The Arizona Water Settlement Act and urban water supplies

The 2004 Arizona Water Settlements Act (AWSA 2004) when implemented will allocate to two Native American tribes, the Gila River Indian Community (GRIC) and the Tohono O’odham Nation (TON) almost ten percent of Arizona’s total developed water supply, which is 7.04 million acre-feet a year. The successful passage of AWSA, given the scale of the water rights settlement and competing uses for finite water supplies, is the topic of this paper. Key motivations for the settlement are that: (1) the 653,500 acre-feet a year allocation is around a third of the GRIC’s Gila River Adjudication 2001 claim; (2) the GRIC signed a number of water leases and exchanges providing water to municipalities and has not ruled out signing more; and (3) AWSA resolved more than tribal water claims; it also settled thorny issues of Central Arizona Project (CAP) debt repayment (for $2 billion in construction costs) and division of water allocation between federal (Indian) and state (non-Indian) uses including the reallocation of high priority uncontracted CAP water to cities.