ILLINOIS WATERWAY

The 'Illinois Waterway' system consists of 336 miles of water from the mouth of the Chicago River to the mouth of the Illinois River at Grafton, Illinois. It is a system of rivers, lakes, and canals which provide a shipping connection from the Great Lakes to the Gulf of Mexico via the Mississippi River. The Illinois and Michigan Canal opened in 1849. In 1900, the Chicago Sanitary and Ship Canal replaced it and reversed the flow of the Chicago River so it no longer flowed into Lake Michigan. The United States Army Corps of Engineers maintains a 9 foot deep navigation channel in the waterway.^[1]
A series of seven locks control water flows from Lake Michigan to the Mississippi River system. The upper lock, O'Brien, is on Lake Michigan and the last lock is 90 miles upstream from the Mississippi at LaGrange. The amount of water released into the Illinois often is a sore point among Lake and river interests. When Lake Michigan water levels are high, Lake interests want to increase the flow and when lake levels are low they want to restrict the flow. That is why an international treaty regulates the flow, as Canada also has an interest in Lake Michigan levels which eventually flow into the Lakes Erie, Huron, and Ontario.
Primary cargoes are coal to powerplants, chemicals and petroleum upstream and corn and soybeans downstream primarily for export through New Orleans.
Some winters ice flows, especially around the locks and dams, preclude towboats and barges from navigating the Illinois.

Contents

Locks and Dams

Schematic

Notes

Locks and Dams

Lock/Dam Name	Location	River Miles Above Mississippi	Pool Level (above sea level)	Geo Coordinates
T.J. O’Brien L&D	Burnham	326
Lockport L&D	Joliet	291
Brandon Road L&D	Joliet	286
Dresden Island L&D	Morris	271
Marseille L&D	Marseilles	245
Starved Rock L&D	North Utica	231
Peoria L&D	Peoria	157
La Grange L&D	Beardstown	80

Schematic

The schematic below illustrates the drop of the Illinois Waterway from (mean) above sea level at Lake Michigan to (mean) at the Mississippi River at Grafton, Illinois. The eight locks and dams (L&D) on the waterway provide the lift for traffic along the waterway.

Notes

1. United States Army Corps of Engineers. "Chapter 6. The Illinois Waterway". page 3. June 3, 2005.