Few issues in the American West are as pressing or as vexing as the escalating water crisis. And as water in the West continues to dry up, Tribal water rights become more and more critical with every passing year. Against this backdrop, the U.S. Supreme Court recently decided Arizona v. Navajo Nation, a case that asked whether the Navajo Nation’s treaties impose on the United States an obligation to assess the Nation’s water needs and develop a plan to meet them. The Supreme Court answered no, in a decision that is likely to shape future Tribal efforts to secure much-needed water resources.
The Winters Doctrine
The law governing Tribal water rights was first established in Winters v. United States (1908). Arising out of Montana, Winters concerned rights to the Milk River, which forms the northern boundary of the Fort Belknap Indian Reservation. Non-Indians upstream from the reservation owned arid lands that they wished to cultivate. They thus built dams, ditches, reservoirs, canals, and other waterways to divert the river’s waters for irrigation of their lands. In so doing, however, the non-Indians interrupted the flow of the river to the reservation and deprived the Indians of the use of its waters. The United States thus brought suit to enjoin the non-Indians from preventing the water from flowing downstream.
The case made its way to the U.S. Supreme Court. To resolve the dispute, the Court assessed the water rights of the Indians living on the reservation. No treaty or other agreement expressly addressed rights to the Milk River. But the agreement the tribes had negotiated to create the reservation specifically set aside the tribes’ lands “as and for a permanent home and abiding place.” The Court thus turned to this compact as the source for any water rights the tribes held.
To construe this agreement, the Court looked at the parties’ intent, which the Court discerned from the negotiating context. The reservation, the Court observed, was a part of a much larger tract that had belonged to the Indians before they entered into the agreement. And in that larger tract, the Indians had possessed not just the lands but the waters—including, the Court noted, “command of all [the waters’] beneficial use, whether kept for hunting, and grazing roving herds of stock, or turned to agriculture and the arts of civilization.” The section of the tract chosen for the reservation, however, was “arid, and, without irrigation, . . . practically valueless.” Indeed, when the tribes and the United States negotiated the treaty, it was obvious to both that the reservation could serve as a permanent homeland only if the tribes could access “the waters which made it valuable or adequate.” In those circumstances, it was plain the tribes had not intended to relinquish their right to the waters of the Milk River. Just the opposite: The Court concluded the tribes had intended to retain the water rights necessary to preserve their existence at their “permanent home and abiding place.” And those retained rights, in turn, superseded those of the non-Indian landowners, whose state law water rights had not been perfected until after the tribes’ agreement was executed.
Winters thus established that the creation of an Indian reservation impliedly reserves water rights needed to serve the purposes for which the reservation was created and that those rights supersede later-arising state law water rights. Since then, the Court has filled in additional contours of the Winters doctrine—providing guidance, for instance, as to how to quantify agricultural Tribal water rights. Many critical questions about Tribal water rights, however, remain unanswered, including questions about how tribes can access their water rights.