The Green Visions Plan for 21st Century Southern California: 21. Hydrology and Water Quality Modeling of the Calleguas Creek Watershed

University of Southern California (USC) | November 2nd, 2009

The hydrology and water quality simulation presented in this report is a part of the Green Visions Plan for 21st Century Southern California project. The primary

The hydrology and water quality simulation presented in this report is a part of the Green Visions Plan for 21st Century Southern California project. The primary focus of the Calleguas Creek Watershed water quality modeling is to determine the pollutant concentration and loads entering the stream network and to what degree surface waters are subject to water quality impairments.

The Human Right To Water In Poor Communities Of Color

University of California, Los Angeles (UCLA) | January 19th, 2021

Since the state enacted the Human Right to Water Legislation (AB 685) eight years ago, California has added more regulatory authority and more funding to help small disa

Since the state enacted the Human Right to Water Legislation (AB 685) eight years ago, California has added more regulatory authority and more funding to help small disadvantaged or severely disadvantaged community water systems. The California Water Resources Control Board (State Water Board) can order mandatory consolidation to merge failing community systems with another, higher-functioning water system. The State Water Board is authorized to issue an enforcement order to mandate that water systems meet water quality standards. Other recent legislation authorizes the State Water Board to designate an Interim Administrator to manage the system, improve it, or consolidate the water system with another. The newly enacted Safer and Affordable Funding for Equity and Resilience (SAFER) drinking water program calls for annual appropriation of $130 million dollars for ten years to address the problems of disadvantaged community water systems. This report identifies the 64 community water systems in Los Angeles County serving disadvantaged or severely disadvantaged populations.

The impacts of climate change on coastal groundwater

Nature Portfolio (Springer Nature) | January 11th, 2024

Coastal groundwater (CGW) is a critical water resource for many communities and can be a key part of coastal ecosystems. Owing to its location, CGW faces both terrestrial

Coastal groundwater (CGW) is a critical water resource for many communities and can be a key part of coastal ecosystems. Owing to its location, CGW faces both terrestrial and marine effects of climate change while simultaneously being impacted by anthropogenic activities. In this Review, we discuss the expected impacts of climate change on CGW and CGW-dependent ecosystems. Sea-level rise, coastal flooding increases and precipitation and aridity changes will drive alterations in the amount, chemistry and fluxes of CGW. Impacts could also arise from changes in storm and cyclone activity, land and ocean temperature rises, cryosphere melt, ocean chemistry and coastal erosion, but the overall effect is understudied. Human-induced stressors, such as groundwater extraction, will interact with climate change impacts to alter CGW at different temporal and spatial scales. CGW-associated ecosystems are expected to respond to changes in an ecosystem and site-specific manner — for example, some coastal temperate and tropical ecosystems might be more impacted by seawater intrusion owing to sea-level rise and coastal flooding, whereas others, such as coastal polar ecosystems, could be more affected by increases in cryosphere melt. A comprehensive and global CGW observatory programme is needed to better understand baseline CGW conditions, track change and support resource management.

The NOAA NCEI marine microplastics database

Nature Portfolio (Springer Nature) | October 20th, 2023

Microplastics (<5 mm) pollution is a growing problem affecting coastal communities, marine ecosystems, aquatic life, and human health. The widespread occurrence of m

Microplastics (<5 mm) pollution is a growing problem affecting coastal communities, marine ecosystems, aquatic life, and human health. The widespread occurrence of marine microplastics, and the need to curb its threats, require expansive, and continuous monitoring. While microplastic research has increased in recent years and generated significant volumes of data, there is a lack of a robust, open access, and long-term aggregation of this data. The National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information (NCEI) now provides a global open access to marine microplastics data on an easily discoverable and accessible GIS web map and data portal. The objective of this data portal is to develop a repository where microplastics data are aggregated, archived, and served in a user friendly, consistent, and reliable manner. This work contributes to NCEI’s efforts towards data standardization, integration, harmonization, and interoperability among national and international collaborators for monitoring global marine microplastics. This paper describes the NOAA NCEI global marine microplastics database, its creation, quality control procedures, and future directions.

The Pacific Decadal Oscillation modulated marine heatwaves in the Northeast Pacific during past decades

Nature Portfolio (Springer Nature) | June 19th, 2023

The pattern of fresh‐water flow in a coastal aquifer

American Geophysical Union (AGU) | April 1st, 1959

Formulas are developed for the flow pattern followed by the seaward‐moving fresh ground water as it nears a beach. It is found that, under steady flow conditions, a sha

Formulas are developed for the flow pattern followed by the seaward‐moving fresh ground water as it nears a beach. It is found that, under steady flow conditions, a sharply defined interface is formed between the fresh and salt water. Along the interface the pressure of the static salt water, owing to its greater density, is counterbalanced by the pressures which drive the fresh water seaward. The fresh water escapes through a gap between this interface and the shore line. An increase in the flow of fresh water widens the gap. Tidal action causes a diffusion of salt water across the interface. This salt is carried back to sea with the fresh‐water flow.

