Rapid groundwater decline and some cases of recovery in aquifers globally

Nature Portfolio (Springer Nature) | January 24th, 2024

Recent and Forecasted Increases in Coccidioidomycosis Incidence Linked to Hydroclimatic Swings, California, USA

U.S. Centers for Disease Control and Prevention (CDC) | March 4th, 2025

Incidence of coccidioidomycosis, an emerging infectious disease caused by Coccidioides spp. fungi, has increased dramatically since 2000. In 2023, California, USA, report

Incidence of coccidioidomycosis, an emerging infectious disease caused by Coccidioides spp. fungi, has increased dramatically since 2000. In 2023, California, USA, reported a near-record 9,054 coccidioidomycosis cases (only surpassed by 9,093 cases in 2019). During April 2023–March 2024, a period capturing the full seasonal rise and fall in incidence, California reported 10,519 cases, 39% higher than the same period the previous year. The 2023 spike in incidence might be attributable, in part, to a swing from extreme drought to heavy precipitation during winter 2022–2023. Transitions from dry to wet years have been linked to increased coccidioidomycosis incidence. Soil moisture during wet winters is hypothesized to support fungal growth, contributing to an abundance of spores available for airborne dispersal during hot, dry conditions characteristic of summer and early fall. Drought preceding rainy seasons might enhance fungal growth by eliminating microbial competitors from soils or by affecting rodent populations, a putative reservoir host and nutrient source for the fungus. During 2020–2022, California experienced severe drought. An unusually wet winter followed in 2022–2023; statewide precipitation exceeded 150% of average, among the top 10 wettest seasons in the past century. Statewide precipitation during the 2023–2024 wet season was 115% of the long-term average, marking the second consecutive wetter-than-average season after a severe drought. That pattern suggested high coccidioidomycosis incidence might continue throughout the 2024 transmission year. We developed a disease forecast to guide public health alerts and messages by pinpointing when and where disease risk is expected to be highest. Such targeted messaging can raise awareness about disease risk, leading to earlier diagnosis and more effective disease management.

Recent California Water Transfers: Implications for Water Management

Natural Resources Journal (University of New Mexico) | January 3rd, 1995

The 1991 and 1992 California Drought Emergency Water Banks were the first large water transfer programs in the nation in which the state served as the predominant broke

The 1991 and 1992 California Drought Emergency Water Banks were the first large water transfer programs in the nation in which the state served as the predominant broker for water trades. Although the state-sponsored Water Banks have drawn widespread attention, there have been a great number of water transfers and exchanges taking place in California independently of the state. These transfers illustrate well the widespread applicability of transfers in managing water resource systems, as well as the multiple mechanisms available for effecting water transfers. This article focuses on California's recent experiences with water transfers, and offers a series of potential lessons for federal, state, and local managers for integrating water transfers in regional water resource systems.

Recent strengthening of eastern Pacific ENSO in the last millennium paleorecord

American Association for the Advancement of Science (AAAS) | August 27th, 2026

The Pacific El Niño–Southern Oscillation (ENSO) generates climate extremes that endanger ecosystems, infrastructure, and human well-being worldwide. The response of th

The Pacific El Niño–Southern Oscillation (ENSO) generates climate extremes that endanger ecosystems, infrastructure, and human well-being worldwide. The response of this system to climate warming is poorly constrained, due both to data scarcity and uncertainties in climate models. The geochemistry of Galápagos coral skeletons across the past millennium reveals a large recent increase in interannual variability of sea surface temperature in the eastern equatorial Pacific compared to existing paleorecords that exceeds simulated natural variability. This increase parallels rising global temperature and results from stronger El Niño events. Central Pacific coral data also show increased variability, although less distinctly than in the Galápagos. Our results provide long-term context for understanding ENSO variability trends, with troubling implications for climate extremes.

Recharge Area Identification, Utilization, and Protection Resource Management Strategy

California Department of Water Resources (DWR) | April 29th, 2024

This resource management strategy (RMS) advances water supply augmentation, resilience, and equity in California by providing summaries of the state of knowledge, applica

This resource management strategy (RMS) advances water supply augmentation, resilience, and equity in California by providing summaries of the state of knowledge, applications, and available information and resources on recharge area identification, utilization, and protection.

