Groups representing states and cities in the Great Lakes region are proposing spending as much as $9.5 billion on a massive engineering project to separate the lakes from the Mississippi River watershed in the Chicago area.
The groups say it is the only sure way to protect both aquatic systems from invasions by destructive species such as Asian carp.
The organizations issued a report suggesting three alternatives for severing an artificial link between the two drainage basins that was constructed more than a century ago. Scientists say it has already provided a pathway for exotic species and is the likeliest route through which carp could reach the lakes, where they could destabilize food webs and threaten a valuable fishing industry, according to media reports.
The Army Corps of Engineers is conducting its own study about how to close off 18 potential pathways between the two systems, including the Chicago waterways. The corps plans to release its findings in late 2015. A pending federal lawsuit by five states — Michigan, Wisconsin, Minnesota, Ohio and Pennsylvania — demands quicker action.
The latest report does not make a detailed proposal for covering the costs, but says the four-barrier plan could be done if the average household in the Great Lakes basin paid about $1 a month through 2059.
The five-barrier and single-barrier plans' price tags could reach about $9.5 billion.
Mark Biel, chairman of an Illinois business coalition called UnLock Our Jobs that opposes separating the watersheds, said the Great Lakes groups' proposals would take many years to carry out and would devastate cargo shipping and pleasure boating in the Chicago area while doing nothing to prevent species invasions elsewhere.