Central Valley Project Water Supply and Yield Study

U.S. Bureau of Reclamation (USBR) | December 26th, 2007

The CALFED Bay-Delta Authorization Act, Title 1 of Public Law 108-361 (the Water Supply, Reliability, and Environmental Improvement Act of 2004) directed the Secretary of

The CALFED Bay-Delta Authorization Act, Title 1 of Public Law 108-361 (the Water Supply, Reliability, and Environmental Improvement Act of 2004) directed the Secretary of the Interior (Secretary), acting through the Bureau of Reclamation (Reclamation), to conduct a study of available water supplies and existing and future needs for water in the State of California. The Secretary is to prepare a report identifying possible projects and water management actions that could provide new firm yield and water supply improvements for the CVP. The Secretary is also required to incorporate and revise, as necessary, the results of the 1995 Least-Cost CVP Yield Increase Plan originally required by section 3408(j) of Central Valley Project Improvement Act (CVPIA) of 1992. The purpose of this Water Supply and Yield (WSAY) Study is to identify the following: 1. Opportunities for new firm yield and water supply improvements for CVP water service contractors (entities with contracts for the delivery of CVP water) 2. Water management actions or projects that would improve firm yield for the CVP while balancing the available supplies with existing demands 3. The financial costs of the water management actions or projects 4. Beneficiaries and beneficiaries’ willingness to pay for identified improvements

Challenges Facing the Sacramento–San Joaquin Delta: Complex, Chaotic, or Simply Cantankerous?

University of California, Davis (UC Davis) | September 17th, 2015

Freshwater is a scarce and precious resource in California; its overall value is being made clear by the current severe drought. The Sacramento–San Joaquin Delta is a c

Freshwater is a scarce and precious resource in California; its overall value is being made clear by the current severe drought. The Sacramento–San Joaquin Delta is a critical node in a complex water supply system that extends throughout much of the western U.S. wherein demand is exceeding supply. The Delta also underpins a major component of the U.S. economy, helps feed a substantial part of the country, is a unique and valuable ecological resource, and is a place with a rich cultural heritage. Sustaining the Delta is a problem that manifests itself in many dimensions including the physical structure of the Delta, the conflicting demands for water, changing water quality, rapidly evolving ecological character, and high institutional complexity. The problems of the California Delta are increasingly complex, sometimes chaotic, and always contentious. There is general agreement that current management will sustain neither the Delta ecosystem nor high-quality water exports, as required under the Delta Reform Act, so there is a renewed urgency to address all dimensions of the problem aggressively. Sustainable management of the Delta ecosystem and California’s highly variable water supply, in the face of global climate change, will require bold political decisions that include adjustments to the infrastructure but give equal emphasis to chronic overuse and misuse of water, promote enhanced efficiency of water use, and facilitate new initiatives for ecosystem recovery. This new approach will need to be underpinned by collaborative science that supports ongoing evaluation and re-adjustment of actions. Problems like the Delta are formally “wicked" problems that cannot be “solved” in the traditional sense, but they can be managed with appropriate knowledge and flexible institutions. Where possible, it is advisable to approach major actions incrementally, with an eye toward avoiding catastrophic unexpected outcomes. Collaborative analyses of risks and benefits that consider all dimensions of the problem are essential. Difficult as the problems are, California has the tools and the intellectual resources to manage the Delta problem and achieve the twin goals of a reliable water supply and an ecologically diverse Delta ecosystem.

Characterizing uncertain sea-level rise projections to support investment decisions

PLOS | February 17th, 2018

Many institutions worldwide are considering how to include uncertainty about future changes in sea-levels and storm surges into their investment decisions regardi

Many institutions worldwide are considering how to include uncertainty about future changes in sea-levels and storm surges into their investment decisions regarding large capital infrastructures. Here we examine how to characterize deeply uncertain climate change projections to support such decisions using Robust Decision Making analysis. We address questions regarding how to confront the potential for future changes in low probability but large impact flooding events due to changes in sea-levels and storm surges. Such extreme events can affect investments in infrastructure but have proved difficult to consider in such decisions because of the deep uncertainty surrounding them. This study utilizes Robust Decision Making methods to address two questions applied to investment decisions at the Port of Los Angeles: (1) Under what future conditions would a Port of Los Angeles decision to harden its facilities against extreme flood scenarios at the next upgrade pass a cost-benefit test, and (2) Do sea-level rise projections and other information suggest such conditions are sufficiently likely to justify such an investment? We also compare and contrast the Robust Decision Making methods with a full probabilistic analysis. These two analysis frameworks result in similar investment recommendations for different idealized future sea- level projections, but provide different information to decision makers and envision different types of engagement with stakeholders. In particular, the full probabilistic analysis begins by aggregating the best scientific information into a single set of joint probability distributions, while the Robust Decision Making analysis identifies scenarios where a decision to invest in near-term response to extreme sea-level rise passes a cost-benefit test, and then assembles scientific information of differing levels of confidence to help decision makers judge whether or not these scenarios are sufficiently likely to justify making such investments. Results highlight the highly-localized and context dependent nature of applying Robust Decision Making methods to inform investment decisions.

