Chicago Sanitary and Ship Canal

The Chicago Sanitary and Ship Canal, historically known as the Chicago Drainage Canal, is the only shipping link between the Great Lakes (specifically Lake Michigan by the Chicago River) with the Mississippi River system, by way of the Illinois and Des Plaines Rivers. The canal also carries Chicago's treated sewage into the Des Plaines River. Before completion of the canal in 1900, the sewage of Chicago was dumped into Lake Michigan, the city's drinking water supply. The canal is part of the Chicago Wastewater System, operated by the Metropolitan Water Reclamation District of Greater Chicago. The system has been named a Civil Engineering Monument of the Millennium by the American Society of Civil Engineers (ASCE). The Chicago Sanitary and Ship Canal is 28 miles (45 kilometers) long, 202 feet (62 m) wide, and 24 feet (7.3 m) deep. Prior to its construction, the Illinois and Michigan Canal connected the same waterways for boat travel.

Reasons for construction

Early Chicago sewage systems discharged directly into Lake Michigan or into the Chicago River, which itself flowed into the lake. The city’s water supply also came from the lake, through water intake cribs located two miles offshore. There were fears that sewage could infiltrate the water supply, leading to typhoid fever, cholera and dysentery. During a tremendous storm in 1885, the rainfall washed refuse from the river far out into the lake (although reports of a 1885 cholera epidemic are untrue), spurring a panic that a future similar storm would cause a huge epidemic in Chicago. The only reason for the storm not causing such a catastrophic event was because the weather was cooler than normal. The Chicago Sanitary District (now The Metropolitan Water Reclamation District) was created by the Illinois legislature in 1889 in response to this close call.

Planning and construction, 1887–1922

By 1887, it was decided to reverse the flow of the Chicago River through civil engineering. Engineer Isham Oliver noted that a ridge about 12 miles from the lake shore divided the Mississippi River drainage system from the Great Lakes drainage system. A plan soon emerged to cut through that ridge and carry waste water away from the lake, through the Des Plaines and Illinois rivers, to the Mississippi River and the Gulf of Mexico. In 1889, the Illinois General Assembly created the Sanitary District of Chicago (now the Metropolitan Water Reclamation District of Greater Chicago) to carry out the plan.

The canal, linking the south branch of the Chicago River to the Des Plaines River at Lockport, was completed in 1900. An extension from 1903-1907 allowed for the canal to extend to Joliet. The rate of flow is controlled by the Lockport Powerhouse, sluice gates at Chicago Harbor and at the O'Brien Lock in the Calumet River, and also by pumps at Wilmette Harbor. Two more canals were later built to add to the system: The North Shore Channel in 1910, and the Cal-Sag Channel in 1922.

Construction of the Ship and Sanitary Canal was the largest earth-moving operation that had been undertaken in North America up to that time. It was also notable for training a generation of engineers, many of whom later worked on the Panama Canal.

Diversion of water from Great Lakes

The Chicago Sanitary and Ship Canal is designed to work by taking water from Lake Michigan and discharging it into the Mississippi River watershed. At the time of construction, these diversions were not yet regulated. Today, diversions from the Great Lakes system are regulated by an international treaty with Canada, through the International Joint Commission, and by governors of the Great Lakes states.

There is some dispute over how much water is actually being diverted by the canal. Recently, researchers at the University of Illinois at Urbana-Champaign built a numerical model of the Chicago River system. The resulting three-dimensional, hydrodynamic simulation successfully proved the likelihood that density currents are causing a bi-directional flow in the Chicago River during winter seasons. At the surface, the river was flowing east to west, away from Lake Michigan, as expected. But deep below, near the riverbed, water was traveling west to east, toward the lake. This flow could be pulling some water out of the Chicago Sanitary and Ship Canal. A summary of the research team's findings was published in the Spring/Summer 2005 edition of the CEE Alumni Association Newsletter

See also

• Treaty of St. Louis
• Chicago 1885 cholera epidemic myth

References

External links

• A History from the Chicago Public Library , however it seems that they have a mistake. They credit Rudolph Hering, not Isham Randolph with the project.
• History and Heritage of Civil Engineering - Reversal of the Chicago River