Unified Interior Regions
California
The Southwest Region includes California, Nevada, and Arizona. The Regional Office, headquartered in Sacramento, provides Center oversight and support, facilitates internal and external collaborations, and works to further USGS strategic science directions.
States L2 Landing Page Tabs
Cuyama Valley Water Availability Study
Currently, groundwater is the only source for domestic, agricultural and municipal water use in the Cuyama Valley groundwater basin in Santa Barbara County, California. Groundwater withdrawals, mainly to irrigate agricultural crops, have resulted in water-level declines of as much as 300 feet in the area since the 1940s. To plan for sustainable future use of the groundwater, the U.S....
Coping with Drought in the Russian River Watershed
Drought in the Russian River region is keyed to the absence of large winter storms-the RR is winter rain-driven, with a few atmospheric river (AR) storms each year bringing 40-50% of the annual rainfall. Two multi-purpose reservoirs provide storage for warm-season uses, and there is little to no snow pack to extend the runoff season. The same ARs that provide beneficial water supply can also...
Borrego Valley Groundwater Conditions
Groundwater is effectively the sole source of water supply for Borrego Valley, California. By the mid-2000s, agriculture, recreation (predominantly golf courses), municipal uses, and the Anza-Borrego Desert State Park required about four times more water than is available through natural recharge. As a result, the U.S. Geological Survey began a cooperative study of the Borrego Valley with the...
Geophysical Infrastructure Study: Success Dam
A study site of the Geophysical Infrastructure Studies: Earthen Dams and Abandoned Mine Lands project.
California Streamgage Information
To help emergency managers and others protect life and property due to floods and other water-related hazards, the USGS delivers a continuous source of streamflow information. The U.S. Geological Survey has been measuring streamflow in the U.S. for over 120 years. We operate more...
California Flood Science
To help emergency managers and others protect life and property due to floods and other water-related hazards, the USGS delivers a continuous source of streamflow information. The USGS California Water Science Center maintains nearly 500 streamgages that collect...
Owens Valley Hydrogeology
The Owens Valley, a long, narrow valley along the east side of the Sierra Nevada in east-central California, is the main source of water for the city of Los Angeles. The city diverts most of the surface water in the valley into the Owens River-Los Angeles Aqueduct system, which transports the water more than 200 miles south to areas of distribution and use. Additionally, ground water is pumped...
Sustainable Groundwater Management
In 2014, the State of California adopted historic legislation to help manage its groundwater, the Sustainable Groundwater Management Act (SGMA) . According to the act, local Groundwater Sustainability Agencies (GSAs) must be formed for all...
California's Central Valley
Competition for water resources is growing throughout California, particularly in the Central Valley. The Central Valley's population is expected to increase to 6 million by 2020. This population growth, along with anticipated reductions in Colorado River water deliveries, drought, and the ecological crisis in the Sacramento-San Joaquin Delta, have created an intense demand for water. The...
California Drought
The USGS closely monitors the effects of drought through data collection and research. USGS science supports water managers in preparing for possible future drought by providing information that takes into account long-term hydrologic, climatic, and environmental changes. These studies support successful planning and science-based decision-making by water managers who must address complex...
Occurrence of Current-use Pesticides in Suisun Bay and Potential Effects on Phytoplankton
Suisun Bay is an area identified as critical habitat for the threatened Delta Smelt. Several important changes in the pelagic food web of this area have been documented over the last two decades indicating that food for Delta Smelt and other threatened fishes is in short.
Evaluation of the groundwater resources of the Petaluma Valley
The city of Petaluma, located in the Petaluma Valley and home to about 12 percent of the population of Sonoma County, faces growth in population and demand for water. Water supply is provided primarily by water delivered via aqueduct from the Russian River; however, groundwater is a vital supplemental source of water for the city of Petaluma and is the primary source of supply for domestic and...
