The Mississippi River handles $7 billion in trade as one of the world's largest navigable inland waterways. A Midwestern drought has brought the river to water levels so low that they threaten to shut down shipping, reports John Schwartz.
Cynthia Barnett says Americans live under an "illusion of water abundance" and calls for government water managers and private water companies to "stem the drain on America's water resources before it's too late."
