North Coast

California forest die-off linked to multi-year deep soil drying in 2012–2015 drought

Nature Portfolio (Springer Nature) | July 1st, 2019

Widespread episodes of recent forest die-off have been tied to the occurrence of anomalously warm droughts, although the underlying mechanisms remain inadequately

Widespread episodes of recent forest die-off have been tied to the occurrence of anomalously warm droughts, although the underlying mechanisms remain inadequately understood. California’s 2012–2015 drought, with exceptionally low precipitation and warmth, and widespread conifer death, provides an opportunity to explore the chain of events leading to forest die-off. Here, we present the spatial and temporal patterns of die-off and moisture deficit during California’s drought, based on field and remote sensing observations. We found that die-off was closely tied to multi-year deep-rooting-zone drying, and that this relationship provides a framework with which to diagnose and predict mortality. Marked tree death in an intensively studied Sierra Nevada forest followed a four-year moisture overdraft, with cumulative 2012–2015 evapotranspiration exceeding precipitation by ~1,500 mm, and subsurface moisture exhaustion to 5–15-m depth. Observations across the entire Sierra Nevada further linked tree death to deep drying, with die-off and moisture overdraft covarying across latitude and elevation. Unusually dense vegetation and warm temperatures accelerated southern Sierran evapotranspiration in 2012–2015, intensifying overdraft and compounding die-off by an estimated 55%. Climate change is expected to further amplify evapotranspiration and moisture overdraft during drought, potentially increasing Sierran tree death during drought by ~15–20% °C−1.

California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project: Domestic-Supply Assessment

U.S. Geological Survey (USGS) | March 14th, 2024

California Groundwater Conditions Update – Spring 2019

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

DWR has completed an evaluation of state-wide groundwater level data reported in spring 2019 for California groundwater basins. Spring data correspond to the time period

DWR has completed an evaluation of state-wide groundwater level data reported in spring 2019 for California groundwater basins. Spring data correspond to the time period immediately before the typical irrigation season begins in a region. This helps show groundwater levels before summer crop irrigation and other uses. In Central and Northern California, the pre-irrigation season is in March, while in Southern California, that season is typically earlier. The Spring 2019 Groundwater Level Data Coverage map (Figure 1) shows a comparison between total spring 2019 reporting and typical reporting in previous years. Typical reporting includes wells with water level data submitted to DWR over the past five spring seasons (2015-2019) by CASGEM Monitoring Entities, other local agencies, and well owners. Although the reporting percentage is high and coverage is good, there are still gaps in spring 2019 coverage throughout the state, including portions of Tulare, Kern, San Bernardino, Riverside, and Imperial counties.

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 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 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: North Coast Hydrologic Region Report

California Department of Water Resources (DWR) | October 30th, 2016

The North Coast Hydrologic Region is a unique setting with an extreme diversity of land use and climate. Land use includes aquaculture and larger urban areas near the coa

The North Coast Hydrologic Region is a unique setting with an extreme diversity of land use and climate. Land use includes aquaculture and larger urban areas near the coast to large cattle operations and low populations in the high mountain deserts. Ranching, farming, rural residential, timber harvest, vineyards, marijuana cultivation, U.S. Forest Service, and park land uses are prevalent. Variation in climate is immense with high precipitation along the coastal mountains to desert conditions in the Modoc Plateau. This chapter begins with an overview of the region, describing the setting and conditions within the region. Topics include information on the watersheds and sub-watersheds in the region with emphasis on developed resources. The chapter continues with a review of activities concerning resource administration and laws affecting resource management. This chapter concludes with a discussion of suggested resource management strategies to help assist local water managers in planning for future water needs.