Topography data collected in the Liberty Island Conservation Bank portion of the Cache Slough Complex, Sacramento-San Joaquin Delta, California, during USGS field activity 2017-649-FA
This portion of the USGS data release presents topography data acquired in the Liberty Island Conservation Wildlands restoration site in 2017 (USGS Field Activity Number 2017-649-FA). Topographic data were collected on June 26 and 27, 2017 by walking with global navigation satellite system (GNSS) receivers mounted on backpacks. Hand-held data collectors were used to log raw data and dis
Anza Land Use Comparison (1934 - 2005)
Compares Anza Valley, CA land use data within the USGS study boundaries for 5 time periods between 1934 and 2005.
Anza Hydrologic Data
A portal for easy access to USGS data collected during hydrogeologic research projects in Anza Valley, CA
High-resolution (1 m) digital elevation model (DEM) of San Francisco Bay, California, created using bathymetry data collected between 1999 and 2016
A 1-m resolution bathymetric digital elevation model (DEM) of all off San Francisco Bay was constructed from bathymetric surveys collected from 1999 to 2016. The DEM has been divided into northern and southern sections due to file size, and is available in both MLLW and NAVD88 versions.
Assessing spatial variability of nutrients and related water quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2018 High resolution mapping surveys
The dataset documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the North Delta, Central Delta, and the Western Delta out to Suisun Bay in the Sacramento-San Joaquin River Delta of California, USA. The dataset includes nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, diss
Inorganic chemistry data for groundwater wells near selected oil fields in the southwestern San Joaquin Valley, central California
This digital dataset contains geochemical and other information for 1,209 samples of groundwater from 343 wells located within 3-miles of the Buena Vista, Elk Hills, Midway-Sunset, and North and South Coles Levee oil fields in the southwestern San Joaquin Valley of central California. Data were compiled by the U.S. Geological Survey (USGS) from preexisting datasets and transferred man
Geochemical, mineralogical, and grain-size data for in-situ solid materials and suspended sediment at Malakoff Diggins State Historic Park, Nevada County, California
This dataset includes data for in-situ solid materials and suspended sediments from surface-water samples, as well as surface-water chemistry from samples collected during storm events at Malakoff Diggins State Historic Park, Nevada County, California. In-situ solid samples were collected during 2015 along six vertical transects along the cliff walls of the mine pit. Surface-water samples w...
Field and Laboratory data of pipe scale forming in acid mine drainage pipelines at Iron Mountain and Leviathan Mines, California
Pipelines carrying acid mine drainage at Iron Mountain and Leviathan Mines (CA, USA) develop pipe scale, a precipitate that forms inside the pipelines. The U.S. Geological Survey is studying the composition of the pipe scale and the acid mine drainage water flowing through the pipeline through field samples and laboratory experimentation. This data release provides the data from the stu
Pesticide Constituent Data from the California Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP), 2004 - 2018
The California Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP) submitted 2,994 samples in 2004-2018 to the USGS National Water Quality Laboratory (NWQL) for analysis of pesticide constituents on NWQL schedules 2003, 2032, or 2033, and 840 samples in 2004-2011 for analysis of pesticide constituents on NWQL schedule 2060. Fram and Stork (201
Chirp and minisparker seismic-reflection data of field activity F-02-07-NC collected offshore San Mateo County, California, from 2007-03-22 to 2007-04-06
High-resolution single-channel Chirp and minisparker seismic-reflection data were collected by the U.S. Geological Survey in March and April 2007, offshore San Mateo County, California. Data were collected aboard the R/V Fulmar during field activity F-02-07-NC. Chirp data were collected using an EdgeTech 512 chirp subbottom system and were recorded with a Triton SB-Logger. Minisparker data
Minisparker seismic-reflection data from field activity L-1-06-SF collected offshore Bolinas to San Francisco, California from 2006-09-25 to 2006-10-03
High-resolution single-channel minisparker seismic-reflection data were collected by the U.S. Geological Survey in September and October 2006 offshore Bolinas to San Francisco, California. Data were collected aboard the R/V Lakota, during field activity L-1-06-SF. Minisparker data were collected using a SIG 2-mille minisparker sound source combined with a single-channel streamer, and reco
Chirp seismic-reflection data from field activity L-1-06-SF collected offshore Bolinas to San Francisco, California on 2006-09-30
High-resolution Chirp seismic-reflection data were collected by the U.S. Geological Survey in September 2006 offshore San Francisco, California. Data were collected aboard the R/V Lakota, during field activity L-1-06-SF. Chirp data were collected using an EdgeTech 512 chirp subbottom profiler and recorded with a Triton SB-Logger.
