Published: April 9, 2021

The Status of Tribal Water Rights in the Colorado River Basin

Water & Tribes Initiative | Colorado River Basin

There are 30 federally recognized tribes in the Colorado River Basin. Twenty two of these tribes have recognized rights to use 3.2 million-acre feet (maf) of Colorado River system water annually, or approximately 22 to 26 percent of the Basin’s average annual water supply.2 In addition, 12 of the tribes have unresolved water rights claims, which will likely increase the overall volume of tribal water rights in the Basin. Under the Upper Colorado River Basin Compact and the U.S. Supreme Court’s decree in Arizona v. California, all tribal water uses are counted against the apportionments made to the states. Tribes’ rights are generally senior to state law-based water rights.

Currently, many tribes are not fully using their recognized rights for several reasons, including lack of necessary infrastructure and funding; antiquated and inefficient The Status of Tribal Water Rights in the Colorado River BasinEnhance Tribal Capacity and Advance Sustainable Water Management | 2 delivery systems; and constraints on off-reservation use. Meanwhile, existing uses of Basin water already exceed reliable supplies.3 With tribes planning to fully develop and use their water rights,4 other water users in the Basin are concerned about how the expanded development of tribal water rights can be integrated with existing and future non-Indian uses of Basin water.

Although there has been some creativity in past decades to find ways to satisfy tribal water right without displacing existing uses, this issue continues to be a concern for many in the Basin. In the course of completing over 100 interviews with tribal and other leaders in the Basin in 2019, the Water & Tribes Initiative found that quantification and development of tribal waterrights consistently ranked among the top issues that need to be addressed in developing the management framework that will replace the 2007 Interim Guidelines and the 2019 Drought Contingency Plans for governing the Colorado River system.

This policy brief provides information on the status of the water rights of the 30 federally recognized tribes in the Colorado River Basin. It provides context for policy discussions on how to address tribes’ interests in fully developing their water rights and the water scarcity challenges already facing the Basin.

Read the full policy brief here.