Total Water Management Study for the Central Valley Basin, California, Interim Water Supply Working Document No. 9

U.S. Bureau of Reclamation (USBR) | March 1st, 1976

Toward a Preemptive Ecology for Rapid, Global, and Increasingly Irreversible Environmental Change: A Discussion Paper with Implications for Research and Management in the Sacramento-San Joaquin Delta

Delta Stewardship Council (Delta Council) | November 15th, 2019

People have extensively modified the Sacramento-San Joaquin Delta since the 1850s. Rapid change is not new, but the nature of rapid change that is beginning to be experie

People have extensively modified the Sacramento-San Joaquin Delta since the 1850s. Rapid change is not new, but the nature of rapid change that is beginning to be experienced has new qualities. The Delta Independent Science Board, working in conjunction with the Delta Science Program and the Delta Plan Interagency Implementation Committee, is assessing the adequacy of environmental and ecological research in the Delta, how well that research is addressing emerging challenges, and how it might be improved. This paper is a part of that process. Each member of the Delta Independent Science Board has contributed to this document, but there is not a consensus among the members around the full content of this paper. This paper is written to inform and stimulate discussion around controversial yet important issues. 

Towards the Protection, Restoration, and Enhancement of the Delta Ecosystem: A Synthesis

Delta Stewardship Council (Delta Council) | March 15th, 2018

Towards the Protection, Restoration, and Enhancement of the Delta Ecosystem: A Synthesis. Appendix A: Summary of Existing Habitat and Species-Specific Plans, Strategies, and Management Approaches

Delta Stewardship Council (Delta Council) | March 15th, 2018

Tracking Organic Matter in Delta Drinking Water

CALFED | April 1st, 2008

Tracking Where Water Goes in a Changing Sacramento–San Joaquin Delta

Public Policy Institute of California (PPIC) | May 26th, 2022

Click here for the accompanying Technical Appendix.

Click here for the accompanying Technical Appendix.

Tracking Where Water Goes in a Changing Sacramento–San Joaquin Delta Technical Appendix: Methods and Detailed Results for 1980–2021

Public Policy Institute of California (PPIC) | May 26th, 2022

Our goal is to provide water policymakers, managers, and regulators with information that will be helpful in managing the Delta and its watershed for multiple objectives

Our goal is to provide water policymakers, managers, and regulators with information that will be helpful in managing the Delta and its watershed for multiple objectives as warming conditions increase water demand, reduce snowpack, and make it harder to balance these objectives. An accompanying policy brief summarizes the findings presented here and highlights the major policy recommendations. This appendix provides details and evidence to support those recommendations and is intended for both a technical and policy audience. In the following sections we first review our approach for categorizing water flows in the watershed, and we review the caveats and limitations of the analysis. We next present key results and discuss several important watershed trends. We then review the management challenges of changing conditions in the Delta in wet and dry years through the lens of detailed water accounting. We conclude with implications for policy and management, including recommendations to improve watershed accounting and adapt the regulatory and management framework to the changing conditions in the watershed. All data assembled for this study, along with the sources and methods used, are detailed in the accompanying PPIC Delta Water Accounting spreadsheets.

Transitions for the Delta Economy

Public Policy Institute of California (PPIC) | January 3rd, 2012

Enormous changes—from natural forces to management decisions—are coming to California’s fragile Delta region and will have broad effects on its residents. This repo

Enormous changes—from natural forces to management decisions—are coming to California’s fragile Delta region and will have broad effects on its residents. This report finds that in the first half of this century, the Delta as a whole is likely to experience a loss of 1 percent of economic activity as a result of these changes. It also identifies planning priorities for managing the Delta’s future.

Translating Science-Based Restoration Strategies into Spatially-Explicit Restoration Opportunities in the Delta (2018 Bay-Delta Science Conference Presentation)

San Francisco Estuary Institute (SFEI) | July 2nd, 2018

In a previous report titled “A Delta Renewed” we offered a collection of guidelines for science-based ecological restoration in the Sacramento-San Joaquin Delta that

In a previous report titled “A Delta Renewed” we offered a collection of guidelines for science-based ecological restoration in the Sacramento-San Joaquin Delta that emphasized restoring or emulating natural processes, anticipating future changes associated with climate change, establishing appropriate configurations of habitat types at the landscape scale, and utilizing a variety multi-benefit management strategies. In this talk, we present on our recent work to support regional restoration planning efforts by developing a repeatable process for using these guidelines to identify spatially-explicit restoration opportunities. The process is largely GIS-based and utilizes spatial data on existing land cover and conservation status, habitat configuration (including patch sizes and distances), surface elevations (including depth of subsidence), and future changes in tidal elevations associated with sea-level rise.  By distilling generalized guidelines into spatially-explicit opportunities, we hope to provide a practical tool for incorporating science into planning. To that end, these new methods are currently being piloted through planning efforts focused on the Central Delta Corridor and the McCormack Williamson Tract, and are also being used to assist with the quantification of ecological restoration potential in the Delta Plan Ecosystem Amendment.

Trapping of Suspended Sediment by Submerged Aquatic Vegetation in a Tidal Freshwater Region: Field Observations and Long-Term Trends

Estuaries and Coasts (Springer) | July 14th, 2020

Widespread invasion by non-native, submerged aquatic vegetation (SAV) may modify the sediment budget of an estuary, reducing the availability of inorganic sediment requir

Widespread invasion by non-native, submerged aquatic vegetation (SAV) may modify the sediment budget of an estuary, reducing the availability of inorganic sediment required by marshes to maintain their position in the tidal frame. The instantaneous trapping rate of suspended sediment in SAV patches in an estuary has not previously been quantified via field observations. In this study, flows of water and suspended sediment through patches of invasive SAV were measured at three tidally forced, freshwater sites, all located within the Sacramento-San Joaquin Delta in California. An acoustic Doppler current profiler deployed from a roving vessel provided velocity and backscatter data used to quantify fluxes of both water and suspended sediment. Sediment trapping efficiency, defined as instantaneous net trapped flux divided by incident flux, was positive in 24 of 29 cases, averaging + 5%. Coupled with 3 years of measured sediment flux data at one site, this suggests that trapping averages 3.7 kg m−2 year−1. This estimate compares favorably with the mean mass accumulation rate of 3.8 kg m−2 year−1 estimated from dated sediment cores collected at the study sites. Long-term measurements made upstream reveal a strong negative trend (− 1.8% year−1) in suspended sediment concentration, and intra-annual changes in both suspended sediment concentration and percent fines. The large footprint and high spatial density of invasive SAV coupled with declining sediment supply are diminishing downstream suspended sediment concentrations, potentially reducing the resiliency of marshes in the Delta and lower estuary to future sea-level rise.