A western United States snow reanalysis dataset over the Landsat era from water years 1985 to 2021

Nature Portfolio (Springer Nature) | November 7th, 2022

Water stored in mountain snowpacks (i.e., snow water equivalent, SWE) represents an important but poorly characterized component of the terrestrial water cycle. The Weste

Water stored in mountain snowpacks (i.e., snow water equivalent, SWE) represents an important but poorly characterized component of the terrestrial water cycle. The Western United States snow reanalysis (WUS–SR) dataset is novel in its combination of spatial resolution (~500 m), spatial extent (31°–49° N; 102°–125° W), and temporal continuity (daily over 1985–2021). WUS–SR is generated using a Bayesian framework with model-based snow estimates updated through the assimilation of cloud-free Landsat fractional snow-covered area observations. Over the WUS, the peak SWE verification with independent in situ measurements show correlation coefficient, mean difference (MD), and root mean squared difference (RMSD) of 0.77, −0.15 m, and 0.28 m, respectively. The effects of forest cover and Landsat image availability on peak SWE are assessed. WUS–SR peak SWE is well correlated (ranging from 0.75 to 0.91) against independent lidar-derived SWE taken near April 1st, with MD

A.D. Edmonston Pumping Plant and Tehachapi Crossing

California Department of Water Resources (DWR) | October 1st, 1985

Abrupt transition to irreversible damage in the overdrafted Sacramento Valley aquifer system

National Academy of Sciences (NAS) | July 27th, 2026

Groundwater extraction can cause both reversible and irreversible ground deformation, with the latter leading to permanent land subsidence and loss of groundwater storage

Groundwater extraction can cause both reversible and irreversible ground deformation, with the latter leading to permanent land subsidence and loss of groundwater storage capacity. Satellite observations of land surface deformation reveal that large areas of the Sacramento Valley abruptly transitioned from reversible to irreversible compaction over the 2020–2022 California drought—a transition not anticipated from the groundwater monitoring network alone. Subsidence rates reaching several decimeters per year and not following groundwater levels indicate lasting damage to the aquifer system and underscore the need for more conservative groundwater management. By imaging this sharp transition at the regional scale, our analysis demonstrates the potential of space-based monitoring for early detection of groundwater overdraft and the resulting loss of aquifer storage capacity worldwide.

Accelerating the Integration of Distributed Water Solutions: A Conceptual Financing Model from the Electricity Sector

Environmental Management (Springer) | August 19th, 2017

Modern challenges require new approaches to urban water management. One solution in the portfolio of potential strategies is the integration of distributed water infrastr

Modern challenges require new approaches to urban water management. One solution in the portfolio of potential strategies is the integration of distributed water infrastructure, practices, and technologies into existing systems. However, many practical barriers have prevented the widespread adoption of these systems in the US. The objective of this paper is to address these challenges by developing a conceptual model encompassing regulatory, financial, and governance components that can be used to incorporate new distributed water solutions into our current network. To construct the model, case studies of successfully implemented distributed electricity systems, specifically energy efficiency and renewable energy technologies, were examined to determine how these solutions have become prominent in recent years and what lessons can be applied to the water sector in a similar pursuit. The proposed model includes four action-oriented elements: catalyzing change, establishing funding sources, using resource pathways, and creating innovative governance structures. As illustrated in the model, the water sector should use suite of coordinated policies to promote change, engage end users through fiscal incentives, and encourage research, development and dissemination of new technologies over time.

Accounting for California’s Water

Public Policy Institute of California (PPIC) | July 13th, 2016

Understanding California’s water balance sheet—how much there is, who has claims to it, and what is actually being “spent”—is key to effectively managing the st

Understanding California’s water balance sheet—how much there is, who has claims to it, and what is actually being “spent”—is key to effectively managing the state’s limited water supply in support of a healthy economy and environment. The latest drought has spotlighted serious gaps and fragmentation in California’s water accounting system. In this report, we identify gaps in California’s water information systems. We recommend that the state adopt an overarching goal of modernizing its water accounting, and that key state agencies—supported by an oversight committee of key stakeholders and independent experts—develop and adopt a common accounting framework. We outline a dozen priority actions to strengthen water accounting by: improving measurements and estimates of water availability and use; firming up legal claims on water rights and water reserved for the environment; establishing protocols, standards, and models for transparent water accounting at all levels across the state; and making water information more available and accessible to water managers, water users, policymakers, and the public.

Accounting for Climate Change

California Department of Water Resources (DWR) | April 29th, 2010

In recent years, evidence that global climate will have significant effects on water resources in California has continued to accumulate. Climate change can affect the am

