San Joaquin River

Recent California Water Transfers: Implications for Water Management

Natural Resources Journal (University of New Mexico) | January 3rd, 1995

The 1991 and 1992 California Drought Emergency Water Banks were the first large water transfer programs in the nation in which the state served as the predominant broke

The 1991 and 1992 California Drought Emergency Water Banks were the first large water transfer programs in the nation in which the state served as the predominant broker for water trades. Although the state-sponsored Water Banks have drawn widespread attention, there have been a great number of water transfers and exchanges taking place in California independently of the state. These transfers illustrate well the widespread applicability of transfers in managing water resource systems, as well as the multiple mechanisms available for effecting water transfers. This article focuses on California's recent experiences with water transfers, and offers a series of potential lessons for federal, state, and local managers for integrating water transfers in regional water resource systems.

Recent California Water Transfers: Implications for Water Management

Natural Resources Journal (University of New Mexico) | December 1st, 1995

The 1991 and 1992 California Drought Emergency Water Banks were the first large water transfer programs in the nation in which the State served as the predominant

The 1991 and 1992 California Drought Emergency Water Banks were the first large water transfer programs in the nation in which the State served as the predominant broker for water trades. Although the State-sponsored Water Banks have drawn widespread attention, there have been a great number of water transfers and exchanges taking place in California independently of the State. These non-State transfers illustrate well the widespread applicability of transfers in managing water resource systems, as well as the multiple mechanisms available for effecting water transfers. This paper focuses on California's recent experiences with water transfers, and offers a series of potential lessons for federal, state, and local managers for integrating water transfers in regional water resource systems.

Recent declines in salmon body size impact ecosystems and fisheries

Nature Portfolio (Springer Nature) | August 19th, 2020

Declines in animal body sizes are widely reported and likely impact ecological interactions and ecosystem services. For harvested species subject to multiple stressors, l

Declines in animal body sizes are widely reported and likely impact ecological interactions and ecosystem services. For harvested species subject to multiple stressors, limited understanding of the causes and consequences of size declines impedes prediction, prevention, and mitigation. We highlight widespread declines in Pacific salmon size based on 60 years of measurements from 12.5 million fish across Alaska, the last largely pristine North American salmon-producing region. Declines in salmon size, primarily resulting from shifting age structure, are associated with climate and competition at sea. Compared to salmon maturing before 1990, the reduced size of adult salmon after 2010 has potentially resulted in substantial losses to ecosystems and people; for Chinook salmon we estimated average per-fish reductions in egg production (−16%), nutrient transport (−28%), fisheries value (−21%), and meals for rural people (−26%). Downsizing of organisms is a global concern, and current trends may pose substantial risks for nature and people.

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 

Recent Scientific Contributions by the U.S. Geological Survey in the San Francisco Bay and Sacramento–San Joaquin Delta Estuary

U.S. Geological Survey (USGS) | January 26th, 2026

Recent strengthening of eastern Pacific ENSO in the last millennium paleorecord

American Association for the Advancement of Science (AAAS) | August 27th, 2026

The Pacific El Niño–Southern Oscillation (ENSO) generates climate extremes that endanger ecosystems, infrastructure, and human well-being worldwide. The response of th

The Pacific El Niño–Southern Oscillation (ENSO) generates climate extremes that endanger ecosystems, infrastructure, and human well-being worldwide. The response of this system to climate warming is poorly constrained, due both to data scarcity and uncertainties in climate models. The geochemistry of Galápagos coral skeletons across the past millennium reveals a large recent increase in interannual variability of sea surface temperature in the eastern equatorial Pacific compared to existing paleorecords that exceeds simulated natural variability. This increase parallels rising global temperature and results from stronger El Niño events. Central Pacific coral data also show increased variability, although less distinctly than in the Galápagos. Our results provide long-term context for understanding ENSO variability trends, with troubling implications for climate extremes.

Recharge Area Identification, Utilization, and Protection Resource Management Strategy

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

This resource management strategy (RMS) advances water supply augmentation, resilience, and equity in California by providing summaries of the state of knowledge, applica

This resource management strategy (RMS) advances water supply augmentation, resilience, and equity in California by providing summaries of the state of knowledge, applications, and available information and resources on recharge area identification, utilization, and protection.

Recharge Net Metering to Enhance Groundwater Sustainability

University of California, Berkeley (UC Berkeley) | April 2nd, 2018

Groundwater sustainability depends on balancing aquifer inflows and outflows. Extraction (pumping of groundwater, typically for human use) and recharge (inflow of

Groundwater sustainability depends on balancing aquifer inflows and outflows. Extraction (pumping of groundwater, typically for human use) and recharge (inflow of water to an aquifer from the land surface and streams) are central components of this water balance. Often, increasing demands for groundwater are exacer- bated by stresses on limited surface water supplies. Changes in land use and shifting climate can result in less infiltration of precipitation into the ground, reducing recharge. Increasing water scarcity has led to increased pumping, and in turn, unsustainable management of groundwater in many basins, resulting in depleted supplies, degraded water quality, and other impacts.

Recommendations for a Modeling Framework to Answer Nutrient Management Questions in the Sacramento-San Joaquin Delta

San Francisco Estuary Institute (SFEI) | March 1st, 2016

Management actions in the Delta related to nutrients could cost billions of dollars to implement in the coming decades depending on decisions that will come before the Ce

Management actions in the Delta related to nutrients could cost billions of dollars to implement in the coming decades depending on decisions that will come before the Central Valley Regional Water Quality Control Board (Water Board). The complexity of the Delta ecosystem and the range of questions to be addressed demand that numerical, processed-based water quality modeling be part of Delta management efforts. In light of this fact, the Water Board convened the Modeling Science Workgroup in 2015, and tasked it with advising on the development and use of water quality models as one component of the Water Board’s Nutrient Research Plan. The Charge to the Modeling Science Workgroup (included in Appendix B) was to provide advice to the Water Board on:  · The types of models would be needed to answer the nutrient management questions raised by stakeholders,  · Organizational arrangements to support and maximize the benefits of models, and  · Cost estimates for the modeling task and how such work might be phased over time. 

Recommendations to the State Water Resources Control Board Pursuant to California Water Code Section 10609

California Department of Water Resources (DWR) | September 29th, 2022

The Department of Water Resources (DWR) is pleased to provide the following recommendations developed in response to the 2018 Legislation (Senate Bill 606 [Hertzberg] and

The Department of Water Resources (DWR) is pleased to provide the following recommendations developed in response to the 2018 Legislation (Senate Bill 606 [Hertzberg] and Assembly Bill 1668 [Friedman]) enacted in support of “Making Water Conservation a California Way of Life.” The Legislation included provisions for advancing urban water use efficiency through developing and implementing various water use efficiency standards, variances for unique uses of water, and commercial, industrial, and institutional (CII) performance measures, among other requirements. Full reports detailing our methods, technical analyses, studies, public input, and recommendations will follow. These recommendations for long-term urban water use efficiency reflect technical considerations, public input, and the imperative to continue California’s progress in urban efficient use of water for future generations. If adopted DWR's recommendations on outdoor residential and CII water use on landscapes with dedicated irrigation meters, combined with the indoor residential water use standard recommendations submitted to the Legislature jointly by DWR and State Water Resources Control Board (State Water Board), pursuant to Water Code 10609.4 (b)(1), would result in expected long-term water savings of approximately 450,000 acre-feet per year starting in 2030 – considering 2019 population and 2017-2019 water use data, the water savings are enough to supply about 1.6 million homes or 4.7 million residents for both indoor and outdoor annual water needs.