But by the 1870s, westward expansion was in full swing. Powell saw the gradual changes in the names on maps—the area labeled “Great American Desert” moving farther west as speculators and railroad companies encouraged people to make a go of farming west of the 100th meridian. Areas that were once labeled “Great Desert” were increasingly re-dubbed “Great Plains,” and throughout the 1870s, (paid) scientists were pushing some absolutely insane theories to encourage people to move west. The most absurd of these may have been the “rain follows the plow” theory. Think Field of Dreams, but for farming. The idea was that once people started farming in dry regions, rain would naturally come. When you plowed soil, even very bad and seemingly un-arable soil, the plowing would just automatically release trapped moisture into the atmosphere. This was, of course, nonsense. At heart, the “great plains” and “rain follows the plow” were marketing slogans, an early instance of real estate developers rebranding a previously undesirable area to turn a profit.
Powell’s reports attempted to show just how hopeless much of this project was. The Homestead Acts were granting western lands (to people but also to corporations, and with very high rates of fraud) in 160-acre tracts. This tract size made sense in the east where irrigation wasn’t necessary. But 160 acres was too large a tract to productively irrigate, and too small a tract to use as unirrigated land in the west. And, Powell calculated, even if you put every ounce of freshwater in the western U.S. to work irrigating farmland, you would still only be able to produce crops from 1-3 percent of the available land. There just wasn’t enough water.
The problem was complex, and so was Powell’s solution. He pushed for a slow, orderly, well-researched expansion of irrigated agriculture using publicly-constructed dams to collect and store water. And, rather than the eastern U.S. method of granting water rights only to those who owned land that touched the river or stream that the water came from, Powell suggested employing a use-permit system to regulate and trade water rights. (The land-adjoining water rights system is called “riparianism,” while the use-based system in the west is called “prior appropriation.” Read the Wikipedia articles for these and you will have learned a good deal of what they’d teach you in a water law class at a top law school.) Finally, Powell recommended organizing our political boundaries to facilitate the communal use and cooperative regulation of water resources. That is, he thought state boundaries in the west should conform to watersheds. This would mean that state governments and residents would have purview over their entire water system and wouldn’t have to fight with other states over upstream or downstream uses.