Chowchilla Subbasin Sustainable Groundwater Management Act (SGMA) Groundwater Sustainability Plan (3rd Revision)

Madera County | January 3rd, 2025

In 2024-2025, the GSAs revised the Subbasin GSP to:  Amend the Domestic Well Mitigation Program Refine the Groundwater Level Representative Monitoring Sites (RMS

In 2024-2025, the GSAs revised the Subbasin GSP to:  Amend the Domestic Well Mitigation Program Refine the Groundwater Level Representative Monitoring Sites (RMS) Network Refine Groundwater Level Sustainable Management Criteria (SMC)  Backstop Projects and Management Actions Refine Subsidence SMC and Provide for Subsidence Mitigation

Chowchilla Subbasin Sustainable Groundwater Management Act (SGMA) Groundwater Sustainability Plan (Revised)

Chowchilla Subbasin GSP Advisory Committee | July 27th, 2022

Due to file size, this document has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10, Part 11, Part 12, Part 13, Part 14, Par

Due to file size, this document has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10, Part 11, Part 12, Part 13, Part 14, Part 15, Part 16, Part 17  

Chowchilla Subbasin Sustainable Groundwater Management Act (SGMA) Groundwater Sustainablity Plan

Chowchilla Subbasin GSP Advisory Committee | January 1st, 2020

City of Santa Barbara Sea-Level Rise Vulnerability Study

California Energy Commission (CEC) | July 31st, 2012

Cliff and bluff erosion, flooding of low-lying areas, and damage to shoreline infrastructure and development will continue to affect California’s coastal communities in

Cliff and bluff erosion, flooding of low-lying areas, and damage to shoreline infrastructure and development will continue to affect California’s coastal communities in the decades ahead. Depending upon the rate of future sea-level rise, changes in wave energy, and coastal storm intensity and frequency, these hazards will be likely become more severe, with increasing risks to coastal communities. This study assesses the vulnerability of the City of Santa Barbara to future sea-level rise and related coastal hazards (by 2050 and 2100) based upon past events, shoreline topography, and exposure to sea-level rise and wave attack. It also evaluates the likely impacts of coastal hazards to specific areas of the City, analyzes their risks and the City’s ability to respond, and recommends potential adaptation responses. By 2050, the risk of wave damage to shoreline development and infrastructure in Santa Barbara will be high. Options are limited and adaptive capacity will be moderate, with retreat being the most viable long-term option. By 2100, the risk will become very high. By 2050, flooding and inundation of low-lying coastal areas will present a moderate risk to the City by 2050, which will have a moderate capacity for adaptation. If the high sea levels projected by the State occur, this risk will become very high, and adaptive capacity will become low by 2100. Cliff erosion has been taking place for decades, and as this process continues or increases, additional public and private property in the Mesa area will be threatened. The risk of increased cliff erosion will be moderate by 2050 and very high by 2100. Because armoring is ineffective here and retreat necessitates the relocation of structures, adaptive capacity will be low. Inundation of beaches presents a low threat to the City by 2050 but a high threat by 2100. The City faces a dilemma: protect oceanfront development and infrastructure or remove barriers and let beaches migrate inland. By 2100 structures will have to be moved if beaches are to be maintained.

Civic Engagement and Water Data: How Can California Make Data Work for Decision Makers?

University of California, Berkeley (UC Berkeley) | September 1st, 2020

 Much attention is focused on water data in California, and for good reason. California is struggling to make decisions that adapt its water systems to pressures such as

 Much attention is focused on water data in California, and for good reason. California is struggling to make decisions that adapt its water systems to pressures such as climate change and population growth. Fully informed decisions are impossible without accurate and accessible data and information to support them. California already produces immense amounts of water-related data. However, agencies and stakeholders currently struggle to bring these data together to support routine decision making. Overall, we lack any systematic understanding of whether and how existing data can support the needs of decision makers. 

Clean Watersheds Needs Survey 2012

U.S. Environmental Protection Agency (EPA) | December 13th, 2012

Clear Lake Watershed and Lake Remediation

University of California, Davis (UC Davis) | December 9th, 2024

The main goal of this joint effort between the University of California Davis, Tahoe Environmental Research Center (UCD-TERC), and the United States Geological Survey (US

The main goal of this joint effort between the University of California Davis, Tahoe Environmental Research Center (UCD-TERC), and the United States Geological Survey (USGS), is to develop the watershed and in-lake monitoring and modeling needed to:  Better understanding of the processes contributing to poor water quality;  Predict watershed and lake responses to changing environmental conditions; and,  Evaluate the impacts and unintended consequences of potential management and restoration activities.