Department of Fish and Game Rationale for Effects of Exports

California Department of Fish and Wildlife (CDFW) | November 2nd, 2011

This document describes the California Department of Fish and Game (DFG) methodology to quantify the surface area in the Sacramento – San Joaquin delta estuary (Delta)

This document describes the California Department of Fish and Game (DFG) methodology to quantify the surface area in the Sacramento – San Joaquin delta estuary (Delta) that is impacted by the operations of the State Water Project (SWP) and Central Valley Project (CVP) pumping facilities. In order to estimate the mitigation required to offset direct and indirect losses of Fish Species due to impacts to surface acres of aquatic habitat in the Delta accounted to the SWP Delta Pumping Facilities operations, DFG used an analysis based on conclusions and information contained in a manuscript that utilizes the Delta Simulation Model-2 Particle Tracking Model (DSM2PTM) (Kimmerer and Nobriga, 2008). This methodology provides the general loss of “particles” to the Delta which is a surrogate for loss of productivity and fish life stages vulnerable to these effects.

Department of Fish and Wildlife Scientific Integrity Policy

California Department of Fish and Wildlife (CDFW) | June 15th, 2017

In order to guide the scientific work by the Department and pursuant to Fish and Game Code Section 715(d), the Department adopts this scientific integrity policy, to ensu

In order to guide the scientific work by the Department and pursuant to Fish and Game Code Section 715(d), the Department adopts this scientific integrity policy, to ensure integrity and public confidence in our scientific work. This Scientific Integrity Policy (Policy) affirms the standards for high quality and ethical scientific inquiry within the Department. Given the vital role of science in the management of natural resources, the Department endeavors to maintain and strengthen its commitment to scientific information that is developed and used according to the highest professional standards. These efforts are essential to maintaining the confidence of the public and other stakeholders, and to enhance the reputation of the Department’s scientific programs, policies and staff. Furthermore, the Department is committed to providing an environment that encourages and supports the conduct, communication, and transparency of excellent science. In support of the above, this Policy is to be considered as the collective guiding principles for all scientific endeavors within the Department. The purposes of this Policy are: To foster the development and use of high quality scientific work that is used to inform policy and management within the Department as well as decisions of the Fish and Game Commission. To ensure that the public and decision makers have access to the scientific methodology and analyses behind the Department’s policy positions. This Policy is intended to provide overarching guidance through the standards and protocols listed below. Guidance documents may be added, changed or removed from the list by the Director (or designee), as needed to remain current and relevant.

Department of the Interior Nature-Based Solutions Roadmap

Nicholas Institute for Energy, Environment & Sustainability (Duke University) | December 1st, 2023

Depletion and Capture: Revisiting “The Source of Water Derived from Wells”

National Groundwater Association (NGWA) | May 28th, 2014

A natural consequence of groundwater withdrawals is the removal of water from subsurface storage, but the overall rates and magnitude of groundwater depletion and capture

A natural consequence of groundwater withdrawals is the removal of water from subsurface storage, but the overall rates and magnitude of groundwater depletion and capture relative to groundwater withdrawals (extraction or pumpage) have not previously been well characterized. This study assesses the partitioning of long‐term cumulative withdrawal volumes into fractions derived from storage depletion and capture, where capture includes both increases in recharge and decreases in discharge. Numerical simulation of a hypothetical groundwater basin is used to further illustrate some of Theis' (1940) principles, particularly when capture is constrained by insufficient available water. Most prior studies of depletion and capture have assumed that capture is unconstrained through boundary conditions that yield linear responses. Examination of real systems indicates that capture and depletion fractions are highly variable in time and space. For a large sample of long‐developed groundwater systems, the depletion fraction averages about 0.15 and the capture fraction averages about 0.85 based on cumulative volumes. Higher depletion fractions tend to occur in more arid regions, but the variation is high and the correlation coefficient between average annual precipitation and depletion fraction for individual systems is only 0.40. Because 85% of long‐term pumpage is derived from capture in these real systems, capture must be recognized as a critical factor in assessing water budgets, groundwater storage depletion, and sustainability of groundwater development. Most capture translates into streamflow depletion, so it can detrimentally impact ecosystems.

Depletion and response of deep groundwater to climate-induced pumping variability

Nature Portfolio (Springer Nature) | January 23rd, 2017

Groundwater constitutes a critical component of our water resources. Widespread groundwater level declines have occurred in the USA over recent decades, including

Groundwater constitutes a critical component of our water resources. Widespread groundwater level declines have occurred in the USA over recent decades, including in regions not typically considered water stressed, such as areas of the Northwest and mid-Atlantic Coast. This loss of water storage reflects extraction rates that exceed natural recharge and capture. Here, we explore recent changes in the groundwater levels of deep aquifers from wells across the USA, and their relation to indices of interannual to decadal climate variability and to annual precipitation. We show that groundwater level changes correspond to selected global climate variations. Although climate-induced variations of deep aquifer natural recharge are expected to have multi-year time lags, we find that deep groundwater levels respond to climate over timescales of less than one year. In irrigated areas, the annual response to local precipitation in the deepest wells may reflect climate-induced pumping variability. An understanding of how the human response to drought through pumping leads to deep groundwater changes is critical to manage the impacts of interannual to decadal and longer climate variability on the nation’s water resources.