Model simulations of flood and debris flow timing in steep catchments after wildfire
Debris flows are a typical hazard on steep slopes after wildfire, but unlike debris flows that mobilize from landslides, most post-wildfire debris flows are generated from water runoff. The majority of existing debris-flow modeling has focused on landslide-triggered debris flows. In this study we explore the potential for using process-based...
Rengers, Francis K.; McGuire, Luke; Kean, Jason W.; Staley, Dennis M.; Hobley, D.E.J
Preliminary results from exploratory sampling of wells for the California oil, gas, and groundwater program, 2014–15
Introduction In 2014 and 2015, the U.S. Geological Survey (USGS) sampled water wells in the Los Angeles Basin and southern San Joaquin Valley, California, and oil wells in the San Joaquin Valley for analysis of multiple chemical, isotopic, and groundwater-age tracers. The purpose of this reconnaissance sampling...
McMahon, Peter B.; Kulongoski, Justin T.; Wright, Michael T.; Land, Michael T.; Landon, Matthew K.; Cozzarelli, Isabelle M.; Vengosh, Avner; Aiken, George R.
Relative distribution and abundance of fishes and crayfish in 2010 and 2014 prior to saltcedar (Tamarix ssp.) removal in the Amargosa River Canyon, southeastern California
The Amargosa River Canyon, located in the Mojave Desert of southeastern California, contains the longest perennial reach of the Amargosa River. Because of its diverse flora and fauna, it has been designated as an Area of Critical Environmental Concern and a Wild and Scenic River by the Bureau of Land Management. A survey of fishes conducted in...
Hereford, Mark E. Evaluation of a floating fish guidance structure at a hydrodynamically complex river junction in the Sacramento-San Joaquin River Delta, California, USA
Survival of out-migrating juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Sacramento–San Joaquin River delta, California, USA, varies by migration route. Survival of salmonids that enter the interior and southern Delta can be as low as half that of salmonids that remain in the main-stem Sacramento River. Reducing entrainment into...
Romine, Jason G.; Perry, Russell W.; Pope, Adam C.; Stumpner, Paul; Liedtke, Theresa L.; Kumagai, Kevin K.; Reeves, Ryan L. Anadromous salmonids in the Delta: New science 2006–2016
As juvenile salmon enter the Sacramento–SanJoaquin River Delta (“the Delta”) they disperse among its complex channel network where they are subject to channel-specific processes that affect their rate of migration, vulnerability to predation, feeding success, growth rates, and ultimately, survival. In the decades before 2006...
Perry, Russell W.; Buchanan, Rebecca A.; Brandes, Patricia L.; Burau, Jon R.; Israel, Joshua A
Estimating juvenile Chinook salmon (Oncorhynchus tshawytscha) abundance from beach seine data collected in the Sacramento–San Joaquin Delta and San Francisco Bay, California
Resource managers rely on abundance or density metrics derived from beach seine surveys to make vital decisions that affect fish population dynamics and assemblage structure. However, abundance and density metrics may be biased by imperfect capture and lack of geographic closure during sampling. Currently, there is considerable uncertainty about...
