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 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.

Primary Production in the Delta: Then and Now

University of California, Davis (UC Davis) | October 3rd, 2016

To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function

To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates and fish. The Delta has a low rate of primary production, but it is unclear whether this was always the case. Recent analyses from the Historical Ecology Team and Delta Landscapes Project provide quantitative comparisons of the areal extent of 14 habitat types in the modern Delta versus the historical Delta (pre-1850). Here we describe an approach for using these metrics of land use change to: (1) produce the first quantitative estimates of how Delta primary production and the relative contributions from five different producer groups have been altered by large-scale drainage and conversion to agriculture; (2) convert these production estimates into a common currency so the contributions of each producer group reflect their food quality and efficiency of transfer to consumers; and (3) use simple models to discover how tidal exchange between marshes and open water influences primary production and its consumption. Application of this approach could inform Delta management in two ways. First, it would provide a quantitative estimate of how large-scale conversion to agriculture has altered the Delta's capacity to produce food for native biota. Second, it would provide restoration practitioners with a new approach—based on ecosystem function—to evaluate the success of restoration projects and gauge the trajectory of ecological recovery in the Delta region.

Principles and Requirements for Federal Investments in Water Resources

Council on Environmental Quality (CEQ) | March 22nd, 2013

Chapter I – Principles for Federal Investments in Water Resources 1. Purpose and Scope 2. The Federal Objective 3. Guiding Principles A. Healthy and Resilient Ecosy

Chapter I – Principles for Federal Investments in Water Resources 1. Purpose and Scope 2. The Federal Objective 3. Guiding Principles A. Healthy and Resilient Ecosystems B. Sustainable Economic Development C. Floodplains D. Public Safety E. Environmental Justice F. Watershed Approach Chapter II – Requirements 1. General Requirements A. Evaluation Framework B. Best Available Science and Commensurate Level of Detail C. Collaboration D. Risk & Uncertainty i. Climate Change ii. Future Land Use iii. Adaptive Management E. Water Use F. Nonstructural Approaches G. International Concerns H. Design of Alternatives I. Transparency in Decision Making J. Plan Selection 2. Interagency Guidelines 3. Effective Date 4. Approval

Priorities for California Water (2017)

Public Policy Institute of California (PPIC) | October 13th, 2017

This past year was a prime example of California’s highly variable climate—and a precursor of the types of extremes that are expected to become more common. After fiv

This past year was a prime example of California’s highly variable climate—and a precursor of the types of extremes that are expected to become more common. After five years of drought exacerbated by record heat, 2017’s record rain and snow brought more challenges—stressing dams and levees, causing landslides, and adding fuel to fire-prone landscapes. Across California, leaders have responded with a number of policy and management reforms, including some that will help the state adapt to droughts and floods of the future. But there’s more work to be done. In this policy brief we outline issues that are front and center for managing California’s water supply and natural environment. We also suggest priorities for actions that would improve California’s water systems and better support the state’s residents, businesses, and ecosystems.

Priorities for California's Water: Responding to the Changing Climate

Public Policy Institute of California (PPIC) | November 18th, 2021

Water is central to how California adapts to a changing climate. To those of us steeped in the complexities of managing the state’s water resources, the current fast-mo

Water is central to how California adapts to a changing climate. To those of us steeped in the complexities of managing the state’s water resources, the current fast-moving drought—coming on the heels of the record-breaking 2012–16 drought—is a stark reminder that we must accelerate preparation for the disruptive changes underway. Californians have taken steps to address major threats to our water resources. But a recent IPCC report underscored that the climate is changing faster than anticipated, and that many of these changes are already locked in. Rising temperatures are making our winters shorter and our droughts more intense, outpacing our ability to manage water supplies and the natural environment. We need to act with urgency to adapt to these changes. And we need to rethink how we store water. This brief examines how the current drought and a changing climate are affecting California’s ability to manage water and lays out priority actions to address major challenges—including some urgent short-term actions should the drought continue into next year.

Priorities for California’s Water

Public Policy Institute of California (PPIC) | November 14th, 2022

This report considers the state of water in California: What changes are we seeing now, and what should we expect in the near future? Then it examines how these climate s

This report considers the state of water in California: What changes are we seeing now, and what should we expect in the near future? Then it examines how these climate shifts will impact urban and rural communities, agriculture, and the environment. Finally, it explores wet-year strategies that will help Californians get through the dry years.