Sacramento River

Delta Levees – Types, Uses, and Policy Options

Delta Vision Blue Ribbon Task Force (Delta Vision) | August 7th, 2008

This document was developed to support Delta Vision discussions on the role of levees in the Delta’s future. It is to clarify the different types (or design standards)

This document was developed to support Delta Vision discussions on the role of levees in the Delta’s future. It is to clarify the different types (or design standards) of levees that now exist for the Delta and what improvements could be considered. It is especially oriented toward an improved understanding of what types of levees are suitable for protecting various land uses or for other applications. Based on understanding the levee types, policy options are identified for a) selecting levee improvements to be included in the vision of the Delta’s future and b) implementing the improvements selected.

Delta Narratives: Saving the Historical and Cultural Heritage of the Sacramento-San Joaquin Delta

Delta Protection Commission (DPC) | August 1st, 2015

From August 2014 through July 2015, the Delta Narratives project, on contract to the Delta Protection Commission, addressed two questions. First, in what ways does the hi

From August 2014 through July 2015, the Delta Narratives project, on contract to the Delta Protection Commission, addressed two questions. First, in what ways does the historical experience of the Sacramento-San Joaquin Delta contribute to an understanding of key themes in regional and American history? Second, how might Delta stories gain wider appreciation within the region, throughout Northern California, and among people in the rest of California and beyond? Scholars on the project team documented ways the history of the Delta illustrates trends in land management and reclamation, technological shifts in transportation and agriculture, the impact of ethnicity and labor specialization on community building, and finally, the shifting visioning of America's promise and fall from grace by artists and writers in response to the intense cultivation of the Delta and the conditions which workers there endured. Their essays testify to the intrinsic value of Delta stories and to the additional perspectives they bring to regional and national history. With these essays in hand, the project team investigated the current infrastructure for the preservation and dissemination of historical and cultural information in the Delta. It created a directory of institutions committed to promoting Delta stories. In order to stimulate conversations between these stakeholders, the team organized two workshops at which the scholars and archivists shared insights and invited commentary and conversation. Subsequently, with the support of the Center for California Studies at Sacramento State University, a conference entitled “More than H2O: Saving the History and Culture of the Sacramento-San Joaquin Delta” presented findings and discussed strategies with an audience of state and local stakeholders. Delta Narratives culminated with a conference organized around an American Assembly model. The conference generated a list of suggestions for further action regarding the recognition, preservation, and dissemination of Delta stories. High on the list of initiatives were adequate mapping of historically significant locations, an organization that would draw together the many cultural and historical groups in the Delta toward common action, the initiation of annual Delta Days to celebrate the region, and the creation of educational materials including web applications (apps), and a website devoted to the region.

Delta Operations for Salmonids and Sturgeon (DOSS) Technical Working Group

Delta Stewardship Council (Delta Council) | November 1st, 2018

Delta Reclamation District Financing and Budgets

Delta Stewardship Council (Delta Council) | August 16th, 2016

This report explains the financing of the 93 reclamation districts that maintain the Delta’s levees. Reclamation districts’ primary method for raising funds is thr

This report explains the financing of the 93 reclamation districts that maintain the Delta’s levees. Reclamation districts’ primary method for raising funds is through assessments, which are levied on a per-acre basis upon property owners within a district’s boundaries. Assessments are subject to Proposition 218 procedures, and they must be approved by a vote of the affected people. A second financing tool that reclamation districts have is charging fees for services, such as irrigation or drainage services for landowners. In addition to relying on these direct financing tools, reclamation districts can also receive funds from the State or from other entities. According to data from the State Controller’s office, the median Delta reclamation districts have annual budgets of around $370,000, with property assessments serving as the primary source of revenue. Typical assessments in these districts are about $32 per acre. State funding is a supplementary source of revenue for these districts, making up about 30 percent of total revenues. On the expenditure side, more than 80 percent of typical reclamation districts’ expenditures are for “services and supplies,” which includes levee work, but also other expenses. Only 12 Delta reclamation districts have long-term debt, so State funding appears to have been successful in helping Delta reclamation districts avoid overly burdensome debt levels. The State has concentrated its reclamation district funding on certain strategic islands. Ten reclamation districts have received 62 percent of state funding over the past five years. These 10 reclamation districts that receive the most state funding also tend to have much higher property assessment rates compared to other reclamation districts. This suggests that reclamation districts are increasing their assessment rates as the State steps up its funding. Finally, reclamation districts receiving a large amount of state funds also spend much more on services and supplies, even after controlling for the size of the reclamation district. This difference suggests that reclamation districts that are not receiving significant funding from the State are primarily paying for levee maintenance projects rather than undertaking large-scale levee improvement projects.

