California Water Science Center

Land-use surveys of the Adelaida Area of San Luis Obisbo County, CA for 1996 and 2014. Numbers indicate acres and percent of total developed acres. Source: California Department of Water Resources, 

Trace 1310 GC with a TSQ 9000 triple quadrupole MS (Thermo Scientific)

Scientists Collect Water Quality Data Prior to Wastewater Treatment Plant Upgrades

USGS Scientists Map Nutrients on Sacramento Delta

One-Water Hydrologic Flow Model: A MODFLOW Based Conjunctive-Use Simulation Software (Boyce and others, 2020).

Diagram showing that water flow and use is interconnected through physically-based processes and management processes. Note that precipitation is not included in figure, but is a source of water that could potentially reduce the landscape water demand and increase aquifer storage and stream flow (

Diagram the MODFLOW-2005 framework and its descendants (Boyce and others, 2020) 

Land use change in the Anza Valley, CA from 1934 to 2005.  

The USGS California Basin Characterization Model (BCM) was used to understand the rate and amounts of natural groundwater recharge in the Indian Wells Valley and to refine historical estimates of groundwater recharge in the valley. Results from this study provide validation of recharge estimates

USGS Research Scientist Ellen Goodrich-Stuart adjusts a CH4 (Methane) analyzer mounted on the eddy covariance flux tower at the Rush Ranch site at Suisun Marsh. 

Locations of the July 2019 earthquake epicenters and six USGS groundwater-monitoring sites. The hydrographs show the response of groundwater levels to the earthquakes.  Sites shown are California (1)