Recharge Area Protection (Resource Management Strategy)

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

Recharge areas are those areas that provide the primary means of replenishing groundwater. Good natural recharge areas are those where good quality surface water is able

Recharge areas are those areas that provide the primary means of replenishing groundwater. Good natural recharge areas are those where good quality surface water is able to percolate through the sediments and rocks to the saturated zone which contains groundwater. If recharge areas cease to function properly, it will limit groundwater replenishment and/or groundwater quality for storage or use. Protection of recharge areas requires a number of actions based on two primary goals: (1) ensuring that areas suitable for recharge continue to be capable of adequate recharge rather than being covered by urban infrastructure, such as buildings and roads, and (2) preventing pollutants from entering groundwater to avoid expensive treatment that may be necessary prior to beneficial use. Protection of recharge areas is necessary to maintain the quantity and quality of groundwater in the aquifer. However, protecting recharge areas by itself does not provide a supply of water. Recharge areas are functioning properly when aquifer storage capacity is available, sufficient permeable surface is present, and the adequate supply of good quality water to recharge the aquifer is available. Protecting existing and potential recharge areas allows them to serve as valuable components of a conjunctive management and groundwater strategy.

Reclamation’s NEPA Handbook

U.S. Bureau of Reclamation (USBR) | January 31st, 2012

This edition of the Bureau of Reclamation’s (Reclamation) National Environmental Policy Act (NEPA) Handbook has been developed in response to the Council on Environment

This edition of the Bureau of Reclamation’s (Reclamation) National Environmental Policy Act (NEPA) Handbook has been developed in response to the Council on Environmental Quality’s (CEQ) and the U.S. Department of the Interior’s (Interior) implementing regulations on NEPA. These regulations state that each agency will interpret the provisions of NEPA as a supplement to its existing authority and as a mandate to view its policies and missions in the light of its national environmental objectives. This handbook has been designed as a guidance tool for use by all Reclamation staff. It should also be useful to applicants, contractors, tribal representatives, the general public, and others who may be involved in Reclamation’s NEPA process, or those who develop environmental reports for Reclamation’s use in preparing NEPA documents. This handbook describes Reclamation guidance for implementing the National Environmental Policy Act of 1969 (42 United States Code [U.S.C.] 4321, et seq.), CEQ’s Regulations for Implementing the Procedural Provisions (40 Code of Federal Regulations [CFR] Parts 1500–1508), Interior’s NEPA Regulations (43 CFR Part 46), and the Departmental Manual (DM) Chapter 516. This handbook draws these requirements together and provides guidance on how to apply them to Reclamation programs and activities. The Reclamation Manual NEPA Policy (ENV P03) refers to this handbook as the source of additional information on NEPA compliance for Reclamation. The handbook also presents and summarizes other related environmental laws and Executive orders (EO) which should be addressed during NEPA compliance. This handbook provides an overview of NEPA in chapter 2. Chapter 3 contains a general description of the requirements and procedures of NEPA. Chapter 4 provides information on integrating NEPA with other Reclamation activities. Specific information on categorical exclusion checklists (CEC), environmental assessments (EA), and environmental impact statements (EIS) can be found in chapters 5, 6, and 7, respectively. This organizational structure has been selected to allow the user to quickly locate specific, step-by-step information on the different levels of NEPA compliance. Chapter 8 addresses EIS content, and chapter 9 discusses the requirements of a record of decision (ROD). Chapters 10 and 11 present other information that can be useful in the various situations that arise in applying NEPA to Reclamation’s Federal actions. Chapter 12 concludes the handbook with information on gaining additional assistance on NEPA issues. In addition, various issues and special problems are discussed throughout the handbook. Where possible, solutions that have worked historically, or approaches that seem most reasonable, are recommended.