Delta Regional Monitoring Program Annual Monitoring Report for Fiscal Year 2015–16: Pesticides and Toxicity

San Francisco Estuary Institute (SFEI) | March 1st, 2018

The primary purpose of this report is to document the first year (FY15/16) of pesticide monitoring by the Delta Regional Monitoring Program (Delta RMP). This document rep

The primary purpose of this report is to document the first year (FY15/16) of pesticide monitoring by the Delta Regional Monitoring Program (Delta RMP). This document reports the results from samples collected monthly from July 2015 through June 2016. The data described in this report are available for download via the California Environmental Data Exchange Network (CEDEN) website. Pesticide monitoring of the Delta RMP includes chemical analysis and toxicity testing of surface water samples. The parameters analyzed include 154 current use pesticides, dissolved copper, field parameters, and “conventional” parameters (ancillary parameters measured in the laboratory, such as dissolved/particulate organic carbon and hardness). Toxicity tests included an algal species (Selenastrum capricornutum, also known as Raphidocelis subcapitata), an invertebrate (Ceriodaphnia dubia, a daphnid or water flea), and a fish species (Pimephales promelas, fathead minnow). Toxicity testing included the evaluation of acute (survival) and chronic (growth, reproduction, biomass) toxicity endpoints. The surface water samples were collected from 5 fixed sites representing key inflows to the Delta that were visited monthly: Mokelumne River at New Hope Road, Sacramento River at Hood, San Joaquin River at Buckley Cove, San Joaquin River at Vernalis, and Ulatis Creek at Brown Road. A total of 52 pesticides were detected above method detection limits (MDLs) in water samples (19 fungicides, 17 herbicides, 9 insecticides, 6 degradates, and 1 synergist). A total of 9 pesticides (5 herbicides, 3 insecticides, and 1 degradate) were detected in suspended sediments in 10 of a total of 60 samples collected during the study period. All collected samples contained mixtures of pesticides ranging from 2 to 26 pesticides per sample. From a total of 154 target parameters, 100 compounds were never detected in any of the samples.

Delta Regional Monitoring Program Nutrients Synthesis: Modeling to Assist Identification of Temporal and Spatial Data Gaps for Nutrient Monitoring

San Francisco Estuary Institute (SFEI) | March 1st, 2018

Nutrient loads are an important water quality management issue in the Sacramento-San Joaquin Delta (Delta) and there is consensus that the current monitoring activities d

Nutrient loads are an important water quality management issue in the Sacramento-San Joaquin Delta (Delta) and there is consensus that the current monitoring activities do not collect all the information needed to answer important management questions.  The purpose of this report is to use hydrodynamic model outputs to refine recommendations for monitoring nutrients and related conditions in the Delta. The basic premise was that variability in water source and hydraulic residence time can serve to estimate variability in water quality. Therefore, using existing hydrodynamic models that are highly resolved in space and time could be a cost-effective way to get information about likely spatial and temporal variability in nutrients and nutrient-associated parameters. We assume that the Delta can be divided into relatively homogeneous subregions (e.g., such as those proposed in a previous report by Jabusch et al. 2016) and that a representative monitoring location can be chosen in each subregion to track status and trends. We also assume that, within any subregion, areas with long hydraulic residence time and source water mixing may represent potential nutrient transformation hotspots.  Two types of modeling approaches were applied: 1) volumetric water source analysis to evaluate the mix of source waters within each subregion; and 2) particle tracking simulations. Results from the source water analysis were evaluated to assess heterogeneity of water sources within each of the subregions. Results from the particle tracking analysis were evaluated to identify high-residence-time areas. Finally, we compared analysis results to current monitoring locations to inform potential monitoring gaps or redundancies within each of the subregions. 

