A federal report released Monday proposes a $275 million array of technological and structural upgrades at a crucial site in Illinois to prevent invasive Asian carp from reaching the Great Lakes and its vulnerable fish populations.
The U.S. Army Corps of Engineers outlined its tentative plan in a report that had been scheduled for release in February but was delayed by the Trump administration, drawing criticism from members of Congress and environmental groups.
It analyzes options for upgrading the Brandon Road Lock and Dam near Joliet on the Des Plaines River, part of an aquatic chain that connects Lake Michigan to the Asian carp-infested Mississippi River watershed. The Brandon Road complex is considered a bottleneck where defenses could be strengthened against fish swimming upstream toward openings to the lake at Chicago.
Scientists say if the large, voracious carp became established in the Great Lakes, they could devastate the region's $7 billion fishing industry by out-competing native species.
The Army corps said the plan outlined in the 488-page document is intended to block the path of invasive species "while minimizing impacts to waterway uses and users." Elected officials and business leaders in Illinois and Indiana have said that significant changes to the Brandon Road complex could hamper cargo shipment on the busy waterway.
Among technologies the report endorses is using sound systems to create "complex noise" underwater that would deter fish from the Brandon Road area, plus installing a new approach channel and placing an electric barrier at its downstream end that would repel fish and stun them if they get too close. Brandon Road is several miles downstream from an existing barrier network in the Chicago Sanitary and Ship Canal.
Other measures would include installing water jets to wash away "small and stunned fish" that might be caught up around barges, plus a new lock where floating invasive species could be flushed away and rapid-response boat mooring and launch spots.
The report says the federal government would pay 65 percent of the costs project's costs, with the rest coming from an unidentified "non-federal sponsor," which Illinois officials said probably meant their state.
If the corps project were implemented, "Illinois taxpayers would be on the hook for over $95 million in construction cost and another $8 million in annual operation and maintenance costs," Lt. Gov. Evelyn Sanguinetti said.
Despite the benefit of protecting the lakes from Asian carp, the Army corps acknowledged its preferred approach could affect other wildlife species, from turtles, frogs and otters caught in the electric current to native fish whose migration paths would be interrupted.
The corps will take public comments on the report until Sept. 21. After a feasibility study and series of federal and state reviews, a final version is scheduled for release in August 2019. Congressional approval and funding would be required to begin construction, which could be finished by 2025.
"The Army Corps report makes clear that it's time for serious preventative actions to keep Asian carp out of the Great Lakes," said Howard Learner, executive director of the Chicago-based Environmental Law and Policy Center. "The ecological and economic costs of further delays are not sensible or acceptable."
In a joint statement, the Alliance for the Great Lakes, Natural Resources Defense Council, Sierra Club and Prairie Rivers Network said the corps plan was "another step in the fight against the upstream movement of Asian carp" but didn't address how to impede Great Lakes fish from migrating downstream into the Mississippi watershed.
The report is the latest of several developed by the Army corps since it began examining species migration between the two watersheds in 2009. The study was inspired by discovery of Asian carp DNA upriver from the electric barriers in the shipping canal, raising questions about whether carp were slipping through them. Two live carp have been found past the barriers, the latter in June.
Most of the eight states adjoining the Great Lakes have called for dams or other structures to physically separate the two watersheds, an idea Illinois and Indiana oppose.
Among six alternatives weighed by the Army corps in its latest report was closing the Brandon Road lock and putting a concrete wall there. But the corps decided against it because of the heavy toll on freight shipping and related businesses.
The corps also said it wasn't acceptable simply to rely on present methods of fighting the carp, such as hiring commercial crews to thin their numbers.
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