Perry, Russell W.; Kirsch, Joseph E.; Hendrix, A. Noble
Gravity and magnetic studies of the eastern Mojave Desert, California and Nevada
IntroductionFrom May 2011 to August 2014, the U.S. Geological Survey (USGS) collected gravity data at more than 2,300 stations and physical property measurements on more than 640 rock samples from outcrops in the eastern Mojave Desert, California and Nevada. Gravity, magnetic, and physical-property data are used to study and locate regional...
Denton, Kevin M.; Ponce, David A.
Historical files from Federal Government mineral exploration-assistance programs, 1950 to 1974
The Defense Minerals Administration (DMA), Defense Minerals Exploration Administration (DMEA), and Office of Minerals Exploration (OME) mineral exploration programs were active over the period 1950–1974. Under these programs, the Federal Government contributed financial assistance in the exploration for certain strategic and critical minerals. The...
Frank, David G.
California State Waters Map Series—Monterey Canyon and vicinity, California
IntroductionIn 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly detailed...
Dartnell, Peter; Cochran, Susan A.; Dartnell, Peter; Maier, Katherine L.; Erdey, Mercedes D.; Dieter, Bryan E.; Golden, Nadine E.; Johnson, Samuel Y.; Hartwell, Stephen R.; Cochrane, Guy R.; Ritchie, Andrew C.; Finlayson, David P.; Kvitek, Rikk G.; Sliter, Ray W.; Greene, H. Gary; Davenport, Clifton W.; Endris, Charles A.; Krigsman, Lisa M. A fault-based model for crustal deformation, fault slip-rates and off-fault strain rate in California
We invert Global Positioning System (GPS) velocity data to estimate fault slip rates in California using a fault‐based crustal deformation model with geologic constraints. The model assumes buried elastic dislocations across the region using Uniform California Earthquake Rupture Forecast Version 3 (UCERF3) fault geometries. New GPS velocity and...
Zeng, Yuehua; Shen, Zheng-Kang Trace elements in stormflow, ash, and burned soil following the 2009 station fire in southern California
Most research on the effects of wildfires on stream water quality has focused on suspended sediment and nutrients in streams and water bodies, and relatively little research has examined the effects of wildfires on trace elements. The purpose of this study was two-fold: 1) to determine the effect of the 2009 Station Fire in the Angeles National...
Burton, Carmen A.; Hoefen, Todd M.; Plumlee, Geoffrey S.; Baumberger, Katherine L.; Backlin, Adam R.; Gallegos, Elizabeth; Fisher, Robert N. Seismic site characterization of an urban dedimentary basin, Livermore Valley, California: Site tesponse, basin-edge-induced surface waves, and 3D simulations
Thirty‐two accelerometers were deployed in the Livermore Valley, California, for approximately one year to study sedimentary basin effects. Many local and near‐regional earthquakes were recorded, including the 24 August 2014 Mw 6.0 Napa, California, earthquake. The resulting ground‐motion data set is used to quantify the seismic response...
Hartzell, Stephen H.; Leeds, Alena L.; Ramirez-Guzman, Leonardo; Allen, James P.; Schmitt, Robert G.
