Storing and managing water for the environment is more efficient than mimicking natural flows

Nature Portfolio (Springer Nature) | June 27th, 2024

Storing Water for the Environment: Operating Reservoirs to Improve California’s Freshwater Ecosystems

Public Policy Institute of California (PPIC) | August 23rd, 2022

Large reservoirs like those that rim the Central Valley are essential for managing water in California’s highly variable climate. They provide multiple benefits includi

Large reservoirs like those that rim the Central Valley are essential for managing water in California’s highly variable climate. They provide multiple benefits including water supply, hydropower, flood management, and recreation. However, construction and operation of these reservoirs have also imposed significant environmental costs, including native fishes’ loss of access to high-quality habitat above dams and degradation of freshwater ecosystems below them. Moreover, regulatory uncertainty for water users is rising as these ecosystems decline. California needs a new approach for managing environmental water in its large reservoirs, particularly as the climate warms and droughts become more intense.

Streamlining Restoration Project Consultation Using Programmatic Biological Opinions

National Marine Fisheries Service (NMFS) | April 24th, 2012

NOAA Fisheries Northwest Region supports efforts to restore the ecological function of our region’s habitat. Restoring habitat contributes to the recovery of species cu

NOAA Fisheries Northwest Region supports efforts to restore the ecological function of our region’s habitat. Restoring habitat contributes to the recovery of species currently protected under the Endangered Species Act (ESA), ensures that critical habitat designated under the ESA will serve its intended conservation role, and advances the conservation and enhancement of essential fish habitat (EFH) designated under the Magnuson-Stevens Fishery Conservation and Management Act (MSA).

Suisun Marsh Monitoring Program Annual Data Summary Water Year 1999

California Department of Water Resources (DWR) | July 31st, 2001

This report summarizes data collected in the Suisun Marsh during Water Year 1999 (October 1, 1998 through September 30, 1999) pursuant to the following agreements, perm

This report summarizes data collected in the Suisun Marsh during Water Year 1999 (October 1, 1998 through September 30, 1999) pursuant to the following agreements, permits, and water rights decisions: • State Water Resources Control Board Decision 1485, August 1978 (SWRCB 1978); • State Water Resources Control Board Order WR 95-6, 1995 (SWRCB 1995a); • Suisun Marsh Preservation Agreement, 1987 (USBR and others 1987); • Suisun Marsh Monitoring Agreement, 1987 (DWR and others 1987); • San Francisco Bay Conservation and Development Commission Permit No. 35-78 (M) Amendment 7, 1997 (for construction of the initial facilities, namely the Roaring River Distribution System, Morrow Island Distribution System, and Goodyear Slough Outfall) (BCDC 1997); • San Francisco Bay Conservation and Development Commission Permit No. 4-84 (M) Amendment 4, 1991 (for construction of the Suisun Marsh Salinity Control Gates) (1991); and, • U.S. Army Corps of Engineers Permit No. 16223E58 (for construction of the Suisun Marsh Salinity Control Gates), Special Condition 1, 1986 (USACE 1986). This report fulfills a portion of the annual reporting requirements of the above-listed, agreements, permits, and water rights decisions as detailed in Table 1. Remaining reporting requirements will be fulfilled in other Department of Water Resources (DWR) and/or University of California Davis reports. DWR and the California Department of Fish and Game (DFG) primarily collected data summarized in this report. The data include • general hydrologic data; • continuous channel water specific conductance and tidal height measurements; • marsh-wide vegetation survey update; • waterfowl abundance; and • salt marsh harvest mouse occurrence.

Summary of Draft Environmental Impact Report Peripheral Canal Project

California Department of Water Resources (DWR) | August 1st, 1974

Summary of NMFS BiOp RPA Actions for Water Year 2014

Delta Stewardship Council (Delta Council) | October 30th, 2014

Summary Report on the Transactions of the Smelt Working Group in Water Year 2014

Delta Stewardship Council (Delta Council) | August 29th, 2014

The Bay‐Delta Fish and Wildlife Office (BDFWO) has prepared this report to summarize the implementation the U.S. Fish and Wildlife Service’s (Service) biological opi

