Sacramento River

California Groundwater Conditions Update – Spring 2020

California Department of Water Resources (DWR) | October 3rd, 2022

In this report, groundwater level change values compare spring 2020 to spring 2019, 2017, 2015, and 2010. The information is summarized in Table 1. Spring groundwater lev

In this report, groundwater level change values compare spring 2020 to spring 2019, 2017, 2015, and 2010. The information is summarized in Table 1. Spring groundwater level data are an important indicator of groundwater conditions because spring generally corresponds to the pre-irrigation season. This time period is representative of the water year’s peak groundwater levels. Associated maps display groundwater level increases and decreases and summarize data by hydrologic region.

California Groundwater Conditions Update – Spring 2021 California’s drought and groundwater

California Department of Water Resources (DWR) | October 3rd, 2022

This report uses maps to depict how groundwater levels have changed over time using two different analytical methods. One method, groundwater level change maps, show the

This report uses maps to depict how groundwater levels have changed over time using two different analytical methods. One method, groundwater level change maps, show the change in groundwater levels between two different springtime measurements. The second method uses trend analysis of water levels for wells having at least 10 annual springtime measurements over a 20-year period to illustrate the statistical magnitude and direction of groundwater level change (a well’s water level increasing or decreasing trend over time). Spring groundwater level data are an important indicator of groundwater conditions because spring generally corresponds to both the pre-irrigation season and the peak groundwater levels in a water year.

California Hydraulic Mining under the Caminetti Act

Scientific American | July 21st, 1900

The gold deposits of California are, for a large part, contained in gravel beds once the channel of rivers which formed the drainage of the west slope of th

The gold deposits of California are, for a large part, contained in gravel beds once the channel of rivers which formed the drainage of the west slope of the Sierra Nevada Mountains. In the course of ages new rivers were formed, leaving the ancient gravel beds elevated often hundreds of feet above the river beds of the present. The depth of the gravel in the old channels is often several hundred feet and the width across them frequently one-half mile, while their courses may be traced for thirty or forty miles in length in detached sections, which are the remnants of once continuous beds. Denudation and the cutting down of the present streams has removed parts of the ancient channels and they often disappear below the surface for several miles underneath coverings of lava which have been spread over them ...  Hydraulic mining became an immense industry. At the time when it had reached its greatest development it was estimated that more than one hundred millions of dollars had been invested in the construction of water supplies, mining plant, tunnels, and flumes, and more than two million dollars have been spent in the equipment of a single mine. Everything was upon an immense scale, and the amounts of gravel removed were in proportion. So large, in fact, that the material washed into the streams caused blockages over spreading agricultural lands in the Sacramento Valley, obstructing and raising the beds of the navigable rivers which enter San Francisco Bay, causing inundations at times of flood, and generally making its influence noticeable 200 miles from the seat of mining. In 1880 it was estimated that in the bed of the Yuba River alone there were stored more than one hundred and forty million cubic yards of accumulations, and the bed of the river had spread over a width of two and one-half miles between the side levees built to confine the spread of the deposits.

California Salmon Strategy for a Hotter, Drier Future: Restoring Aquatic Ecosystems in the Age of Climate Change

California Department of Fish and Wildlife (CDFW) | January 20th, 2024

The infrastructure built generations ago in California continues to limit salmon migration, and some dams that remain on the landscape are well beyond their useful life.

The infrastructure built generations ago in California continues to limit salmon migration, and some dams that remain on the landscape are well beyond their useful life. In the Central Valley, large dams were built starting in the early 1900s on almost all major rivers. Those dams now block salmon access to over 90 percent of their historical spawning and rearing habitat higher in mountain streams.

