Projecting groundwater storage changes in California’s Central Valley

Nature Portfolio (Springer Nature) | August 27th, 2018

Accurate and detailed knowledge of California’s groundwater is of paramount importance for statewide water resources planning and management, and to sustain a

Accurate and detailed knowledge of California’s groundwater is of paramount importance for statewide water resources planning and management, and to sustain a multi-billion-dollar agriculture industry during prolonged droughts. In this study, we use water supply and demand information from California’s Department of Water Resources to develop an aggregate groundwater storage model for California’s Central Valley. The model is evaluated against 34 years of historic estimates of changes in groundwater storage derived from the United States Geological Survey’s Central Valley Hydrologic Model (USGS CVHM) and NASA’s Gravity Recovery and Climate Experiment (NASA GRACE) satellites. The calibrated model is then applied to predict future changes in groundwater storage for the years 2015–2050 under various precipitation scenarios from downscaled climate projections. We also discuss and project potential management strategies across different annual supply and demand variables and how they affect changes in groundwater storage. All simulations support the need for collective statewide management intervention to prevent continued depletion of groundwater availability.

Pumping for the masses: evolution of groundwater management in metropolitan Los Angeles

Geo Journal (Springer) | August 7th, 2015

Groundwater supports many aspects of human life. In cities, groundwater can provide a cost-effective source of water for drinking and industrial uses, while groundwater b

Groundwater supports many aspects of human life. In cities, groundwater can provide a cost-effective source of water for drinking and industrial uses, while groundwater basins provide storage. The role of groundwater in a city’s water supply tends to change over time. In the Los Angeles metropolitan area, groundwater is critical. Over decades, users in the region’s many basins allocated annual pumping rights to groundwater among users through adjudications. These rights were determined through collective processes over decades, which contributed to the complex array of public and private organizations involved in water management. The rights also continue to evolve. We analyzed changes in the distribution of groundwater rights over time for adjudicated basins in Southern Los Angeles County. Results indicate that groundwater rights are increasingly: (1) controlled or regulated by public institutions and municipalities, and (2) consolidated among larger users. Yet, both the percentage of total supplies provided by groundwater, as well as the distribution of groundwater rights, varies widely among cities and communities throughout Los Angeles. As metropolitan Los Angeles faces reduced water imports and emphasizes local water reliance, access to pumping rights and storage capacity in groundwater basins will become even more vital. We discuss implications of our results for future urban water management.

Recent decreases in snow water storage in western North America

Nature Portfolio (Springer Nature) | May 22nd, 2023

Mountain snowpacks act as natural water towers, storing winter precipitation until summer months when downstream water demand is greatest. We introduce a Snow Storage Ind

Mountain snowpacks act as natural water towers, storing winter precipitation until summer months when downstream water demand is greatest. We introduce a Snow Storage Index (SSI), representing the temporal phase difference between daily precipitation and surface water inputs—sum of rainfall and snowmelt into terrestrial systems—weighted by relative magnitudes. Different from snow water equivalent or snow fraction, the SSI represents the degree to which the snowpack delays the timing and magnitude of surface water inputs relative to precipitation, a fundamental component of how snow water storage influences the hydrologic cycle. In western North America, annual SSI has decreased (p 

Recharge Roundtable Call to Action: Key Steps for Replenishing California Groundwater

Groundwater Resources Association of California (GRA) | September 24th, 2018

The age of tacitly treating groundwater as primarily an extractive resource is over, both for California and the rest of the world. This will require vastly more

The age of tacitly treating groundwater as primarily an extractive resource is over, both for California and the rest of the world. This will require vastly more managed aquifer recharge than ever previously imagined. It was in this spirit of profound concern for the future of not only groundwater resources, but also for water security and sustainability in general, that on October 2, 2017 the Groundwater Resources Association of California (GRA) and the University of California Water Security and Sustainability Research Initiative (UC Water) convened the Recharge Roundtable in Sacramento. The Recharge Roundtable consisted of 50 attendees with a diverse cross-section of disciplines and professions, including water managers, consultants, academics, hydrologists, and social scientists. The strong experience and expertise assembled in this group, together with the sincere interest in solving a daunting water challenge, made the meeting very productive and led to the proposed actions included in this document.

Report Card for California's Infrastructure 2019

American Society of Civil Engineers (ASCE) | May 9th, 2019

Report of Waste Discharge and Technical Report

Westlands Water District | July 10th, 2019

This Technical Report is in support of a Report of Waste Discharge (ROWD) for an agricultural aquifer storage and recovery (Ag-ASR) program for Westlands Water District

This Technical Report is in support of a Report of Waste Discharge (ROWD) for an agricultural aquifer storage and recovery (Ag-ASR) program for Westlands Water District (Westlands or District). The District is located in western Fresno and Kings Counties in the San Joaquin Valley. With the new Sustainable Groundwater Management Act (SGMA) signed into law in 2014, Westlands is pursuing means to recharge groundwater within the District’s boundaries, which coincide with the Westside Subbasin (Groundwater Subbasin Number 5-22.09). Due to the presence of poor quality shallow groundwater, fine-grained soils, and the Corcoran Clay restrictive layer, surface recharge opportunities are limited (Schmidt, 2009). Direct injection using Ag-ASR wells holds promise as a more widely implementable recharge method in the District.

