Sacramento River

Conceptual model for salinity in the Central Valley and Sacramento-San Joaquin Delta

Central Valley Drinking Water Policy Workgroup | July 13th, 2007

This report examines the state of knowledge about the causes of salinity increase in the system and opportunities to improve the Delta as a source of municipal and agricu

This report examines the state of knowledge about the causes of salinity increase in the system and opportunities to improve the Delta as a source of municipal and agricultural water supply. It begins with background information about salinity, its measurement, and its impacts. Following that, we present observed salinity in the Bay-Delta system. The conceptual models section, the core of this report, then seeks to explain the forces and processes (drivers) that cause the salinity patterns we observe. The computational models section introduces some of the tools available to assist with salinity management and planning. The last chapter explores the implications of the conceptual model for monitoring and management of salinity.

Conduct Airborne Electromagnetic Surveys

California Department of Water Resources (DWR) | July 15th, 2020

Confined Animal Facility Permitting and Reporting Under the Porter-Cologne Water Quality Control Act: An Analysis of Regional Board Activities

Stanford University | February 2nd, 2026

This white paper analyzes reports containing (1) data from 2023 for the five regions with the largest numbers of CAFs in California; and (2) data from 2024 from the regio

This white paper analyzes reports containing (1) data from 2023 for the five regions with the largest numbers of CAFs in California; and (2) data from 2024 from the region with the most CAFs in the state. We identify six central problems with the self-reporting regime: CAFs frequently underreport wastewater production, or fail to report it at all. CAFs frequently underreport manure production. CAFs do not disclose, or inadequately document, where waste goes. Most CAFs fail to report how much waste they apply to their crops. (Those that do typically report significant overapplication.) CAFs frequently fail to account for all nutrients in the waste they produce. Regional Boards do not adequately enforce reporting requirements.

Confirmation of Initial Incidental Take for Adult Delta Smelt for the 2018 Water Year

U.S. Fish and Wildlife Service (FWS) | January 4th, 2018

Conjunctive Water Management Resource Management Strategy

California Department of Water Resources (DWR) | April 29th, 2024

Conjunctive water management, also referred to as conjunctive use, is broadly defined as the coordinated and planned use and management of the different sources of water

Conjunctive water management, also referred to as conjunctive use, is broadly defined as the coordinated and planned use and management of the different sources of water in time and space. It is usually focused on surface water and groundwater resources to maximize the availability and reliability of water supplies in a region to meet various management objectives. It is a holistic approach to water resource management that can increase available water for beneficial uses, allow water agencies greater flexibility in scheduling deliveries, and improve drought resiliency (California Department of Water Resources 2003).

Conservation Strategy for Restoration of the Sacramento-San Joaquin Delta, Sacramento Valley and San Joaquin Valley Regions

CALFED | May 15th, 2014

The Conservation Strategy describes ERP goals and conservation priorities for Stage 2 of the CALFED Bay-Delta Program (CALFED) and was developed by the Department of Fish

The Conservation Strategy describes ERP goals and conservation priorities for Stage 2 of the CALFED Bay-Delta Program (CALFED) and was developed by the Department of Fish and Wildlife (CDFW) in coordination with the United States Fish and Wildlife Service (USFWS) and the National Oceanic and Atmospheric Administration Fisheries Service (NOAA Fisheries), collectively known as the ERP Implementing Agencies. This document serves as the conceptual framework that will guide future ERP environmental restoration, including development of conservation priorities and processes to identify and implement restoration opportunities, and monitoring to guide and improve its success in the Sacramento-San Joaquin Delta (Delta), and the Sacramento Valley and the San Joaquin Valley regions. This Conservation Strategy builds on information presented in the Ecosystem Restoration Program Plan (ERPP) (CALFED 2000a), the Multi-species Conservation Strategy (MSCS) (CALFED 2000d), ERP Milestones Reports (CALFED 2001b) and Annual Reports (DFG 2011b), the best available science on current ecological conditions, related programs and planning efforts, and input from stakeholders and the general public. There are many different kinds of conservation planning currently underway for the Delta, Sacramento and San Joaquin Valley regions and restoration is very much a shared vision between and among the agencies, various resource users, and the public. ERP Implementing Agencies will be using this ERP Stage 2 Conservation Strategy as a guide through the end of Stage 2 (2030). It provides a comprehensive ecosystem restoration strategy for ERP efforts in the Focus Area (Focus Area) (Figure 1), allowing flexibility in adapting responses accordingly to new scientific findings, changed circumstances and new or modified future conservation priorities. This Conservation Strategy will serve as a guide to identify programmatic-level types and locations of potential restoration actions based on conservation priorities. It is not a prescription for restoration actions at any specific site. Within this strategy is a compilation of conservation priorities, articulated from lessons learned during Stage 1, which may be used to meet ERP goals. All agencies, groups, or individuals interested in resource conservation and management within the Focus Area are encouraged to use this document as a guide to help coordinate activities to address ERP conservation priorities.

