California Waters - Fall 2024 - Vol. IV | Issue III
Welcome to the Fall 2024 edition of the USGS California Water Science Center newsletter. The purpose of this newsletter is to keep its readers updated with current research projects, the latest publications, and other work the center is doing.
In situ chlorophyll fluorometer validation and comparison study
The Sacramento-San Joaquin Delta (Delta) supplies drinking water to much of California. The Delta also provides irrigation water to the Central Valley and is an important habitat to many aquatic and terrestrial species. In the past decade, there has been an increase in harmful algal blooms (HABs) in the Delta. While some HABs are nontoxic, others contain cyanobacteria that can produce dangerous toxins, posing health risks to people and animals.
USGS Scientists Present Findings at Clear Lake Integrated Science Symposium 2024
Located in California’s Coast Range, approximately 60 miles north of San Francisco Bay, Clear Lake is the largest natural lake entirely within the state. The USGS California Water Science Center (CAWSC) conducts a variety of research at Clear Lake, including surface-water monitoring, watershed modeling, and aquatic habitat studies.
Groundwater quality near the Placerita Oil Field, California, 2018
Groundwater-quality data and potential fluid-migration pathways near the Placerita Oil Field in Los Angeles County, California, were examined by the U.S. Geological Survey to determine if oil-field fluids (water and gas from oil-producing and non-producing zones) have mixed with groundwater resources. Six of the 13 new groundwater samples collected for this study contained petroleum hydrocarbons,
New Maps Identify Legacy Mercury Contamination in California’s Sierra Nevada
Legacy Mercury Contamination from Historical Gold Mining -- A visualization tool for spatial data on sediment, water, and biota in the Sierra Nevada, California

The California Water Science Center Welcomes Dr. Ryan Banta as Associate Director of Projects
On October 21st, Dr. Ryan Banta assumed the role of Associate Director of Projects for the California Water Science Center (CAWSC). Dr. Banta comes to CAWSC from the Colorado Water Science Center where he held the position of Hydrologic Studies Chief.
Dr. Banta received a bachelor’s degree from University of California, Davis majoring in Soil and Water Science with an Environmental Toxicology minor. He received his M.S. and Ph.D. in Hydrology from the University of Nevada, Reno. His graduate and postdoctoral research focused on interdisciplinary approaches to investigate high resolution trace element ice core records from Greenland and Antarctica. He currently focuses on local, state, and national topics related to water quality, water quantity, and hydrologic processes.
Read Dr. Banta's staff profile to learn more about his work.
Evaluating Seawater Intrusion Forecast Uncertainty under Climate Change in Pajaro Valley, California: Model Archive
Climate change and climate variability impacts such as rising sea levels have the potential to exacerbate seawater intrusion and the strain on coastal freshwater resources in already stressed groundwater basins such as those in the Pajaro Valley groundwater basin, California. The U.S. Geological Survey (USGS) developed the Pajaro Valley Hydrologic model (PVHM) to quantitatively assess aquifer-syst
USGS Water Science Centers Join Forces at 2024 Lake Tahoe Summit
Scientists from the California and Nevada Water Science Centers attended the 28th annual Lake Tahoe Summit to discuss the work the USGS is doing in the Tahoe Basin. The theme of this year’s event was “Connecting Tahoe: Investing in Transit, Trails, and Technology for the Future.”
Post Carr Fire bioassessment data report, Whiskeytown National Recreation Area, Shasta County, California
The U.S. Geological Survey, in cooperation with the National Park Service, analyzed water and sediment chemistry, benthic macroinvertebrate assemblages, fish and amphibian assemblages, fish and invertebrate tissues, instream habitat characteristics, and sediment heterogeneity at 10 stream sites within Whiskeytown National Recreation Area, Shasta County, California, during August 2020, 2 years afte
Evaluating the Geohydrology in the San Gorgonio Pass Area
The San Gorgonio Pass, in southern California, is located between the San Bernardino and San Jacinto Mountain ranges. The mountain ranges to either side of the pass rise almost 9,000 feet (2,700 meters) above. The San Gorgonio Pass serves as a corridor for U.S. Interstate 10. It is also known for its strong winds that make it a popular spot for wind turbine energy production.
Habitat Vulnerability to Climate Change: Identifying Climate Change Induced Mass Mortality Events Across Large Landscapes of the United States
USGS researchers will characterize extreme climatic events across U.S. following a review of case studies of mass mortality events associated with climate extremes including drought, precipitation, freeze, heat waves, and storm events.
Carmel River Basin Hydrologic Models: Future Climate Data
This digital dataset contains the gridded future climate data used for the Carmel River Basin Hydrologic Model. The daily climate data for the Carmel River Basin Hydrologic Model Hydrologic Model are based on the Salinas and Carmel River Basins Study (SCRBS) future climate scenarios (Henson and others, 2024). SCRBS considers one baseline climate scenario that represents recent historical climate c