Sanitary and Ship Canal. Before this time, the Chicago River was known by many local residents of Chicago as "the stinking river" because of the massive amounts of sewage and pollution which poured into the river from Chicago's booming industrial economy. Through the 1980s, the river was quite dirty and often filled with garbage; however, during the 1990s, it underwent extensive cleaning as part of an effort at beautification by Chicago Mayor Richard M. Daley.

Recently, researchers at the University of Illinois at Urbana-Champaign created a three-dimensional, hydrodynamic simulation of the Chicago River, which suggested that density currents are the cause of an observed bi-directional wintertime flow in the river. At the surface, the river flows east to west, away from Lake Michigan, as expected. But deep below, near the riverbed, water travels west to east, toward the lake.^[11]

All outflows from the Great Lakes Basin are regulated by the joint U.S.-Canadian Great Lakes Commission, and the outflow through the Chicago River is set under a U.S. Supreme Court decision (1967, modified 1980 and 1997). The city of Chicago is allowed to remove 3200 cubic feet per second (91 m³/s) of water from the Great Lakes system; about half of this, 1 billion US gallons a day (44 m³/s), is sent down the Chicago River, while the rest is used for drinking water.^[12] In late 2005, the Chicago-based Alliance for the Great Lakes proposed re-separating the Great Lakes and Mississippi River basins to address such ecological concerns as the spread of invasive species