Report on Colorado River Evaporation Loss

Metropolitan Water District of Southern California (MWD) | December 12th, 2022

Root Causes Analyses of the Oroville Dam Gated Spillway Failures and Other Developments

University of California, Berkeley (UC Berkeley) | July 20th, 2017

We have performed forensic Root Causes Analyses of the Oroville Dam Gated Spillway failures and other associated developments as unfunded (approximately 3,000 pro-bono h

We have performed forensic Root Causes Analyses of the Oroville Dam Gated Spillway failures and other associated developments as unfunded (approximately 3,000 pro-bono hours) volunteers of the University of California at Berkeley (UCB) Center for Catastrophic Risk Management (CCRM) Oroville Dam Advisory Group (ODAG). We initiated this work on January 27, 2017. The results contained in this report have been developed based on the currently available public document and information sources cited at the end of this report, included in the Preliminary Root Causes Analysis of the Failures of the Oroville Dam Gated Spillway report dated April 17, 2017, and in the Legislative Oversight Report: Oroville Dam report dated May 11, 2017.  This report documents our analyses of the Root Causes of the initial failure of the Gated Spillway. Appendix A of this report provides summaries of the procedures and processes we used to perform the Root Causes analyses, background on the components that comprise Engineered Systems, and background on the Human and Organizational Factor malfunctions (errors) responsible for failures of Engineered Systems. Appendix B provides details of our analyses of the Physical and Organizational Root Causes of the initial failure of the Gated Spillway. The opinions expressed in this Report are ours alone. The opinions expressed herein are a fair and accurate summary of our opinions, based upon our experience, education, training, and expertise.

Seasonal variation in total water storage in California inferred from GPS observations of vertical land motion

American Geophysical Union (AGU) | March 12th, 2014

GPS is accurately recording vertical motion of Earth's surface in elastic response to seasonal changes in surface water storage in California. California's mountains subs

GPS is accurately recording vertical motion of Earth's surface in elastic response to seasonal changes in surface water storage in California. California's mountains subside up to 12 mm in the fall and winter due to the load of snow and rain and then rise an identical amount in the spring and summer when the snow melts, the rain runs off, and soil moisture evaporates. We invert the GPS observations of seasonal vertical motions to infer changes in equivalent water thickness. GPS resolves the distribution of change in total water across California's physiographic provinces at a resolution of 50 km, compared to 200 km resolution from the Gravity Recovery and Climate Experiment. The seasonal surface water thickness change is 0.6 m in the Sierra Nevada, Klamath, and southern Cascade Mountains and decreases sharply to about 0.1 m east into the Great Basin and west toward the Pacific coast. GPS provides an independent inference of change in total surface water, indicating water storage to be on average 50% larger than in the NLDAS‐Noah hydrology model, likely due to larger changes in snow and reservoir water than in the model.

Shasta Lake Water Resources Investigation

U.S. Bureau of Reclamation (USBR) | July 1st, 2015

The purpose of this Shasta Lake Water Resources Investigation (SLWRI) Feasibility Report is to document the U.S. Department of Interior (Interior), Bureau of Reclamation

The purpose of this Shasta Lake Water Resources Investigation (SLWRI) Feasibility Report is to document the U.S. Department of Interior (Interior), Bureau of Reclamation (Reclamation) and cooperating agencies’ evaluation of the potential enlargement of Shasta Dam and Reservoir to (1) improve anadromous fish survival in the upper Sacramento River, (2) increase water supply reliability in the Central Valley of California, and (3) address related water resource problems, needs, and opportunities. This Final Feasibility Report presents the results of planning, engineering, environmental, social, economic, and financial studies and potential benefits and effects of alternative plans, and is a companion document to the Final Environmental Impact Statement (EIS), published under separate cover. This Final Feasibility Report, along with the Final EIS, will be used by the U.S. Congress to determine the type and extent of Federal interest in enlarging Shasta Dam and Reservoir. The SLWRI is a feasibility study that was authorized by Congress in 1980 in Public Law 96-375 and is being conducted by Reclamation, in coordination with cooperating agencies, other resource agencies, stakeholders, and the public. The SLWRI is being conducted consistent with the 1983 U.S. Water Resources Council Economic and Environmental Principles and Guidelines for Water and Related Land Resources Implementation Studies (P&G), Reclamation directives and standards, National Environmental Policy Act (NEPA), and other pertinent Federal, State of California (State), and local laws and policies. The SLWRI is one of five surface water storage studies recommended in the July 2000 CALFED Bay-Delta Program (CALFED) Programmatic Environmental Impact Statement/Report (PEIS/R) and August 2000 Programmatic Record of Decision (ROD). Preliminary studies in support of the CALFED PEIS/R considered more than 50 surface water storage sites throughout California and recommended more detailed study of the five sites identified in the CALFED Programmatic ROD. The Final EIS, accompanying this Final Feasibility Report, tiers to the CALFED PEIS/R.