3.0 METHODS 



3.1 Site Description 



Today's Illinois Waterway is approximately 327 miles (526 km) long 

 connecting Lake Michigan and the Chicago-Joliet metropolitan area with 

 the Mississippi River and the agricultural heartland, near Grafton, 

 Illinois (Figure 1.1). The headwaters are in the highly industrialized 

 Chicago area where the flow of the Chicago River was reversed to carry 

 wastes away from Lake Michigan into the Illinois River via the Chicago 

 Sanitary and Ship Canal and the downstream portion of the Des Plaines 

 River (Figure 1.2). The Calumet Sag Channel enters the Sanitary and 

 Ship Canal near Lemont. The Illinois River proper begins with the 

 confluence of the Des Plaines and Kankakee rivers, and flows through a 

 predominantly agricultural drainage, although the industrial city of 

 Peoria is situated approximately mid-way along the waterway. 



Locations on the waterways are designated by river mile as record- 

 ed in river charts prepared by the U.S. Army Corps of Engineers (1987) 

 and by markers along the waterways, starting with mile 0.0 at the con- 

 fluence with the Mississippi and proceeding upstream to Chicago. The 

 following abbreviations are used in the text, figures, and tables to 

 identify reaches of the waterway, and stations are identified by reach 

 abbreviation and river mile: 



IR Illinois River proper 



DP Des Plaines River 



CS Calumet Sag Channel 



SS Chicago Sanitary and Ship Canal 



CR Chicago River 



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