FOR decades the Great Lakes region has seen a slow ebb. Factories have moved abroad or, more insulting, to the South. Residents have fled to sunnier states. But the lakes themselves remain; and while much of America is regularly afflicted by drought, they hold enough water to submerge the entire country. Now the Great Lakes states are reconsidering their main asset. Water, the boosters say, will bring prosperity once more. The first task is to protect the water itself. Environmentalists raise the spectre of Central Asia’s Aral Sea, all but drained by Soviet irrigation projects. Nightmares have been fed by radical plans such as a scheme in the 1990s to ship water to Asia. More insidious threats include climate change and thirsty cities just beyond the Great Lakes Basin-death by 1,000 straws, according to Peter Annin’s ‘The Great Lakes Water Wars. An important protection came in 2008, when George Bush signed the Great Lakes Compact. This agreement bars new diversions beyond the Great Lakes Basin, with few exceptions. Great Lakes states continue to have their own unique water problems, however. Illinois is exempt from the Compact. Since 1900, when engineers reversed the flow of the Chicago river, […]