California Single Family Water Use Efficiency Study

California Department of Water Resources (DWR) | April 20th, 2011

The California Single Family Home Water Use Efficiency Study includes data from many traditional sources such as billing data, survey data, weather data and aerial photo

The California Single Family Home Water Use Efficiency Study includes data from many traditional sources such as billing data, survey data, weather data and aerial photo information to analyze the water use patterns of a sample of over 700 single-family homes across ten water agencies throughout the State of California. Detailed flow trace data was obtained from portable data loggers which were attached to the water meters of each of the study homes. These flow traces provided flow readings at ten second intervals from the magnetic pickup, which generate 80-100 pulses per gallon. These highly detailed flow data make it possible to identify individual water use events and to categorize them by their end-use. The flow trace data tell not just how many gallons per day the home used, but how many gallons per day were used for individual end uses such as toilet flushing, clothes washing, dishwashers, showers, irrigation, faucets and leaks. Detailed use information can be pulled from the trace, giving for example, a count of toilet flushes and toilet flush volumes during a logging period. Researchers used flow trace data to determine levels of daily use in the homes and the efficiency of that use. Although the flow trace technique contains marginal error, such as from the mis-categorization of some events, it provides information on end uses-that is not available from any other source. This report summarizes the results of the study which began in 2005 and was completed in 2010. Water use patterns found during the 2007 logging period were analyzed to show how much potential remains for conservation savings from both indoor and outdoor efforts. 

California State Water Project 2006 Watershed Sanitary Survey Update

California Department of Water Resources (DWR) | June 20th, 2007

The State Water Project (SWP) provides drinking water to approximately two-thirds of California’s population and is the nation’s largest state-built water development

The State Water Project (SWP) provides drinking water to approximately two-thirds of California’s population and is the nation’s largest state-built water development project. The SWP extends from the mountains of Plumas County in the Feather River watershed to Lake Perris in Riverside County. It is linked with the Central Valley Project (CVP) that extends from southern Oregon in the Sacramento River watershed to the Mendota Pool. The watershed of the SWP is vast; encompassing the 27,000-square-mile Sacramento River and 13,000-square-mile San Joaquin River watersheds and at times, the 13,000-square-mile Tulare Basin watershed. The contaminant sources in the SWP watersheds have been well documented in the three previous sanitary surveys. The California Department of Health Services (CDHS) requested that the 2006 Update address the Jones Tract levee failure and emergency response procedures, efforts to coordinate pathogen monitoring in response to the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR), and a review of significant changes to the watersheds and their impacts on water quality.   A Technical Review Committee (TRC) was formed to guide development of the scope of work and provide technical expertise and review of the draft report. In addition to addressing the issues raised by CDHS, the TRC determined that the 2006 Update should focus on evaluating the sources of the water quality problems that the SWP Contractors face and recommending actions that the SWP Contractors can take that will lead to improvements in water quality over the next five years. TABLE OF CONTENTS CHAPTER 1 INTRODUCTION CHAPTER 2 REGULATORY SETTING CHAPTER 3 WATER QUALITY IN THE WATERSHEDS AND THE STATE WATER PROJECT CHAPTER 4 KEY CONCERNS IN THE CENTRAL VALLEY WATERSHED AND THE DELTA CHAPTER 5 KEY CONCERNS WITH STATE WATER PROJECT FACILITIES CHAPTER 6 INCIDENTS AND EMERGENCY RESPONSE MEASURES CHAPTER 7 CONCERNS WITH SYSTEM OPERATION AND MAINTENANCE

California State Water Project: Past, Present, Future

California Department of Water Resources (DWR) | July 1st, 2006

California Water Plan 2013: Mountain Counties Regional Report

California Department of Water Resources (DWR) | October 30th, 2014

As the State works to solve the water crisis in California, the potential for redirected impacts in the Mountain Counties Area is acute. It is critical that the State rec

