How Western cattle ranchers cut off indigenous water rights
The question of who has the right to use Colorado River water is determined by law. Allocations are determined according to priority — but some users have rights to more water because they have older rights or were awarded higher priority. A 1908 U.S. Supreme Court decision established what became known as the Winters Doctrine, which recognized that tribes should have the right to enough water to establish a permanent homeland within their reservation boundaries. When interpreted fairly, this means Native tribes have some of the most senior rights to Colorado River water. In practice, however, tribes have been granted a mere fraction of these rights.