Tuesday - May 13, 2025

 6:00 to 8:00 p.m. PDT

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"Threats to Western Water Security as Viewed from Space"

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By: Dr. Jay Famiglietti

Hydrologist and Global Futures Professor 

Arizona State University   

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ABSTRACT:

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Changes in terrestrial water storage (TWS) are a critical indicator of freshwater availability.  The focus of this presentation is TWS change in the western United States, and especially the Colorado River Basin (CRB), where the balance between surface and groundwater use is critical, yet groundwater management receives considerably less attention.  NASA Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On satellite data were used along with several additional ground- and model-derived datasets to show that groundwater depletion accounted for 50% of TWS loss in the Upper CRB and 75% in the Lower CRB, far greater than the losses in Lakes Powell and Mead. However, groundwater management practices and access to surface water have reduced depletion rates in managed areas of the Lower CRB compared to unmanaged regions.  Expansion of groundwater management and inclusion of groundwater in interstate water discussions may help chart a path to water sustainability across the western United States.

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BIO:

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Jay Famiglietti is a hydrologist and Global Futures Professor at Arizona State University where he is Director of Science for the Arizona Water Innovation Initiative. He is President-Elect of the American Geophysical Union’s Hydrology Section. Before moving to Arizona State University, Famiglietti was founding Chief Scientist of the Silicon Valley tech startup, Waterplan; he was Executive Director of the Global Institute for Water Security at the University of Saskatchewan; he was Senior Water Scientist at NASA’s Jet Propulsion Laboratory; he was appointed to the California State Water Boards by Governor Jerry Brown; and he held faculty positions at UC Irvine and UT Austin.  His research group uses satellites to track how freshwater availability is changing around the globe, and they pioneered the methods to detect groundwater depletion from space.  A fellow of the American Geophysical Union (AGU), Geological Society of America, and recipient of AGU's Peter S. Eagleson Hydrological Sciences Award, he is committed to science communication and to multi-sectoral advising on water security issues.

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