Conserving for the common good: Preferences for water conservation policies during a severe drought in Northern California

Water Resources and Economics | December 3rd, 2021

During the 2011–2017 drought in California, water providers used a variety of demand-side management (DSM) policies to successfully reduce water consumption by over 20

During the 2011–2017 drought in California, water providers used a variety of demand-side management (DSM) policies to successfully reduce water consumption by over 20%. Unfortunately, because utilities used numerous conservation policies simultaneously, little is known about support for specific policies—specifically, an untested water budgeting policy wherein utilities gave households an allotment of water and charged higher prices for water used in excess of the budget. California recently legislated mandatory long-term reductions in water usage. It is therefore critical to obtain a better understanding of which policies, including water budgeting, have strongest public support, and to understand how the drought experience changed residents’ water use behaviors, attitudes, beliefs, habits, and personal capabilities surrounding conservation. This work surveyed individuals residing in northern California, the “North State,” during a period of severe drought. We used best-worst scaling to determine households’ preferences for DSM policies; asked households how their water use behaviors changed; and evaluated psychological attitudes toward drought and water conservation. Results show the vast majority of households changed their water use behaviors during the drought. Over two-thirds of respondents never exceeded their water budgets and said they would continue to conserve after the state lifted conservation requirements. Respondents preferred water budgets relative to more familiar DSM policies, a result with implications for forecasting future water demand. Last, our survey finds only minor differences in policy preferences for respondents with different demographics and attitudes toward water use, even for variables (e.g., income) that previous literature has found to have disparate welfare effects across users.

Contaminant Effects on California Bay-Delta Species & Human Health

University of California, Davis (UC Davis) | December 1st, 2016

Many contaminants in the California Bay-Delta exceed regulatory standards, impact aquatic species, and potentially affect human health. Recent studies provide evidence th

Many contaminants in the California Bay-Delta exceed regulatory standards, impact aquatic species, and potentially affect human health. Recent studies provide evidence that contaminants impact species of concern in the Bay-Delta (e.g., the decline of several important fish species referred to as the “Pelagic Organism Decline”). Multiple chemicals impair processes at cellular and physiological levels (measured as growth, development, and behavior abnormalities), ultimately affecting populations. As an important example, the population decline of the endangered delta smelt (Hypomesus transpacificus) is significantly associated with multiple stressors, including insecticide use. New analyses presented in this paper show significant correlations between pyrethroid (an insecticide) use and declining abundance of POD fish species. Water sampled from the Bay-Delta causes multiple harmful effects in fish and delta smelt. Fish prey items are also impacted by contaminants; this may have an indirect effect on their populations. Co-occurrence with thermal changes or disease can worsen contaminant effects. Contaminants also pose threats to human health via consumption of fish, drinking water, and contact recreation, in particular, mercury, toxins, disinfection byproducts, pesticides, pharmaceuticals, and personal care products. The role of contaminants in the decline of Bay-Delta species is difficult to accurately assess in a complex, dynamic system. However, tools and approaches are available to evaluate contaminant impacts on Bay-Delta species, and separate the effects of multiple stressors. Integrated monitoring and focused mechanistic studies are instrumental for addressing management needs. Impact and risk assessments should be conducted for different species across multiple life stages, with emphasis on early life stages of high-priority Bay-Delta species.  

Contributions of Climate Change and ENSO Variability to Future Precipitation Extremes Over California

American Geophysical Union (AGU) | June 14th, 2023

Coordinated Long-Term Operation of the Central Valley Project and State Water Project, Final Environmental Impact Statement

U.S. Bureau of Reclamation (USBR) | November 30th, 2015