Linking mountain-valley water cycles to enable and promote water sustainability

The 2011-2016 California drought has raised awareness of the need to adapt water-resources management to a warming climate, growing population, lagging infrastructure and increasingly intense competition for water.  California, known worldwide for its diversity of ecosystems and its robust society and economy, is currently “over-pumping” groundwater to sustain its very productive agriculture,w hich feeds a significant fraction of the nation. Dr. Roger Bales, Distinguished Professor of Engineering and Director of Sierra Nevada Research Institute at the University of California, Merced, is bringing better knowledge, real-time information and advanced technology to bear on water-related decision-making, to find sustainable solutions for water resources and areas that depend on them.

Given that the past is not an adequate guide for a future with a warmer climate and 7+ billion people on Earth, Dr. Bales feels an urgent need to bring new technology to bear on water resources and their challenges by conducting field-measurement-based hydrologic research at multiple scales in the mountains and downstream valleys. Focusing on California as a platform for making a local, national, and global impact, his current work supports the state’s efforts to both build the knowledge base and implement policies that adapt our water supplies, critical ecosystems, and economy to the impacts of climate warming. This includes watershed management (natural capital), consideration of other ecosystem services, and bringing accuracy, transparency and timeliness to decision-making. In 2014, with seed funding from the UC Office of the President, Dr. Bales founded the multi-campus UC Water Security and Sustainability Research Initiative. UC Water works closely with decision makers and other stakeholders on strategic research to build the knowledge base for 21st century water-resources management. It also has a major focus on water and climate communications to build support for solutions.

Current projects include:

  • Sustainable Forest: In the Sierra Nevada, how would the water cycle - particularly the balance between evapotranspiration and runoff, or streamflow -- change if our forest were in a more sustainable condition? Over the past century, fire suppression has approximately resulted in much denser forests and thus use more water and less runoff from our mountain headwaters.  A second result is increased high-intensity wildfires, with water-quality implications. Using spatially intensive field measurements and satelite data to inform hydrologic modeling, Dr. Bales uses data-driven research to discover how water cycle may be improved if forests were restored to sustainable densities. His research also informs innovative financing for forest restoration.

  • Improved Water Accounting and Forecasting: Currently, we don’t accurately know either the amount of water stored in our natural reservoirs across the landscape, or the amount of water entering and leaving those reservoirs.  Better estimation and forecasting of the whole-basin water cycle can dramatically improve water decision-making; and Dr. Bales develops systems and tools to accurately estimate how much water is in snowpacks, soil, and groundwater, plus the associated precipitation, infiltration, runoff and flows.  Seasonal and inter-annual water storage are a central foundation for water security, and these natural water reservoirs are at least as important as built storage such as dams. By looking at how these three areas are changing daily, monthly, annually and longer, we can bring accurate water accounting, i.e. better hydrologic information to bear on a wide range of resource-management challenges.

  • Integrated Water Management: Both infrastructure and institutions need to be updated to meet the demands that society places on them for a sustainable water supply. In order to integrate the range of institutions’ interest and scientific issues, Dr. Bales travels from the mountain crests of the Sierra Nevada to the valley floors of San Joaquin Valley and actively collaborates with resources managers and other stakeholders.


When Dr. Roger Bales was a college student, there was much discourse regarding environmental protection and Congress was passing laws like the Clean Water Act. It was truly an exciting time for engineers to emerge and tackle environmental problems of their parents’ generations, and Dr. Bales was pulled right into that. Enjoying people and places, he cherishes the feeling of contributing to solutions. “We’re at that point again with climate change,” he remarks, and that he would like to create a “more sustainable world for [his] children and their generation.”

Although he jokes that his mountain climbing has really dropped after starting his research in the mountains, he still sets intentional time apart for skiing and hiking. As a researcher whose fieldwork is integral to his research, he loves the mountains and the valleys that serve as his laboratory and field, but he can also be found in the cities where he would spend time relishing the people and the scene. Dr. Bales particularly values watching ballet and modern dance with family and friends.

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Fellow, American Geophysical Union

Fellow, American Meteorological Society

Fellow, American Association for the Advancement of Science