Conference proceedings – California Water Library

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Water/Wastewater Utilities and Extreme Climate and Weather Events: Case Studies on Community Response, Lessons Learned, Adaptation, and Planning Needs for the Future

Water Research Foundation | July 21st, 2014

Summary

This project consisted of a series of workshops that (1) examined the actions taken by water and wastewater utility practitioners who faced a recent extreme weather and c

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Waterline responses to climate forcing along the North American West Coast

Nature Portfolio (Springer Nature) | June 7th, 2025

Summary

Understanding waterline variability at seasonal to interannual timescales is crucial for predicting coastal responses to climate forcing. However, relationships between l

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Watershed Action Plan Santa Ana Region - Riverside County

Riverside County | January 18th, 2017

Summary

The Watershed Action Plan (WAP) for the Santa Ana Watershed Region of Riverside County (SAR) and its Permittees is a requirement of the Riverside County Municipal Separat

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Watershed Condition, Turbidity, and Implications for Anadromous Salmonids in North Coastal California Streams

California State Water Resources Control Board (SWRCB) | May 21st, 2008

Summary

It is widely acknowledged that historically intensive human disturbances increased erosion and sediment delivery rates to extreme levels in the 1950s through the 1970s ac

It is widely acknowledged that historically intensive human disturbances increased erosion and sediment delivery rates to extreme levels in the 1950s through the 1970s across the north coast, and are likely continuing to affect turbidity durations to some degree. A more controversial question is to what extent contemporary land use is affecting present-day erosion, sediment delivery and turbidity. Using turbidity exceedence levels to indicate watershed disturbance, we approached this question from several perspectives. Part A of this report follows up and expands on an earlier analysis (Klein, 2003) for which turbidity data sets from only eight sites were available. In the present study, annual turbidity data sets were assembled from up to 28 continuous turbidity and stage recording stations located on small streams in the northcoast region from Del Norte County in the north to Mendocino County in the south. Data spanning three water years (WY2003-2005) were processed to calculate lengths of time turbidity was higher than several thresholds. Turbidity thresholds ranged from 25 (frequently cited in the salmonid literature as causing ill effects when exceeded) to 1000 FNU. Turbidity exceedence analyses, similar to conventional flow exceedence analyses, were also performed, allowing comparison of turbidity levels at various exceedence probabilities. Part B of this report uses turbidity relationships to harvest rate to model potential effects on anadromous salmonids within a cumulative watershed effects (CWE) framework. To evaluate CWEs on anadromous salmonids and the stream ecosystem, annual turbidigraphs were produced from WY1991 through WY2005 at annual average harvest rates of 0% to 6% for an 8 mi2 old second-growth watershed in North Coastal California. The turbidigraphs were very conservative in that they used the ‘Lower Bound Lines’ to estimate turbidity from discharge, rather than a line of best fit. Turbidity thresholds established at 10, 25, and 50 FNU were applied to assess chronic background, moderate, and severe stress to stream ecosystems in each water year. A simple model of smolt growth and survival-to-adult-return (SAR), as influenced by the annual turbidigraph, indicated the minimum supportable adult steelhead population size could be more than halved at the 2% average annual timber harvest rate compared to that supported by an old second-growth watershed.

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Watershed Management (Resource Management Strategy)

California Department of Water Resources (DWR) | July 29th, 2016

Summary

Watershed management is the process of creating and implementing plans, programs, projects, and activities to restore, sustain, and enhance watershed functions. These fun

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Watershed Modeling for the Santa Clara River in Southern California

Ventura County Public Works Agency (VCPWA) | July 24th, 2019

Summary

A calibrated watershed hydrologic model of the Santa Clara River (SCR) Watershed was developed for use as a tool for watershed planning, resource assessment, and ultima

A calibrated watershed hydrologic model of the Santa Clara River (SCR) Watershed was developed for use as a tool for watershed planning, resource assessment, and ultimately, water quality management purposes. The study was a joint effort of the Ventura County Watershed Protection District (VCWPD), Los Angeles County Department of Public Works (LACDPW), and U.S. Army Corp of Engineers Los Angeles District. The modeling package used for the study was the U.S. EPA Hydrologic Simulation Program – FORTRAN (HSPF). The SCR main stem flows east-to-west from the San Gabriel Mountains of central Los Angeles County to its mouth at the Pacific Ocean near the cities of Ventura and Oxnard. The 4,263 square kilometer watershed includes rapidly urbanizing valleys and extensive agriculture, and is subject to severe flooding and erosion. There are four large reservoirs within the watershed. Although the Santa Clara River watershed remains primarily in a natural physical state, the flow regime within the watershed is highly engineered to optimize water deliveries and aquifer recharge. The SCR Watershed was segmented into 209 subwatersheds and 192 stream reaches, based on precipitation patterns, drainage boundaries, hydrography, stream gage locations, and impaired water segments. Each land segment was further subdivided into individual model segments based on land use/cover categories. A long-term data base of 46 years of model input data (precipitation, evaporation, diversions, POTWs, etc.) was developed. The model was calibrated and validated to observed flow at multiple locations, using both graphical and statistical model-data comparisons. Long-term simulations were run to assess the impacts of alternative conditions (baseline, natural) on flow and flood frequencies. The model was also used to generate design storm event hydrographs for selected return intervals with synthetic input rainfall hyetographs for the corresponding rainfall return period developed from available rain gage data. The design storm results were submitted to FEMA for the Flood Insurance Study currently underway.

