South Coast

Extreme Precipitation-Temperature Scaling in California: The Role of Atmospheric Rivers

American Geophysical Union (AGU) | July 25th, 2023

Extremophile hotspots linked to containerized industrial waste dumping in a deep-sea basin

Oxford University Press (OUP) | September 9th, 2025

Decaying barrels on the seafloor linked to DDT contamination have raised concerns about the public health implications of decades old industrial waste dumped off the coas

Decaying barrels on the seafloor linked to DDT contamination have raised concerns about the public health implications of decades old industrial waste dumped off the coast of Los Angeles. To explore their contents, we collected sediment cores perpendicular to five deepsea barrels. The concentration of DDT and its breakdown products were highly elevated relative to control sites yet did not vary with distance from the barrels, suggesting that they were not associated with the contamination. Sediment cores collected through white halos surrounding three barrels were enriched in calcite and had elevated pH. The associated microbial communities were low diversity and dominated by alkalophilic bacteria with metagenome-assembled genomes adapted to high pH. A solid concretion sampled between a white halo and barrel was composed of brucite, a magnesium hydroxide mineral that forms at high pH. Based on these findings, we postulate that leakage of containerized alkaline waste triggered the formation of mineral concretions that are slowly dissolving and raising the pH of the surrounding sediment pore water. This selects for taxa adapted to extreme alkalinity and drives the precipitation of “anthropogenic” carbonates forming white halos, which serve as a visual identifier of barrels that contained alkaline waste. Remarkably, containerized alkaline waste discarded >50 years ago represents a persistent pollutant creating localized mineral formations and microbial communities that resemble those observed at some hydrothermal systems. These formations were observed at one-third of the visually identified barrels in the San Pedro Basin and have unforeseen, long-term consequences for benthic communities in the region.

Facing the Climate Gap: How Environmental Justice Communities are Leading the Way to a More Sustainable and Equitable California

University of Southern California (USC) | October 31st, 2012

California has traditionally led the nation in protecting and preserving the environment – and we have proudly continued the trend with the 2006 passage and ong

California has traditionally led the nation in protecting and preserving the environment – and we have proudly continued the trend with the 2006 passage and ongoing implementation of the California Global Warming Solutions Act (AB 32). Aimed at reducing greenhouse gas emissions (GHGs) and slowing climate change, AB 32 came under political attack in 2010 when an initiative, funded largely by oil refiners, sought to delay application of the legislation’s rules. Fortunately, voters soundly rejected that effort, but many observers have worried that California’s concerns about climate could wane, particularly since the actual impacts of climate change can seem abstract and far-off. Against this backdrop, a wide range of community-based organizations have been working to “make it real” by connecting the dots between global warming and human impacts, and by helping residents adapt now and not later. In what might be a surprise to some observers, many of these organizations are working with low-income communities of color – those often stereotyped as the least concerned about climate change.

Federal Reserved Water Rights and Groundwater: Quantity, Quality, and Pore Space

Congressional Research Service (CRS) | February 8th, 2018

Tribal rights to groundwater have not been legally established to the same extent as rights to other natural resources (e.g., surface water, timber, minerals). A March 2

Tribal rights to groundwater have not been legally established to the same extent as rights to other natural resources (e.g., surface water, timber, minerals). A March 2017 decision of the U.S. Court of Appeals for the Ninth Circuit upheld the rights of a California Indian tribe (the Agua Caliente band of Cahuilla Indians) to groundwater beneath the tribe's reservation in the Coachella Valley. In November 2017, the U.S. Supreme Court declined to review the decision; the case now proceeds to other phases that may partially shape this ruling's significance. This is the first case in which an appellate court has held that a tribe's "reserved" rights under the Winters doctrine apply to groundwater. Pursuant to Winters, when Congress reserves land for a reservation, it also reserves a right to water necessary to accomplish the purposes for which the reservation was created. For decades, tribal reserved rights for surface water have been established and have required settlements between the federal government (as authorized by Congress), tribes, and nonfederal users. Thus, some have raised concerns about the implications of interpreting Winters rights to include groundwater. This Insight explores three aspects of groundwater relevant to Agua Caliente: quantity, quality, and "pore space." The legal outcome may affect how groundwater is allocated among tribal and nontribal interests and may influence groundwater allocations at other federal reservations. The Supreme Court has not declared outright that groundwater is subject to the Winters doctrine, but declining to review the Ninth Circuit decision essentially upheld phase one of the three-phase case: a federally reserved right to the groundwater resource for the tribe. Phase two will address whether the tribe has the right to receive groundwater of a certain quality from the aquifer and whether it owns the pore space beneath tribal lands. Phase three will determine the quantity of groundwater to which the tribe is entitled, pursuant to its reserved rights. The outcome of phases two and three could have implications for expanding the scope of federal preemption of state water law. It also could affect how much groundwater is available for nontribal water agencies and water districts and those entities' ability to store water in an aquifer beneath federally reserved lands. Congress has authority over federal water law and could influence this legal framework.