The Bay‐Delta Fish and Wildlife Office (BDFWO) has prepared this report to summarize the implementation the U.S. Fish and Wildlife Service’s (Service) biological opinion on the Central Valley Project (CVP) and State Water Project (SWP) Long‐term Operations (BiOp) in Water Year (WY) 2014. In addition to background information pertinent to implementation of the BiOp , this report provides a summary of the transactions of the Smelt Working Group (SWG), as well as water operations and during WY 2014. The SWG is a technical team that evaluates biological and technical issues regarding Delta Smelt (Hypomesus transpacificus) and develops recommendations for consideration by the Service during implementation of the BiOp’s Reasonable and Prudent Alternative (RPA) actions. During WY 2014 the SWG made no recommendations for more restrictive water operations and the Service issued no determinations to reduce water exports.

Summary Report on the Transactions of the Smelt Working Group in Water Year 2018

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

Supplement to the 2007 Colorado River Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for Lake Powell and Lake Mead

U.S. Bureau of Reclamation (USBR) | May 6th, 2024

This ROD revises the 2007 Interim Guidelines for the near-term operation of Glen Canyon and Hoover Dams to address the potential for continued low-runoff conditions in th

This ROD revises the 2007 Interim Guidelines for the near-term operation of Glen Canyon and Hoover Dams to address the potential for continued low-runoff conditions in the Basin. Reclamation has concluded that the potential impacts of low-runoff conditions pose unacceptable risks to routine operations of Glen Canyon and Hoover Dams during the remainder of the interim period (through the end of the 2026 operating year) and that modified operating guidelines need to be expeditiously developed.

Synthesis of data and studies relating to Delta Smelt biology in the San Francisco Estuary, emphasizing water year 2017

Interagency Ecological Program (IEP) | November 1st, 2021

In the San Francisco Estuary (SFE), the effects of freshwater flow on the aquatic ecosystem have been studied extensively over the years and remains a contentious managem

In the San Francisco Estuary (SFE), the effects of freshwater flow on the aquatic ecosystem have been studied extensively over the years and remains a contentious management issue. It is especially contentious with regards to the Delta Smelt (Hypomesus transpacificus), a species endemic to the SFE that has been listed as threatened under the Federal Endangered Species Act and endangered by the State of California. Early studies of Delta Smelt distribution within the SFE suggested that Delta Smelt habitat is determined largely by freshwater flow; however, the exact mechanisms and processes producing such benefits remained unclear. In the summer of 2017, the Flow Alteration Management, Analysis, and Synthesis Team (FLOAT-MAST) was established to analyze, synthesize, and summarize the data collected from the various flow-related monitoring and special studies occurring in 2017(see Table Intro 4). This report will focus on the 2017 summer-fall status of Delta Smelt and its habitat following a record wet year. There has been a long-term decline in the abundance of Delta Smelt associated with a decline in other pelagic fishes. Investigators concluded that the decline has likely been caused by the interactive effects of several causes, including changes in both physical and biotic habitats, many of which are tied to amount and timing of freshwater flow. For this report, we formulated a number of basic predictions about the likely effects of high flows in 2017 on Delta Smelt and their habitat (Table 3). We use a qualitative weight of evidence approach to evaluate whether these predictions were supported by available data. Data sources included a variety of long-term monitoring surveys conducted by Interagency Ecological Program (IEP) agencies, as well as model outputs. Delta Smelt population, health, and life history metrics rarely responded as predicted. Water temperature appears to have a stronger effect on Delta Smelt growth rate and some metrics of life history diversity than outflow or X2 position. Other life history diversity attributes varied but did not appear to be driven by outflow or temperature. Health status was difficult to interpret. Low prevalence of lesions and improved nutritional condition during the drought was contradicted by declining overall population levels. Because of the sparse catches of Delta Smelt in the post-POD years, we consider the data insufficient to reach firm conclusions about the predictions concerning range and distribution of Delta Smelt, especially in the fall. The prediction of high survival was not supported. The 2017 Delta Smelt year class began with poor recruitment in spring of 2017 and below average survival for spring to summer and summer to fall. Thus, low production and low survival led to low abundance of all life stages. During the fall to winter period survival improved, yet the resulting adults were low in number. Foraging success of the fish captured, as measured by stomach fullness, was high for juveniles and adults in 2017 relative to recent years associated with the higher densities of common zooplankton prey that occurred in 2017.