William & Mary Environmental Law and Policy Review
Abstract
All reservations of federal land, including Native American reservations and national forests, have water rights. These rights are referred to as “Winters rights” after the seminal U.S. Supreme Court case. That case recognized such rights’ existence, but it did not quantify the amount of water of those rights. Federal courts have applied various approaches to quantifying Winters rights. Recent decisions in Arizona state courts have taken new and different approaches to quantification of both tribal and non-tribal Winters rights. These state court decisions have important implications for federal water rights throughout the United States. This Article examines these new approaches to quantifying Winters rights, evaluates them for their impact on equitable and sustainable water policy, and proposes reforms to better adapt the adjudication of Winters rights to responding to water variability caused by climate change.