Sacramento River

Irrigation Water Use in the Central Valley of California

California Department of Water Resources (DWR) | January 1st, 1985

Isolating the Poroelastic Response of the Groundwater System in InSAR Data From the Central Valley of California

American Geophysical Union (AGU) | April 28th, 2023

James Groundwater Sustainability Agency Groundwater Sustainability Plan (Revised)

James Groundwater Sustainability Agency (JGSA) | July 22nd, 2022

*Submitted to the Department of Water Resources on July 22, 2022. No date or signature accompany the seal from the preparer at Provost and Pritchard.

*Submitted to the Department of Water Resources on July 22, 2022. No date or signature accompany the seal from the preparer at Provost and Pritchard.

Jet stream dynamics, hydroclimate, and fire in California from 1600 CE to present

National Academy of Sciences (NAS) | March 4th, 2019

Moisture delivery in California is largely regulated by the strength and position of the North Pacific jet stream (NPJ), winter high-altitude winds that influence regiona

Moisture delivery in California is largely regulated by the strength and position of the North Pacific jet stream (NPJ), winter high-altitude winds that influence regional hydroclimate and forest fire during the following warm season. We use climate model simulations and paleoclimate data to reconstruct winter NPJ characteristics back to 1571 CE to identify the influence of NPJ behavior on moisture and forest fire extremes in California before and during the more recent period of fire suppression. Maximum zonal NPJ velocity is lower and northward shifted and has a larger latitudinal spread during presuppression dry and high-fire extremes. Conversely, maximum zonal NPJ is higher and southward shifted, with narrower latitudinal spread during wet and low-fire extremes. These NPJ, precipitation, and fire associations hold across pre–20th-century socioecological fire regimes, including Native American burning, postcontact disruption and native population decline, and intensification of forest use during the later 19th century. Precipitation extremes and NPJ behavior remain linked in the 20th and 21st centuries, but fire extremes become uncoupled due to fire suppression after 1900. Simulated future conditions in California include more wet-season moisture as rain (and less as snow), a longer fire season, and higher temperatures, leading to drier fire-season conditions independent of 21st-century precipitation changes. Assuming continuation of current fire management practices, thermodynamic warming is expected to override the dynamical influence of the NPJ on climate–fire relationships controlling fire extremes in California. Recent widespread fires in California in association with wet extremes may be early evidence of this change.

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.

Klamath/San Joaquin/Sacramento Hydroclimatic Reconstructions from Tree Rings

California Department of Water Resources (DWR) | February 7th, 2014

This is a draft final report for Agreement Number 4600008850, “Klamath/San Joaquin/Sacramento Hydroclimatic Reconstructions”, signed October 13, 2010.  Work includes

This is a draft final report for Agreement Number 4600008850, “Klamath/San Joaquin/Sacramento Hydroclimatic Reconstructions”, signed October 13, 2010.  Work includes developing new and updated tree-ring chronologies, reconstructing specified streamflow and/or precipitation records in the Klamath, San Joaquin and Sacramento River Basins, and analyzing the time series properties of the reconstructions. These reconstructions allow assessment of hydrologic variability over centuries to millennia and give context for assessing recent drought events. Tasks on this project included field collections; laboratory work in sample preparation, dating and measurement; and statistical work in chronology development, reconstruction, and analysis of those reconstructions. The interpretation of the reconstructions includes five main components : 1) place instrumental-period flow statistics in a long-term context, 2) quantify droughts and wet periods, 3) identify cycles in wetness and dryness, 4) check consistency with other paleoclimatic data, and 5) assess reconstructed flow variations in the context of expected scenarios of climate. A total of 16 different hydroclimatic series – 11 flow records and 5 precipitation records, were reconstructed. This report summarizes the research project products and results. The Data and Methods section of this report describes the field collections and development of tree-ring chronologies, reconstruction modeling, and methods of analyzing reconstructions. The Results section focuses on the interpretation of selected key reconstructions for the Klamath, Sacramento, and San Joaquin basins. Annual time series of the 16 reconstructions are included as products in an appendix and in a digital spreadsheet.

