Earthquakes and High Water as Levee Hazards in the Sacramento-San Joaquin Delta

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

EcoAtlas: Enhancing Regional Capacity for Habitat Restoration Project Tracking, Assessment and Reporting

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

This project consolidates information from a variety of existing datasets to signicantLly expand the project tracking functionality in EcoAtlas to include hundreds of h

This project consolidates information from a variety of existing datasets to signicantLly expand the project tracking functionality in EcoAtlas to include hundreds of habitat protection, enhancement, and restoration projects throughout the Central Valley and San Francisco Bay-Delta regions. The Project Tracker database has been redesigned to better accommodate detailed project information such as acres of distinct habitat types, species benefitted, progress and status, and funding sources. Additional functionality was added to enhance visual displays and queries of the tabular and spatial project data. As new projects are developed and existing projects enter new phases, information can be expanded and updated through the new online data entry forms. Additional spatial data layers such as “Modern Delta Habitat Types” allow users to evaluate projects within the context of existing ecological resources and other landscape characteristics and uses. Additional data, querying and mapping functionality will allow for improved analyses of changes in habitat extent, landscape-scale conservation planning, evaluation of progress towards meeting conservation objectives, and partnership building. By providing the tools needed to track and analyze landscape change, we will improve our ability to strategically conserve important habitats in the future.

Ecological implications of modeled hydrodynamic changes in the upper San Francisco Estuary

San Francisco Estuary Institute (SFEI) | May 2nd, 2016

Understanding how the pre-development upper San Francisco Estuary supported native wildlife is challenging because our current understanding of local wildlife ecology is

Understanding how the pre-development upper San Francisco Estuary supported native wildlife is challenging because our current understanding of local wildlife ecology is largely based on the profoundly altered modern landscape. This difficulty is compounded by the dynamic nature of the upper estuary’s aquatic habitats, which naturally experience tremendous temporal variability, largely due to the region’s Mediterranean climate. One approach to understanding how the system historically supported native wildlife is through a lens of landscape ecology (Whipple et al. 2012; SFEI-ASC 2014). This memorandum documents the first efforts to understand the landscape ecology of the upper estuary, comprising the Sacramento-San Joaquin River Delta and Suisun Bay, using a 3D hydrodynamic model of the pre-development system. By studying the pre-development landscape, we hope to gain insight into the deficiencies of the contemporary landscape and to help develop solutions for remedying these deficiencies. 

Ecological Studies of the Sacramento-San Joaquin Estuary, A Decennial Report 1961-1971

California Department of Fish and Wildlife (CDFW) | June 15th, 1972

Economic and water supply effects of ending groundwater overdraft in California’s Central Valley

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

Surface water and groundwater management are often tightly linked, even when linkage is not intended or expected. This link is especially common in semi-arid regions,

Surface water and groundwater management are often tightly linked, even when linkage is not intended or expected. This link is especially common in semi-arid regions, such as California. This paper summarizes a modeling study on the effects of ending long-term overdraft in California’s Central Valley, the state’s largest aquifer system. The study focuses on economic and operational aspects, such as surface water pumping and diversions, groundwater recharge, water scarcity, and the associated operating and water scarcity costs. This analysis uses CALVIN, a hydro-economic optimization model for California’s water resource system that suggests operational changes to minimize net system costs for a given set of conditions, such as ending long-term overdraft. Based on model results, ending overdraft might induce some major statewide operational changes, including large increases to Delta exports, more intensive conjunctive-use operations with increasing artificial and in-lieu recharge, and greater water scarcity for Central Valley agriculture. The statewide costs of ending roughly 1.2 maf yr-1  of groundwater overdraft are at least $50 million per year from additional direct water shortage and additional operating costs. At its worst, the costs of ending Central Valley overdraft could be much higher, perhaps comparable to the recent economic effects of drought. Driven by recent state legislation to improve groundwater sustainability, ending groundwater overdraft has important implications statewide for water use and management, particularly in the Sacramento–San Joaquin Delta. Ending Central Valley overdraft will amplify economic pressure to increase Delta water exports rather than reduce them, tying together two of California’s largest water management problems.

