Separating the Great Lakes from the Mississippi River basin
Asian carp were imported into the U.S. and have invaded the Mississippi River basin, infesting waters from Louisiana to South Dakota to Ohio. Now, the fish are poised to gain a foothold in the Great Lakes through an artificial connection to the Mississippi basin in the Chicago area called the Chicago Area Waterway System. Separation of the Mississippi River and Great Lakes basins at the Chicago Area Waterway System is the only permanent way to stop the movement of aquatic species between these two watersheds, and the only way to ensure the Great Lakes stay Asian carp free.
What is the Chicago Area Waterway System?
The Chicago Area Waterway System is an artificial connection between the Great Lakes and Mississippi basins. During the late 1800s Chicago suffered severe water quality problems and public health emergencies when sewage waste was drained into Lake Michigan. The sewage outflows were near to the drinking water intakes. To overcome the health problems, the flow of the Chicago river was reversed, and the Chicago Sanitary and Ship Canal was built to connect the Chicago River to the Mississippi basin. After additional modifications throughout the years, the CAWS now consists of 78 miles of canals and modified streams of the Chicago River, including the Chicago River North and South Branch, as well as the Cal-Sag Channel, the Chicago Sanitary and Ship Canal, and nearby tributaries.
For more information check out the Lake Michigan LaMP factsheet: http://gleams.altarum.org/files/gleams/WatershedFactSheets/ChicagoAreaWaterwaySystem.pdf
Can the artificial connection be closed?
Work is being done to explore how the Great Lakes can be physically separated from the Mississippi. Permanent physical separation is the only long-term solution to keep the Asian carp out and prevent future invasive species, but it will take time to develop the engineering solutions and implement them. Physical separation would not only stop the Asian carp, but also halt the transfer of all aquatic organisms between the two basins that could be transported through the Chicago Area Waterway System. Separation is a critical piece of invasive species prevention in the Mississippi and Great Lakes region, and a cornerstone to Great Lakes restoration.
For more information:
A preliminary feasibility study was initiated by the Great Lakes Fishery Commission and analyzed by the Alliance for the Great Lakes: http://www.greatlakes.org/Document.Doc?id=473
The U.S. Army Corps of Engineers was authorized in 2007 to examine how to "prevent the spread of aquatic nuisance species between the Great Lakes and Mississippi River Basins through the Chicago Sanitary and Ship Canal and other pathways" and has initiated "The Great Lakes Mississippi River Interbasin Study": http://glmris.anl.gov/index.cfm
The Great Lakes Commission and the Great Lakes St. Lawrence Cities Initiative have begun an 18 month in-depth investigation exploring separation scenarios, that could be implemented by the U.S. Army Corps of Engineers: http://glc.org/ans/chicagowaterway.html