Conducting a high tide waterbird survey on San Fransisco Bay
San Francisco Bay and the surrounding wetlands and ponds provide important habitat for waterfowl and shorebirds. To aid land and resource managers in tracking wildlife responses to habitat restoration efforts, Biological Science Technician, Aliya, conducts a high tide waterbird survey of a restored salt pond in the Napa-Sonoma Marshes Wildlife Area at the northern edge of
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Measuring a red fir tree in the Sierra Nevada
This is Teodora Rautu. She is a Biological Science Technician on the field crew for USGS Western Ecological Research Center's Sierra Nevada Forest Dynamics project. She is measuring the diameter of a red fir and trying to navigate the tape through the branches. All of the trees in the Sierra Nevada Forest Dynamics plots are measured every 5 years, not only for
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Measuring a Giant sequoia in the Sierra Nevada
This is Teodora Rautu. She is a Biological Science Technician on the field crew for USGS Western Ecological Research Center's Sierra Nevada Forest Dynamics project. She is measuring the diameter of a Giant Sequoia. All of the trees in the Sierra Nevada Forest Dynamics plots are measured every 5 years, not only for determining the size of the trees but also for tracking
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Beginning a 'tree autopsy' in the Sierra Nevada
This is Teodora Rautu. She is a Biological Science Technician on the field crew for USGS Western Ecological Research Center's Sierra Nevada Forest Dynamics project. The tree she is getting read to cut into has recently died. Teo is going to remove bark to look for signs of insects or pathogens than may have been involved in the tree's death--the first step in a 'tree
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It takes two to measure this Giant Sequoia
Teodora Rautu and Eva Lopez, Biological Science Technicians on the field crew for the USGS Western Ecological Research Center's Sierra Nevada Forest Dynamics project, work together to measure the diameter of a Giant Sequoia. Every tree in the project's long-term study plots are re-measured every 5 years, not only for determining the size of the trees but also for tracking
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ShakeAlert Sensor and Station
This is b-roll footage of a ShakeAlert earthquake early warning system seismic station. These seismic stations and sensors are deployed around California and are used to monitor earthquake activity.
2019 Ridgecrest Earthquake Sequence: July 4, 2019–July 16, 2019
3,557 earthquakes recorded since July 4, 2019 above Magnitude 2
M6.4 12km W of Searles Valley, CA
2019-07-04 17:33:49 (UTC)
51,000+ responses via Did You Feel It?
M7.1 18km W of Searles Valley, CA
2019-07-06 03:19:53 (UTC)
42,000+ responses via Did You Feel It?
631 M3+
...
Animation of Ridgecrest Foreshock Seq up to M7.1 (Prelim. Results)
This animation shows preliminary results from precise relocation of the Ridgecrest foreshock sequence, up to the the time of occurrence of the M 7.1 mainshock. The animation begins in a map view and then transitions into a rotating vertical slice. Earthquakes are colorcoded by time of occurrence, with early events in dark blue and later events (up to the M 7.1) in dark
Animation of Ridgecrest Earthquake Seq. thru July 6 (Prelim. Results)
This animation shows preliminary results from precise relocation of the Ridgecrest earthquake sequence, through July 6 (UTC), including the foreshock sequence and the first ~20 hours of aftershocks from M 7.1 mainshock. The animation begins in a map view and then transitions into a rotating vertical slice. Earthquakes are colorcoded by time of occurrence, with early
Portable Seismic Station
Two portable sensors: a strong motion sensor (to record strong shaking that can be felt) and a broadband sensor (to record weak motion for detecting small earthquakes) buried into the ground to detect earthquakes. These stations can be quickly deployed and send real-time data back to the USGS via cellular telemetry immediately after they are installed.
California Earthquakes (July 2019) - Animation Sequence
This video shows the earthquake events a few hours before the M6.4 on July 4th, 2019 till after the M7.1 on July 8th, 2019. The blue dots are the events associated with the M6.4 and then red dots are events associated with the M7.1
USGS provides briefing to Navy about Ridgecrest Earthquake Sequence
Kate Scharer (USGS) provides CO CAPT Paul Dale (Navy) with the field mapping team’s initial product, showing the surface fault rupture at NAWSCL as well as the temporarily deployed seismic and GPS sensors that were rapidly deployed. Contributions of field data from within the base were from CGS & USGS, and from outside the base were from Univ. of Nevada, Reno, EERI,
...A recently-published study co-authored by two CalVO scientists brings attention to the role that lava dams played in shaping Lake Tahoe.
In a newly published study, U.S. Geological Survey scientists and their partners calculate possible alert times that earthquake early warning systems can provide people at different levels of ground motion from light to very strong shaking.
MEDIA ADVISORY
During the week of March 26, scientists from the U.S. Geological Survey will begin four days of mapping selected beaches and the adjacent seafloor in Santa Barbara and Ventura counties. Results will be compared to surveys from last fall to highlight changes due to winter waves, and to sediment inputs from area streams.
