Annual Report Clean Water State Revolving Fund and the Water Quality, Supply, and Infrastructure Improvement Act of 2014 State Fiscal Year 2017-2018

California State Water Resources Control Board (SWRCB) | December 30th, 2018

The California State Water Resources Control Board (State Water Board), Division of Financial Assistance (DFA) presents the Clean Water State Revolving Fund (CWSRF) annua

The California State Water Resources Control Board (State Water Board), Division of Financial Assistance (DFA) presents the Clean Water State Revolving Fund (CWSRF) annual report for State Fiscal Year (SFY) 2017-18. The State Water Board provided approximately $707 million in new CWSRF financing to 44 projects in SFY 2017-18, which represent a wide variety of projects eligible under the CWSRF. This report describes how the State Water Board met the objectives identified in the SFY 2017-18 CWSRF Intended Use Plan (IUP). 

Annual Report of Activities October 1, 2013 to September 30, 2014, American River Group (ARG)

Delta Stewardship Council (Delta Council) | September 30th, 2014

Annual Report of Activities October 1, 2013, to September 30, 2014, Delta Operations for Salmonids and Sturgeon (DOSS) Technical Working Group

Delta Stewardship Council (Delta Council) | October 31st, 2014

Annual Report of Activities Water Year 2018 Stanislaus Operations Group (SOG)

Delta Stewardship Council (Delta Council) | November 1st, 2018

Annual Report of Activities, October 1, 2013 to September 30, 2014, Stanislaus Operations Group (SOG)

Delta Stewardship Council (Delta Council) | September 30th, 2014

Annual Report on the Colorado River Basin Salinity Control Program 2020

Colorado River Basin Salinity Control Advisory Council (CRBSCAC) | December 31st, 2020

Antecedent moisture enhances early warning of atmospheric river flood hazards

Publisher not available | February 12th, 2026

Atmospheric rivers are narrow bands of water vapor transport and serve as key drivers of water supplies and flood hazards in mid-latitude regions. The atmospheric river s

Atmospheric rivers are narrow bands of water vapor transport and serve as key drivers of water supplies and flood hazards in mid-latitude regions. The atmospheric river scale supports early-warning communication by ranking events from potentially beneficial to hazardous based on atmospheric forcing represented by water vapor transport magnitude and duration. However, the scale does not consider land-surface conditions that can influence how precipitation derived from water vapor translates into streamflow and flood hazards. Analyzing atmospheric river landfalls across catchments in California and central Chile, we show that divergences between atmospheric river rank and flood response are primarily explained by pre-existing soil moisture conditions. Based on this insight, we develop a simple modification to the atmospheric river scale that nearly doubles the scale’s correspondence with peak streamflow and increases the number of flood-generating atmospheric rivers classified as hazardous by more than 30%. These findings demonstrate that incorporating land-surface conditions can enhance early-warning hazard classification tools.

Antelope Valley Groundwater Cases

Superior Court of California, County of Los Angeles | December 23rd, 2015

The complaints and cross-complaints in the Action frame many legal issues. The Action includes over 4,000 Parties, as well as the members of the Non-Pumper Class and the

The complaints and cross-complaints in the Action frame many legal issues. The Action includes over 4,000 Parties, as well as the members of the Non-Pumper Class and the members of the Small Pumper Class. The Basin’s entire Groundwater supply and Groundwater rights, extending over approximately 1390 square miles, have been brought to issue. The numerous Groundwater rights at issue in the case include, without limitation, overlying, appropriative, prescriptive, and federal reserved water rights to Groundwater, rights to return flows from Imported Water, rights to recycled water, rights to stored Imported Water subject to the Watermaster rules and regulations, and rights to utilize the storage space within the Basin. After several months of trial, the Court made findings regarding Basin characteristics and determined the Basin’s Safe Yield. The Court’s rulings and judgments in this case, including the Safe Yield determination, form the basis for this Judgment. For annual reports go to the Department of Water Resources Adjudicated Annual Reporting page.

Anthropogenic aerosols mask increases in US rainfall by greenhouse gases

Nature Portfolio (Springer Nature) | February 22nd, 2024

Anthropogenic and geologic causes of anomalously high uranium concentrations in groundwater used for drinking water supply in the southeastern San Joaquin Valley, CA

Journal of Hydrology (Elsevier) | October 1st, 2019

Concentrations of uranium (U) >30 µg/L in groundwater are relatively uncommon in drinking water in the United States but can be of concern in those areas where comp

Concentrations of uranium (U) >30 µg/L in groundwater are relatively uncommon in drinking water in the United States but can be of concern in those areas where complex interactions of aquifer materials and anthropogenic alterations of the natural flow regime mobilize U. High concentrations (>30 µg/L) of U in the southeastern San Joaquin Valley, California, USA, have been detected in 24 percent of 257 domestic, irrigation, and public-supply wells sampled across an approximately 110,000 km2 area. In this study we evaluated mechanisms for mobilization of U in the San Joaquin Valley proposed in previous studies, confirming mobilization by HCO3 and refuting mobilization by NO3 and we refined our understanding of the geologic sources of U to the scale of individual alluvial fans. The location of high concentrations depends on the interactions of geological U sources from fluvial fans that originate in the Sierra Nevada to the east and seepage of irrigation water that contains high concentrations of HCO3 that leaches U from the sediments. In addition, interactions with PO4 from fertilized irrigated fields may sequester U in the aquifer. Principal component analysis of the data demonstrates that HCO3 and ions associated with high total dissolved solids in the aquifer and the percentage of agriculture near the well sampled are associated with high U concentrations. Nitrate concentrations do not appear to control release of U to the aquifer. Age dating of the groundwater and generally increasing U concentrations of the past 25  years in resampled wells where irrigation is prevalent suggests that high U concentrations are associated with younger water, indicating that irrigation of fields over the past 100  years has significantly contributed to increasing concentrations and mobilizing U. In some places, the groundwater is supersaturated with uranyl-containing minerals, as would be expected in roll front deposits. In general, the interaction of natural geological sources high in U, the anthropogenically driven addition of HCO3 and possibly phosphate fertilizer, control the location and concentration of U in each individual fluvial fan, but the addition of nitrate in fertilizer does not appear control the location of high U. These geochemical interactions are complex but can be used to determine controls on anomalously high U in alluvial aquifers.