Sacramento River

Fresh Submarine Groundwater Discharge to the Near‐Global Coast

American Geophysical Union (AGU) | April 24th, 2019

Abstract: The flow of fresh groundwater to the ocean through the coast (fresh submarine groundwater discharge or fresh SGD) plays an important role in global biogeochemic

Abstract: The flow of fresh groundwater to the ocean through the coast (fresh submarine groundwater discharge or fresh SGD) plays an important role in global biogeochemical cycles and coastal water quality. In addition to delivering dissolved elements from land to sea, fresh SGD forms a natural barrier against salinization of coastal aquifers. Here we estimate groundwater discharge rates through the near‐global coast (60°N to 60°S) at high resolution using a water budget approach. We find that tropical coasts export more than 56% of all fresh SGD, while midlatitude arid regions export only 10%. Fresh SGD rates from tectonically active margins (coastlines along tectonic plate boundaries) are also significantly greater than passive margins, where most field studies have been focused. Active margins combine rapid uplift and weathering with high rates of fresh SGD and may therefore host exceptionally large groundwater‐borne solute fluxes to the coast. Plain Language Summary: Fresh groundwater flows from land to sea through coastal rocks and sediment. While the amount of groundwater flow is small compared with rivers, it plays an important role in carrying dissolved chemicals like nutrients to sea, and it helps protect aquifers against salinization. We estimate groundwater flow through the near‐global coast. Tropical regions have more groundwater flow, while dry midlatitudes have less. Dry midlatitude regions are therefore more vulnerable to salinization, which is problematic because these regions are also more likely to depend on groundwater to meet their water needs. Additionally, mountainous coastlines along tectonic plate boundaries have relatively large rates of groundwater discharge and may be associated with higher dissolved chemical fluxes to the coast.

Friant Division Central Valley Project

U.S. Bureau of Reclamation (USBR) | January 4th, 1994

Water is life the cliché goes, but in California, the reality is water is power. The Eureka State is blessed with warm days and productive soil, but deprived of enough w

Water is life the cliché goes, but in California, the reality is water is power. The Eureka State is blessed with warm days and productive soil, but deprived of enough water to go around. The pursuit of the power conferred by the water flowing in its rivers, and bubbling up from underground, is a much more complicated part of the Central Valley Project (CVP) than authorization, design, and construction. An anomaly in the CVP's labyrinthine history, the Friant Division developed along lines similar to other Reclamation projects in the West. One of three original segments of the CVP, the Friant Division, is separate, simple in design, but has seen it share of the same kinds of controversy plaguing the rest of the project. In spite of the disputes Friant generated, of the top five agricultural producing counties in the nation, three -- Fresno, Tulare and Kern -- are watered by Friant Division facilities. The clear sky, fertile land, and dry air of the southern San Joaquin Valley provide the backdrop where great promises have been met and modest hopes destroyed all in order to create "the richest agricultural region in the history of the world."

Friends of the Earth v. Coleman

United States Court of Appeals, Ninth Circuit | March 10th, 1975

Friends of the River v. Sites Project Authority

California Courts of Appeal, Third Appellate District | September 20th, 2024

From Climate Traces to Climate Insights: Future Scenarios Analysis for the California Central Valley

California Department of Water Resources (DWR) | October 2nd, 2023

California Water Code Section 10004.6 requires the California Department of Water Resources (DWR) to quantify current and future water conditions in the state. This infor

California Water Code Section 10004.6 requires the California Department of Water Resources (DWR) to quantify current and future water conditions in the state. This information is published in the California Water Plan (Water Plan), which is updated every five years. Water managers and planners constantly face the challenges of planning for an uncertain future where the only constant is change. To address the potential future changes and mitigate the probable risks, water managers must consider and quantify uncertainties and their impacts on water system vulnerability. Although it is not possible to know for certain how population growth, land use decisions, climate, and other factors change over time, water planners must consider these system stressors in long-term planning to evaluate future risks and uncertainty. The Water Plan evaluates many alternative future scenarios as an integral part of its analytical approach to quantify system vulnerability under a range of population and urban growth scenarios, land use, and climate uncertainties.

