Estimated ground-water discharge by evapotranspiration from Death Valley, California

U.S. Geological Survey (USGS) | July 1st, 2003

Estuary News, October 2021

San Francisco Estuary Partnership (SFEP) | October 15th, 2021

Evaluating groundwater quality influences from oil field operations and other anthropogenic activities in an urban setting, Santa Fe Springs, California

Science of the Total Environment (Elsevier) | June 22nd, 2026

Groundwater quality is often affected by anthropogenic activities in urban settings. This study examines groundwater quality in and around the Santa Fe Springs Oil Field

Groundwater quality is often affected by anthropogenic activities in urban settings. This study examines groundwater quality in and around the Santa Fe Springs Oil Field in Los Angeles County, California, where oil and gas production commonly intersects with high density industrial, commercial and residential land uses. Utilizing a combination of new and historical data, we evaluated potential pathways that would allow for oil field formation fluids to migrate into groundwater and whether mixing may have occurred based on the distribution of groundwater and oil field formation fluid tracers in samples. Samples were analyzed for a wide array of constituents including volatile organic compounds, light hydrocarbons, major ions, and various isotopic compositions. Despite evidence of oil field infrastructure providing potential pathways of migration via uncemented annular spaces, casing breaches and historical disposal of oil field formation water in surface ponds, the distribution and occurrence of stable isotopes of water, chloride, boron, and total dissolved solids do not indicate mixing of oil field formation water and groundwater. However, methane isotopic signatures and the presence of heavier alkanes suggest gas from oil-bearing formations have migrated from depth via oil field well infrastructure. Volatile organic compound detections were mainly from manufactured compounds unrelated to oil and gas production, with a relatively limited number of petroleum hydrocarbons also detected. Volatile organic compounds were generally found in wells tapping shallow, modern aged groundwater, indicating anthropogenic activities occurring at or near land surface as the source. Study results suggest that while oil field infrastructure provides migration pathways for oil field formation fluids to be introduced into groundwater, urban land uses not related to oil and gas production are the primary drivers of groundwater quality degradation.

Feather River Hydrologic Observatory: Improving Hydrological Snowpack Forecasting for Hydropower Generation Using Intelligent Information Systems

California Energy Commission (CEC) | August 31st, 2018

Changing climatic conditions and a lack of representative snow cover data challenge the ability to accurately model and fully utilize the water resources of montane snowp

Changing climatic conditions and a lack of representative snow cover data challenge the ability to accurately model and fully utilize the water resources of montane snowpack on which California depends. This project aims to improve scientific understanding of snowpack modeling and streamflow forecasting techniques. Though relevant across industries and the state, this research focuses on hydropower applications in the North Fork of the Feather River. Central components of the project are four wireless sensor networks, installed in locations that are representative of vegetation and topography patterns across the basin. The networks collect snow, temperature, relative humidity, soil moisture, and soil temperature data every 15 minutes. By blending this information with remote sensing data and historical maps, we estimate the spatial distribution of snow water resources at high resolution. These outputs can help improve runoff forecasting tools such as the Precipitation-Runoff Modeling System (PRMS). Preliminary results show that wireless sensor networks can successfully track hydrologic states and fluxes in real time and provide a more representative picture of snowpack accumulation and melt than traditional index stations. Network data are also used to gain insight into rain-on-snow events, which are a key streamflow generation mechanism for the Feather River. The data show that the current calibration of PRMS on the Feather River could overestimate snowfall and underestimate liquid precipitation. Future steps include a sensitivity analysis of PRMS to identify its dominant parameters and conceptual limitations, as well as a full, dynamic recalibration of the model. Blended maps of snow water equivalent will also be assimilated into the model. These results will be included in the decision-support suite for PG&E, California’s largest electric and natural gas utility, and an analysis will be performed to assess results’ economic value for stakeholders in the energy and water-supply sectors. 

Fill Mead First: A Technical Assessement

Utah State University | October 11th, 2016

The Fill Mead First (FMF) plan would establish Lake Mead reservoir as the primary water storage facility of the main-stem Colorado River and would relegate Lake Powell re

The Fill Mead First (FMF) plan would establish Lake Mead reservoir as the primary water storage facility of the main-stem Colorado River and would relegate Lake Powell reservoir to a secondary water storage facility to be used only when Lake Mead is full. The objectives of the FMF plan are to re-expose some of Glen Canyon’s sandstone walls that are now inundated, begin the process of re-creating a riverine ecosystem in Glen Canyon, restore a more natural stream-flow, temperature, and sediment-supply regime of the Colorado River in the Grand Canyon ecosystem, and reduce system-wide water losses caused by evaporation and movement of reservoir water into ground-water storage. 

From wastewater treatment plants to decentralized resource factories

Nature Portfolio (Springer Nature) | June 10th, 2024

Geohydrology and Evapotranspiration at Franklin Lake Playa, Inyo County, California

U.S. Geological Survey (USGS) | July 1st, 1997

Geostatistical Mapping of Salinity Conditioned on Borehole Logs, Montebello OilField, California

National Groundwater Association (NGWA) | December 3rd, 2021

We present a geostatistics-based stochastic salinity estimation framework for the Montebello Oil Field that capitalizes on available total dissolved solids (TDS) data fro

We present a geostatistics-based stochastic salinity estimation framework for the Montebello Oil Field that capitalizes on available total dissolved solids (TDS) data from groundwater samples as well as electrical resistivity (ER) data from borehole logging. Data from TDS samples (n = 4924) was coded into an indicator framework based on falling below four selected thresholds (500, 1000, 3000, and 10,000 mg/L). Collocated TDS-ER data from the surrounding groundwater basin were then employed to produce a kernel density estimator to establish conditional probabilities for ER data (n = 8 boreholes) falling below the selected TDS thresholds within the Montebello Oil Field area. Directional variograms were estimated from these indicator coded data, and 500 TDS realizations from conditional indicator simulation were generated for the subsurface region above the Montebello Oil Field reservoir. Simulations were summarized as 3D maps of median TDS, most likely salinity class, and probability for exceeding each of the specified TDS thresholds. Results suggested TDS was below 500 mg/L in most of the study area, with a trend toward higher values (500 to 1000 mg/L) to the southwest; consistent with the average regional groundwater flow direction. Discrete localized zones of TDS greater than 1000 mg/L were observed, with one of these zones in the greater than 10,000 mg/L range; however, these areas were not prevalent. The probabilistic approach used here is adaptable and is readily modified to include additional data and types and can be employed in time-lapse salinity modeling through Bayesian updating.

Greenhouse gas emissions from US irrigation pumping and implications for climate-smart irrigation policy

Nature Portfolio (Springer Nature) | January 23rd, 2024

Groundwater quality near the Placerita Oil Field, California, 2018

U.S. Geological Survey (USGS) | September 26th, 2024

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 Surve

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, thermogenic gas, inorganic chemical signatures, and (or) isotopic values consistent with potential mixing with fluids from hydrocarbon-bearing formations.