Asian carp have been making their way up the Mississippi and Illinois Rivers toward the Great Lakes for decades.
A coalition of U.S. and Canadian mayors says the solution is to physically separate the Great Lakes basin from the Mississippi River system forever. In other words... they want to completely stop the flow of water between the two systems to permanently block carp from swimming up into Lake Michigan... and stop any kind of invaders from moving between the basins.
A new report out today outlines how that massive separation might happen.
Tim Eder is the executive director of the Great Lakes Commission. His group put out the report, along with the Great Lakes and St. Lawrence Cities Initiative. The report identifies three different places on the Chicago waterway system where a physical separation could be put in place.
“It’s just putting some sheet piling, some metal and earth and concrete in the river to make a dam, basically.”
But the manmade system of canals in the Chicago area has been in place for a century (it was originally put in place to reverse the flow of the Chicago River away from Lake Michigan because untreated sewage was being dumped in the lake and making people sick - and even killing them).
Eder says there are a lot of people who depend on the waterway system as it is now.
“The river in Chicago now serves some really important purposes for managing floodwaters, for dealing with wastewater, and for transportation. Commercial transportation depends on that waterway, so our options propose solutions to maintain and even enhance all of those existing important uses of the waterway.”
Physical separation would not be cheap. The report estimates the different options could cost between $3.2 billion and $9.5 billion.
George Kuper is President of the Council of Great Lakes Industries. He served on an advisory committee for the Great Lakes Commission/Great Lakes and St. Lawrence Cities Initiative along with representatives of the shipping and barge industries, sport fishing interests and tour boat operators. He was out of the country yesterday but responded to my questions by email. I asked him: Do you think physical separation is a good idea - or not?
"Given what we now know about ecosystems, the Chicago Sanitary and Ship Canal probably would never have been built. Undoing that investment is, of course, possible at huge expense and significant social and economic disruption. Doing so to prevent Asian carp from entering the Great Lakes Basin is probably a waste of money and effort as human behavior is far more likely to be the pathway for introduction. And, there are other natural routes for Asian carp to enter the G.L. Basin."
The report makes a point of saying that physical separation is expensive... but letting invaders in is extremely costly too.
Here's an excerpt:
Preventing the introduction of invasive species is critical. Once established, they are usually impossible to eradicate and difficult and costly to manage or control. For example, more than $20 million is spent annually to control sea lamprey in the Great Lakes (one of the few AIS that can be significantly controlled), and approximately $50 million is now being devoted each year on Asian carp control, management, research and prevention. Without a long-term solution, the costs for Asian carp will continue indefinitely and the door will be left open for new invasive species.
Tim Eder says construction of a barrier is - realistically - at least ten years away. Some scientists worry Asian carp could be established in Lake Michigan by then.