Economic Sustainability Plan for the Sacramento-San Joaquin Delta

Delta Protection Commission (DPC) | July 19th, 2012

The Sacramento-San Joaquin River Delta is a unique place of economic, environmental, historic, and cultural significance. The land and water resources of the Delta suppor

The Sacramento-San Joaquin River Delta is a unique place of economic, environmental, historic, and cultural significance. The land and water resources of the Delta support significant agricultural and recreation economies, and the Delta also has an important role as an infrastructure hub for water, energy, and transportation. The region’s rich history boasts of bustling, river-based commerce before the automobile age, and its cultural uniqueness includes the only rural town in America build by early Chinese immigrants. As the largest estuary on the west coast of the Americas, the Delta also is a place of striking natural beauty and ecological significance that is struggling with serious environmental degradation problems. Although surrounded by growing cities, the Delta remains a highly-productive agricultural area with rural charms, landscapes, and waterscapes not found elsewhere in California. In recent years, there has been great concern over increasing environmental degradation in the Delta and over court decisions that reduced the quantity of water delivered to southern California through the state and federal water project intakes in the south Delta to protect endangered fish. Combined with additional concerns about the stability of the Delta’s levee system, these concerns led the California legislature to pass the Delta Reform Act of 2009. The Act created the Delta Stewardship Council and charged it with developing a Delta Plan to achieve the coequal goals of “providing a more reliable water supply for California and protecting, restoring, and enhancing the Delta ecosystem.” Recognizing the potential impact of the Delta Plan on the people and economy of the Delta, the Delta Reform Act stated that the coequal goals of water supply reliability and restoring the Delta ecosystem “shall be achieved in a manner that protects and enhances the unique cultural, recreational, natural resource, and agricultural values of the Delta as an evolving place.” Among the measures to address this goal, the Delta Protection Commission was tasked with developing this Economic Sustainability Plan to inform the Delta Stewardship Council’s development of the Delta Plan. The Legislature established the following guidelines for the Economic Sustainability Plan in the Delta Reform Act of 2009: "The economic sustainability plan shall include information and recommendations that inform the Delta Stewardship Council’s policies regarding the socioeconomic sustainability of the Delta region. (b) The economic sustainability plan shall include, but not be limited to, all of the following: 1) Public safety recommendations, such as flood protection recommendations. 2) The economic goals, policies, and objectives in local general plans and other local economic efforts, including recommendations on continued socioeconomic sustainability of agriculture and its infrastructure and legacy communities in the Delta. 3) Comments and recommendations to the Department of Water Resources concerning its periodic update of the flood management plan for the Delta. 4) Identification of ways to encourage recreational investment along the key river corridors, as appropriate. Since a key purpose of this Economic Sustainability Plan is to inform the Delta Plan under development by the Delta Stewardship Council, this report analyzes the impact of key policies being considered for the plan on the economic sustainability of the Delta. Many of the most significant proposals for the Delta are being developed in the Bay Delta Conservation Plan (BDCP). The policy proposals can be grouped into four categories: 1) water conveyance, 2) habitat creation, 3) levees, and 4) land use regulation. The report also considers many aspects of economic sustainability in the Delta that are unrelated to these water policy proposals including economic development recommendations in the 2008 Delta Vision Strategic Plan.

Ecosystem variability along the estuarine salinity gradient: Examples from long-term study of San Francisco Bay

Limnology and Oceanography (Wiley) | March 25th, 2017

The salinity gradient of estuaries plays a unique and fundamental role in structuring spatial patterns of physical properties, biota, and biogeochemical processes. We use

