Review of Research on the Sacramento-San Joaquin Delta as an Evolving Place

Delta Stewardship Council (Delta Council) | May 11th, 2017

Research on the social and natural processes that sustain the unique values of the Delta as an evolving place is sparse and sporadic. We found seven research projects and

Research on the social and natural processes that sustain the unique values of the Delta as an evolving place is sparse and sporadic. We found seven research projects and no established research programs directly aimed at developing an understanding of the processes supporting the Delta as an evolving place. Far more research occurs on other Delta topics, such as water flows, contaminants and nutrients, and at risk species. Nor did we find evidence that research in these other areas is identifying natural processes that could protect and enhance the values of the changing Delta. We therefore recommend an expanded, sustained commitment to research on the unique cultural, recreational, natural resource, and agricultural values of the Delta as an evolving place. The level of effort could resemble that in other Delta subject areas. Priority should be given to research that supports achieving the coequal goals in a manner that protects and enhances these unique values.

Review of SWRCB’s “Working Draft Scientific Basis Report for New and Revised Flow Requirements on the Sacramento River and Tributaries, Eastside Tributaries to the Delta, Delta Outflow, and Interior Delta Operations”

Delta Stewardship Council (Delta Council) | February 23rd, 2017

Insightful, informative, well-illustrated, clearly written—these are among our overall impressions of “Working Draft Scientific Basis Report for New and Revised Flow

Insightful, informative, well-illustrated, clearly written—these are among our overall impressions of “Working Draft Scientific Basis Report for New and Revised Flow Requirements on the Sacramento River and Tributaries, Eastside Tributaries to the Delta, Delta Outflow, and Interior Delta Operations”. The comments below focus on recommended improvements. In particular, we recommend clarifying, and further justifying scientifically, the proposed use of percent of “unimpaired flow” as the main basis for establishing an annual environmental water budget. We also suggest presenting a further review of cold-water management, a deeper analysis of non-flow stressors, additional consideration of near-term responses to climate change, and elaboration of how regulations managed adaptively may improve scientific understanding of environmental flows.

Revised Incidental Take Methodology for the Coordinated Long-Term Operation of the CVP and SWP

U.S. Fish and Wildlife Service (FWS) | January 30th, 2019

RipZET: Documentation of Tool Demonstration in Marin County

San Francisco Estuary Institute (SFEI) | March 31st, 2015

The San Francisco Estuary Institute and Aquatic Science Center (SFEI‐ASC) has developed the Riparian Zone Estimation Tool (RipZET) to help the California community of

The San Francisco Estuary Institute and Aquatic Science Center (SFEI‐ASC) has developed the Riparian Zone Estimation Tool (RipZET) to help the California community of riparian interests visualize and characterize riparian areas as habitat unto themselves as well as their capacity to function as buffers for protecting the ecosystem services of the state’s streams, lakes and wetlands. RipZET is a tool used with Geographic Information System (GIS) and spreadsheet software to estimate “functional riparian width,” or the width associated with different riparian functions (e.g., large woody debris input, shading, floodwater storage), which varies with channel type and watershed location. The concept of functional riparian width is central to the riparian definition recommended by the National Research Council (NRC 2002) and is integral in many recently developed riparian design and management guidelines around the country.

Ruling on Plaintiffs’ Motion for Preliminary Injunction, Case No. Bcv-22-103220-Gap, Bring Back the Kern et al v. City of Bakersfield et al

Superior Court of California, County of Kern | October 30th, 2023

SacPAS Fish Model: A model for emergence, migration and survival of Sacramento River salmon

Delta Stewardship Council (Delta Council) | November 1st, 2017

Sacramento Valley Salmon Resiliency Strategy June 2017

California Natural Resources Agency (CNRA) | June 2nd, 2017

The Sacramento Valley Salmon Resiliency Strategy (Strategy) is a science-based document that has been prepared by the State of California (State) to address specific near

The Sacramento Valley Salmon Resiliency Strategy (Strategy) is a science-based document that has been prepared by the State of California (State) to address specific near- and long-term needs of Sacramento River winter-run Chinook salmon (winter-run), Central Valley spring-run Chinook salmon (spring-run), and California Central Valley steelhead (steelhead). The Strategy mirrors the approach taken with the Delta Smelt Resiliency Strategy developed by the State in 2016: science-driven, focused, and designed to provide resource agencies, the public, Congress, and the California State Legislature with information critical to collaborative approaches to species resiliency. The Strategy relies heavily on the National Marine Fisheries Service Final Recovery Plan for winter-run, spring-run, and steelhead (NMFS 2014), and is guided by conceptual models of factors driving winter-run population dynamics at key life stages developed by the salmon and sturgeon assessment of indicators by life-stage (SAIL) teams (Johnson et al. 2016; Heublein et al. 2017). The actions are also supported, where indicated, by other salmonid recovery planning documents and efforts. The Strategy is an aggressive approach to improving species viability and resiliency by implementing specific habitat restoration actions. The State will take leadership roles in each action, although in all cases federal and local agency leadership, coordination, and partnerships are required for success. Recent successful restoration efforts led by local agencies and landowners demonstrate the importance and value of these collaborative partnerships. State agencies that could implement this Strategy include the California Natural Resources Agency, the Department of Water Resources (DWR) and the Department of Fish and Wildlife (DFW). The U.S. Bureau of Reclamation (Reclamation) will be a primary partner in many of the actions. In many cases, included actions will benefit an array of aquatic and terrestrial species. Coordination and alignment across various resource management agencies will ensure achievement of maximum public benefit. All of the actions will comply with applicable laws including the U.S. Endangered Species Act (ESA), California Endangered Species Act, California Environmental Quality Act, National Environmental Policy Act, and the federal Clean Water Act.