Delta Salinity Management Workshops 2022 Information Sheet

Delta Stewardship Council (Delta Council) | March 7th, 2022

Delta Science Plan (2019)

Delta Stewardship Council (Delta Council) | May 23rd, 2019

A coordinated, science-based approach is essential for managing the Sacramento-San Joaquin Delta (Delta) to achieve the vision of One Delta, One Science and further the

A coordinated, science-based approach is essential for managing the Sacramento-San Joaquin Delta (Delta) to achieve the vision of One Delta, One Science and further the coequal goals in a manner that enhances and protects the Delta as an evolving place. As members of the 18 federal and state agencies composing the Delta Plan Interagency Implementation Committee (DPIIC), we recognize that we must avoid a siloed, single-interest approach to management and science issues in the Delta. Such an approach hampers effective management and efficient resource use to address complex issues including increasing risks from climate change related effects such as sea level rise, prolonged dry periods, and floods. Our focus must be twofold: a more integrated effort among federal and state agencies and stakeholders to advance Delta-relevant scientific knowledge and using that knowledge to inform decisions that address these complex natural resource management issues. The Delta Science Plan is a call to action for a more collaborative Delta science community that contributes to improving decision-making in the Delta. This document provides direction for collectively prioritizing research questions, setting goals, developing shared protocols for how science is conducted, and verifying and communicating scientific results with an eye towards usability for decision-makers and the public. This direction is only possible if the Delta science community, including members of DPIIC, work together to implement and conduct work consistent with the actions identified in the document and to speak with one voice to marshal support for scientific efforts. The members of DPIIC are committed to promoting and investing in coordinated and collaborative efforts that generate scientific knowledge to support both the Delta Plan and the objectives identified in the 2009 Delta Reform Act. This commitment has been expressed through DPIIC’s endorsement and acceptance of the Interim Science Action Agenda (2014), the High-Impact Science Actions (2015), and the Science Action Agenda (2017); documents that identify and prioritize collaborative science efforts. In endorsing the Delta Science Plan, we accept the document as a shared guide to build the collaborative science community and support efforts to work together in carrying out integrated actions that achieve the vision of One Delta, One Science.

Delta smelt resiliency strategy

California Department of Water Resources (DWR) | July 11th, 2016

The Delta Smelt Resiliency Strategy (Strategy) is a science-based document that has been prepared by the State of California (State) to voluntarily address both immediate

The Delta Smelt Resiliency Strategy (Strategy) is a science-based document that has been prepared by the State of California (State) to voluntarily address both immediate and near-term needs of Delta Smelt, to promote their resiliency to drought conditions as well as future variations in habitat conditions. The Strategy relies on the MAST Report and Conceptual Models (IEP 2015) to articulate a suite of actions that can be implemented in the next few years that are intended to benefit Delta Smelt. Although the feasibility and effectiveness of each action included in the Strategy requires further exploration and study, the Strategy is an aggressive approach to implementing any actions that can be implemented in the near term, can be implemented by the State with minimal involvement of other entities, and have the potential to benefit Delta Smelt. State agencies that could implement this Strategy include Department of Water Resources (DWR), Department of Fish and Wildlife (DFW), and Division of Boating and Waterways (DBW). Several of the actions identified in this Strategy could also benefit other species, and coordination across various resource management agencies as appropriate may allow for benefits beyond Delta Smelt. All of the actions will be in compliance with applicable laws, including the Federal Endangered Species Act, California Endangered Species Act, California Environmental Quality Act, National Environmental Policy Act, and the Federal Clean Water Act. The Collaborative Science and Adaptive Management Program (CSAMP) will be used to determine the appropriate research approach to designing and assessing the outcomes of these management actions individually and synergistically. Additionally, it is expected that the Bureau of Reclamation (Reclamation) would participate in the implementation of this Strategy, including providing enhanced outflows in 2016.

Delta Smelt: Life History and Decline of a Once-Abundant Species in the San Francisco Estuary

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

The delta smelt is endemic to the upper San Francisco Estuary. Much of its historic habitat is no longer available and remaining habitat is increasingly unable to sustain

The delta smelt is endemic to the upper San Francisco Estuary. Much of its historic habitat is no longer available and remaining habitat is increasingly unable to sustain the population. As a listed species living in the central node of California’s water supply system, delta smelt has been the focus of a large research effort to understand causes of decline and identify ways to recover the species. Since 2008, a remarkable record of innovative research on delta smelt has been achieved, which is summarized here. Unfortunately, research has not prevented the smelt’s continued decline, which is the result of multiple, interacting factors. A major driver of decline is change to the Delta ecosystem from water exports, resulting in reduced outflows and high levels of entrainment in the large pumps of the South Delta. Invasions of alien species, encouraged by environmental change, have also played a contributing role in the decline. Severe drought effects have pushed delta smelt to record low levels in 2014–2015 and diverse and substantial management actions are needed to preserve delta smelt.