Lahar Hazard Zones for Eruption-Generated Lahars in the Lassen Volcanic Center, California

U.S. Geological Survey (USGS) | September 25th, 2012

Lahars, Indonesian for volcanic mudflows or debris-flows, are a rapidly flowing mixture of rock debris and water that originates on the slopes of a volcano. Lahar generat

Lahars, Indonesian for volcanic mudflows or debris-flows, are a rapidly flowing mixture of rock debris and water that originates on the slopes of a volcano. Lahar generation requires an adequate source of water, abundant unconsolidated debris, steep slopes, significant relief, and a triggering mechanism (Vallance, 2000). Various triggering mechanisms include the rapid melting of snow and ice by pyroclastic flows, intense rainfall on loose volcanic rock deposits, a breakout of a lake dammed by volcanic deposits, and a debris avalanche.

Land Reclamation Impacts on Tidal Landscape Evolution

American Geophysical Union (AGU) | August 21st, 2025

Fertile and low-lying coastal landscapes are often densely populated due to food supply (agriculture, aquaculture, and fisheries) and easy navigability (shipping lanes).

Fertile and low-lying coastal landscapes are often densely populated due to food supply (agriculture, aquaculture, and fisheries) and easy navigability (shipping lanes). Much of the low-lying land that is regularly inundated by the sea has been converted to agricultural land or urban environments to meet the need for land. This reclamation of land influences the tidal dynamics of the coastal environment, which in turn modifies its morphology. Through various complex tide-topography interactions identified in this paper, we explore how the location and extent of land reclamation influences tides and bed levels in various tidal environments. We especially point to the key role of sediments herein, introducing feedback mechanisms that lead to large impacts on tidal landscapes, but also long adaptation times. This is especially the case for estuaries due to their confinement and the typically large availability of sediments.

Land subsidence in the San Joaquin Valley, California, as of 1972

U.S. Geological Survey (USGS) | July 10th, 1975

Land subsidence which began in the mid-1920's due to groundwater overdraft in the San Joaquin Valley has caused widespread concern for the past two decades. Withdrawals

Land subsidence which began in the mid-1920's due to groundwater overdraft in the San Joaquin Valley has caused widespread concern for the past two decades. Withdrawals for irrigation increased from 3 million acre-feet in 1942 to 10 million acre-feet in 1966. Water levels declined at unprecedented rates during the 1950's and early 1960's. Pumping lifts became inordinately high, well casings failed at alarming rates, and differential settlement caused numerous farming and engineering problems. By 1970,5,200 square miles of valley land had been affected, and maximum subsidence exceeded 28 feet. The valley-wide volume of subsidence totaled 15.6 million acre-feet, one-half the initial storage capacity of Lake Mead. This subsidence represents one of the great environmental changes imposed by man. Importation of surface water to the northwestern and eastern areas of overdraft in the valley began in the 1950's and to the much larger western and southern areas in the late 1960's. Canal imports have largely replaced ground-water pumpage in these areas. As of 1973, after three decades of continued declining water levels, many hundreds of irrigation wells are idle and water levels are rising. Throughout much of the valley, artesian pressures are recovering toward their presubsidence levels, and elevations of the subsiding land surface are stabilizing. Basic-data graphs and computer-plotted stress-strain relationships constitute a major part of this report. They are based on 10-13 years of detailed field measurements of both water-level change and compaction collected by the U.S. Geological Survey at 20 selected locations in the San Joaquin Valley. The recharge characteristics of a ground-water reservoir are indicated roughly by the volume ratio, which is subsidence/pumpage. In the Los Banos-Kettleman City area, the values of this ratio range from less than 0.2 near the perimeter to more than 0.6 in the central part of the area. In the corresponding parts of the Arvin-Maricopa area, the ratio ranges from near 0 to more than 0.4.

Land Transitions and Dust in the San Joaquin Valley

Public Policy Institute of California (PPIC) | July 24th, 2022

The Sustainable Groundwater Management Act (SGMA) requires groundwater users to bring their basins into balance over the next two decades. In the San Joaquin Valley, this

The Sustainable Groundwater Management Act (SGMA) requires groundwater users to bring their basins into balance over the next two decades. In the San Joaquin Valley, this will mean taking more than 500,000 acres of agricultural land out of intensive irrigated production. Among other issues, this could potentially lead to air quality impacts if the lands become new sources of dust, especially windblown dust, which can have numerous negative short- and long-term health and environmental impacts. In addition, the changing climate may exacerbate risks as warmer temperatures can dry out soils and increase dust emissions. The overall air quality impact of transitioning agricultural land to new uses is nuanced, but proactive management can help to identify high-risk areas and at-risk communities, and direct effort and funding to the most cost-effective interventions.