As the State works to solve the water crisis in California, the potential for redirected impacts in the Mountain Counties Area is acute. It is critical that the State recognize the significance and importance of the Sierra Nevada mountain range to the local communities, the environment, the Delta, and all of California, now and for future generations. Water resource managers are working with elected officials, governmental agencies, businesses, farmers and conservationists on innovative programs for watershed management, water use efficiency, conservation, reuse, and recycling. Water managers and others in the region are actively balancing the water supplies that support both a vibrant economy and a healthy environment. They are also continually improving the management of surface and groundwater sources to sustain this important balance for this region and California. Statewide Significance Water is the number one resource exported from the Sierra Nevada, and the 16-county Mountain Counties Area is the primary source for most of that exported water. The Mountain Counties Area is over 15,700 square miles and represents 9.9 percent of the state. More than 40 percent of California’s developed water supply originates in the Mountain Counties area serving end users throughout the state. -The reservoirs in the region produce hydroelectricity to supply homes and businesses in the western United States. Mountain Counties has more hydroelectric generation facilities than any other region in California. - Agriculture in this region feeds the state and the world and is an economic driver for California’s economy. Recreation and tourism in the Sierra Nevada mountains help communities thrive economically as guests come from all over the world to hike, ski, fish, raft, and boat. Water stored behind designated reservoirs in the ten major watershed areas have dedicated in-stream flow releases designed to meet the many beneficial uses for the environment, agriculture, and urban users and provides storage to reduce the magnitude of flood flows.

California Water Plan 2013: Sacramento River Hydrologic Region Report

California Department of Water Resources (DWR) | October 30th, 2014

The Sacramento River Hydrologic Region (see Figure SR-1 includes the entire California drainage area of the Sacramento River (the state’s largest river) and its tributa

The Sacramento River Hydrologic Region (see Figure SR-1 includes the entire California drainage area of the Sacramento River (the state’s largest river) and its tributaries. The region extends from Chipps Island in Solano County north to Goose Lake in Modoc County. It is bounded by the Sierra Nevada on the east, the Coast Ranges on the west, the Cascade and Trinity mountains on the north, and the Sacramento-San Joaquin River Delta (Delta) on the south.  The Sacramento River Basin actually begins in Oregon, north of Goose Lake, a near-sink that intercepts the Pit River drainage at the California-Oregon border. Some key issues for this region are summarized here and discussed further later in this report. Agriculture. Between 2005 and 2010, the region supported about 1.95 million acres of irrigated agriculture on average. Approximately 1.58 million acres is irrigated on the valley floor. The surrounding mountain valleys add about 370,000 irrigated acres to the region’s total — primarily as pasture and alfalfa. The gross value of agricultural production in the Sacramento Valley for 2011 was about $4.1 billion (California Department of Food and Agriculture 2013). Rice and walnuts are the highest grossing crops in the region followed by almonds and tomatoes. The direct, indirect, and induced effects of the agricultural industry to the regional economy are discussed in this report. Groundwater. With a 2005-2010 average annual extraction volume of 2.7 million acre-feet (maf), groundwater pumping in the Sacramento River Hydrologic Region accounts for 17 percent of all the groundwater extraction in California — the third highest among the 10 hydrologic regions in California, behind Tulare Lake Hydrologic Region with 38 percent and San Joaquin River Hydrologic Region with 19 percent of the total. Overall, groundwater contributes to about 31 percent of the total water supply. Most groundwater extraction in the region occurs for agricultural water use (2.4 maf), meeting about one-third of agricultural water demands. Groundwater extraction for urban water use is significantly less (465 thousand acre-feet [taf]), which meets about half of the urban water needs. Groundwater levels for much of the region have declined from 2005 to 2010. Groundwater level declines ranging from 20 to 30 feet are seen in the northwestern portion of the Sacramento Valley Groundwater Basin. Declines ranging from to 10 to 20 feet are seen in the northern, the mid- to south-western, and the southeastern portions of the valley. For the rest of the Sacramento Valley Groundwater Basin and the Redding Area Groundwater Basin, groundwater level declines have ranged from zero to 10 feet. Flood. Exposure to a 500-year flood event in the region threatens approximately one in three residents, almost $65 billion in assets (crops, buildings, and public infrastructure), 1.2 million acres of agricultural land, and over 340 sensitive species. Almost 95 percent of Sutter County residents, more than 55 percent of Yuba County and Yolo County residents, and more than 50 percent of agricultural land region-wide are exposed to the 500-year flood event. Climate Change. Several different climate regions overlie portions of the Sacramento River Hydrologic Region. Air temperature data collected for the past century has been summarized by the Western Regional Climate Center (WRCC) for the different regions which are outlined below. Within the WRCC North Central climate region, mean temperatures have increased by about 0.8 to 1.7 °F (0.4 to 0.9 °C) in the past century, with minimum and maximum temperatures increasing by about 1.2 to 2.1 °F (0.7 to 1.2 °C) and 0.1 to 1.5 °F (0.1 to 0.8 °C), respectively. Within the WRCC North East climate region, mean temperatures have increased by about 0.8 to 2.0 °F (0.5 to 1.1 °C) in the past century, with minimum and maximum temperatures increasing by about 0.9 to 2.2 °F (0.5 to 1.2 °C) and by 0.5 to 2.1 °F (0.3 to 1.2 °C), respectively. Within the WRCC Sierra climate region, mean temperatures have increased by about 0.8 to 2.0 °F (0.5 to 1.1 °C) in the past century, with minimum and maximum temperatures increasing and decreasing by about 1.7 to 2.8 °F (0.9 to 1.5 °C) and by -0.2 to 1.3 °F (-0.1 to 0.7 °C), respectively. Within the WRCC Sacramento-Delta climate region, mean temperatures have increased by about 1.5 to 2.4 °F (0.9 to 1.3 °C) in the past century, with minimum and maximum temperatures increasing by about 2.1 to 3.1 °F (1.2 to 1.7 °C) and by 0.8 to 2.0 °F (0.4 to 1.1 °C), respectively (Western Regional Climate Center 2013). The region also is currently experiencing impacts from climate change through changes in statewide precipitation and surface runoff volumes, which in turn affect availability of local and imported water supplies. During the last century, the average early snowpack in the Sierra Nevada decreased by about 10 percent, which equates to a loss of 1.5 maf of snowpack storage (California Department of Water Resources 2008). Projections and impacts based on modeling of climate change are included in this report.

