Fish-Habitat Relationships Along the Estuarine Gradient of the Sacramento-San Joaquin Delta, California: Implications for Habitat Restoration

Estuaries and Coasts (Springer) | June 6th, 2018

Estuaries are highly variable environments where fish are subjected to a diverse suite of habitat features (e.g., water quality gradients, physical structure) that filt

Estuaries are highly variable environments where fish are subjected to a diverse suite of habitat features (e.g., water quality gradients, physical structure) that filter local assemblages from a broader, regional species pool. Tidal, climatological, and oceanographic phenomena drive water quality gradients and, ultimately, expose individuals to other habitat features (e.g., stationary physical or biological elements, such as bathymetry or vegetation). Relationships between fish abundances, water quality gradients, and other habitat features in the Sacramento-San Joaquin Delta were examined as a case example to learn how habitat features serve as filters to structure local assemblages in large river-dominated estuaries. Fish communities were sampled in four tidal lakes along the estuarine gradient during summer-fall 2010 and 2011 and relationships with habitat features explored using ordination and generalized linear mixed models (GLMMs). Based on ordination results, landscape-level gradients in salinity, turbidity, and elevation were associated with distinct fish assemblages among tidal lakes. Native fishes were associated with increased salinity and turbidity, and decreased elevation. Within tidal lakes, GLMM results demonstrated that submersed aquatic vegetation density was the dominant driver of individual fish species densities. Both native and non-native species were associated with submersed aquatic vegetation, although native and non-native fish populations only minimally overlapped. These results help to provide a framework for predicting fish species assemblages in novel or changing habitats as they indicate that species assemblages are driven by a combination of location within the estuarine gradient and site-specific habitat features.

Fishes, Hydrology, and Ecology of the Klamath River Basin

National Academy of Sciences (NAS) | February 11th, 2008

The Klamath River basin in southern Oregon and northern California is the focus of a prominent conflict over competing uses for water in the American West. Management mea

The Klamath River basin in southern Oregon and northern California is the focus of a prominent conflict over competing uses for water in the American West. Management measures for the protection of threatened and endangered fish species in the basin that have left less water available for irrigation have increased tensions among farmers and other stakeholders and brought into question the scientific justification of these measures. Two National Research Council studies evaluate a series of federal scientific assessments and recommend scientifically justified approaches to the problem.

Five Decades of Magical Thinking: How California's Water Policy is Founded on a Bankrupt 53-year-old Fantasy

California Water Impact Network (C-WIN) | May 5th, 2012

Recent revelations confirm that California's water policy is founded on a decades-old water deficit, one that will only be compounded by Jerry Brown's Twin Tunnels projec

Recent revelations confirm that California's water policy is founded on a decades-old water deficit, one that will only be compounded by Jerry Brown's Twin Tunnels project—a boondoggle scheme that would attempt to meet unsustainable contractual obligations by draining the Sacramento/San Joaquin Delta of fresh water. The real issue here is not about how water is conveyed; it's about whether there is enough water for more conveyance or storage. When California officials built the State Water Project in 1960, they knew it would run out of water by 1981. To make up the shortfall, the state overappropriated water from the Delta. Operation of the Twin Tunnels is predicated on 1960 water availability estimates of anticipated diversions from north state rivers. These diversions from the Middle Fork Eel, the Mad and Van Duzen Rivers did not occur due to their ultimate state and federal designation as Wild and Scenic Rivers.

Five Guiding Principles for Effective Voluntary Agreements

University of California, Berkeley (UC Berkeley) | January 3rd, 2024

California has increasingly emphasized efforts to develop voluntary agreements (VAs) with water users as a means of achieving regulatory goals in certain watersheds. In t

California has increasingly emphasized efforts to develop voluntary agreements (VAs) with water users as a means of achieving regulatory goals in certain watersheds. In theory, a VA can combine the protectiveness of a regulatory backstop with the creativity and flexibility of a negotiated deal to produce outcomes as good as, or better than, those achievable through strict application of regulatory requirements alone. However, reality has not always measured up to this ideal. This policy paper uses the Bay-Delta watershed as a case study to inform five principles to guide the appropriate use and evaluation of VAs.

