San Francisco Bay

Letter from National Marine Fisheries Service: Re: Proposed Modification to the Annual Review Schedule Required as Part of the Reasonable and Prudent Alternative in the National Marine Fisheries Service’s 2009 Biological Opinion on the Coordinated Long-term Operation of the Central Valley Project and State Water Project (June 30, 2016)

Delta Stewardship Council (Delta Council) | June 30th, 2016

Letter from U.S. Bureau of Reclamation: Proposed Modification to the Annual Review Schedule Required as Part of the Reasonable and Prudent Alternative in the National Marine Fisheries Service’s 2009 Biological Opinion on the Coordinated Long-term Operation of the Central Valley Project and State Water Project (April 25, 2016)

Delta Stewardship Council (Delta Council) | April 25th, 2016

Letter to State Water Board re: Flow Criteria that use Percent of Unimpaired Flow

Delta Stewardship Council (Delta Council) | May 22nd, 2012

The proposed use of percent of unimpaired flow is a step toward improving the outlook for fish and other wildlife utilizing the San Joaquin River and its tributaries. Fal

The proposed use of percent of unimpaired flow is a step toward improving the outlook for fish and other wildlife utilizing the San Joaquin River and its tributaries. Fall-run Chinook salmon are likely to benefit from February-through-June flows that are more natural in timing and variability than current flows. Compared with the existing maze of flow standards for the San Joaquin River and its tributaries, unimpaired flow comes closer to approximating natural flow, and it does so more transparently. Caveats include: (1) flow is but one of many stressors affecting fish and wildlife; (2) the choice of flow criteria and metrics needs to serve the broader needs of ecosystems as well as individual species; (3) a chosen percentage of unimpaired flow may fall short of the minimum needed by fish and wildlife in some years; and (4) such critical years are likely to become more common as Sierra Nevada snowpacks diminish as a consequence of climate change. This qualified endorsement is based on our reading of the “Technical Report on the Scientific Basis for Alternative San Joaquin River Flow and Southern Delta Salinity Objectives” (State Water Resources Control Board, February 2012).

Levee Decisions and Sustainability for the Sacramento-San Joaquin Delta

University of California, Davis (UC Davis) | August 15th, 2010

Levee Failures in the Sacramento-San Joaquin River Delta: Characteristics and Perspectives

Texas A&M University | December 15th, 2011

Between 1850 and 1922, agriculturalists built 1,700 kilometers of levees to convert 250,000 hectares of tidal marsh to farmland where the San Joaquin and Sacramento River

Between 1850 and 1922, agriculturalists built 1,700 kilometers of levees to convert 250,000 hectares of tidal marsh to farmland where the San Joaquin and Sacramento Rivers enter the San Francisco Bay (the Delta). Drained, farmed and isolated from the water channels, the organic soils behind the levees subsided to elevations as low as 8 meters below sea level, turning "levees" into "dams" that hold back water constantly. Engineers built water transfer projects in the mid-20th century, transferring water from the south Delta to 25 million Californians who now rely on the "dams" accidentally converted into supply channels. In 1972, however, a levee failure caused a salt-water intrusion into the Delta, raising the prominence of the polemic Peripheral Canal which, if built would replace the levees in the trans-Delta water transport role. Levee failures in 2004 (the Delta) and 2005 (New Orleans) have re-ignited the debate, fueled by comments made by public officials who warned that the Delta levees posed more risk of failure than did the pre-Katina Louisiana levees. This background motivates two research questions: What are the social perspectives regarding levee failures of the experts managing the Delta; and what is the history of levee failures that might support their perspectives? The research employed Q-Method to identify and describe four social perspectives: Delta Sustainers, Abandon the Levees, Levee Pragmatists, and Multi-Purpose Levee Advocates. A critical element underlying differences among the perspectives revolved around the perceived history of failures of Delta levees. This dissertation employed semi-structured interviews, archival record searches, and historic map and aerial photograph comparisons to compile a history of 265 levee failures since 1868, many of which are referenced to location, segment, and levee type. In addition, the dissertation compiled a list of emergency repairs and successful flood-fights. The history of failures indicates that important levees of the Delta have performed significantly better than previously identified. Sharing these social perspectives and research results among the key actors addressing Delta issues may lead to improved consensus decisions.

Leveraging Wetlands for a Better Climate Future

San Francisco Estuary Institute (SFEI) | July 15th, 2022

Managing Natural and Working Lands (NWL) to enhance carbon sinks and limit greenhouse gas (GHG) emissions is a key component of California’s ambitious strategy to achie

Managing Natural and Working Lands (NWL) to enhance carbon sinks and limit greenhouse gas (GHG) emissions is a key component of California’s ambitious strategy to achieve net carbon neutrality by 2045. The California Air Resources Board (CARB) Climate Change Scoping Plan includes 7 NWL categories in its GHG emission reduction scenarios, one of which is wetlands. Coastal wetlands in California are a high- leverage NWL type for GHG management relative to their small spatial footprint. These ecosystems have high rates of carbon sequestration and can accumulate large stocks of carbon, due to high productivity, efficient sediment trapping, and low decomposition rates (Chmura et al. 2003, Mcleod et al. 2011). In the absence of management interventions focused on wetland conservation, however, conversion of coastal wetlands to other land uses such as agriculture, grazing, development, impounded wetlands, or subtidal or upland habitat can halt or reverse carbon sequestration, and can shift these ecosystems from long-term GHG sinks to large GHG sources (Hatala et al. 2012, Tan et al. 2019). Filling of wetlands for infrastructure and development was a common practice throughout the early 20th century (Goals Project 1999), dramatically reducing the state’s coastal wetland area and associated carbon sink.

