MARY LOUISE KELLY, host:
Well, more now about that permanent separation that Mr. Goss just mentioned. A host of public officials and environmental groups are pushing to cut off the manmade waterways that connect Lake Michigan to the Mississippi River. But the plan is both costly and controversial because it would involve re-reversing -that's right, reversing again - the flow of the Chicago River.
NPR's David Schaper has that story.
(Soundbite of water)
DAVID SCHAPER: I'm floating on a kayak in the Chicago River right downtown Chicago, amidst a canyon of high-rises and skyscrapers. I'm at a fork in the river called Wolf Point, and I'm with Josh Ellis, who is a water resources project manager with the Metropolitan Planning Council.
Mr. JOSH ELLIS (Program Associate, Metropolitan Planning Council): So here at Wolf Point, the south branch, the north branch met and flowed east through the main stem of the river directly out to Lake Michigan.
SCHAPER: Ellis says we wouldn't have wanted to be here on the river a century ago when raw sewage, storm water runoff, even runoff from the filthy Chicago stockyards flowed into the river and into Lake Michigan, which is where Chicago gets its drinking water.
Mr. ELLIS: And people were getting sick. Outbreaks of typhoid and cholera and other diseases were common. People were dying.
SCHAPER: So in the late 1880s, local leaders decided to re-engineer the river. They reversed the flow and built a 28-mile canal to connect the Chicago River with other rivers leading to the Mississippi, so the city could flush its wastewater down toward Peoria and St. Louis. It was a remarkable engineering feat for its time and opened up a vital transportation link between the Great Lakes and the Gulf of Mexico.
But it also opened up a highway for invasive species to move between ecosystems that had never before been connected, says Joel Brammeier of the Alliance for the Great Lakes.
Mr. JOEL BRAMMEIER (President/CEO, Alliance for the Great Lakes): If you set out with the goal of causing an invasion, there'd be just about no better way to do it than to build a hundred-foot-wide channel with free flowing water and let a fish loose and see where it goes. And that's what we've got here in Chicago.
SCHAPER: Right now, no Asian carp have been found in this part of the river. But the fear they're on their way spurred Brammeier's group and others to call for re-separating the Mississippi and the Great Lake watersheds by walling off or filling in part of the canal that links them and then re-reversing the flow of the Chicago River back into Lake Michigan. Not only would it stop the Asian carp but other invasive species, too.
Another benefit to re-separating the watersheds is that much of the two billion gallons of water Chicago takes out of Lake Michigan each day and currently flushes down toward the Gulf of Mexico could instead be returned to the lake. And it would force officials to clean up the still-dirty Chicago River. But none of this would be easy.
Mr. RICHARD LANYON (Executive Director, Water Reclamation District): Right now, they're closing the west lock gates, and you see there's a boat in the lock...
SCHAPER: Richard Lanyon is executive director of the Water Reclamation District, a regional agency created way back when the Chicago River was reversed.
Mr. LANYON: This lock here at the mouth of the Chicago River is one of the busiest in the world, with all of the recreational traffic. And we have a lock out on the Calumet River, the O'Brien Lock and Dam, which carries a lot of commercial traffic and a lot of commodities are passed though that system.
SCHAPER: Lanyon says separating the watersheds would sever this vital shipping link. And he says the storm water sewer system in Chicago and surrounding suburbs would have to over-hauled to avoid severe flooding.
And then there's this...
Mr. LANYON: We do not have effluent disinfection at our three large plants that discharge to this network of waterways.
SCHAPER: Chicago is one of the few places in the country that still doesn't disinfect its raw sewage before discharging it into a waterway. And Lanyon says doing so would cost billions. Lanyon says it's certainly possible to address all of these issues, but the cost would be huge, it would take years, and he questions whether it's worth it to stop a fish he's not convinced is a real threat.
Mr. LANYON: Well, in a word, David, I think it's overblown.
SCHAPER: Just overblown. Just...
Mr. LANYON: Just overblown. Much ado about nothing.
SCHAPER: Lanyon says only one Asian carp has been found above electric barriers on the Sanitary and Ship Canal that are designed to stun the fish into turning back. And he and others question the scientific evidence that many cite that could indicate more Asian carp could have gotten through.
The U.S. Army Corps of Engineers is now studying how and where to possibly sever the watersheds, and its cost and impacts. But a federal judge in Chicago could step in and order the closing of the connection between Lake Michigan and the Mississippi, as soon as the end of this month in response to a lawsuit filed by Michigan and other states, who are seeking to keep Asian carp out of the Great Lakes.
David Schaper, NPR News, Chicago.