“The CRIT are federally recognized and include four distinct Tribes: the Mohave, Chemehuevi, Hopi, and Navajo. Their reservation borders 56 miles of the Colorado River below Lake Havasu, and they have the oldest and one of the largest water rights on the Colorado River, over 700,000 acre-feet. They’re among the luckier tribes since their water rights are adjudicated and settled in law, but that’s somewhat hollow because they lack the infrastructure to use their entire water rights. Throughout the Colorado River Basin, I estimate Indigenous nations have rights to at least 2.5 million acre-feet, or about 20% of the river. They currently can physically access less than half of these rights, but they stand to play a larger and larger role in the river’s future.
– From "Whose Law of the River?," p. 11Tribal Water Rights
This table concludes that tribes have 2,504,367 acre-feet (2.5 million acre-feet maf) of consumptive water rights to the Colorado River. Consumptive rights should be distinguished from diversion rights, which are larger because some of the diversion is not consumed but returns to the Colorado River as return flows. Daniel Cordalis, attorney with the Native American Rights Fund, believes total tribal water rights to the Colorado River exceed 2.5 maf. Tribal water rights compiled at the University of Colorado Getches-Wilkinson Center total nearly 4 maf, but they include water rights of the 30 Colorado Basin tribes that are not included in this table, and they often reference diversion rights, which accounts for some of the 1.5 maf discrepancy (see, Tribal Water Uses in the Colorado River Basin, Julie Nania, Getches-Wilkinson Center, University of Colorado Law School, downloaded 6-7-25, https://www.tribalwateruse.org/).
This table combines consumptive water rights reported by the Bureau of Reclamation’s 2018 Study with 650,724 af of Central Arizona Project (CAP) tribal water rights decreed in Section 104 of the Arizona Water Settlements Act passed by Congress on Dec. 10, 2004. See Reclamation’s 2018 Colorado River Basin Ten Tribes Partnership Tribal Water Study Report (the “2018 BuRec Study”), available at https://www.usbr.gov/lc/region/programs/crbstudy/tws/finalreport.html. Current and future consumption of 10 tribes in the Upper and Lower Basins is estimated in Chapter 5 of the 2018 BuRec Study, with a separate chapter section for each tribe. As of 2018, the total decreed consumption in Chapter 5 totaled 1,522,032 acre-feet (af), of which 895,839 af was currently being consumed, and 626,193 af still had to be developed. The 1,522,032 af total includes 178,528 af in the Northeastern Arizona Indian Water Rights Settlement Agreement (NAIWRSA) resolved in 2025; The Arizona Governor signed this on 11-17-24 but Congress must still ratify the treaty settlement before it is effective.
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