South Coast

California’s Water: The Colorado River

Public Policy Institute of California (PPIC) | October 1st, 2016

The Colorado River—a major water source for Southern California’s cities and farms—is shared among seven states and Mexico. Water use now outstrips supply. The

The Colorado River—a major water source for Southern California’s cities and farms—is shared among seven states and Mexico. Water use now outstrips supply. The environmental impacts of water use in this basin pose special challenges. This brief describes adaptation strategies so that the river can continue to provide essential benefits to the region. This publication is part of a briefing kit that summarizes a dozen of the state’s most pressing water management issues.

Californians Without Safe Water and Sanitation: California Water Plan Update 2013

California Department of Water Resources (DWR) | February 20th, 2015

This report was prepared as part of the California Water Plan Update 2013 process and is an update to the 2005 Californians without Safe Water report. It continues the d

This report was prepared as part of the California Water Plan Update 2013 process and is an update to the 2005 Californians without Safe Water report. It continues the dialogue regarding Californians without safe drinking water and/or adequate sanitation facilities and includes 14 recommendations towards ensuring that all Californians have safe drinking water and adequate sanitation facilities. The report also highlights Governor Brown’s goal of ensuring that all Californians have access to safe drinking water, as specified by his signing of Assembly Bill (AB) 685 and the release of the California Water Action Plan that includes Action 7, “Provide Safe Water for All Communities.”

CaliPopGen: A genetic and life history database for the fauna and flora of California

Nature Portfolio (Springer Nature) | July 5th, 2022

CaliPopGen is a database of population genetic data for native and naturalized eukaryotic species in California, USA. It summarizes the published literature (1985–2020)

CaliPopGen is a database of population genetic data for native and naturalized eukaryotic species in California, USA. It summarizes the published literature (1985–2020) for 5,453 unique populations with genetic data from more than 187,394 individuals and 448 species (513 species plus subspecies) across molecular markers including allozymes, RFLPs, mtDNA, microsatellites, nDNA, and SNPs. Terrestrial habitats accounted for the majority (46.4%) of the genetic data. Taxonomic groups with the greatest representation were Magnoliophyta (20.31%), Insecta (13.4%), and Actinopterygii (12.85%). CaliPopGen also reports life-history data for most included species to enable analyses of the drivers of genetic diversity across the state. The large number of populations and wide taxonomic breadth will facilitate explorations of ecological patterns and processes across the varied geography of California. CaliPopGen covers all terrestrial and marine ecoregions of California and has a greater density of species and georeferenced populations than any previously published population genetic database. It is thus uniquely suited to inform conservation management at the regional and state levels across taxonomic groups.

Carbon accumulation and vertical accretion in a restored versus historic salt marsh in southern Puget Sound, Washington, United States

Society for Ecological Restoration | March 4th, 2019

Few comparisons exist between vertical accretion (VA) and carbon accumulation rates (CARs) in restored versus historic (i.e. reference) marshes. Here, we compare these pr

Few comparisons exist between vertical accretion (VA) and carbon accumulation rates (CARs) in restored versus historic (i.e. reference) marshes. Here, we compare these processes in a formerly diked, sparsely vegetated, restored salt marsh (Six Gill Slough, SG), whose surface is subsided relative to the tidal frame, to an adjacent, relatively pristine, historic salt marsh (Animal Slough, AS). Six sediment cores were collected at both AS and SG approximately 6 years after restoration. Cores were analyzed for bulk density (BD), % loss of ignition, % organic carbon, and 210Pb. We found that sharp changes in BD in surface layers of SG cores were highly reliable markers for the onset of restoration. The mean VA since restoration at SG (0.79 [SD = 0.29] cm/year) was approximately twice that of AS (0.41 [SD = 0.16] cm/year). In comparison, the VA at AS over 50 years was 0.30 (SD = 0.09) cm/year. VA consisted almost entirely of inorganic sediment at SG whereas at AS it was approximately 55%. Mean CARs at SG were somewhat greater than at AS, but the difference was not significant due to high variability (SG: 81–210 g C m−2 year−1; AS: 115–168 g C m−2 year−1). The mean CAR at AS over the past 50 years was 118 (SD = 23) g C m−2 year−1. This study demonstrates that a sparsely vegetated, restored salt marsh can quickly begin to accumulate carbon and that historic and restored marshes can have similar CARs despite highly divergent formation processes.

Carbon and nitrogen isotopes of different native fish tissues from the Santa Ana River, California

Oxford University Press (OUP) | November 17th, 2026

Stable isotopes are commonly used to understand the role of fishes in aquatic food webs. However, variability in species- and tissue-specific isotopic values can affect t

Stable isotopes are commonly used to understand the role of fishes in aquatic food webs. However, variability in species- and tissue-specific isotopic values can affect the inference that is drawn from a stable isotope study. We evaluated differences in stable isotopes of carbon (δ13C) and nitrogen (δ15N) among three tissue types (white muscle, caudal fin rays, and eye lenses) for Santa Ana Sucker Pantosteus santaanae and Arroyo Chub Gila orcuttii to inform the design of a stable isotope study in the Santa Ana River, an urban river that is located in southern California.

