Historical Ecology of the Los Angeles River Watershed and Environs, Infrastructure for a Comprehensive Analysis

University of Southern California (USC) | June 15th, 2020

Historical Expenditures and Current and Future Funding Needs

California Department of Water Resources (DWR) | December 13th, 2018

This document supports information contained in the California Water Plan Update 2018. The purpose of this document is to provide a description of California’s water re

This document supports information contained in the California Water Plan Update 2018. The purpose of this document is to provide a description of California’s water resources management historical expenditures and the existing funding needs in the State. The historical expenditure data includes capital and ongoing public agencies’ (State, local, and Federal agencies) historical expenditures. Historical expenditure data is organized by management action type and water sectors. In this document, capital management actions include infrastructure development, repair, replacement or rehabilitation. Ongoing actions include planning, data management, tracking and reporting, operations, and maintenance. Historical expenditure data is provided for State fiscal year 2005/2006 (2006) to 2014/2015 (2015). This timeframe was selected due to data availability at the local, State, and Federal levels. This document also provides information on the accrued interest on debt from State general obligation (GO) bonds.  This document provides information pertaining to the projected existing water management funding needs and existing water management funding gap. Projected water management funding need was estimated from planned and proposed management actions collected from State, local, and Federal agencies.  Historical expenditure and funding need information is used in the California Water Plan Update 2018 to provide context and data for inclusion into the funding analysis, described in the Funding Scenario Analysis supporting document. 

Historical Fresh Water and Salinity Conditions in the Western Sacramento-San Joaquin Delta and Suisun Bay

Contra Costa Water District (CCWD) | February 23rd, 2010

The watershed of the Sacramento–San Joaquin Delta (Delta) provides drinking water to more than 23 million Californians as well as irrigation water for millions of acres

The watershed of the Sacramento–San Joaquin Delta (Delta) provides drinking water to more than 23 million Californians as well as irrigation water for millions of acres of agriculture in the Central Valley. The Delta itself is a complex estuarine ecosystem, with populations of many native species now in serious decline. The Delta estuary as we know it began to form about 6,000 years ago, following the end of the last ice age. Because the estuary is connected to the Pacific Ocean through San Francisco Bay, seawater intrusion causes the salinity of Suisun Bay and the Delta to vary depending on hydrological conditions. This seawater intrusion into the Delta affects estuarine species as well as drinking water and irrigation water supplies. Successful restoration of the Delta ecosystem requires an understanding of the conditions under which native species evolved. Contra Costa Water District’s report on “Historical Fresh Water and Salinity Conditions in the Western Sacramento-San Joaquin Delta and Suisun Bay” presents a detailed review of more than 100 years of studies, monitoring data, scientific reports, and modeling analyses that establish an historical record of the salinity conditions in the Western Delta and Suisun Bay.

Historical Seawater Intrusion Map Pressure 180-Foot Aquifer - 500 mg/L or Greater Chloride Areas

Monterey County Water Resources Agency (MCWRA) | April 11th, 2018

History and Sources of Co-Occurring Pesticides in an Abstraction Well Unraveled by Age Distributions of Depth-Specific Groundwater Samples

American Chemical Society (ACS) | November 24th, 2019

When groundwater-based drinking water supply becomes contaminated, the timing and source of contamination are obvious questions. However, contaminants often have diffuse

When groundwater-based drinking water supply becomes contaminated, the timing and source of contamination are obvious questions. However, contaminants often have diffuse sources and different contaminants may have different sources even in a single groundwater well, making these questions complicated to answer. Age dating of groundwater has been used to reconstruct contaminant travel times to wells; however, critics have highlighted that groundwater flow is often complex with mixing of groundwater of different ages. In drinking water wells, where water is typically abstracted from a large depth interval, such mixing is even more problematic. We present a way to overcome some of the obstacles in identifying the source and age of contaminants in drinking water wells by combining depth-specific sampling with age tracer modeling, particle tracking simulations, geological characterization, and contaminant properties. This multitool approach was applied to a drinking water well, where bentazon and dichlorprop contamination was found to have different pollutant sources and release histories, even though both pesticides can be associated with the same land use. Bentazon was derived from recent application to a golf course, while dichlorprop was derived from agricultural use more than 30 years ago. The advantages, limitations, and pitfalls of the proposed course of action are then further discussed.

History and Sources of Co-Occurring Pesticides in an Abstraction Well Unraveled by Age Distributions of Depth-Specific Groundwater Samples

American Chemical Society (ACS) | November 24th, 2019

When groundwater-based drinking water supply becomes contaminated, the timing and source of contamination are obvious questions. However, contaminants often have diffuse

When groundwater-based drinking water supply becomes contaminated, the timing and source of contamination are obvious questions. However, contaminants often have diffuse sources and different contaminants may have different sources even in a single groundwater well, making these questions complicated to answer. Age dating of groundwater has been used to reconstruct contaminant travel times to wells; however, critics have highlighted that groundwater flow is often complex with mixing of groundwater of different ages. In drinking water wells, where water is typically abstracted from a large depth interval, such mixing is even more problematic. We present a way to overcome some of the obstacles in identifying the source and age of contaminants in drinking water wells by combining depth-specific sampling with age tracer modeling, particle tracking simulations, geological characterization, and contaminant properties. This multitool approach was applied to a drinking water well, where bentazon and dichlorprop contamination was found to have different pollutant sources and release histories, even though both pesticides can be associated with the same land use. Bentazon was derived from recent application to a golf course, while dichlorprop was derived from agricultural use more than 30 years ago. The advantages, limitations, and pitfalls of the proposed course of action are then further discussed.

History of Legislation and Policy Formation of the Central Valley Project

U.S. Department of Agriculture (USDA) | March 15th, 1946

History of the All-American Canal: Boulder Canyon Project

U.S. Bureau of Reclamation (USBR) | December 1st, 2009

A narrative history of the construction of the All American Canal, Imperial Dam, and the Coachella Canal.

A narrative history of the construction of the All American Canal, Imperial Dam, and the Coachella Canal.

History of the Delta Division, Central Valley Project

U.S. Bureau of Reclamation (USBR) | October 1st, 1994

The Delta Division of the Central Valley Project (CVP) acts as the hub around which the CVP revolves. The Delta Division contains the facilities that transfer water from

The Delta Division of the Central Valley Project (CVP) acts as the hub around which the CVP revolves. The Delta Division contains the facilities that transfer water from the Sacramento River, to bolster irrigation supplies to thirsty lands formerly dependent on water from the San Joaquin River. In time, the Delta Division became the hub for controversy revolving around the Central Valley Project. This document recounts the history of the Delta Division.  It was produced by the Bureau of Reclamation.

History of Water Project Conveyance in the Delta

California Natural Resources Agency (CNRA) | January 6th, 2016

A fact sheet on the history of conveyance in  the Delta; includes a timeline from the 1950s to present.  Prepared by the Department of Water Resources.

A fact sheet on the history of conveyance in  the Delta; includes a timeline from the 1950s to present.  Prepared by the Department of Water Resources.