Historical and projected freshwater withdrawals and irrigation consumptive use for Arizona, 1896–2099

Sayantan Majumdar , Ryan G. Smith, Peter ReVelle, Md Fahim Hasan, Collin Wogenstahl, Danielle E. Tadych, Laney Meeker

Sustainable water management needs spatially resolved withdrawal estimates, yet such data remain scarce worldwide. In Arizona, USA, decades of aquifer overdraft and Colorado River over-allocation have outpaced local withdrawal data, constraining policymaking. We present annual freshwater withdrawal and irrigation consumptive use estimates for Arizona at 2 km resolution over 1896–2099, partitioned by source (groundwater, surface water) and use (irrigation, non-irrigation). A machine learning model trained on flowmeter records (1984–2024) estimated total withdrawal, partitioned into eight withdrawal categories and three consumptive-use products. A stream capture index flags where groundwater withdrawal may deplete surface-water supplies. Because post-2026 Colorado River shortages are not yet set, projections are also provided under eight Central Arizona Project (CAP) shortage scenarios, up to a complete loss of CAP deliveries. Every product carries per-pixel uncertainty, and a well package disaggregates the predictions to ~170,000 registered consumptive wells. Outputs were validated against U.S. Geological Survey, Arizona Department of Water Resources, and CAP records. The dataset supports groundwater modeling, aquifer-depletion assessment, and water-resources planning in Arizona and its transboundary watersheds.