Data

This report documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the North Delta in the Sacramento-San Joaquin River Delta of California, USA. The data set includes nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, turbidity, and chlorophyll. Data-collection were conducted o

The U.S. Geological Survey, in cooperation with the California Department of Water Resources (DWR), has constructed a new spatially distributed Precipitation-Runoff Modeling System (PRMS) for the Merced River Basin (Koczot and others, 2021), which is a tributary of the San Joaquin River in California. PRMS is a deterministic, distributed-parameter, physical-process-based modeling system developed

Ground-based transient electromagnetic (TEM) data were acquired by the U.S. Geological Survey (USGS) at 16 locations of California’s southwestern San Joaquin Valley and Central Coast regions to define the electrical resistivity structure of hydrogeologic materials. Data were acquired using the ABEM WalkTEM system (Guideline Geo Ab, Sundbyberg, Sweden). TEM data were processed and numerically inver

These data describe microbiological analyses performed on groundwater samples from domestic drinking water supply collected from 42 groundwater wells in the Central Valley of California. Samples were collected between January 2014 and April 2014 for the Groundwater Ambient Monitoring and Assessment (GAMA) program priority basin assessment of the Madera, Chowchilla, and Kings (MACK) groundwater sub

Stakeholder science needs were determined by reviewing more than 200 recently published literature items and web pages from Colorado River Basin (CRB) stakeholders. These stakeholder communications were used to characterize over 400 stakeholder science needs by reviewing their priorities, strategies, issues, missions, and concerns related to drought in the CRB. Members of the CRB Integrated Scienc

Borehole erosion tests were performed to quantify sediment erosion rates as a function of depth below grade and flow speed at locations along the Sacramento and American Rivers in 2019. The dataset consists of: - borehole caliper files describing the initial geometry of the borehole, and its shape after each test flow event, - where available, a digital time series describing discharge into the ho

Neonicotinoids have become the most widely used insecticides in world with rapid growth in applications as seed coatings. Nontarget organisms are exposed to concentrated levels of pesticidal active ingredients through ingestion of treated seeds. To better understand pesticide fate, analytical methods are necessary to rapidly screen and accurately quantitate contaminants in environmental and biolog

Applications of pesticides in agricultural and urban settings play an essential role in increasing crop yields, preserving food and materials, reducing pest-borne diseases, and eradicating or deterring pests. Pesticides are transported from their point of application to environmental media, including surface water. To better understand the fate of fate and transport of pesticides in the environmen

This data release contains acoustic Doppler current profiler (ADCP) data used in generating a model of sediment flux through Carquinez Strait, CA at Benicia Bridge. The ADCP outputs binary data files containing measurement scheme, location, time, velocity, backscatter, boat heading, depth, and other parameters. There are two forms of data provided, one collected from two transects along the wester

The U.S. Geological Survey collected groundwater samples from 46 wells used for domestic and small system drinking water supplies in San Joaquin, Calaveras, and Stanislaus counties, California in 2019. The wells were sampled for the Northern San Joaquin Valley Domestic-Supply Aquifer Study Unit of the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAM

Optical sensors measuring fluorescent dissolved organic matter (fDOM) are increasingly being used in water quality studies because they provide proxy measurements for dissolved organic matter concentrations (DOC). Similarly, chlorophyll-a (chl-a) fluorescence sensors have gained popularity as a means to measure phytoplankton concentration, biomass, and even primary productivity using various appro

This data release documents grid cells and modeled groundwater levels for hydrologic characterization of aquifer areas used for public drinking-water supply in California’s Central Valley from 1990 to 2020. Observations of spring groundwater level (median depth to groundwater measured from January through April) were calculated for selected wells from the California Department of Water Resources (