As an environmental scientist, Roger Viadero had to scratch his head over news reports last summer of the thirsty demand in Palm Springs and Las Vegas, among other western cities, for water from the Mississippi River and the Great Lakes.

The letters pages of the Palm Springs Desert Sun newspaper broke their own records for online traffic last June with readers’ proposals to siphon some 22 billion gallons of water per day from the Midwest. To solve the Southwest’s water crisis, the desert denizens wrote, a series of canals and reservoirs could pipe water from the flood-prone Mississippi River to the Colorado River, a supposed win-win for everyone.