Preface to the Environmental Assessment for 2019 Ocean Salmon Fisheries Management Measures

National Marine Fisheries Service (NMFS) | April 1st, 2019

Preliminary Evaluation of Impacts of Potential Groundwater Sustainability Indicators on Future Groundwater Extraction Rates – Oxnard Plain and Pleasant Valley Groundwater Basins

United Water Conservation District (UWCD) | April 4th, 2017

This evaluation was performed to estimate the combined sustainable yield of the Oxnard Plain (including the Forebay) and Pleasant Valley groundwater basins (the study are

This evaluation was performed to estimate the combined sustainable yield of the Oxnard Plain (including the Forebay) and Pleasant Valley groundwater basins (the study area). The purpose is to provide supporting information to United Water Conservation District’s (United) management and Board of Directors in establishing groundwater management policies that are consistent with the mission of the agency. United recognizes that the compliance actions associated with the Sustainable Groundwater Management Act (SGMA), the formation of a Groundwater Sustainability Agency (GSA), and the creation and implementation of Groundwater Sustainability Plans (GSPs) have the potential to change how groundwater resources are managed in Ventura County. This report was prepared for the benefit of United’s Board of Directors and senior management, and is not intended to serve as a GSP, define how the sustainable yield should be determined by the GSA, or specify what value or range of values should be used as the sustainable yield. The analyses and results are meant to be used as a starting point in evaluating potential impacts to United’s operations as a result of sustainability planning already underway by the Fox Canyon Groundwater Management Agency (FCGMA) for the study area. Note: an addendum to this was published on November 7, 2017

Preliminary Evaluation of the Hydrogeologic System in Owens Valley, California

U.S. Geological Survey (USGS) | January 8th, 1988

Owens Valley is a major source of water for southern California and presently (1986) provides more than 60 percent of the supply for Los Angeles. Since 1970, ground-water

Owens Valley is a major source of water for southern California and presently (1986) provides more than 60 percent of the supply for Los Angeles. Since 1970, ground-water withdrawal from Owens Valley has increased, and a decline in the health of vegetation has been reported. In 1982, a cooperative project to study the hydrogeology and plant ecology of Owens Valley was begun by Inyo County, the Los Angeles Department of Water and Power, and the U.S. Geological Survey. As part of this project, the available data and present hydrologic concepts of Owens Valley were evaluated by using a ground-waterflow model. Results of this preliminary evaluation are being used to guide data collection and the development of more sophisticated hydrologic models.

Preliminary hydrogeologic assessment near the boundary of the Antelope Valley and El Mirage Valley groundwater basins, California

U.S. Geological Survey (USGS) | July 19th, 2017

Preliminary Results from Exploratory Sampling of Wells for the California Oil, Gas, and Groundwater Program, 2014–15

U.S. Geological Survey (USGS) | January 26th, 2017

In 2014 and 2015, the U.S. Geological Survey (USGS) sampled water wells in the Los Angeles Basin and southern San Joaquin Valley, California, and oil wells in the San Joa

In 2014 and 2015, the U.S. Geological Survey (USGS) sampled water wells in the Los Angeles Basin and southern San Joaquin Valley, California, and oil wells in the San Joaquin Valley for analysis of multiple chemical, isotopic, and groundwater-age tracers (fig. 1). The purpose of this reconnaissance sampling was to evaluate the utility of tracers for assessing the effects of oil and gas production activities on groundwater quality in California. The study was done in cooperation with the California State Water Resources Control Board. Results of the study are intended to help design a regional groundwater monitoring program to be implemented as part of California Senate Bill 4 (SB 4 statutes of 2013). The regional monitoring program plans to assess the effects of oil and gas production activities on groundwater quality and to provide a regional context for local monitoring of the groundwater-quality effects from well-stimulation treatments, which are techniques used to improve oil and gas production by increasing their rate of flow to the well. California SB 4 mandates that this local monitoring is to be done by oil-well operators in accordance with monitoring criteria established by the State Water Board. This report evaluates the utility of the chemical, isotopic, and groundwater-age tracers for assessing sources of salinity, methane, and petroleum hydrocarbons in groundwater overlying or near several California oil fields. Tracers of dissolved organic carbon in oil-field-formation water are also discussed. Tracer data for samples collected from 51 water wells and 4 oil wells are examined.

Preliminary update of DWR evaluation of San Joaquin Valley - Kern County basin Groundwater Sustainability Plan (GSP)

California Department of Water Resources (DWR) | December 9th, 2021

Preparation Checklist for Groundwater Sustainability Plan Submittal

California Department of Water Resources (DWR) | December 22nd, 2016

Guidance Document for the Sustainable Management of Groundwater The objective of this Guidance Document is to provide Groundwater Sustainability Agencies (GSAs) and ot

Guidance Document for the Sustainable Management of Groundwater The objective of this Guidance Document is to provide Groundwater Sustainability Agencies (GSAs) and other interested stakeholders a checklist of Groundwater Sustainability Plan (GSP) content requirements for the purpose of verifying a GSP is complete and is ready for submission to DWR. Please note that if multiple GSAs develop multiple GSPs for a basin, the coordinated submission of those GSPs shall not occur until the entire basin is covered by GSPs. The Preparation Checklist for GSP Submittal is only intended to provide a guide to GSAs and other stakeholders. This guidance is optional, since the content of this Guidance Document does not create any new requirements or obligations for the GSA or other stakeholders.

