Fourth Supplement to State Water Resources Board Bulletin No. 11 San Joaquin County Investigation, Basic Data, Calaveras Unit 1957-58

California Department of Water Resources (DWR) | March 27th, 1959

Free Water While It Lasts: An Analysis of Wholesale Water Pricing in the Lower Colorado River Basin States

University of California, Los Angeles (UCLA) | December 11th, 2025

The Colorado River is facing a shortage of between two million and four million acre-feet per year (MAFY), nearly one-third of its current annual flow and the equivalent

The Colorado River is facing a shortage of between two million and four million acre-feet per year (MAFY), nearly one-third of its current annual flow and the equivalent of the amount needed to supply up to 30 million people with water each year (Shutt, 2022). Following a century of declining flow and two decades of the worst drought in more than 1,200 years to grip the U.S. Southwest, the U.S. Bureau of Reclamation is putting pressure on states that draw from the Colorado River to reduce water usage and create a long-term plan for responsible water management. But the price that agricultural and municipal water districts and utilities pay to divert federal water supplies in the western United States disincentivizes sustainable water practices and conservation efforts. In this paper, the UCLA Institute of the Environment and Sustainability (IoES) and the Natural Resources Defense Council (NRDC) explored the current state of water pricing for surface water supplies across Arizona, California, and Nevada, the three states comprising the Lower Colorado River Basin. We demonstrate that the vast majority of water sourced through the federal government from the Colorado River and other federal projects is sold or supplied at prices that do not reflect the scarcity of the resource; we also identify significant disparities between large agricultural districts and municipal utilities in the price paid for water at the wholesale level.

Frequently Asked Questions Related to the CASGEM Program

California Department of Water Resources (DWR) | August 21st, 2023

Since 2009, the California Statewide Groundwater Elevation Monitoring (CASGEM) Program has tracked seasonal and long-term groundwater elevation trends in groundwater basi

Since 2009, the California Statewide Groundwater Elevation Monitoring (CASGEM) Program has tracked seasonal and long-term groundwater elevation trends in groundwater basins statewide. The program’s mission is to establish a permanent, locally-managed program of regular and systematic monitoring in all of California's alluvial groundwater basins. Senate Bill x7-6, passed by the legislature in 2009, established collaboration between local monitoring parties and DWR to collect statewide groundwater elevations, to be made available to the public. In response to the law, we developed the CASGEM program. Collecting and evaluating these groundwater data on a statewide scale is a fundamental step toward improving management of California's groundwater resources. The CASGEM program relies and builds upon the many previously established local long-term groundwater monitoring and management programs. Click here for the CASEGEM Data and Resources directory from the Department of Water Resources.

Freshwater Scarcity

Annual Review of Environment and Resources (Annual Reviews) | October 24th, 2021

The availability and use of fresh water are critical for human health and for economic and ecosystem stability. But the growing mismatch between human demands and natur

The availability and use of fresh water are critical for human health and for economic and ecosystem stability. But the growing mismatch between human demands and natural freshwater availability is contributing to water scarcity, affecting industrial and agricultural production and a wide range of social, economic, and political problems, including poverty, deterioration of ecosystem health, and violent conflicts. Understanding and addressing different forms of water scarcity are vital for moving toward more sustainable management and use of fresh water. We provide here a review of concepts and definitions of water scarcity, metrics and indicators used to evaluate scarcity together with strategies for addressing and reducing the adverse consequences of water scarcity, including the development of alternative sources of water, improvements in water-use efficiency, and changes in systems of water management and planning.

Friant Division Central Valley Project

U.S. Bureau of Reclamation (USBR) | January 4th, 1994

Water is life the cliché goes, but in California, the reality is water is power. The Eureka State is blessed with warm days and productive soil, but deprived of enough w

Water is life the cliché goes, but in California, the reality is water is power. The Eureka State is blessed with warm days and productive soil, but deprived of enough water to go around. The pursuit of the power conferred by the water flowing in its rivers, and bubbling up from underground, is a much more complicated part of the Central Valley Project (CVP) than authorization, design, and construction. An anomaly in the CVP's labyrinthine history, the Friant Division developed along lines similar to other Reclamation projects in the West. One of three original segments of the CVP, the Friant Division, is separate, simple in design, but has seen it share of the same kinds of controversy plaguing the rest of the project. In spite of the disputes Friant generated, of the top five agricultural producing counties in the nation, three -- Fresno, Tulare and Kern -- are watered by Friant Division facilities. The clear sky, fertile land, and dry air of the southern San Joaquin Valley provide the backdrop where great promises have been met and modest hopes destroyed all in order to create "the richest agricultural region in the history of the world."

Friant Water Supply Protection Association vs. Del Puerto Water District et al

Superior Court of California, County of Stanislaus | October 31st, 2022

Friant-Kern Canal Middle Reach Capacity Correction

U.S. Bureau of Reclamation (USBR) | January 25th, 2022

From Climate Traces to Climate Insights: Future Scenarios Analysis for the California Central Valley

California Department of Water Resources (DWR) | October 2nd, 2023

California Water Code Section 10004.6 requires the California Department of Water Resources (DWR) to quantify current and future water conditions in the state. This infor

California Water Code Section 10004.6 requires the California Department of Water Resources (DWR) to quantify current and future water conditions in the state. This information is published in the California Water Plan (Water Plan), which is updated every five years. Water managers and planners constantly face the challenges of planning for an uncertain future where the only constant is change. To address the potential future changes and mitigate the probable risks, water managers must consider and quantify uncertainties and their impacts on water system vulnerability. Although it is not possible to know for certain how population growth, land use decisions, climate, and other factors change over time, water planners must consider these system stressors in long-term planning to evaluate future risks and uncertainty. The Water Plan evaluates many alternative future scenarios as an integral part of its analytical approach to quantify system vulnerability under a range of population and urban growth scenarios, land use, and climate uncertainties.

From Climate-Change Spaghetti to Climate-Change Distributions for 21st Century California

University of California, Davis (UC Davis) | March 1st, 2005

The uncertainties associated with climate-change projections for California are unlikely to disappear anytime soon, and yet important long-term decisions will be needed t

The uncertainties associated with climate-change projections for California are unlikely to disappear anytime soon, and yet important long-term decisions will be needed to accommodate those potential changes. Projection uncertainties have typically been addressedby analysis of a few scenarios, chosen based on availability or to capture the extreme cases among available projections. However, by focusing on more com-mon projections rather than the most extreme projections (using a new resampling method), new insights into current projections emerge: (1) uncertainties associated with future greenhouse-gas emissions are comparable with the differences among climate models, so that neither source of uncertainties should be neglected or underrepresented; (2) twenty-first century temperature projections spread more, overall, than do precipitation scenarios; (3) projections of extremely wet futures for California are true outliers among current projections; and (4) current projections that are warmest tend, overall, to yield a moderately drier California, while the cooler projections yield a some-what wetter future. The resampling approach appliedin this paper also provides a natural opportunity to objectively incorporate measures of model skill and the likelihoods of various emission scenarios into future assessments.

Funding Opportunity for Voluntary Participation in the Lower Colorado Conservation and Efficiency Program

U.S. Bureau of Reclamation (USBR) | October 12th, 2022