Augmentation Opportunities for Arizona and Mexico

1. Augmentation Opportunities for Arizona and Mexico David Roberts Manager, Water Rights & Contracts Department Salt River Project Karl Kohlhoff, P.E., B.C.E.E. HDR Engineering Arizona-Mexico Commission – Comision Sonora-Arizona June 14, 2007

2. Arizona/Mexico Augmentation Arizona/Northwest Mexico Region • Water resources issues are well documented • Groundwater – overdraft in many areas • Surface water – over allocated and significantly affected by periodic droughts – some long-term • Reclaimed water – growing supply; reuse opportunities • Regional demographics are major influence • Arizona – fastest growing US state; population expected to double by 2050 • Sonora/Baja growth rate similar to Arizona Arizona-Mexico Commission/Comision Sonora-Arizona

4. Arizona/Mexico Augmentation Arizona/Northwest Mexico Region • Regional economy is significant • Agriculture (>1,000,000 acres) • Manufacturing/Services (>90% of GP) • Tourism • Developing sustainable water supplies is the single most important factor that affects the future of the region Arizona-Mexico Commission/Comision Sonora-Arizona

5. Arizona/Mexico Augmentation Arizona/Northwest Mexico Region • Future water supply requirements • Arizona – 1,000,000 acre-feet by 2100 • Sonora/Baja demands currently exceed reliable supplies – probable need >1,000,000 acre-feet by 2100 • Water augmentation options • Improved efficiency of water use • Conversion/transfer of agricultural water rights • Reuse of reclaimed water • Out-of-region importation • Desalination Arizona-Mexico Commission/Comision Sonora-Arizona

6. Arizona/Mexico Augmentation Water Augmentation Options • Efficiency improvements • Helpful in firming existing supplies • Not reliable to serve new water demand • Agricultural water rights conversions/transfers • Impact to regional economy needs to be considered • Temporary transfers are helpful in firming existing supplies Arizona-Mexico Commission/Comision Sonora-Arizona

7. Arizona/Mexico Augmentation Water Augmentation Options • Reuse of reclaimed water • Growing supply – great augmentation opportunity • Uses likely will be agricultural and industrial • Helps firm existing supplies and can create new drinking water supplies through exchanges and groundwater recharge • Out-of-region importation • Third party impacts need to be considered • Complex legal, environmental, and political issues Arizona-Mexico Commission/Comision Sonora-Arizona

8. Arizona/Mexico Augmentation Water Augmentation Options • Desalination • Drought proof • Significant supply available – could meet long-term needs of Arizona, Sonora and Baja through direct deliveries and/or exchanges • Currently costly to produce, but improved treatment technology will reduce costs over time Arizona-Mexico Commission/Comision Sonora-Arizona

10. Arizona/Mexico Augmentation Conclusion • Sustaining Arizona/Northwest Mexico’s economy will require significant augmentation of the region’s water supply • Short-term focus should be on firming existing supplies • Improve water use efficiency • Reuse of reclaimed water • Temporary transfers of agricultural water rights • Long-term option is desalination • AMC is ideal place to re-initiate discussion Arizona-Mexico Commission/Comision Sonora-Arizona