Workshop report—Earthquakes and High Water as Levee Hazards in the Delta

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

Earthquakes and high water as hazards to Delta levees were reviewed in a seven-hour workshop organized by the Delta Independent Science Board and held at the campus of th

Earthquakes and high water as hazards to Delta levees were reviewed in a seven-hour workshop organized by the Delta Independent Science Board and held at the campus of the University of California, Davis. Earthquake hazards in the Delta were described in terms of ground motions from Bay Area earthquakes, infrequent earthquake recurrence on faults beneath the Delta, and levee fills prone to earthquake-induced liquefaction. Large uncertainties attend all these seismic elements of levee hazard. Those uncertainties, according to presentations in the workshop, include whether the Delta ground motions previously computed for Bay Area earthquakes were too large.  Hazards from high water were deemed greatest from the confluence of high river discharge, wind-driven surge and waves, and high tides. Major risk assessments have used available data on these hazards without mandates to advance the science. Research needs and opportunities identified in the workshop include expanded observations of Delta ground motions, improved estimates of geologically recent displacement on faults beneath the Delta, further identification of liquefiable materials and mechanisms beneath levees, continued airborne measurements of land-level change, updated mapping of the contracting area of remaining peat, and fuller documentation of past levee failures. Recurring assessments of earthquake hazards and climate change provide precedents for periodic reappraisal of Delta levee risk. The workshop brought together different parts of the diverse community of Delta levee specialists. Positive responses to the workshop suggest that it served levee specialists and outsiders alike.

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

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

Yolo Bypass Juvenile Salmon Utilization Study 2016— Summary of Acoustically Tagged Juvenile Salmon and Study Fish Releases, Sacramento River, California

U.S. Geological Survey (USGS) | September 12th, 2017

The Yolo Bypass is a flood control bypass in Sacramento Valley, California. Flood plain habitats may be used for juvenile salmon rearing, however, the potential value of

The Yolo Bypass is a flood control bypass in Sacramento Valley, California. Flood plain habitats may be used for juvenile salmon rearing, however, the potential value of such habitats can be difficult to evaluate because of the intermittent nature of inundation events. The Yolo Bypass Juvenile Salmon Utilization Study (YBUS) used acoustic telemetry to evaluate the movements and survival of juvenile salmon adjacent to and within the Yolo Bypass during the winter of 2016. This report presents numbers, size data, and release data (times, dates, and locations) for the 1,197 acoustically tagged juvenile salmon released for the YBUS from February 21 to March 18, 2016. Detailed descriptions of the surgical implantation of transmitters are also presented. These data are presented to support the collaborative, interagency analysis and reporting of the study findings.

Yolo Bypass Salmon Habitat Restoration and Fish Passage Analytical Tool Review

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

NOAA’s National Marine Fisheries Service (NMFS) and the U.S. Fish and Wildlife Service (USFWS) have issued a Biological Opinion (BiOp) on the long-term operat

NOAA’s National Marine Fisheries Service (NMFS) and the U.S. Fish and Wildlife Service (USFWS) have issued a Biological Opinion (BiOp) on the long-term operations of the Central Valley Project (CVP) and State Water Project (SWP) that includes Reasonable and Prudent Alternatives (RPA) designed to alleviate jeopardy to listed species and adverse modification of critical habitat. NMFS’ RPA requires the U.S. Bureau of Reclamation (Reclamation) to increase juvenile flood plain rearing habitat and improve adult fish passage for ESA-listed salmonids and sturgeon. The BiOp requires seventy-three (73) habitat restoration actions, five of which are specific to the Yolo Bypass. The California Department of Water Resources (DWR) and Reclamation have developed project alternatives for the Draft Yolo Bypass Fish Passage and Habitat Restoration EIS/EIR focused on the following two Yolo Bypass actions, which are the subject of this review:  - Increase seasonal floodplain inundation in the lower Sacramento River Basin  - Improve fish passage throughout the Yolo Bypass Alternatives The alternatives developed to address these two actions consist of a notch in the Fremont Weir, with alternative locations and configurations (width and weir-crest elevations), designed to increase the frequency and duration of hydraulic connectivity between the main-stem Sacramento River and the Yolo Bypass and to improve fish passage. Six alternative locations / configurations for a notch were identified.

