Issue Paper for the San Joaquin River spring-run Chinook experimental population – Delta impacts

National Marine Fisheries Service (NMFS) | July 23rd, 2013

Juvenile Production Estimate (JPE) Calculation and Use/Application of Survival Data from Acoustically-tagged Chinook Salmon Releases Report

Delta Stewardship Council (Delta Council) | February 21st, 2014

Each year, NOAA’s National Marine Fisheries Service (NMFS) estimates the number of juvenile winter-run Chinook salmon expected to enter the Delta. NMFS’ June 4, 2009

Each year, NOAA’s National Marine Fisheries Service (NMFS) estimates the number of juvenile winter-run Chinook salmon expected to enter the Delta. NMFS’ June 4, 2009, biological and conference opinion on the long-term operation of the Central Valley Project and State Water Project provides an incidental take limit on natural juvenile winter-run based on the juvenile production estimate.

Kern Water Bank Status Report No. 3

California Department of Water Resources (DWR) | April 1st, 1990

Kern Water Bank: Myth and Reality

Kern Water Bank Authority | September 21st, 2010

A recent lawsuit filed by the Center for Biological Diversity claims that the Kern Water Bank was a “ripoff’ that benefited a few large farms in the Central Valley, t

A recent lawsuit filed by the Center for Biological Diversity claims that the Kern Water Bank was a “ripoff’ that benefited a few large farms in the Central Valley, to the detriment of the state of California. Numerous media outlets have reported on this lawsuit, reciting almost word for word from the CBD’s press release, despite the fact that the lawsuit has yet to be heard and none of the claims in the lawsuit have been substantiated by a court. The following is the response by the Kern Water Bank Authority to the misinformation and erroneous reporting surrounding the Kern Water Bank and the lawsuit filed by CBD.

Letter in support of the Temporary Urgency Change Petition (TUCP)

California State Water Resources Control Board (SWRCB) | February 19th, 2023

Local hydraulics influence habitat selection and swimming behavior in adult California Central Valley Chinook salmon at a large river confluence

Fisheries Research (Elsevier) | February 2nd, 2023

Losses of Sacramento River Chinook Salmon and Delta Smelt to Entrainment in Water Diversions in the Sacramento-San Joaquin Delta

University of California, Davis (UC Davis) | June 30th, 2008

Pumping at the water export facilities in the southern Sacramento-San Joaquin Delta kills fish at and near the associated fish-salvage facilities. Correlative analyses of

Pumping at the water export facilities in the southern Sacramento-San Joaquin Delta kills fish at and near the associated fish-salvage facilities. Correlative analyses of salvage counts with population indices have failed to provide quantitative estimates of the magnitude of this mortality. I estimated the proportional losses of Sacramento River Chinook salmon (Oncorhynchus tshawytscha) and delta smelt (Hypomesus transpacificus) to place these losses in a population context. The estimate for salmon was based on recoveries of tagged smolts released in the upper Sacramento River basin, and recovered at the fish-salvage facilities in the south Delta and in a trawling program in the western Delta. The proportion of fish salvaged increased with export flow, with a mean value around 10% at the highest export flows recorded. Mortality was around 10% if pre-salvage losses were about 80%, but this value is nearly unconstrained. Losses of adult delta smelt in winter and young delta smelt in spring were estimated from salvage data (adults) corrected for estimated pre-salvage survival, or from trawl data in the southern Delta (young). These losses were divided by population size and accumulated over the respective seasons. Losses of adult delta smelt were 1–50% (median 15%) although the highest value may have been biased upward. Daily losses of larvae and juveniles were 0–8%, and seasonal losses accumulated were 0–25% (median 13%). The effect of these losses on population abundance was obscured by subsequent 50-fold variability in survival from summer to fall.