The Perennial Streams Assessment (PSA): An Assessment of Biological Condition using the New California Stream Condition Index (CSCI)

California State Water Resources Control Board (SWRCB) | June 1st, 2015

PSA stream surveys found that the majority of stream length in the Sierra Nevada and North Coast is in good biological condition, while the majority of stream len

PSA stream surveys found that the majority of stream length in the Sierra Nevada and North Coast is in good biological condition, while the majority of stream length in the South Coast, Chaparral and Central Valley is in poor or very poor condition. Similarly, most of the stream length draining forested watersheds is in good condition, while most of the stream length draining watersheds dominated by agricultural and urban land use is in poor or very poor condition. On average, stream condition showed no directional change over time, either for better or for worse. Streams where phosphorous concentration or riparian disturbance exceeded thresholds had the greatest relative risk of biological impairment.  

The Pulse of the Bay 2019: Pollutant Pathways

San Francisco Estuary Institute (SFEI) | September 26th, 2019

Pollutants make their way to San Francisco Bay from near and far. Some pollutants come from the other side of the world, such as the mercury that is emitted into the atmo

Pollutants make their way to San Francisco Bay from near and far. Some pollutants come from the other side of the world, such as the mercury that is emitted into the atmosphere by coal-fired power plants in Asia, transported across the Pacific Ocean by the wind, and deposited on the surface of the Bay and in the Bay watershed. Some pollutants come from the far corners of the Bay’s watershed, which encompasses 40% of the land surface of California. Mercury used in historic gold mining regions in the Sierra Nevada is still flowing downstream into Central Valley rivers, through the Delta, and into the Bay.  Most pollutants, however, originate from activities closer to home in the small, local watersheds that surround the Bay. Rain that falls onto yards, roofs, parking lots, streets, farms, pastures, and other surfaces in the watersheds picks up pollutants and carries them to the Bay through an intricate network of thousands of miles of storm drain pipes, culverts, and creeks. Most of this stormwater flows to the Bay without any form of pollutant removal.  Another parallel and intricate network of thousands of miles of pipes carries wastewater from homes, business, and industries through sewage collection systems to municipal wastewater treatment plants. These treatment plants are highly effective at removing most pollutants from the wastewater stream, but some are not effectively treated and pass through to the Bay.  Some industrial operations, such as the Bay Area’s petroleum refineries, are large enough to warrant having their own wastewater treatment facilities that remove pollutants so the effluent can be safely discharged into the Bay, reused in plant operations, or applied to land.  Disposal of dredged material at designated sites within the Bay is another activity that introduces pollutants to specific areas in the Bay, but in this case the pollutants are simply transferred from one part of the Bay to another. Much of the pollutant mass in dredged material is also removed from the Bay via disposal in the ocean or beneficial reuse in wetlands and upland sites. This edition of the Pulse of the Bay features articles on the four major pollutant pathways that are the primary focus of Bay water quality managers: municipal wastewater, industrial wastewater, stormwater, and dredging and dredged material disposal.

The Pulse of the Bay 2022: 50 Years after the Clean Water Act

San Francisco Estuary Institute (SFEI) | October 13th, 2022

This August an algal bloom of historic proportions blanketed San Francisco Bay. The most concerning aspect of the bloom was the death of thousands of fish across wide are

This August an algal bloom of historic proportions blanketed San Francisco Bay. The most concerning aspect of the bloom was the death of thousands of fish across wide areas of the Bay, including 10,000 yellowfin goby, hundreds of striped bass and white sturgeon, and other species like green sturgeon, bat rays, and sharks. This is the most widespread and deadliest fish kill in the Bay in recent memory.

The Pulse of the Bay: The 25th Anniversary of the RMP

San Francisco Estuary Institute (SFEI) | July 1st, 2017

San Francisco Bay is the defining feature of our region and a world-class ecosystem. The Bay Area is also known world-wide as a cradle of innovation, excellence, and succ

San Francisco Bay is the defining feature of our region and a world-class ecosystem. The Bay Area is also known world-wide as a cradle of innovation, excellence, and success, especially in the technology sector. Less well known is the fact that over the past 25 years the Bay Area has been a world leader in water quality monitoring, supporting a pioneering program for the Bay that demonstrates how regional collaboration can provide the science needed to protect and improve water quality in a treasured ecosystem. The Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) was established in 1993 and, with sustained local funding and continuous improvement, is going stronger than ever a quarter century later.