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Watershed-scale Evaluation of Agricultural BMP Effectiveness in Protecting Critical Coastal Habitats: Final Report on the Status of Three Central California Estuaries

Central Coast Regional Water Quality Control Board (CCRWQCB) | April 30th, 2010

Summary

Along California's Central Coast, the Pajaro, Salinas, and Santa Maria Rivers drain to coastal estuaries that provide essential habitat for early life stages of commercia

Along California's Central Coast, the Pajaro, Salinas, and Santa Maria Rivers drain to coastal estuaries that provide essential habitat for early life stages of commercially and recreationally important marine fish species, threatened anadromous fish species, migratory birds, and other wildlife. These are the largest watersheds on the central coast and each contains year-round, intensively cultivated agricultural land that supports a $3.5 billion/year industry producing most of the nation's lettuce, artichokes, and crucifer crops. Runoff from irrigated agriculture constitutes a significant portion of river flow during most of the year, and a number of studies have documented pesticide occurrence and biological impacts in these watersheds. Evidence of pesticide impacts has encouraged diverse stakeholders to begin implementing farm management practices (MPs) to reduce pesticide concentrations and toxicity in agricultural runoff. This project is designed to complement ongoing evaluations of individual MPs with measurements of pesticide concentrations throughout the estuarine environments, including the water column, sediments, and in resident biota. Biological effects were measured at the organism and community levels. Chemical analyses emphasized pesticide impacts because previous research in these watersheds has indicated these are the primary chemicals of concern impacting beneficial uses. A broad suite of pesticides were measured, including legacy organochlorines, widely-used organophosphates, increasingly-used pyrethroids, herbicides and fungicides. Sampling in the three estuaries was conducted from January 2008 until October 2009. A total of fifteen sampling events were conducted in each estuary, and these were divided between eleven irrigation season events and four storm events. Storm and irrigation monitoring included water toxicity and chemistry analyses for pesticides. Samples were collected at multiple stations in the estuaries and in key tributaries flowing to the estuaries. In addition, sediment toxicity was assessed at eight estuary stations and the tributary stations during three irrigation season sampling events. Benthic community characterizations were also conducted in May and October 2008. All sediment samples were analyzed for pesticides, as well as grain size and total organic carbon. Pesticide analyses in resident fish and sand crab tissues were conducted once in each estuary. The goal of this project was to establish a baseline of estuary conditions with respect to pesticide impacts as MPs are beginning to be implemented.

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Waterweed Invasions

Scientific American | October 1st, 1989

Summary

Populations of plants and animals ordinarily migrate and multiply slowly over time as a result of the natural interplay among many ecological factors: soils, waters,

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We Don't Do Groundwater: A Morsel of California Legal History

Berkeley Law Scholarship Repository | January 1st, 2002

Summary

It must seem surprising to people elsewhere that California, unlike other western states, continues to treat surface water and groundwater under separate and distinct leg

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Wells of Southern California

Scientific American | March 22nd, 1902

Summary

In the Series of Water Supply Irrigation Papers, the United States Geological Survey has in press, but not yet published, the “Wells of Southern California" (Nos. 59

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Water/Wastewater Utilities and Extreme Climate and Weather Events: Case Studies on Community Response, Lessons Learned, Adaptation, and Planning Needs for the Future

Waterline responses to climate forcing along the North American West Coast

Watershed Action Plan Santa Ana Region - Riverside County

Watershed Condition, Turbidity, and Implications for Anadromous Salmonids in North Coastal California Streams

Watershed Management (Resource Management Strategy)

Watershed Modeling for the Santa Clara River in Southern California

Watershed-scale Evaluation of Agricultural BMP Effectiveness in Protecting Critical Coastal Habitats: Final Report on the Status of Three Central California Estuaries

Waterweed Invasions

We Don't Do Groundwater: A Morsel of California Legal History

Wells of Southern California

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