From the extreme to the mean: Acceleration and tipping points of coastal inundation from sea level rise

American Geophysical Union (AGU) | December 18th, 2014

Relative sea level rise (RSLR) has driven large increases in annual water level exceedances (duration and frequency) above minor (nuisance level) coastal flooding elevat

Relative sea level rise (RSLR) has driven large increases in annual water level exceedances (duration and frequency) above minor (nuisance level) coastal flooding elevation thresholds established by the National Weather Service (NWS) at U.S. tide gauges over the last half-century. For threshold levels below 0.5 m above high tide, the rates of annual exceedances are accelerating along the U.S. East and Gulf Coasts, primarily from evolution of tidal water level distributions to higher elevations impinging on the flood threshold. These accelerations are quantified in terms of the local RSLR rate and tidal range through multiple regression analysis. Along the U.S. West Coast, annual exceedance rates are linearly increasing, complicated by sharp punctuations in RSLR anomalies during El Niño Southern Oscillation (ENSO) phases, and we account for annual exceedance variability along the U.S. West and East Coasts from ENSO forcing. Projections of annual exceedances above local NWS nuisance levels at U.S. tide gauges are estimated by shifting probability estimates of daily maximum water levels over a contemporary 5-year period following probabilistic RSLR projections of Koppet al.(2014) for representative concentration pathways(RCP) 2.6, 4.5, and 8.5. We suggest a tipping point for coastal inundation (30 days/per year with a threshold exceedance) based on the evolution of exceedance probabilities. Under forcing associated with the local-median projections of RSLR, the majority of locations surpass the tipping point over the next several decades regardless of specific RCP.

From the Sierra to the Sea: The Ecological History of the San Francisco Bay-Delta Watershed

Bay Institute | July 15th, 2003

A vast watershed connects the mountain streams surrounding California’s Central Valley with San Francisco Bay and the ocean beyond. Over the course of the last two cent

A vast watershed connects the mountain streams surrounding California’s Central Valley with San Francisco Bay and the ocean beyond. Over the course of the last two centuries, much of the natural productivity, biodiversity and ecological integrity of the watershed has been destroyed by modifying the environment without fully understanding the long-term environmental consequences. Long the site of some of the nation’s most intensive conflicts over the use of land and water resources, this system is now emerging as the focus of one of the most ambitious ecological restoration efforts ever undertaken in the United States. This report was designed to provide a coherent and defensible ecological framework and information base for restoration. The need for such an historical, broad-scale perspective on system ecology stems from two fundamental principles of ecological restoration - the need to manage toward a natural template and to manage at ecosystem and landscape levels.

From the Sierra to the Sea: The Ecological History of the San Francisco Bay-Delta Watershed

Bay Institute | January 1st, 1998

A vast watershed connects the mountain streams surrounding California’s Central Valley with San Francisco Bay and the ocean beyond. Over the course of the last two cent

A vast watershed connects the mountain streams surrounding California’s Central Valley with San Francisco Bay and the ocean beyond. Over the course of the last two centuries, much of the natural productivity, biodiversity and ecological integrity of the watershed has been destroyed by modifying the environment without fully understanding the long-term environmental consequences. Long the site of some of the nation’s most intensive conflicts over the use of land and water resources, this system is now emerging as the focus of one of the most ambitious ecological restoration efforts ever undertaken in the United States. This report was designed to provide a coherent and defensible ecological framework and information base for restoration. The need for such an historical, broad-scale perspective on system ecology stems from two fundamental principles of ecological restoration - the need to manage toward a natural template and to manage at ecosystem and landscape levels.

Further Trade Wars Will Harm California Agriculture

University of California, Davis (UC Davis) | September 30th, 2024

As protectionist policies gain momentum in the United States, the future of California’s agricultural trade faces pessimism. With proposals to expand tariffs on imports

As protectionist policies gain momentum in the United States, the future of California’s agricultural trade faces pessimism. With proposals to expand tariffs on imports from China and other nations, California farmers—who depend on global markets as an outlet for their almonds, wine, and other agricultural goods—are aware that there would be trade retaliation from our trading partners. If a significant new trade war develops, California could see a quarter of its agricultural exports wiped out, costing the state’s economy $6 billion annually.

Future Atmospheric Rivers and Impacts on Precipitation: Overview of the ARTMIP Tier 2 High-Resolution Global Warming Experiment

American Geophysical Union (AGU) | March 14th, 2023

Atmospheric rivers (ARs) are long and narrow weather features often referred to as “rivers in the sky.” They often transport water from lower latitudes to higher lati

Atmospheric rivers (ARs) are long and narrow weather features often referred to as “rivers in the sky.” They often transport water from lower latitudes to higher latitudes typically across climate zones and produce precipitation necessary for local climates. Understanding ARs in a warming climate is challenging because of the variety of ways an AR can be defined on gridded data sets. Unlike weather features such as tropical cyclones where identification methodologies are similar, algorithms that determine the characteristics of ARs vary depending on the science question posed. Because there is no real consensus on AR identification methodology, we aim to quantify the algorithmic uncertainty in AR metrics and precipitation. We compare 16 different ways of defining an AR on gridded data sets and present the range of possibilities in which an AR could change under global warming. Generally, ARs are projected to increase but the amount of that increase is a function of the algorithm. Across all algorithms and focus regions, AR precipitation is projected to become more extreme.