In early January, the Corps of Engineers delivered its “Great Lakes and Mississippi River Interbasin Study” to Congress.

The GLMRIS examines ways to prevent the transfer of aquatic nuisance species (ANS) between the Great Lakes and Mississippi River basins through aquatic pathways.

“In recent years, invasions of ANS have severely impacted the economic and environmental resources of these ecosystems,” the study says. “GLMRIS addresses the need for a comprehensive effort to reduce the risk of future ANS transfers between the two basins.”

There are 13 species noted in the report, including Asian carp, which has garnered the most attention over the past few years. 

“For the past decade, our industry has worked with the Corps, the Coast Guard, Environmental Protection Agency and other federal and state government entities to control the Asian carp population and limit its movement through installation of electric fish barriers in the Chicago-area waterways,” Thomas Allegretti, president and CEO of the American Waterways Operators, said in a statement commenting on the study. “Due to the success of these efforts, the Asian carp population front has not advanced since 2007. We will continue to work cooperatively to balance valid environmental concerns with the need to preserve commercial navigation.” 

The building blocks of the new study are its eight possible approaches to the problem:

• No new federal action — sustained activities assumes that the current and previously planned future actions for ANS control will continue without any additional GLMRIS controls. 

• Nonstructural control technologies — involve ANS controls that do not require implementation of structural features and may be implemented quickly.

• Mid-system control technologies without a buffer zone — focuses on maintaining the current operations of the Chicago Area Waterway System (CAWS) with a minimal number of control points. The nonstructural measures from alternative two would also be implemented.

• Control technology alternative with a buffer zone — would maintain the current operations of CAWS and creates an ANS-treated buffer zone within CAWS. The nonstructural measures from alternative two would also be implemented.

• Lakefront hydrologic separation — focuses on separating the hydrologic connection between the Great Lakes and Mississippi River basins at the Chicago Lake Michigan lakefront. The nonstructural measures from alternative two would also be implemented.

• Mid-system hydrologic separation — would prevent the mixing of untreated water between the two basins by separating the hydrologic connection between them. The nonstructural measures from alternative two would also be implemented.

• Mid-system separation Cal-Sag (Calumet-Saganashkee Channel) open control technologies with a buffer zone — proposes the use of three physical barriers that would hydrologically separate four of the five aquatic pathways between CAWS and Lake Michigan to minimize the impacts to existing CAWS uses and users. The nonstructural measures from alternative two would also be implemented.

• Mid-system separation CSSC (Chicago Sanitary and Ship Canal) open control technologies with a buffer zone — combines technologies and hydrologic separation to minimize impacts to existing CAWS uses and users. The nonstructural measures from alternative two would also be implemented.

Immediately following the release of the report, the public comment period began so that interested parties could provide statements via the study’s website (http://glmris.anl.gov/), by traditional mail (U.S. Army Corps of Engineers, Chicago Office, 231 S. LaSalle St., Suite 1500, Attention: GLMRIS Comments, Dave Wethington, Chicago, IL 60604), or at a series of public meetings held throughout the Great Lakes and Upper Mississippi River basins. 

The comment period ends on March 3. — Ken Hocke