Recommendations to the State Water Resources Control Board Pursuant to California Water Code Section 10609

California Department of Water Resources (DWR) | September 29th, 2022

The Department of Water Resources (DWR) is pleased to provide the following recommendations developed in response to the 2018 Legislation (Senate Bill 606 [Hertzberg] and

The Department of Water Resources (DWR) is pleased to provide the following recommendations developed in response to the 2018 Legislation (Senate Bill 606 [Hertzberg] and Assembly Bill 1668 [Friedman]) enacted in support of “Making Water Conservation a California Way of Life.” The Legislation included provisions for advancing urban water use efficiency through developing and implementing various water use efficiency standards, variances for unique uses of water, and commercial, industrial, and institutional (CII) performance measures, among other requirements. Full reports detailing our methods, technical analyses, studies, public input, and recommendations will follow. These recommendations for long-term urban water use efficiency reflect technical considerations, public input, and the imperative to continue California’s progress in urban efficient use of water for future generations. If adopted DWR's recommendations on outdoor residential and CII water use on landscapes with dedicated irrigation meters, combined with the indoor residential water use standard recommendations submitted to the Legislature jointly by DWR and State Water Resources Control Board (State Water Board), pursuant to Water Code 10609.4 (b)(1), would result in expected long-term water savings of approximately 450,000 acre-feet per year starting in 2030 – considering 2019 population and 2017-2019 water use data, the water savings are enough to supply about 1.6 million homes or 4.7 million residents for both indoor and outdoor annual water needs.

Recovery Plan for Sacramento-San Joaquin Delta native fishes

U.S. Fish and Wildlife Service (FWS) | November 26th, 1996

Eight fish species are included in the Sacramento-San Joaquin Delta Native Fishes Recovery Plan. The delta smelt is listed as a threatened species. The Sacramento splitta

Eight fish species are included in the Sacramento-San Joaquin Delta Native Fishes Recovery Plan. The delta smelt is listed as a threatened species. The Sacramento splittail (splittail) was proposed as a threatened species on January 6, 1994. This recovery plan will recommend restoration criteria for the splittail that would be appropriate recovery criteria should the species be listed. Longfin smelt, green sturgeon, spring-run, late fall-run, and San Joaquin fall-run chinook salmon are species of concern for which restoration criteria are recommended. Information is also included on Sacramento perch, a species believed to be extirpated from the Delta at this time. Habitat Requirements and Limiting Factors: The eight species included in this recovery plan depend on the Sacramento-San Joaquin Delta for a significant segment of their life history. Threats to the Delta ecosystem and these species include loss of habitat due to increased freshwater exports resulting in increased salinity, loss of shallow-water habitat due to dredging, diking and filling, introduced aquatic species that have disrupted the food chain, and entrainment (movement offish by currents produced by diversions) in State, Federal and private water diversion. State and Federal water projects have also changed the pattern and timing of flows through the Delta. The salmon races are affected by sport and commercial harvest as well as by interactions with hatchery stocks. Recovery and Restoration Objective: Delisting of delta smelt. Restoration of splittail, longfin smelt, green sturgeon, spring-run, late fall-run, San Joaquin fall-run chinook salmon, and Sacramento perch. Recovery and Restoration Criteria: Recovery criteria are quantifiable and species specific and can be used to (1) monitor effectiveness of recovery actions, (2) determine when a species has recovered to a secure level (stabilized), and (3) determine when a species qualifies for delisting. In many cases, criteria are based on two independent measures: population abundance and geographic distribution. For each species a historic base period was established using available data to characterize abundance and distribution during a pre-decline period. The time period over which abundance and distribution criteria must be met was set at five generations. For five of the eight species there is an additional requirement of meeting the criteria through a minimum number of years of stressful environmental conditions. Action Needed: 1. Enhance and restore aquatic and wetland habitat in the Sacramento-San Joaquin River estuary. 2. Reduce effects of commercial and recreational harvest. 3. Reduce effects of introduced aquatic species on Delta native fishes. 4. Change and improve enforcement ofregulatory mechanisms. 5. Conduct monitoring and research on fish biology and management requirements. 6. Assess recovery management actions and re-assess prioritization of actions. 7. Increase public awareness of importance of Delta native fishes.

Redefining expectations for urban water supply systems to fight wildfires

Springer Nature | March 5th, 2025

When considering massive new costs for urban water systems to fight wildfires, we also need to look hard at the distribution of benefits from these investments, and desig

When considering massive new costs for urban water systems to fight wildfires, we also need to look hard at the distribution of benefits from these investments, and design legal and fiscal cost recovery mechanisms that align with those benefits. In the service area for the Los Angeles Department of Water and Power, greatly expanding capacity for water supply and fire-flow for the highest-elevation areas of the city would be delivering a benefit to communities that are much wealthier, on average, than the rest of the city. There is danger of placing a burden on less-resourced households to pay for the protection of well-resourced households, which would compound existing and profound environmental inequities in the city.