Final Environmental Impact Report Volume II: Revised Draft EIR Comprehensive Groundwater Cleanup Strategy for Historical Chromium Discharges from PG&E’s Hinkley Compressor Station, San Bernardino County

California State Water Resources Control Board (SWRCB) | April 20th, 2013

Click here for Volume I.

Click here for Volume I.

Final Sensitive Beneficial Use Literature Review (Task 3.1.1)

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-Salts) | May 16th, 2023

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.

Fire influence on land–water interactions in aridland catchments

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

Wildfires have increased in size, frequency, and intensity in arid regions of the western United States because of human activity, changing land use, and rising temperatu

Wildfires have increased in size, frequency, and intensity in arid regions of the western United States because of human activity, changing land use, and rising temperature. Fire can degrade water quality, reshape aquatic habitat, and increase the risk of high discharge and erosion. Drawing from patterns in montane dry forest, chaparral, and desert ecosystems, we developed a conceptual framework describing how interactions and feedbacks among material accumulation, combustion of fuels, and hydrologic transport influence the effects of fire on streams. Accumulation and flammability of fuels shift in opposition along gradients of aridity, influencing the materials available for transport. Hydrologic transport of combustion products and materials accumulated after fire can propagate the effects of fire to unburned stream–riparian corridors, and episodic precipitation characteristic of arid lands can cause lags, spatial heterogeneity, and feedbacks in response. Resolving uncertainty in fire effects on arid catchments will require monitoring across hydroclimatic gradients and episodic precipitation.

First flush analysis of urban storm runoff

Science of the Total Environment (Elsevier) | July 3rd, 2003

Stormwater runoff was monitored on 13 separate urban watersheds, which were chosen to represent distinct types of residential and industrial development, along with vario

Stormwater runoff was monitored on 13 separate urban watersheds, which were chosen to represent distinct types of residential and industrial development, along with various watershed characteristics. A total of 38 storm events were monitored to investigate the first flush phenomenon. The first flush phenomenon may be defined as the initial period of stormwater runoff during which the concentration of pollutants is substantially higher than during later stages. The magnitude of the first flush phenomenon, and if it actually occurs, was calculated using a method of data analysis which results in determining the ‘event mean concentration’ (EMC). The magnitude of the first flush phenomenon was found to be greater for some pollutants (e.g. suspended solids from residential areas) and less for others (e.g. chemical oxygen demand from industrial areas). No correlation was observed between the first flush phenomenon and the antecedent dry weather period, however, the first flush phenomenon was greater for smaller watershed areas.

Fish die-offs are concurrent with thermal extremes in north temperate lakes

Nature Portfolio (Springer Nature) | July 8th, 2019

As environmental temperatures continue to rise and organisms experience novel and potentially lethal conditions, the possibility of increased mass mortality events for an

As environmental temperatures continue to rise and organisms experience novel and potentially lethal conditions, the possibility of increased mass mortality events for animal populations appears likely. Yet, due to die-off rarity and unpredictability, there have been few large-scale attempts to quantify the relationship between mass die-offs and local environmental temperatures. Here, we address this issue by analysing a database of 502 freshwater fish die-offs combined with lake-specific temperature profiles simulated for north temperate lake ecosystems. Die-offs driven by extreme summer conditions occurred disproportionately in lakes with warmer average surface temperatures and during periods of extreme heat. In contrast, we observed no relationships between current thermal extremes and die-offs attributed to infectious disease or winter environmental conditions. We forecast fish die-offs driven by summer environmental conditions to double by mid-century for north temperate lakes (2041–2059) and to increase more than fourfold by late century (2081–2099), particularly at southern latitudes. These results expose a direct link between novel temperature regimes and the increased probability of catastrophic ecological events in freshwater ecosystems.

Fish-Habitat Relationships Along the Estuarine Gradient of the Sacramento-San Joaquin Delta, California: Implications for Habitat Restoration

Estuaries and Coasts (Springer) | June 6th, 2018

Estuaries are highly variable environments where fish are subjected to a diverse suite of habitat features (e.g., water quality gradients, physical structure) that filt

Estuaries are highly variable environments where fish are subjected to a diverse suite of habitat features (e.g., water quality gradients, physical structure) that filter local assemblages from a broader, regional species pool. Tidal, climatological, and oceanographic phenomena drive water quality gradients and, ultimately, expose individuals to other habitat features (e.g., stationary physical or biological elements, such as bathymetry or vegetation). Relationships between fish abundances, water quality gradients, and other habitat features in the Sacramento-San Joaquin Delta were examined as a case example to learn how habitat features serve as filters to structure local assemblages in large river-dominated estuaries. Fish communities were sampled in four tidal lakes along the estuarine gradient during summer-fall 2010 and 2011 and relationships with habitat features explored using ordination and generalized linear mixed models (GLMMs). Based on ordination results, landscape-level gradients in salinity, turbidity, and elevation were associated with distinct fish assemblages among tidal lakes. Native fishes were associated with increased salinity and turbidity, and decreased elevation. Within tidal lakes, GLMM results demonstrated that submersed aquatic vegetation density was the dominant driver of individual fish species densities. Both native and non-native species were associated with submersed aquatic vegetation, although native and non-native fish populations only minimally overlapped. These results help to provide a framework for predicting fish species assemblages in novel or changing habitats as they indicate that species assemblages are driven by a combination of location within the estuarine gradient and site-specific habitat features.

Flame retardants and plastic additives in San Francisco Bay: Targeted monitoring of organophosphate esters and bisphenols

San Francisco Estuary Institute (SFEI) | January 31st, 2020

Flood Risk and Management of California's Sacramento-San Joaquin Delta Levee System

University of California, Santa Cruz (UC Santa Cruz) | September 15th, 2020

Flow Augmentations Modify an Estuarine Prey Field

University of California, Davis (UC Davis) | June 15th, 2023