Watershed Studies
DWR’s Watershed Studies explore opportunities to turn California’s increasingly extreme storms into long-term benefits for communities, farms and ecosystems across the state. The Watershed Studies show how using high-tech weather forecasts to inform reservoir operations can reduce flood risk, refill underground aquifers, and increase water supplies during dry times. These studies provide a basis for strategies that state, federal, and local agencies can use to better coordinate, prepare for climate extremes, and safeguard communities, farms, and ecosystems into the future.
San Joaquin Basin Flood-MAR Watershed Studies
The San Joaquin Basin Flood-MAR Watershed Studies cover the Calaveras, Stanislaus, Tuolumne, Merced, and Upper San Joaquin watersheds and evaluate how the basin can better manage water resources in extreme wet years and long dry periods.
View the Basinwide Summary and Next Steps or the fact sheet for an overview of the studies and find answers to frequently asked questions about the studies.
View the individual watershed study reports and factsheet using the links below.
- Calaveras Watershed Study Area Report | Factsheet
- Stanislaus Watershed Study Area Report | Factsheet
- Tuolumne Watershed Study Area Report | Factsheet
- Merced Watershed Study Area Report | Factsheet
- Upper San Joaquin Watershed Study Area Report | Factsheet
DWR utilized eight different models to develop the Watershed Studies for the San Joaquin Basin, which generated more than 8 million data points. A user-friendly dashboard that will allow users to view and explore the data, along with a data download tool, will soon be available.
Additional Resources
San Joaquin Conveyance Study
DWR’s San Joaquin Valley Conveyance Study, released in November 2025, assesses water conveyance needs in the San Joaquin Valley and outlines the rising risks to water management.
State Water Project Adaptation Strategy
DWR’s first-ever State Water Project Adaptation Strategy, released in August 2025, examines a combination of strategies to help the State Water Project (SWP) maintain reliable water deliveries and adapt to a changing climate.