Chicago Sanitary and Ship Canal
Canal reversing Chicago River flow to protect Lake Michigan water.
The Chicago Sanitary and Ship Canal, historically known as the Chicago Drainage Canal, is a 32-mile-long canal system in Northeast Illinois that connects the Chicago River to the Des Plaines River. It was built to reverse the flow of the Chicago River, sending sewage away from Lake Michigan and into the Mississippi River watershed, thereby protecting Chicago's drinking water supply. The canal is a landmark of civil engineering and served as practical training for engineers who later worked on the Panama Canal.
- length
- 32 miles (51 km)
- location
- Northeast Illinois, US
- operated_by
- Metropolitan Water Reclamation District of Greater Chicago
Lore & Background
Construction involved cutting through a low divide known since pre-Columbian times as the Chicago Portage.
Reader's Guide
The Chicago Sanitary and Ship Canal was a transformative public health and engineering project. By permanently reversing the Chicago River, it diverted sewage away from Lake Michigan, the city's drinking water source, and sent it diluted with lake water through the Des Plaines and Illinois Rivers to the Mississippi. This solved a recurring public health crisis and set a precedent for large-scale water diversion. The canal also served as a training ground for engineers who later built the Panama Canal. Its construction was the largest earth-moving operation in North America up to that time. The system remains in operation, managed by the Metropolitan Water Reclamation District of Greater Chicago, and its water diversion is now regulated by international treaty.
Did You Know?
- The canal reversed the flow of the Chicago River so that it now flows out of Lake Michigan rather than into it.
- The canal was the largest earth-moving operation in North America up to its time.
- Engineers who worked on the canal later helped build the Panama Canal.
Frequently Asked Questions
Why was the Chicago Sanitary and Ship Canal built?
The canal was designed to reverse the natural flow of the Chicago River so that sewage and waste would drain toward the Mississippi River watershed instead of back into Lake Michigan. This kept Chicago's primary drinking-water source clean.
How long is the Chicago Sanitary and Ship Canal and where does it run?
The canal stretches 32 miles (51 km) across Northeast Illinois, connecting the Chicago River system to the Des Plaines River. It effectively creates a navigable and drainage corridor between the Great Lakes basin and the Mississippi River watershed.
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