South Coast

Monitoring Special Study (MSS) Salinity Point Source and Ion Sampling CY 2022–2023

California Department of Water Resources (DWR) | August 15th, 2022

The interior southern Delta region of the San Francisco Estuary (SFE) has relatively higher seasonal-based salinity compared to other interior freshwater regions. Some of

The interior southern Delta region of the San Francisco Estuary (SFE) has relatively higher seasonal-based salinity compared to other interior freshwater regions. Some of this degradation in water quality in the interior southern Delta likely originates in upstream salt loading from agriculture drainage in the San Joaquin River prior to reaching the channels of Old River and Grant Line Canal. However, there is also measurable increases in salt loading within the channel networks of Old River at Head (OH1) east to lower Old River near Mountain House Creek (ORM) and the interconnected sloughs of Paradise and Sugar Cut in the region of Doughty Cut (Figure 1) (in-Delta agriculture drainage), as well as other naturally occurring (i.e., groundwater) sources and other non-point and point sources. The California Department of Water Resources (DWR) and U.S. Bureau of Reclamation (Reclamation), under the State Water Resources Control Board’s (State Water Board) Water Right Decision 1641 (D-1641), are assigned partial responsibility for meeting interior southern Delta water quality objectives each year at multiple compliance stations that measure specific conductance (EC) data continuously at 15-minute intervals.

Mono Lake Committee request for an emergency action to protect Mono Lake and its public trust resources

California State Water Resources Control Board (SWRCB) | December 16th, 2022

Mono Lake in a Changing Climate

University of California, Los Angeles (UCLA) | March 17th, 2026

This summary report provides an accessible overview of the methods and takeaways from using the University of California, Los Angeles Mono Lake Model (UCLA-MLM) to study

This summary report provides an accessible overview of the methods and takeaways from using the University of California, Los Angeles Mono Lake Model (UCLA-MLM) to study Mono Lake’s water level for varying export and climate conditions. This is also intended to be a summary of the main report. This summary was created for policy makers, organizers, community advocates and members of the public.

More state and local attention to financing can advance sustainable groundwater management

Berkeley Law Center for Law, Energy, & the Environment | April 12th, 2025

Mound Basin Groundwater Sustainability Plan

Mound Basin Groundwater Sustainability Agency | December 31st, 2021

The goal of this GSP is to sustainably manage the groundwater resources of the Mound Basin for the benefit of current and anticipated future beneficial users of groundwat

The goal of this GSP is to sustainably manage the groundwater resources of the Mound Basin for the benefit of current and anticipated future beneficial users of groundwater and the welfare of the general public who rely directly or indirectly on groundwater. This GSP describes the approach to achieve and maintain a sustainable groundwater resource free of undesirable results pursuant to the SGMA, while establishing long-term reliability no later than 20 years from GSP adoption through implementation. Due to size, this file has been divided into three parts. Part 1, Part 2, Part 3

Multiple lines of evidence point to pesticides as stressors affecting invertebrate communities in small streams in five United States regions

Science of the Total Environment (Elsevier) | January 24th, 2024

Multiscale drivers of extreme southern California flooding: ENSO, MJO, North Pacific jet, and atmospheric rivers

Nature Portfolio (Springer Nature) | November 20th, 2025

Extreme rainfall and flooding, driven by a powerful atmospheric river (AR) and a persistent Madden-Julian Oscillation (MJO), hit Southern California in February 2024 duri

Extreme rainfall and flooding, driven by a powerful atmospheric river (AR) and a persistent Madden-Julian Oscillation (MJO), hit Southern California in February 2024 during the 2023–2024 El Niño, affecting over 10 million people. ARs are key contributors to extreme rainfall and flooding along the U.S. West Coast. Although the AR-MJO link has been documented, its spatio-temporal variability remains a major forecasting and risk-management challenge. Combining precipitation, stream gauge and demographic data, we quantify the physical drivers and population exposure to this extreme event. Leveraging a Lagrangian MJO precipitation tracking algorithm, we unravel the multiscale interactions responsible for the AR’s development. El Niño favored a large, long-lived MJO that interacted with the North Pacific Jet (NPJ) over more than three weeks. The MJO convective outflow modulated the NPJ by inducing negative potential vorticity advection along the tropopause. The ensuing NPJ extension and acceleration induced explosive cyclogenesis, whose AR-driven moisture transport resulted in extreme rainfall.

Municipal Service Review and Sphere of Influence Update for the Orange County Water District Including a Feasibility Analysis of the Potential Consolidation of Orange County Water District and Municipal Water District of Orange County

Local Agency Formation Commission of Orange County | November 15th, 2024

Municipal Stormwater Management Spending in California: Data Extraction, Compilation, and Analysis

Environmental Management (Springer) | March 23rd, 2022

Communities in the U.S. fund stormwater management programs to reduce flooding and improve and protect water quality. Few studies have attempted to quantify municipal sto

Communities in the U.S. fund stormwater management programs to reduce flooding and improve and protect water quality. Few studies have attempted to quantify municipal storwmater management expenditures. This task is important given efforts to meet increasing water quality standards and develop new revenue sources. The purpose of this study was to evaluate trends in municipal stormwater management expenditures across the state of California. The study identified and compiled publicly-available data on reported stormwater expenditures (spending) and budgets for local governments in California. Data were extracted from annual reports for over 160 public agencies. A standardized rubric of activities was developed and used to create a first-of-its-kind database of municipal stormwater budgets and expenditures. The results indicated that there is over $700 million in annual municipal stormwater spending, but this total does not represent all spending due to gaps in publicly-available data. Counties and flood control districts often have the largest total expenditures in a region, but in aggregate cities reported more spending statewide. Available data are not sufficient to adequately evaluate whether current spending meets regulatory requirements. Additionally, publicly-available data are inconsistent across geographic regions regulated by different agencies. The analysis offers a template for improved cost reporting of stormwater programs in U.S. municipalities, which can help answer key questions such as the sufficiency of current funding. Future research can use the method to evaluate spending in other states and regions, evaluate trends over time to improve outcomes, and refine the spending categories based on examples from other states. Click here for related post at UC Davis site California WaterBlog

National-Scale Flood Hazard Data Unfit for Urban Risk Management

American Geophysical Union (AGU) | July 19th, 2024