Five-century record of climate and groundwater recharge variability in southern California

Nature Portfolio (Springer Nature) | December 3rd, 2019

Modifications to the rates of water flowing from the surface to groundwater (groundwater recharge) due to climate variability are the most difficult to assess because of

Modifications to the rates of water flowing from the surface to groundwater (groundwater recharge) due to climate variability are the most difficult to assess because of the lack of direct long-term observations. Here, we analyze the chloride salt distribution below the surface soil on a plateau near Los Angeles to reconstruct the amount of recharge that occurred in the last five centuries. Over this time interval, periods of major high and low recharge with different duration follow each other and this cyclicity is consistent with long-term atmospheric forcing patterns, such as the Pacific Decadal Oscillation. This study determines the range and the natural variability of recharge to groundwater, which sustains local freshwater flow system, and helps forecast future availability of groundwater resource in southern California, where water scarcity is critical to both local and global populations.

Fixing the Delta: How Will We Pay for It?

Public Policy Institute of California (PPIC) | August 4th, 2009

This report examines the question of how to pay for urgently needed investments in the Sacramento–San Joaquin Delta. For years, stakeholders have been at odds over bene

This report examines the question of how to pay for urgently needed investments in the Sacramento–San Joaquin Delta. For years, stakeholders have been at odds over beneficiary financing (charging those who use the water). But recent federal intervention to save endangered fish species and the decline of state and federal funding sources may finally break the impasse. This report situates the beneficiary payment debate in historical, legal, and political context. It also explores how this kind of financing might work for several “big ticket” items: water conveyance facilities, storage reservoirs, environmental mitigation, and levee improvements.

Fixing the Flawed Colorado River Compact

American Geophysical Union (AGU) | June 16th, 2023

Flame retardants and plastic additives in San Francisco Bay: Targeted monitoring of organophosphate esters and bisphenols

San Francisco Estuary Institute (SFEI) | January 31st, 2020

Flexibility and intensity of global water use

Nature Portfolio (Springer Nature) | June 3rd, 2019

Water stress is often evaluated by scarcity: the share of available water supply being consumed by humans. However, some consumptive uses of water are more or less flexib

Water stress is often evaluated by scarcity: the share of available water supply being consumed by humans. However, some consumptive uses of water are more or less flexible than others, depending on the costs or effects associated with their curtailment. Here, we estimate the share of global water consumption over the period 1980–2016 from the relatively inflexible demands of irrigating perennial crops, cooling thermal power plants, storing water in reservoirs and supplying basic water for humans and livestock. We then construct a water stress index that integrates the share of runoff being consumed (scarcity), the share of consumption in these inflexible categories (flexibility) and the historical variability of runoff weighted by storage capacity (variability), and use our index to evaluate the trends in water stress of global major river basins on six continents. We find that the 10% most stressed basins encompass ~19%, 19% and 35% of global population, thermal electricity generation and irrigated calorie production, respectively, and some of these basins also experience the largest increases in our identified stress indexes over the study period. Water consumption intensities (water used per unit of goods or service produced) vary by orders of magnitude across and within continents, with highly stressed basins in some cases characterized by high water consumption intensities. Our results thus point to targeted water mitigation opportunities (for example, relocating crops and switching cooling technologies) for highly stressed basins.

Flood Control System Status Report

California Department of Water Resources (DWR) | December 12th, 2011

This Flood Control System Status Report (FCSSR) describes the current status (physical condition) of SPFC facilities at a systemwide level. DWR prepared the FCSSR to meet

This Flood Control System Status Report (FCSSR) describes the current status (physical condition) of SPFC facilities at a systemwide level. DWR prepared the FCSSR to meet the legislative requirements of California Water Code Section 9120, and to contribute to development of the Central Valley Flood Protection Plan (CVFPP). The CVFPP will guide future State investments through projects to address identified problems in the SPFC. The FCSSR is primarily intended to present information on the physical condition of SPFC facilities, and to help guide future inspection, evaluation, reconstruction, and improvement of the facilities. Information contained in the FCSSR should not be used to predict how a levee orassociated facilities may perform in a specific flood event. More detailed information (such as additional geotechnical explorations and analyses at a greater frequency) would be necessary to meet other purposes, such as assessing whether a levee could be certified under Federal Emergency Management Agency (FEMA) standards to provide base flood protection under the National Flood Insurance Program.