The salinity gradient of estuaries plays a unique and fundamental role in structuring spatial patterns of physical properties, biota, and biogeochemical processes. We use variability along the salinity gradient of San Francisco Bay to illustrate some lessons about the diversity of spatial structures in estuaries and their variability over time. Spatial patterns of dissolved constituents (e.g., silicate) can be linear or nonlinear, depending on the relative importance of river-ocean mixing and internal sinks (diatom uptake). Particles have different spatial patterns because they accumulate in estuarine turbidity maxima formed by the combination of sinking and estuarine circulation. Some constituents have weak or no mean spatial structure along the salinity gradient, reflecting spatially distributed sources along the estuary (nitrate) or atmospheric exchanges that buffer spatial variability of ecosystem metabolism (dissolved oxygen). The density difference between freshwater and seawater establishes stratification in estuaries stronger than the thermal stratification of lakes and oceans. Stratification is strongest around the center of the salinity gradient and when river discharge is high. Spatial distributions of motile organisms are shaped by species-specific adaptations to different salinity ranges (shrimp) and by behavioral responses to environmental variability (northern anchovy). Estuarine spatial patterns change over time scales of events (intrusions of upwelled ocean water), seasons (river inflow), years (annual weather anomalies), and between eras separated by ecosystem disturbances (a species introduction). Each of these lessons is a piece in the puzzle of how estuarine ecosystems are structured and how they differ from the river and ocean ecosystems they bridge.

Effect of the South Delta Agricultural Barriers on Emigrating Juvenile Salmonids

California Department of Water Resources (DWR) | November 15th, 2018

The California Department of Water Resources’ (DWR) Temporary Barriers Project (TBP) is an ongoing project that installs, operates, and monitors up to four temporary ro

The California Department of Water Resources’ (DWR) Temporary Barriers Project (TBP) is an ongoing project that installs, operates, and monitors up to four temporary rock-fill barriers constructed in waterways located in the southern portion of the Sacramento-San Joaquin Delta (Delta) near the cities of Tracy and Lathrop in San Joaquin County, California (Figure 1-1). Three of the temporary barriers—Old River at Tracy (ORTB), Middle River (MRB), and Grant Line Canal (GLCB), collectively, the south Delta agricultural barriers (SDABs)—are constructed and operated during the agricultural irrigation season, usually April through November. The SDABs are designed to act as flow control structures, retaining tidal fresh water behind each barrier following a flood tide. The fourth barrier, Head of Old River Barrier (HORB), is installed during the spring and fall as a fish guidance barrier. The HORB is normally installed in the spring to prevent juvenile fall-run San Joaquin River Chinook Salmon (Oncorhynchus tshawytscha) and juvenile Central Valley steelhead (Oncorhynchus mykiss) 2 from emigrating through Old River toward the south Delta water export facilities at the intakes of the State Water Project (SWP) and federal Central Valley Project (CVP). In the fall, the HORB helps to guide adult San Joaquin River Chinook Salmon to spawning locations in the upper watershed. Installation, operation, and removal of the SDABs has the potential to harm, harass, or cause mortality to fish species of management concern to the National Marine Fisheries Service (NMFS), specifically, juvenile fall-run Chinook Salmon which are NMFS Species of Concern (NMFS 2010), juvenile Central Valley steelhead which is a threatened species, an Endangered Species Act (ESA) Section 10j experimental population (63 Federal Register [FR] 13347), and juvenile Green Sturgeon (Acipenser medirostris), also a federally listed threatened species (71 FR 17757). The TBP is implemented in compliance with the terms and conditions of two NMFS Biological Opinions (BiOp) (NMFS 2008, 2009).

Effective at Any Scale: Watershed-based Decision Support Tools

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

EcoAtlas  tools apply the USEPA’s three-level wetland monitoring and assessment framework for wetland and stream protection in a variety of California watersheds, an

EcoAtlas  tools apply the USEPA’s three-level wetland monitoring and assessment framework for wetland and stream protection in a variety of California watersheds, and it can be adjusted to more generally support natural resource planning, assessment, monitoring, and reporting. EcoAtlas operationalizes the Wetland and Riparian Area Monitoring Plan (WRAMP) by enabling users to assess the abundance, distribution, diversity, and condition of wetlands in the landscape or watershed context.

Effects Analysis for the Delta Smelt Fall Habitat Action in 2019

U.S. Bureau of Reclamation (USBR) | August 1st, 2019