Early in his college career, U.S. Geological Survey geophysicist Rufus Catchings became drawn to the mysteries that lie beneath the earth’s surface — and was determined to understand them.
USGS oceanographer Juliette Finzi Hart shot 360-degree videos of king tides—the highest high tides of the year—throughout the Los Angeles region in 2016 and 2017.
Acting deputy director of the USGS Pacific Coastal and Marine Science Center Nadine Golden attended a workshop on restoring a sand-mining operation on California’s Monterey Bay.
Days after fatal debris flows devastated Southern California’s Montecito community, a team of U.S. Geological Survey geologists joined county, state, and federal partners to survey and evaluate the aftermath.
USGS geologist Patrick Barnard spoke to the public at a “Coffee and King Tides” gathering held in Half Moon Bay, California, on December 4.
News reporters are invited to attend a reception to kick off the U.S. Geological Survey’s STEP-UP Program in Menlo Park. STEP-UP (Secondary Transition to Employment Program – USGS Partnership) provides young adults (ages 18-22) with disabilities a variety of life and job skills to enable them to transition from school to work and to live independently.
It isn't often that scientists and land managers spend two entire days together talking about volcanoes outside of an eruptive crisis, but a special FEMA training course allows them to do just that.
Coastal communities count on beaches for recreation and for protection from large waves, but beaches are vulnerable to threats such as erosion by storms and flooding. Whether beaches grow, shrink, or even disappear depends in part on what happens just offshore. How do features like shifting sandbars affect waves, currents, and the movement of sand from the beach to offshore and back?
On October 12, USGS drones collected video footage of the Mud Creek landslide, which buried California State Highway 1 under a third-of-a-mile-wide mass of rock and dirt on May 20.
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Locations
Southwest Regional Director's Office
Phone: (916) 278-9551
Fax: (916) 278-9566
Pacific Coastal and Marine Science Center
Phone: 831-460-7401
Fax: 831-427-4748
Sacramento Projects Office (USGS California Water Science Center)
Phone: 916-278-3000
Fax: 916-278-3070
Western Ecological Research Center - Headquarters
Phone: (916) 278-9485
Fax: (916) 278-9475
Geology, Minerals, Energy and Geophysics Science Center
Phone: (650) 329-4881
Earthquake Science Center
Western Geographic Science Center - Main Office
San Diego Projects Office (USGS California Water Science Center)
Phone: 619-225-6100
Fax: 619-225-6101
Fort Collins Science Center
Phone: 970-226-9100
Fax: 970-226-9230
USGS California Volcano Observatory (CalVO package delivery)
askcalvo@usgs.gov
Phone: 650-329-5083
Poway Field Office (USGS California Water Science Center)
Phone: 858-679-4015
Fax: 858-679-4019
Truckee Field Office (USGS California Water Science Center)
Phone: 530-587-0910
Fax: 530-587-0914
Redding Field Office (USGS California Water Science Center)
Phone: 530-246-5282
Fax: 530-246-0717
Ukiah Field Office (USGS California Water Science Center)
Phone: 707-468-4040
Fax: 707-468-4022
Redlands Field Office (USGS California Water Science Center)
Phone: 909-798-3272
West Sacramento Projects Office (USGS California Water Science Center)
Phone: 916-617-2799
Eureka Satellite Office (USGS California Water Science Center)
Phone: 707-442-3169
Fax: 707-445-7860
Sacramento Field Office (USGS California Water Science Center)
Phone: 916-381-0207
Fax: 916-381-0556
Santa Cruz Field Office (USGS California Water Science Center)
Phone: 831-460-7494
Santa Maria Field Office (USGS California Water Science Center)
Phone: 805-928-9539
Fax: 805-928-9220
USGS Menlo Park Library
men_lib@usgs.gov
Phone: 650-329-5027
Fax: 650-329-5132