Managing Freshwater Discharge to the San Francisco Bay/Sacramento-San Joaquin Delta Estuary―The Scientific Basis for an Estuarine Standard

San Francisco Estuary Project | October 26th, 1992

Aquatic resources of the Sacramento-San Joaquin Delta and upper portions of San Francisco Bay have undergone significant declines over the past several decades. Species c

Aquatic resources of the Sacramento-San Joaquin Delta and upper portions of San Francisco Bay have undergone significant declines over the past several decades. Species characteristic of the Delta and rivers, such as striped bass and salmon, began to decline during the late 1970s. Prolonged drought, large diversions of fresh water, and dramatic increases in populations of introduced aquatic species during the 1980s and 1990s brought a number of indigenous aquatic species to extremely low levels. Species that spend more of their lives downstream of the Delta, including Delta smelt, longfin smelt, and many zooplankton, maintained large populations through the 1970s, but declined sharply after the mid-1980s. Declines in aquatic resources have led to curtailed fishing seasons, to petitions for endangered species status, and general concern about the health of the estuarine ecosystem.

Mark/Recapture Experiments at Clifton Court Forebay to Estimate Pre-Screening Loss to Juvenile Fishes: 1976-1993

California Department of Fish and Wildlife (CDFW) | September 30th, 1997

From October 1976 through November 1993, the California Department of Fish and Game conducted mark/recapture experiments at Clifton Court Forebay, designed to estimate pr

From October 1976 through November 1993, the California Department of Fish and Game conducted mark/recapture experiments at Clifton Court Forebay, designed to estimate pre-screen loss to entrained juvenile fishes. Ten studies were conducted; eight evaluated losses to hatchery-reared juvenile chinook salmon, and two evaluated losses to hatchery-reared juvenile striped bass. Pre-screen loss was calculated from the proportion of marked fish released at the radial gates that were subsequently recaptured during salvage operations at Skinner Fish Facility. The proportion was adjusted for handling mortality, fish facility louver effiCiency, and any subsampling at the facility. Studies were conducted across a wide range of environmental conditions and State Water Project operations, with a wide range in the size ofexperimental fish. Pre-screen loss estimates for juvenile chinook salmon were 63-99%. Potential biases in estimates of pre-screen loss may be due to (1) the calculation for pre-screen loss, (2) underrepresentative and over-representative salvage of experimental fish at Skinner Fish Facility, and (3) the introduction of experimental fish directly into Clifton Court Forebay. A multiple-regression analysis of pre-screen loss to juvenile salmon showed that 91% of the variance in pre-screen loss can be explained by export rate, experimental fish size, and water temperature. 

Mean and Extreme Climate Change Impacts on the State Water Project

California Department of Water Resources (DWR) | August 27th, 2018

Warming temperatures, shifting hydrology, and rising sea levels will challenge management of California’s water resources. This study quantifies climate change risks t

Warming temperatures, shifting hydrology, and rising sea levels will challenge management of California’s water resources. This study quantifies climate change risks to California’s State Water Project (SWP) and federal Central Valley Project (CVP). This study uses the California Department of Water Resources’ (DWR’s) newly developed water planning model, CalSim 3.0, as a risk assessment tool. Impacts were assessed for 20 climate change scenarios (10 global climate models and two emission scenarios, representative concentration pathway (RCP) 4.5 and RCP 8.5). Water supply and water quality metrics evaluated include Delta exports, North of Delta Carryover storage, reservoir dead storage (i.e. when reservoir levels fall below the lowest outlets), and Delta salinity. Results for the driest future scenario were also analyzed to examine future drought impacts. In addition, a series of sensitivity tests were implemented to assess individual impacts of four climate change factors: flow seasonal pattern shift, sea level rise, annual flow volume change, and water demand change on the State Water Project and Central Valley Project operations. It was found that flow seasonal pattern shift will become a major climate change factor and sea level rise a secondary factor, leading to a half million‐acre feet of Delta export reduction as well as a roughly 25% decrease of North‐of‐Delta carryover storage by around 2060. The results also indicate that the extra runoff from early snow melting and higher percentage of rain in the winter and early spring is not conserved in reservoirs and thus cannot be used to meet the higher summer demand in the current SWP/CVP system. This extra water is released as flood water in the winter and early spring to become Delta outflow.