In recent years, evidence that global climate will have significant effects on water resources in California has continued to accumulate. Climate change can affect the amount, timing, and form of precipitation, whether rain or snow, that California receives, as well as the sea level of the Pacific Ocean. Moreover, changes in weather, especially temperature, and atmospheric composition can affect water use and consumption. Changes in climate have occurred during the 20th century, with noticeable warming in the last two decades. Most scientists feel that changes during the last several decades are likely mostly due to human activities, but natural causes and variability cannot be ruled out as a significant component. Likewise, projections of amount of warming and other climate changes during the 21st century are wide ranging, depending on assumptions and models. A major cause of expected climate change is the increasing amounts of greenhouse gases, such as carbon dioxide, in the atmosphere as a result of man’s activities. These gases, as well as water vapor, allow solar radiation to pass inward through the atmosphere, but trap the longer wave infrared radiation reflected back from the earth’s surface. Greenhouse gases are accumulating in the atmosphere; the following chart shows the gradual build up in carbon dioxide at Mauna Loa in Hawaii, as measured by Scripps Institution of Oceanography scientists. The annual cycle is caused by northern hemisphere vegetation uptake during the growing season. Other significant greenhouse gases are methane, nitrous oxide, halocarbons (like freon and its replacements), and, of course, water vapor itself. Cloud cover is an important element in the global radiation balance. Whatever the causes, the prospects of significant changes warrant examination of how the State’s water infrastructure and natural systems can accommodate or adapt to climate changes and whether more needs to be done to detect, evaluate and respond to water resource system effects. Many uncertainties remain, primarily on the degree of change to be expected. Responsible planning requires that the California water planning community work with climate scientists and others to reduce these uncertainties and to begin to prepare for those impacts that are well understood, already appearing as trends, or likely to appear. In this section we review possible impacts and address some of the responses appropriate for water planners and managers.

Accounting for Water "Wasted to the Sea"

University of California, Davis (UC Davis) | April 19th, 2018

Freshwater outflow from the Sacramento–San Joaquin Delta is a contentious management issue. Once mixed with salt water of San Francisco Bay, outflow is often characteri

Freshwater outflow from the Sacramento–San Joaquin Delta is a contentious management issue. Once mixed with salt water of San Francisco Bay, outflow is often characterized as having no value for urban and agricultural water supply, and thus “wasted to the sea.” In the July issue of San Francisco Estuary and Watershed Science, Cloern et al. (2017) showed how outflow from the Delta provides multiple and diverse benefits to the San Francisco estuary. Rather than being “wasted,” this outflow improves ecosystem conditions and water quality, and reduces wastewater treatment costs. The Cloern et al. (2017) essay highlights the importance of considering the multiple benefits of water as it moves within and out of the Delta. To do this, however, California needs a better water accounting system. In this report, we present an alternative approach. For the period 1980–2016, we assign inflow to the Delta to four categories: 1. Water used for diversions, 2. Outflow needed to meet salinity standards for diversions, 3. Outflow to meet ecosystem regulations, and 4. Water that results in outflow because of a lack of capacity for diversion. This approach highlights that much of the outflow from the Delta — particularly during dry periods — achieves multiple economic and environmental benefits and is hardly “wasted to the sea.”

Achievements in Conservation, Recycling, and Groundwater Recharge Covering Fiscal Year July 2018-June 2019

Metropolitan Water District of Southern California (MWD) | March 1st, 2020

Achieving Equitable, Climate-Resilient Water and Sanitation for Frontline Communities Water, Sanitation, and Climate Change in the United States Series, Part 3

Pacific Institute | March 18th, 2025

This report contains numerous documented efforts of ways that frontline communities are making progress toward equitable, climate-resilient water and sanitation. Built in

This report contains numerous documented efforts of ways that frontline communities are making progress toward equitable, climate-resilient water and sanitation. Built infrastructure is being adapted to better withstand the impacts of extreme storms, floods, and drought. Technologies and innovations are being designed and deployed in remote, hard-to-reach communities to deliver climate-resilient water and sanitation to homes for the first time. Natural infrastructure strategies are being used to enhance the climate resilience of water and sanitation by helping recharge aquifers and attenuate floodwaters, for example. Water managers and planners are incorporating climate resilience and centering frontline communities in efforts to deliver equitable, climate-resilient water and sanitation access to all. Frontline communities are overcoming barriers to accessing the financial resources that they need to pay for climate adaptation of water and sanitation or recover and respond to climate disasters. Climate and water knowledge and information from government agencies, water managers, local experts, and climate scientists are being integrated with place-based knowledges to ensure frontline communities and people in positions of power and authority can understand and access the data and information they need for decision making. The capacity of water and sanitation systems staff and decision makers is growing to better center the needs of frontline communities, educate and support the water and sanitation sector workforces in improving climate resilience, and build connections with interdependent sector. This is part three  in the Pacific Institute’s three-part Water, Sanitation, and Climate Change in the United States series. Click here for part one and  here for part two.

Achieving Groundwater Access for All: Why Groundwater Sustainability Plans are Failing Many Users

Groundwater Leadership Forum | July 3rd, 2023

California made a serious commitment to bring the most depleted groundwater basins back into balance when it passed the Sustainable Groundwater Management Act (SGMA) in 2

California made a serious commitment to bring the most depleted groundwater basins back into balance when it passed the Sustainable Groundwater Management Act (SGMA) in 2014. This commitment is being carried out at the local level through the formation of hundreds of new groundwater agencies, the launch of basin-level planning processes, and the creation of groundwater sustainability plans. This report summarizes the results of a scientific study published in Nature Communications. that analyzed the degree to which these groundwater plans equitably integrate and protect vulnerable groundwater users, and suggests course corrections in the ongoing SGMA process to ensure we are preparing our groundwater basins for a changed climate.