Linked fire activity and climate whiplash in California during the early Holocene

Nature Portfolio (Springer Nature) | November 23rd, 2022

Recent wildfire activity in semi-arid regions like western North America exceeds the range of historical records. High-resolution paleoclimate archives such as stalagmi

Recent wildfire activity in semi-arid regions like western North America exceeds the range of historical records. High-resolution paleoclimate archives such as stalagmites could illuminate the link between hydroclimate, vegetation change, and fire activity in pre-anthropogenic climate states beyond the timescale of existing tree-ring records. Here we present an analysis of levoglucosan, a combustion-sensitive anhydrosugar, and lignin oxidation products (LOPs) in a stalagmite, reconstructing fire activity and vegetation composition in the California Coast Range across the 8.2 kyr event. Elevated levoglucosan concentrations suggest increased fire activity while altered LOP compositions indicate a shift toward more woody vegetation during the event. These changes are concurrent with increased hydroclimate volatility as shown by carbon and calcium isotope proxies. Together, these records suggest that climate whiplash (oscillations between extreme wetness and aridity) and fire activity in California, both projected to increase with anthropogenic climate change, were tightly coupled during the early Holocene.

Linking variation in water democracy to system performance on the human right to water

Springer Nature | October 8th, 2025

Listen to the River: An Independent Review of the CVPIA Fisheries Program

U.S. Bureau of Reclamation (USBR) | December 12th, 2008

In 1992 Congress directed the Department of Interior to develop and implement a program that makes “all reasonable efforts” to ensure and sustain on a long-term basis

In 1992 Congress directed the Department of Interior to develop and implement a program that makes “all reasonable efforts” to ensure and sustain on a long-term basis a doubling of the number of naturally produced anadromous fish in Central Valley rivers and streams by 2002. Doubling did not happen by the legislative goal of 2002, or by 2008, nor is it likely to ever occur unless renewed commitments and improvements are made to the CVPIA program. The specific “doubling” mission itself may make little scientific or policy sense, especially within the time frames demanded. Yet it is also far from clear that the agencies have done what is possible and necessary to improve freshwater conditions to help these species weather environmental variability, halt their decline and begin rebuilding in a sustainable way. A number of the most serious impediments to survival and recovery are not being effectively addressed, especially in terms of the overall design and operation of the Central Valley Project system. Underlying this independent review of the CVPIA anadromous fish program, asked for by the federal agencies, is the question why the CVPIA program has not been successful in achieving its mission. In this report, we identify scientific, institutional and programmatic obstacles to the success of the CVPIA, drawing conclusions from the information provided. Based on these conclusions, we make recommendations to Reclamation and the Service on how these obstacles might be overcome.

Long-Term Operations of the Central Valley Project and State Water Project Draft Environmental Impact Statement

U.S. Bureau of Reclamation (USBR) | July 26th, 2024

The Bureau of Reclamation (Reclamation) prepared this Environmental Impact Statement (EIS) for the 2021 Endangered Species Act Reinitiation of Section 7 Consultation on t

The Bureau of Reclamation (Reclamation) prepared this Environmental Impact Statement (EIS) for the 2021 Endangered Species Act Reinitiation of Section 7 Consultation on the Long-Term Operation of the Central Valley Project (CVP) and State Water Project (SWP). This EIS is meant to inform the public and decision-makers on potential federal actions by examining a range of reasonable alternatives and the potential effect on the environment. Reclamation manages the Central Valley Project (CVP). The California Department of Water Resources (DWR) manages the State Water Project (SWP). Collectively, the operation of the CVP and SWP provides flood control and navigation, delivers water to 30 million people, supports 4 million acres of agriculture, maintains 19 wildlife refuges on the Pacific Flyway, protects numerous iconic and endemic species such as Chinook salmon, coho salmon, steelhead, sturgeon, and smelt, generates 4.5 million megawatt hours of electricity, maintains water quality for beneficial uses in the California Bay-Delta, and supports recreation throughout Northern California. This summary provides a succinct overview of the development of alternatives in coordination with other agencies and the public, major conclusions for key environmental resource areas, the identification of avoidance and mitigation measures to address potential impacts, and issues that have been in dispute as raised by the public and other interested parties. This summary provides the material required by the Council on Environmental Quality’s National Environmental Policy Act (NEPA) Implementing Regulations regarding the contents of an EIS summary. Click here to read Maven's Notebook background article to the new DEIS.