Depletion Requiremements in California’s Sustainable Groundwater Management Act

Environmental Defense Fund (EDF) | May 17th, 2018

Successful implementation of the Sustainable Groundwater Management Act (SGMA), including its provision to avoid signicant and unreasonable depletion of interconn

Successful implementation of the Sustainable Groundwater Management Act (SGMA), including its provision to avoid signicant and unreasonable depletion of interconnected surface water, is a high priority for the Environmental Defense Fund (EDF). The lack of established mechanisms for addressing depletions of interconnected surface water makes the implementation of this aspect of SGMA especially challenging. Accordingly, EDF offers recommendations to address the requirements of the law related to depletion of interconnected surface water, commonly referred to as “Undesirable Result No. 6” (UR #6). We believe that our proposed approach provides a reasonable balance among the con icting factors of rigor, cost, uncertainty, and enforceability that weigh on the implementation of this requirement. Our goal is to offer a pathway to achieve the fundamental and critical objective of UR#6 – preventing signi cant impacts to water users and ecosystems—in a way that is not unreasonably costly or unproductively burdensome on the Groundwater Sustainability Agencies (GSAs), water users, and state agencies who will bear most of the burden of complying with—or ensuring compliance with—SGMA.

Depth-dependent seismic sensing of groundwater recovery from the atmospheric-river storms of 2023

American Association for the Advancement of Science (AAAS) | February 13th, 2025

In early 2023, a series of intense atmospheric-river storms eased California’s historic drought, yet the spatiotemporal extent of groundwater recovery remains poorly un

In early 2023, a series of intense atmospheric-river storms eased California’s historic drought, yet the spatiotemporal extent of groundwater recovery remains poorly understood. We tracked two-decadal changes in groundwater in Greater Los Angeles using seismic ambient-field interferometry. The derived seismic hydrographs reveal distinct expressions of groundwater and surficial water droughts: Whereas surface and near-surface water storage nearly fully recovered in the epic wet season of 2023, only about 25% of the groundwater lost since 2006 was restored. On a decadal scale, we find substantial depletion in aquifers below 50-meter depth, with only limited storm-related recovery. Our analysis underscores the need to monitor deep aquifers for a more complete assessment of total water deficits, using high-resolution tools such as seismic sensing. Click here for a plain language summary of this research from the Stanford press office.

Desalination - Brackish and Sea Water (Resource Management Strategy)

California Department of Water Resources (DWR) | July 29th, 2016

Desalination, the removal of salts from saline waters, is one of the few options available to augment California’s water supply. California has facilities that desalina

Desalination, the removal of salts from saline waters, is one of the few options available to augment California’s water supply. California has facilities that desalinate sea water for coastal communities and brackish groundwater for inland water users — many of which have provided high-quality water to their customers for more than 10 years. As water supplies in California become more constrained, many water suppliers with nearby saline water sources are evaluating desalination as a way to provide reliable supply in response to uncertainties relating to future drought and climate change. While desalination is not a viable method for many water suppliers in the state, some not yet engaged in the process could realize significant supply and reliability benefits — even though desalination of both sea water and brackish groundwater comes with financial and environmental challenges. For water suppliers with desalination opportunities, how they implement environmentally sustainable projects is a key issue facing multiple California communities.

Desalination and Membrane Technologies: Federal Research and Adoption Issues

Congressional Research Service (CRS) | January 2nd, 2015

In the United States, desalination and membrane technologies are used to augment municipal water supply, produce high-quality industrial water supplies, and reclaim conta

In the United States, desalination and membrane technologies are used to augment municipal water supply, produce high-quality industrial water supplies, and reclaim contaminated supplies (including from oil and gas development). Approximately 2,000 desalination facilities larger than 0.3 million gallons per day (MGD) operate in the United States; this represents more than 2% of U.S. municipal and industrial freshwater use. At issue for Congress is what should be the federal role in supporting desalination and membrane technology research and facilities. Desalination issues before the 114th Congress may include how to focus federal research, at what level to support desalination research and projects, and how to provide a regulatory context that protects the environment and public health without disadvantaging desalination’s adoption. Construction of desalination facilities, like many other types of projects, often requires a significant number of local, state, and federal approvals and permits.  Emerging technologies (e.g., forward osmosis, capacitive deionization, and chlorine resistant membranes) show promise for reducing desalination costs. Research to support emerging technologies and to reduce desalination’s environmental and human health impacts is particularly relevant to future adoptions of desalination and membrane technologies. The federal government generally has been involved primarily in desalination research and development (including for military applications), some demonstration projects, and select full-scale facilities. For the most part, local governments, sometimes with state-level involvement, are responsible for planning, testing, building, and operating desalination facilities. Some states, universities, and private entities also undertake and support desalination research. While interest in desalination persists among some Members, especially in response to drought concerns, efforts to maintain or expand federal activities and investment are challenged by the domestic fiscal climate and differing views on federal roles and priorities.

Desalination and sustainability - An appraisal and current perspective

Water Research, Elsevier | February 1st, 2016

Desalination technologies have evolved and advanced rapidly along with increasing water demands around the world since 1950s. Many reviews have focused on the techno-econ

Desalination technologies have evolved and advanced rapidly along with increasing water demands around the world since 1950s. Many reviews have focused on the techno-economic and environmental and ecological issues of the desalination technologies and emphasized the feasibility of desalination industry as an alternative to meet the water demands in many water scarce regions. Despite these efforts, many perceptions about desalination processes hinder their applications for potential water supplies. This article has two specific aims: 1) provide an overview of the desalination trends around the world and discuss the sustainability components of desalination processes in comparison with other water supply alternatives; and 2) discuss case studies for desalination, and drivers and factors that influence sustainable desalination and other alternative water sources for desalination to increase our current understanding on the sensitive and futuristic issues of water supply and resource management options for drought facing regions. Although some of the facts and recent developments discussed here show that desalination can be affordable and potentially sustainable, contributions that meaningfully address socio-economic and ecological and environmental issues of desalination processes are urgently required in this critical era of severe water stress for the present context and the future development of desalination technologies.