Hamby holds the trump card. The Law of the River — the compacts, laws and court rulings that govern how the river is allocated — reflects a time when water use was encouraged to bring settlers west. And court decisions have favored users with senior priority rights, meaning those who were first to plant stakes along the river, file claims in county recorders’ offices and prove their claims by taking water before federal and state water laws were codified. Those with such rights are legally entitled to receive their share of the river before the next person or agency in line receives any. The Imperial Irrigation District holds some of the basin’s oldest rights, dating back to 1901.
Hamby defends this system, which allows the Imperial Valley — home to only half of a percent of the river’s users, Hamby included — to control about a quarter of the river’s flow. That’s more than 10 times southern Nevada’s allocation and more than the entire state of Arizona receives. A recent ProPublica and Desert Sun analysis found that 20 valley farming families use about 387 billion gallons of cheap water annually, most of it to grow cattle feed, and one family uses more water than the entire Las Vegas metropolitan area.