Fillmore Basin Groundwater Sustainability Plan

Fillmore and Piru Basins Groundwater Sustainability Agency | December 16th, 2021

The Fillmore Basin (the Basin) is managed (along with the upslope Piru Basin) by the Fillmore and Piru Basins Groundwater Sustainability Agency (the Agency). The Basin is

The Fillmore Basin (the Basin) is managed (along with the upslope Piru Basin) by the Fillmore and Piru Basins Groundwater Sustainability Agency (the Agency). The Basin is planned to remain sustainable over the Sustainable Groundwater Management Act (SGMA) implementation and sustainability period based on the current understanding of historical, current (2019), and projected (2022 through 2072) groundwater conditions in relation to the sustainability indicators specified in SGMA. A sustainability indicator refers to any of the effects caused by groundwater conditions occurring throughout the basin that, when significant and unreasonable, cause undesirable results. The Agency, with consideration of feedback from active stakeholder engagement, has identified and planned for the prevention of significant and unreasonable undesirable results.

Final Environmental Impact Report for Adoption of a Regulation for the Hexavalent Chromium Maximum Contaminant Level

California State Water Resources Control Board (SWRCB) | April 17th, 2024

As the lead agency in accordance with sections 15089 and 15132 of the California Environmental Quality Act (CEQA) Guidelines (Cal. Code Regs., tit. 14, § 15000 et seq.),

As the lead agency in accordance with sections 15089 and 15132 of the California Environmental Quality Act (CEQA) Guidelines (Cal. Code Regs., tit. 14, § 15000 et seq.), this document is the Final Environmental Impact Report (Final EIR) for the adoption of statewide regulations setting the maximum contaminant level (MCL) for hexavalent chromium (Proposed Regulations). The Proposed Regulations include a maximum contaminant level (MCL) of 10 μg/L for hexavalent chromium. (Cal. Code Regs. tit. 22, § 64431 Table 64431-A.) The Proposed Regulations also include a compliance schedule based on public water system size, by adding subdivision (p) and Table 64432-B to section 64432 of title 22 of the California Code of Regulations, identifies a detection limit for purposes of reporting, sets monitoring and reporting requirements and public notice requirements for violations of the MCL, and establishes the Best Available Technologies (BAT) for treating hexavalent chromium in drinking water. California State Water Resources Control Board (SWRCB) Chrom VI MCL rulemaking chronology.

Final Groundwater Assessment Study: A Status Report on the Use of Groundwater in the Service Area of the Metropolitan Water District of Southern California

Metropolitan Water District of Southern California (MWD) | September 3rd, 2007

Final Groundwater Sustainability Plan for the Yucaipa Groundwater Subbasin

San Bernardino Valley Municipal Water District | January 27th, 2022

The Yucaipa Groundwater Sustainability Agency (GSA), acting as the GSA for the Yucaipa Subbasin (Plan Area, Subbasin), developed this Groundwater Sustainability Plan (GS

The Yucaipa Groundwater Sustainability Agency (GSA), acting as the GSA for the Yucaipa Subbasin (Plan Area, Subbasin), developed this Groundwater Sustainability Plan (GSP) in compliance with the 2014 Sustainable Groundwater Management Act (SGMA) and the California Department of Water Resources (DWR) GSP Regulations. The Yucaipa Subbasin lies within the Upper Santa Ana River Basin Hydrologic Region (DWR Basin Number 8-002.07) and underlies an area of approximately 25,300 acres under portions of the cities of Calimesa, Redlands, and Yucaipa, as well as unincorporated San Bernardino and Riverside Counties. DWR designated the Yucaipa Subbasin a high priority basin based primarily on its reliance on groundwater for water supply. However, this Subbasin is not in a state of critical overdraft. Under SGMA, GSAs “have the responsibility for adopting a Plan that defines the basin setting and establishes criteria that will maintain or achieve sustainable groundwater management.” The requirement of the GSP is to maintain or achieve sustainable groundwater management in the Yucaipa Subbasin by 2042. Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6

Final State Water Project Delivery Capability Report 2023

California Department of Water Resources (DWR) | July 31st, 2024

This Delivery Capability Report presents California Department of Water Resources (DWR) analysis of the State Water Project (SWP) system and provides important planning i

This Delivery Capability Report presents California Department of Water Resources (DWR) analysis of the State Water Project (SWP) system and provides important planning information for users of SWP water. The analysis provides information about how changing climate, regulatory, and operational considerations impact SWP delivery capability.

Final Technical Report #1: Condition Assessment of Coastal Streams in Southern and Central California

California Department of Fish and Wildlife (CDFW) | July 1st, 2004

Historical assessments of stream condition have usually focused on describing the chemical quality of streams. As we have made progress in controlling chemical problems�

Historical assessments of stream condition have usually focused on describing the chemical quality of streams. As we have made progress in controlling chemical problems it has become obvious that the ultimate concern is actually the health of the plants and animals that inhabit these streams (EPA 2000). Streams in good ecological condition provide habitat for diverse aquatic communities, and provide clean drinking water and recreational opportunities for people. Biological organisms in a stream integrate the many chemical and physical stressors that act on the stream ecosystem, thus stream condition can be determined by assessing appropriate biological indicators, or combinations of these indicators, called indices. California’s Aquatic Bioassessment Lab recently developed a benthic index of biotic integrity (B-IBI) for the central and southern coasts of California (Ode et. al. in review). The index is based on benthic macroinvertebrate (BMI) samples collected from 275 sites in this region by the US Forest Service, US EPA and regional Water Quality Control Boards. The index defines the composition of BMI assemblages when human disturbance is absent or minimal (reference conditions), and because it is based on metrics that are responsive to key stressor gradients, it allows detection of potential ecological impairment when BMI samples from test sites are compared to reference conditions. Thus, the B-IBI provides a yardstick for measuring ecological conditions, and allows us to categorize site conditions as either “Good”, “Fair” or “Poor” based on BMI assemblages.