Is U.S. water availability rising or falling across the country?
Core argument: Water availability has been rising on about 54% of land in the contiguous United States and falling on 46%, with drying regions losing more than moistening regions gain, leaving aggregate net losses equal to 0.04% of average annual U.S. rainfall.
Overall, water availability has been rising on about 54% of the land in the contiguous United States and decreasing on 46%. On net, total U.S. water volumes have declined slightly as the drying regions have lost more water than the moistening regions have gained, though aggregate losses are only 0.04% of average annual U.S. rainfall. Most of the western and southwestern United States has been losing substantial quantities of water: Almost all of the land in the bottom 10% of water trends are located in central and southern California and the Ogallala aquifer region at the intersection of Texas, Oklahoma, Kansas, New Mexico, and Colorado. Some of these regions are in the top 1% for water depletion among all global arable land. By contrast, the Great Plains and upper Midwest have largely been gaining water resources, and the vast majority of land east of the Mississippi River has seen stable to increasing water resources over time.