Case Studies of Natural Shoreline Infrastructure in Coastal California: A Component of Identification of Natural Infrastructure Options for Adapting to Sea Level Rise

Nature Conservancy | November 27th, 2017

Sea level rise and erosion are major threats to California’s coast, requiring solutions to preserve the many benefits a healthy coastline provides: flood protec

Sea level rise and erosion are major threats to California’s coast, requiring solutions to preserve the many benefits a healthy coastline provides: flood protection, recreation, habitat for wildlife, water quality and more. Seawalls and other engineered structures, are commonly installed in order to hold the shoreline in place and hold back the ocean; however, they ultimately make the situation worse in most cases by increasing erosion and thus causing already vulnerable shorelines to shrink more. Natural shoreline infrastructure is an alternative that is more likely to preserve the benefits of coastal ecosystems while also maintaining coastal access. The California coastline is very diverse, and no single solution will address all the chal- lenges anticipated in the future. While there is a continuum of approaches to address sea level rise and coastal erosion— ranging from fully natural approaches that preserve or restore natural systems, hybrid solutions that integrate engineered aspects into restored or created natural features, and fully engineered structures like seawalls and revetments—prop- erty owners and managers don’t typically consider the entire range of options when making coastal management decisions. To address the gap in familiarity with natural infrastructure and the lack of technical guidance to aid decision-makers and engineers in the appropriate application of different strategies for different situations, this report summarizes natural infrastructure projects for a range of settings in coastal California. Each case study covers the background, permitting, planning, implementation, performance, and key lessons learned from each project in order to provide the critical information needed to implement successful adaptation strategies to address coastal issues, and inspire other communities by highlighting the lessons learned.

CASGEM Alternative Monitoring Plan Fact Sheet

California Department of Water Resources (DWR) | August 15th, 2023

Causes of the Extreme Dry Conditions over California During Early 2013

American Meteorological Society (AMS) | September 30th, 2014

The state of California experienced extreme dry conditions during early 2013. In particular, January and February received 28% and 15%, respectively, of their nor

The state of California experienced extreme dry conditions during early 2013. In particular, January and February received 28% and 15%, respectively, of their normal monthly rainfall. When January and February are combined, January/ February 2013 is ranked as the driest of the period 1895–2014. Such large precipitation deficits exerted enormous stress on water resources in an already high water-demand region. Thus, it is of practical importance to investigate the causes of this extreme climate event so as to assess its predictability. *Chapter 3, Explaining Extreme Events of 2013 from a Climate Perspective, Bull. Amer. Meteor. Soc., 95 (9)

Central and West Basin Water Replenishment District, etc. v. Charles E. Adams, et al

Superior Court of California, County of Los Angeles | December 23rd, 2013

Note from “An Evaluation of California’s Adjudicated Groundwater Basins” by Langridge et al: "Third Amendment Judgment to the Central Basin adjudication ... allo

Note from “An Evaluation of California’s Adjudicated Groundwater Basins” by Langridge et al: "Third Amendment Judgment to the Central Basin adjudication ... allowed parties holding water rights to store water in the Central Basin for later recovery; DWR was replaced with a new Watermaster consisting of three separate arms with different functions: Administrative Body, Water Rights Panel, and a Storage Panel."

Changes in the productivity of US West Coast fish stocks

Fisheries Research (Elsevier) | April 21st, 2023

The California Current ecosystem is highly dynamic at interannual to interdecadal time scales. Variability has been documented in pelagic and other fish species, but clim

The California Current ecosystem is highly dynamic at interannual to interdecadal time scales. Variability has been documented in pelagic and other fish species, but climate change may be altering the historical models of variation. This study investigates changes in productivity of 31 fish stocks in the California Current ecosystem. Productivity was measured from recent stock assessments, as the per-capita recruitment rate, estimated with a dynamic stock-recruitment model. Contrary to expectations, the dynamic stock-recruitment model fit better than the corresponding stationary model for only seven of the 31 stocks. There was little evidence of linear drift in productivity that might be expected to result from climate change. Climate variables improved forecast accuracy for a few stocks, but there was no common climate signal in productivity. One explanation of these results is that most of the west coast stocks are above their biomass levels for maximum sustainable yield, making them less susceptible to environmental variation. On the other hand, the dynamic recruitment models improved short-term forecasts for all stocks, which may be useful for quota setting. Finally, results for the subset of stocks with dynamic recruitment models could be used to establish dynamic biological reference points.