Preparing for California’s Next Drought—Changes Since 1987-92

California Department of Water Resources (DWR) | July 19th, 2000

Preparation of this report was initiated in response to the unusually dry conditions experienced through January 2000. California was in the second year of a La Niña eve

Preparation of this report was initiated in response to the unusually dry conditions experienced through January 2000. California was in the second year of a La Niña event, typically characterized by dryer than normal conditions in the southern part of the State. December 1999 was one of the driest Decembers on record. Snowpack levels in early January in the northern Sierra, the source of much of California’s developed water supply, were only some 20 percent of seasonal average. Given that California had previously experienced a record five consecutive wet years, it seemed probable that 2000 would not be another wet year.  Subsequently, climatic conditions demonstrated the great variability typical of California. Substantial precipitation and snowpack accumulation brought Northern California to near average water conditions before the end of February. A dry 2000 would not have constituted a drought for most Californians, especially not with storage in the State’s major reservoirs at above average levels as a consequence of the past five wet years. It was recognized, however, that planning should begin for actions to be taken in the event that the following year was also dry. In response to the substantial public interest created by the dry weather conditions, the Department evaluated water supply conditions, changed circumstances since the last drought, and other factors that would affect drought readiness in 2001. The purpose of this report is to review items that the Department should consider in near-term drought planning, putting California’s conditions today into perspective with experiences gained in the 1987-92 drought. The report begins with an overview of California hydrology and water supply, then describes conditions encountered in the 1987-92 drought. Changed conditions since that drought are summarized, and their implications discussed. The report concludes with a list of actions that the Department could take to respond to future drought conditions. It is essential that California prepare for the return of very dry conditions. On June 9, 2000 Governor Davis and Interior Secretary Babbitt announced a “Framework for Action” as the completion of a five-year planning program to implement specific actions of the CALFED Bay-Delta Program. The Framework included a recommendation that Governor Davis appoint a panel to develop a Drought Contingency Plan by the end of 2000. This report will be used to brief the panel on drought actions considered to date, with the expectation that further and more focused actions/programs may be included in the Governor’s Drought Contingency Plan.

Preparing for New Risks: Addressing Climate Change in California’s Urban Water Management Plans

California Department of Water Resources (DWR) | June 20th, 2013

Urban Water Management Plans (UWMPs) are a central component of California’s efforts to assure reliable water supplies, particularly during drought conditions that are

Urban Water Management Plans (UWMPs) are a central component of California’s efforts to assure reliable water supplies, particularly during drought conditions that are frequently experienced in the state. Prepared by water suppliers every five years, UWMPs include supply and demand projections for the next 20 years, and describe strategies to assure adequate supplies during average, single-­year, and multi-­year drought conditions. UWMPs also contain plans to implement a 20% reduction in per capita urban water use by the year 2020, as required under the Water Conservation Act of 2009 (SBX7-­7). Climate change is introducing new risks in water planning, such as increasing temperatures, reduced snowpack, changing precipitation patterns, and accelerating sea level rise, which are already being observed in the state. It is increasingly important for water suppliers to consider how these trends are impacting water supply, demand, and drought patterns. Water suppliers can also make important contributions to reducing greenhouse gas emissions (GHGs), through energy savings from water conservation as well as other measures. In its guidance to water suppliers for preparing 2010 UWMPs, the California Department of Water Resources (DWR) included an optional section focused on consideration of climate change impacts and GHG emissions. This study assesses how water suppliers have incorporated these factors into their 2010 plans. Drawing upon a sample of 2010 UWMPs, it examines the nature and extent of climate change discussion and analysis, and assesses how climate change risks have been incorporated into water supply and demand projections. The report also provides recommendations for how DWR could improve its guidance for 2015 UWMPs to support water suppliers in addressing climate change. All public and investor-­owned utilities serving 3,000 customers or supplying at least 3,000 acre-­feet of water annually are required to submit an Urban Water Management Plan to DWR every five years. Of the approximately 400 agencies submitting UWMPs, most are relatively small, with 90% serving less than 300,000 people, and 40% serving less than 50,000.  Most are public entities, but some are private companies, including three investor-­owned utilities with multiple service areas across the state. Large and small water suppliers tend to differ in their access to resources for planning and analysis of issues such as climate change. For many small suppliers, UWMP preparation serves as their primary long-­term planning process. Suppliers also vary in the nature of their vulnerability to drought and the impacts of climate change. Larger suppliers usually have multiple sources of supply, while small suppliers are more likely to rely on a single source, especially groundwater. These small utilities are less likely to have relationships with other suppliers, thereby reducing their options for coping with severe droughts. This study is based on an analysis of 49 individually submitted UWMPs, seven regional UWMPs, and UWMPs from three investor-­owned utilities with multiple service areas across the state. The sample was stratified so that it represents water suppliers of all sizes. It includes all large suppliers (serving 300,000 or more customers), and 10% of medium-­sized and small suppliers (serving 50,000 – 300,000 and less than 50,000 customers, respectively). Each UWMP was analyzed for its content related to climate change, and classified according to the degree and focus of discussion. This report is also informed by informal consultations with representatives of water supply agencies of different sizes.

Preparing Scientists, Policy-Makers, and Managers for a Fast-Forward Future

University of California, Davis (UC Davis) | June 15th, 2021