Salton Sea Exceedances of California’s Air-Quality Standards Highlight Governance Gaps and Monitoring Needs

University of California, Los Angeles (UCLA) | September 4th, 2025

The Salton Sea region is known for its poor air-quality, which is often linked to dust and contributes to alarmingly high rates of respiratory problems among residents. H

The Salton Sea region is known for its poor air-quality, which is often linked to dust and contributes to alarmingly high rates of respiratory problems among residents. However, air-quality issues extend beyond dust. Residents also face the distressing reality of frequent hydrogen sulfide (H2S) emissions. Depending on individual experiences, these emissions can range from uncomfortable to severely suffocating. To gauge the severity of these concerns, the Salton Sea Environmental Timeseries (SSET), a community-based research group, recently installed two hydrogen sulfide monitors in the area. Their data indicates that H₂S emissions consistently exceed the California Air Resources Board state standard of 30 parts per billion (ppb), with 243 hours above this threshold recorded between May and September 2024 alone. Existing government air-quality monitors, located north of the Salton Sea, primarily detect H₂S only when winds blow from the southeast, whereas SSET data show elevated emissions occur regardless of wind direction. This highlights a critical gap in the current government monitoring network, which fails to capture the full scope of H₂S pollution. As more data highlight connections between water and air-quality, it is crucial to monitor air-quality in all its aspects, not just those related to dust. The Salton Sea region has a predominantly low-income Latinx, immigrant, and Indigenous population across two California counties. The persistent issue of hydrogen sulfide pollution serves as a clear example of environmental injustice. For over two decades, the state and federal governments have been legally obligated to restore the Salton Sea—meeting that obligation today means pairing public health action with robust monitoring.

Salton Sea Fisheries Long-term Monitoring Sampling Report: Summer 2017

California Natural Resources Agency (CNRA) | July 13th, 2017

In early 2016, historic indices of tilapia abundance at the Salton Sea appeared to have reversed: tilapia fry were no longer observed in places where fish were regularly

In early 2016, historic indices of tilapia abundance at the Salton Sea appeared to have reversed: tilapia fry were no longer observed in places where fish were regularly visible in the past, piscivorous bird numbers at the lake were severely reduced, anglers were only catching a small fraction of past numbers of fish, and only a few small fish kills were observed. As observations of these conditions continued in early 2017, the question of whether the tilapia population was still viable was the impetus for the California Department of Fish and Wildlife (CDFW) to re-initiate gillnetting efforts.

Salton Sea Management Program Conceptual Project Implementation and Cost Estimates to Meet State Board Targets

California Natural Resources Agency (CNRA) | April 27th, 2017

The Salton Sea Management Program (SSMP) has developed a 10-year plan for Phase I that envisions a range of activities for habitat creation and dust management as

The Salton Sea Management Program (SSMP) has developed a 10-year plan for Phase I that envisions a range of activities for habitat creation and dust management as the Salton Sea recedes over 2018–2028. The California State Water Resources Control Board (SWRCB), through an order revising Order WRO 2002–0013, outlines annual and cumulative target areas for restoration through creation of habitat and dust suppression projects. These targets are defined for each year, ranging from a cumulative 500 acres by January 1, 2019, to a cumulative 29,800 acres by January 1, 2029, with a minimum 50 percent of the area being designated for fish and wildlife habitat projects. Areas around the sea are proposed for restoration projects, specifically at the southern end of the sea near the inflows of the Alamo and New rivers, and the northern end of the sea near the inflow of the Whitewater River. In a prior document (Salton Sea Management Plan Phase I: 10 Year Plan, March 2018), an overview of the project areas and activities was presented. This document presents a high-level plan for achieving the annual goals in the SWRCB order, by means of creation of wet habitat and dust control areas in different parts of the Salton Sea lakebed. This document identifies conceptual habitat ponds to be created, the associated wetted areas, and the additional dust control areas required to meet the order targets. For each of the conceptual project areas, there are estimates for berm lengths, heights, and needs for additional infrastructure, such as pumps and pipelines, causeways for equipment access, and levee extensions along river channels for flood protection of newly created habitat. Planned cross sections for the different types of linear structures are shown. Cost estimates are provided for each of the project areas over time to develop a total cost estimate. The conceptual habitat and dust control areas are based on the best current information on Salton Sea bathymetry, and demonstrate a reasonable path forward to attain the State Board order targets. The costs associated with these targets as presented in this document can be used for additional planning as part of the SSMP over the next decade. It is recognized that the actual footprints of individual projects may change in future years as better information becomes available on lakebed elevations, and relationships with other non-SSMP projects for habitat and dust control are better understood. These cost estimates are a refinement of estimates presented in the Salton Sea Management Plan Phase I: 10-Year Plan (March 2017). The cost estimates incorporate the best available cost information, and include the development of conceptual berm designs and supporting infrastructure, such as water diversions, pumps, and pipelines, and levees for river extensions. For these reasons, the cost estimate presented here supersedes the March 2017 estimate of $383 million for the 10-year implementation. But, all cost estimates at this stage are considered preliminary, and subject to revision as new field and construction data become available, and as designs are adjusted to best meet overall program needs. In the remainder of this document, two key topics are presented. In Chapter 2, there are estimates of the projected elevations of the Salton Sea over the 2018–2028 period, based on a hydrologic model of the sea. This is needed to allow estimation of exposed lakebed with the goal of constructing new habitat under dry conditions. Proposed conceptual project footprints, design and cost assumptions, and cost summaries are presented in Chapter 3.