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San Francisco Bay-Delta

The Bay-Delta is a nexus for challenging issues about water, ecosystems, and human use. USGS science helps address key problems and uncertainties.

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Grand Canyon Monitoring and Research Center

How does Glen Canyon Dam affect downstream Colorado River resources?

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Lake Tahoe

An underwater view of periphyton growing on rocks near the shore of Lake Tahoe with a reflection of the rocks on the water surface

Explore the Lake Tahoe Hydro Mapper

Salton Sea

The Salton Sea is facing many challenges as inflows and water levels decline. USGS science helps identify problems and evaluate possible solutions.

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New Technologies for Mapping Surface Soil Moisture

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Stinson Beach

Flood map from Our Coast, Our Future

Coastal Storm Modeling System (CoSMoS)

Coastal Dwellers

Read more about sea otter research

Southwest Region

The Southwest Region covers Arizona, California, Nevada, and a portion of southern Oregon. Our scientists do a broad array of research and technical assistance throughout the U.S. and across the globe. The Regional Office, headquartered in Sacramento, provides Center oversight & support, facilitates internal & external collaborations, and works to further USGS strategic science direction.

News

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New Models Show Restoration Can Benefit Salmon While Reducing Flood Risks to Pacific Northwest River Deltas

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Elwha River: New Study Examines Effects of Dam Removals on Coastal Ecosystems

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Tribal Engagement Series: Drought in the Colorado River Basin

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Publications

Soil surface treatments and precipitation timing determine seedling development across southwestern US restoration sites

Restoration in dryland ecosystems often has poor success due to low and variable water availability, degraded soil conditions, and slow plant community recovery rates. Restoration treatments can mitigate these constraints but, because treatments and subsequent monitoring are typically limited in space and time, our understanding of their applicability across broader environmental gradients remains
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Hannah Lucia Farrell, Seth M. Munson, Bradley J. Butterfield, Michael C. Duniway, Aksasha M Faist, Elise S Gornish, Caroline Havrilla, Loralee Larios, Sasha C. Reed, Helen I Rowe, Katherine M. Laushman, Molly L. McCormick
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Ecosystems Mission Area, Southwest Biological Science Center

Addressing stakeholder science needs for integrated drought science in the Colorado River Basin

Stakeholders need scientific data, analysis, and predictions of how drought the will impact the Colorado River Basin in a format that is continuously updated, intuitive, and easily accessible. The Colorado River Basin Actionable and Strategic Integrated Science and Technology Pilot Project was formed to demonstrate the effectiveness of addressing complex problems through stakeholder involvement an
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Anne C. Tillery, Sally House, Rebecca J. Frus, Sharon L. Qi, Daniel Jones, William J. Andrews
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Ecosystems Mission Area, Water Resources Mission Area, Arizona Water Science Center, California Water Science Center, Colorado Water Science Center, Fort Collins Science Center, Geology, Geophysics, and Geochemistry Science Center, Nevada Water Science Center, New Mexico Water Science Center, Southwest Biological Science Center, Utah Water Science Center, Washington Water Science Center, Wyoming-Montana Water Science Center, Colorado River Basin: Actionable and Strategic Integrated Science and Technology

Approaches for assessing long-term annual yields of highway and urban runoff in selected areas of California with the Stochastic Empirical Loading and Dilution Model (SELDM)

The California Department of Transportation, commonly known as CalTrans, and other municipal separate storm sewer system permittees in California as well as other State departments of transportation nationwide need information about potential loads and yields (loads per unit area) of constituents of concern in stormwater runoff and discharges from stormwater best management practices (BMPs). Altho
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Gregory E. Granato, Paul J. Friesz
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Water Resources Mission Area, New England Water Science Center
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Science

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map of Long Beach earthquake

M6.4 March 10, 1933 Long Beach, California Earthquake

The magnitude 6.4 Long Beach, California earthquake, which struck near 5pm local time on March 10, 1933, was a landmark event. It was the largest known earthquake in the Los Angeles region at the time, since the advent of written record-keeping. It occurred at a pivotal point historically, during an active debate about seismic hazard in the area.
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Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center
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M6.4 March 10, 1933 Long Beach, California Earthquake

The magnitude 6.4 Long Beach, California earthquake, which struck near 5pm local time on March 10, 1933, was a landmark event. It was the largest known earthquake in the Los Angeles region at the time, since the advent of written record-keeping. It occurred at a pivotal point historically, during an active debate about seismic hazard in the area.
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Photo of a large, deep, circular depression in the desert with an elevated rim

Planetary Defense

At the USGS Astrogeology Science Center we conduct research on Planetary Defense. Planetary Defense involves predicting potential impactors (asteroids, comets), and studying how to deflect or divert them, as well as the potential effects of an impact. Effects include short-term effects such as blast damage, but also long-term effects such as climate and social impacts.
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Core Science Systems Mission Area, Natural Hazards Mission Area, Astrogeology Science Center
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Planetary Defense

At the USGS Astrogeology Science Center we conduct research on Planetary Defense. Planetary Defense involves predicting potential impactors (asteroids, comets), and studying how to deflect or divert them, as well as the potential effects of an impact. Effects include short-term effects such as blast damage, but also long-term effects such as climate and social impacts.
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View of beach from roof top, edge of roof in foreground, pier extending from beach out over water in center, park in background.

Remote Sensing Coastal Change

We use remote-sensing technologies—such as aerial photography, satellite imagery, structure-from-motion (SfM) photogrammetry, and lidar (laser-based surveying)—to measure coastal change along U.S. shorelines.
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Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, Big Sur Landslides
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Remote Sensing Coastal Change

We use remote-sensing technologies—such as aerial photography, satellite imagery, structure-from-motion (SfM) photogrammetry, and lidar (laser-based surveying)—to measure coastal change along U.S. shorelines.
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