Yolo Bypass Salmonid Habitat Restoration and Fish Passage Final Environmental Impact Statement / Environmental Impact Report (Chapters 1-8)

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

The Yolo Bypass Salmonid Habitat Restoration and Fish Passage Project (Project) has been developed to improve fish passage and increase floodplain fisheries rearing habit

The Yolo Bypass Salmonid Habitat Restoration and Fish Passage Project (Project) has been developed to improve fish passage and increase floodplain fisheries rearing habitat in the Yolo Bypass and the lower Sacramento River basin. The United States Department of the Interior, Bureau of Reclamation (Reclamation), as the Federal lead agency under the National Environmental Policy Act (NEPA), and the California Department of Water Resources (DWR), as the State of California (State) lead agency under the California Environmental Quality Act (CEQA), have prepared this joint Environmental Impact Statement/Environmental Impact Report (EIS/EIR) to assess impacts of the Project. The Project actions would implement Reasonable and Prudent Alternative (RPA) action I.6.1 and, in part, RPA action I.7, as described in the 2009 National Oceanic and Atmospheric Administration National Marine Fisheries Service (NMFS) Biological Opinion and Conference Opinion on the Long-Term Operations of the Central Valley Project and State Water Project and the 2012 Yolo Bypass Salmonid Habitat Restoration and Fish Passage Implementation Plan (Reclamation and DWR 2012).  Authority for combined Federal and State documents is provided in Title 40, Code of Federal Regulations (CFR), Sections 1502.25, 1506.2, and 1506.4 (Council on Environmental Quality’s Regulations for Implementing NEPA [CEQ Regulations]) and California Code of Regulations (CCR) Title 14, Division 6, Chapter 3 (State CEQA Guidelines), Section 15222 (Preparation of Joint Documents). This document was prepared consistent with United States Department of the Interior regulations specified in 43 CFR, Part 46 (United States Department of the Interior Implementation of NEPA, Final Rule).  This EIS/EIR evaluates reasonably foreseeable potential direct, indirect, and cumulative impacts on the environment that could result from implementing the Project alternatives. In addition, this EIS/EIR includes feasible mitigation measures to avoid, minimize, rectify, reduce, or compensate for adverse impacts. 

Yolo Bypass Salmonid Habitat Restoration and Fish Passage Final Environmental Impact Statement / Environmental Impact Report (Chapters 9-12)

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

Yolo Bypass Salmonid Habitat Restoration and Fish Passage Final Environmental Impact Statement / Environmental Impact Report (Executive Summary)

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

The Yolo Bypass Salmonid Habitat Restoration and Fish Passage Project (Project) Environmental Impact Statement/Environmental Impact Report (EIS/EIR) addresses methods to

The Yolo Bypass Salmonid Habitat Restoration and Fish Passage Project (Project) Environmental Impact Statement/Environmental Impact Report (EIS/EIR) addresses methods to improve fish passage and increase floodplain fisheries rearing habitat in the Yolo Bypass to benefit Sacramento River winter-run Chinook salmon, Central Valley spring-run Chinook salmon, Central Valley steelhead, and Southern Distinct Population Segment of North American green sturgeon. The Project actions would implement Reasonable and Prudent Alternative actions I.6.1 and I.7, as described in the 2009 National Oceanic and Atmospheric Administration National Marine Fisheries Service Biological Opinion and Conference Opinion on the Long-Term Operations of the Central Valley Project and State Water Project and the 2012 Yolo Bypass Salmonid Habitat Restoration and Fish Passage Implementation Plan.  This EIS/EIR has been prepared according to requirements of the National Environmental Policy Act and the California Environmental Quality Act. Direct, indirect, and cumulative impacts resulting from the project alternatives on the environment of the region are evaluated.  Full document files: Chapters 1-8 Chapters 9-12 Chapters 13-26 Appendices and drafts

Your Delta, Your Voice

California Department of Water Resources (DWR) | May 28th, 2021

In Fall 2020, the California Department of Water Resources (DWR) launched an environmental justice community survey entitled Your Delta, Your Voice. The survey was live f

In Fall 2020, the California Department of Water Resources (DWR) launched an environmental justice community survey entitled Your Delta, Your Voice. The survey was live from September 30 through December 11, 2020. Survey development and outreach was led by Ag Innovations and supported by numerous partners and agency staff. The survey had the following goals: 1) to gather information from disadvantaged communities in the Delta region about how they work, live, recreate and experience the Delta, 2) to understand how the community values and uses its natural, economic, and social resources, and 3) increase awareness of the proposed project and interest in participating in public engagement among disadvantaged community members in the Delta region. These goals were pursued in order to inform the proposed Delta Conveyance Project environmental review and planning process, with a particular emphasis on the environmental justice chapter of the CEQA Environmental Impact Report. Ag Innovation’s intent was to faithfully reflect the input and perspectives gathered via the survey within this report. In January 2021, DWR began developing a Delta Conveyance Project Community Benefits Program. The information gathered from the survey will also be used to inform DWR’s efforts to work towards community benefits in the Delta region, although that was not part of the original intent of the survey as the program did not exist at that time.