Water securityThe effects of climate change on California watersheds

Published 23 March 2018

California relies on the Sierra Nevada snowpack for a significant portion of its water needs, yet scientists understand very little about how future changes in snowpack volume and timing will influence surface water and groundwater. Now researchers are developing an advanced hydrologic model to study how climate change might affect California watersheds.

California relies on the Sierra Nevada snowpack for a significant portion of its water needs, yet scientists understand very little about how future changes in snowpack volume and timing will influence surface water and groundwater. Now researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) are developing an advanced hydrologic model to study how climate change might affect California watersheds.

LBL says that the new collaborative study, with $3.7 million in funding from the UC Laboratory Fees Research Program, will improve the projection of water resources under a range of future scenarios. The goal of the project is to provide information that can be used to optimize water storage, water quality, and groundwater sustainability as precipitation varies, temperatures warm, and population grows.

“We will use a high-resolution and physically based numerical modeling approach for simulating how water moves from the atmosphere to surface waters and into groundwaters,” said scientist Erica Woodburn of Berkeley Lab’s Earth and Environmental Sciences Area. “Water management across the state currently relies on simpler models that have been calibrated and made to work correctly with historical data. But because we are likely moving into a future where water delivery may be very different from past years, there is significant uncertainty in the use of these current models to predict the distribution of future water.”

The three-year project, titled “Headwaters to Groundwater: Resources in a Changing Climate,” is led by Jeff Dozier of UC Santa Barbara, and includes researchers from Lawrence Livermore National Laboratory, UC Davis, UC Irvine, UCLA, and UC Merced.

Woodburn, a hydrogeologist by training, along with Carl Steefel, head of Berkeley Lab’s Geochemistry Department, will develop a mechanistic numerical model of the Cosumnes River watershed, which extends from the Sierra Nevada to south of Sacramento, ultimately feeding into the Sacramento-San Joaquin River Delta and the California State Water Project, the major source of water for much of Southern California.