The corps did not recommend which option it considers most effective, but Dave Wethington, Chicago-area waterway system project manager for the US Army Corps of Engineers, told reporters Monday that physical separation has the greatest “ability to buy down risk.” None of the options are guaranteed to fully prevent invasive species from reaching the Great Lakes, he added, because the carp will still have the potential to bypass the barriers via intentional or accidental bird or human transfer. “The ultimate decision is up to the collaborative group of stakeholders.” 
 
 The study focuses on the Chicago Area Waterway System (CAWS), a 128-mile stretch of canals and rivers in metropolitan Chicago connecting Lake Michigan and the Mississippi River. Another option, carrying a $15 billion price tag, would allow portions of the Chicago River, Sanitary and Ship Canal and Calumet River to flow into Lake Michigan. Two years in the making, the study comes amid a series of alarming findings that raise the possibility it might be too late for new federal action to stop Asian carp from getting into the Great Lakes and threatening the region's $7 billion fishing industry. Experts agree the primary routes for carp and other invasive species to cross between the Mississippi watersheds and the Great Lakes are the Chicago-area waterways. Environmental DNA evidence of live Asian carp has been discovered in and around CAWS for several years, triggering an outcry from officials in all the Great Lakes states for more federal action. A coalition of conservation leaders from the Great Lakes that is advocating for a permanent barrier says it will comment further on the report Tuesday. With the Corps scheduling a series of public hearings around the region, the long-simmering and still-unresolved debate likely makes it more difficult for Congress to reach a consensus about what to do next.
– The fight to keep Asian carp from colonizing the Great Lakes could take longer than any war America has ever fought, the Army Corps of Engineers warns in a report commissioned by Congress. The report offered eight strategies to keep the invasive species from overwhelming the ecosystem and ruining a $7 billion fishing industry, the most effective of which could take up to 25 years and cost around $18 billion, the Christian Science Monitor reports. Physical separation of the Mississippi watershed from Lake Michigan was the most drastic option, but the Army engineers also looked at methods including new locks and electronic barriers to keep out the carp and other invasive species. The $18 billion plan may be a tough sell, but environmentalists fear that cheaper options won't be enough to keep the carp out. "If you really want to prevent the movement of species and keep Lake Michigan clean, it's going to cost money," the president of the Alliance for the Great Lakes tells the Chicago Tribune. "We can't just keep patching over these problems and hoping they go away."