California Water Plan 2013: Sacramento-San Joaquin Delta Regional Report

California Department of Water Resources (DWR) | October 30th, 2014

Some areas of the state with common water issues or interests cross the boundaries from one hydrologic region to another. To acknowledge this, the California Department o

Some areas of the state with common water issues or interests cross the boundaries from one hydrologic region to another. To acknowledge this, the California Department of Water Resources (DWR) developed the concept of “overlay areas” and first described overlay areas in California Water Plan Update 2005. The purpose of the overlay areas is to collect and provide information that will better enable planners and decision-makers to address issues in areas of special interest where both of the following criteria apply: (1) the area is of statewide significance — meaning that water management strategies and actions taken in one area affect much of the remainder of the state — and (2) common water management conditions exist in the area — meaning that issues and integrated planning opportunities span more than one of the 10 hydrologic regions. The two overlay areas of special interest are the Sacramento-San Joaquin Delta (Delta) and Mountain Counties.  For Update 2005, the Delta and Suisun Marsh were included as an overlay area because of its common characteristics, environmental significance, and the important role it has in the State’s water systems. The Delta and Suisun Marsh encompasses about 840,000 acres of tidal influenced land near the confluence of the Sacramento and San Joaquin rivers; and occupies portions of the Sacramento, San Joaquin, and San Francisco hydrologic regions. The geographic extent of the Delta overlay coincides with the statutory Delta boundary that defines the Legal Delta (California Water Code [CWC] Section 12220) and the Suisun Marsh as defined in California Public Resources Code Section 29101.