Possible Future Changes to Water Resources in the Salt and Verde River Basins Associated with Atmospheric River Events

The Salt and Verde river basins in northeastern Arizona are a vital source of fresh water for the greater Phoenix metropolitan area and for two Native American tribes who rely on the basins’ natural resources for their livelihoods. The region depends on winter rain and snow to replenish the river basins’ water supply. Atmospheric rivers – long, narrow channels in the atmosphere that carry water vapor from the Pacific Ocean – supply a substantial portion of this winter precipitation. While atmospheric rivers are critical for maintaining water resources and preventing drought, they occasionally cause extreme storms that lead to flooding. Scientists project that climate change will affect the intensity and frequency of atmospheric rivers in the Southwest, but little is known about what these changes will entail. This project will use modeling and observations to assess how climate change will affect water resources and the occurrence of floods in the Salt and Verde river basins through changes to atmospheric rivers. These projections will enable natural resource managers, water managers, and tribes in the region to plan for upcoming periods of extremely intense rainfall within the next decade.