San Joaquin River

Over‐pumping leads to California groundwater arsenic threat

Nature Portfolio (Springer Nature) | June 5th, 2018

Water resources are being challenged to meet domestic, agricultural, and industrial needs. To complement finite surface water supplies that are being stressed b

Water resources are being challenged to meet domestic, agricultural, and industrial needs. To complement finite surface water supplies that are being stressed by changes in precipitation and increased demand, groundwater is increasingly being used. Sustaining groundwater use requires considering both water quantity and quality. A unique challenge for groundwater use, as compared with surface water, is the presence of naturally occurring contaminants within aquifer sediments, which can enter the water supply. Here we find that recent groundwater pumping, observed through land subsidence, results in an increase in aquifer arsenic concentrations in the San Joaquin Valley of California. By comparison, historic groundwater pumping shows no link to current groundwater arsenic concentrations. Our results support the premise that arsenic can reside within pore water of clay strata within aquifers and is released due to overpumping. We provide a quantitative model for using subsidence as an indicator of arsenic concentrations correlated with groundwater pumping.

Pacific Coast Federation of Fishermen’s Associations et al v. Wilbur Ross et al

U.S. District Court, Northern District of California | December 12th, 2019

Paradise Regained: Solution for restoring Yosemite's Hetch Hetchy Valley

Environmental Defense Fund (EDF) | July 15th, 2004

In this report Environmental Defense provides a planning-level analysis for replacing the water and hydropower benefits that the Hetch Hetchy Reservoir and O’Shaughness

In this report Environmental Defense provides a planning-level analysis for replacing the water and hydropower benefits that the Hetch Hetchy Reservoir and O’Shaughnessy Dam provide.We show how practical, proven water storage, conveyance and treatment alternatives can provide San Francisco a healthy, reliable and secure supply of water that is adequate for current and future needs.  We also explain how hydropower lost as a result of restoring the valley can be replaced without contributing to air pollution or global warming. The alternatives analyzed do not comprise all possible options, but they do demonstrate that workable solutions for restoring Hetch Hetchy Valley exist. We began this study with the premise that all solutions must be technologically feasible and affordable and must assure a dependable supply of safe drinking water. In addition to addressing the water and power needs of San Francisco and other Bay Area communities that rely on the Tuolumne River, solutions must also protect all affected California communities. Most obviously, any restoration plan must protect the Turlock and Modesto Irrigation Districts, whose uses of the Tuolumne River predate and are intertwined with those of the San Francisco Public Utilities Commission (SFPUC) and its customers. Of course, a restoration plan must also consider the Groveland area, both as a user of the Tuolumne River water and as a gateway community to the Hetch Hetchy region of Yosemite National Park. Our analysis focuses mainly on alternative ways to move and store San Francisco’s existing supply of Tuolumne River water. Environmental Defense developed the TREWSSIM (Tuolumne River Equivalent Water Supply Simulation) model to evaluate the SFPUC’s system performance under a range of water supply alternatives, with and without Hetch Hetchy Reservoir.TREWSSIM incorporates features of both the SFPUC’s planning model HHSM-LSM and the state-federal CALSIM model. The TREWSSIM analysis addresses not only water supply issues, but also water treatment and hydropower. Three expert consultants assisted in our analysis: Schlumberger Water Services provided engineering analyses and modeling assistance; Eisenberg, Olivieri and Associates analyzed water quality issues; and Somach, Simmons  & Dunn assessed the legal landscape. Academic experts provided peer review. The San Francisco Public Utilities Commission, the Bay Area Water Supply and Conservation Agency, and the Turlock and Modesto Irrigation Districts also provided information to help ensure an accurate report.

Pared-Down Water Plan to Be Submitted in 1987

Los Angeles Times | June 17th, 1985

SACRAMENTO — Gov. George Deukmejian’s Administration is preparing to submit a new water package to the Legislature in 1987, a stripped-down version of the plan that f

SACRAMENTO — Gov. George Deukmejian’s Administration is preparing to submit a new water package to the Legislature in 1987, a stripped-down version of the plan that failed in 1984, according to David N. Kennedy, director of the state Department of Water Resources. The plan, contingent on Deukmejian’s reelection next year, would reverse the position the governor took after the stinging rebuke of a year ago, when he blamed Democratic lawmakers for the defeat. He said then that it would be up to the Legislature to produce an acceptable plan for supplying the state’s water needs. But now the Administration is once again gearing up to take the initiative on the water issue. The package would contain three key elements: - Authorization for $300 million in Sacramento-San Joaquin Delta projects needed to ship additional surplus water south. - A commitment to help maintain and restore deteriorating delta levees. - Environmental protections for San Francisco Bay.

Passage and Flow Considered Anew: Wild Salmon Restoration Via Hyrdo Relicensing

University of Montana | May 24th, 2016

Patterns and magnitude of flow alteration in California, USA

Freshwater Biology (Wiley) | December 27th, 2017

The importance of the natural flow regime to stream and river health has received growing attention over the last two decades. Quantifying natural river flows has become

The importance of the natural flow regime to stream and river health has received growing attention over the last two decades. Quantifying natural river flows has become an essential component of water resource planning, including assessments of water supplies (Vicuna,Maurer, Joyce, Dracup, & Purkey, 2007; Wurbs, 2005), reservoir operations (Hejazi, Cai, & Ruddell, 2008) and drought risk (Meko,Therrell, Baisan, & Hughes, 2001). Understanding the natural flow regime is also crucial for managing stream ecosystems.

Patterns in the use of a restored California floodplain by native and alien fishes

University of California, Davis (UC Davis) | July 7th, 2007

Fishes were sampled on the restored floodplain of the Cosumnes River in Central California in order to determine patterns of floodplain use. The floodplain was sampled fo

Fishes were sampled on the restored floodplain of the Cosumnes River in Central California in order to determine patterns of floodplain use. The floodplain was sampled for seven years (1998-2002, 2004-2005) during the winter-spring flooding season. The fishes fell into five groups: (1) floodplain spawners, (2) river spawners, (3) floodplain foragers, (4) floodplain pond fishes, and (5) inadvertent users. Eight of the 18 abundant species were natives, while the rest were aliens. There was a consistent pattern of floodplain use, modified by timing and extent of flooding. The first fishes to appear were floodplain foragers, inadvertent users, and juvenile Chinook salmon (river spawners). Next were floodplain spawners, principally Sacramento splittail and common carp. At the end of the season, in ponds of residual water, non-native annual fishes, mainly inland silverside and western mosquitofish, became abundant. Adult spawners left when inflow decreased; their juveniles persisted as long as flood pulses kept water levels up and temperatures low. Juvenile splittail and carp quickly grew large enough to dominate floodplain fish samples, along with smaller numbers of juvenile Sacramento sucker and pikeminnow (river spawners). Such juveniles left the Relatively few fishes that used the floodplain for spawning or rearing became stranded, except late season alien fishes. Most alien fishes had resident populations in adjacent river, sloughs, and ditches and were not dependent on the floodplain for persistence. This indicates that Central Valley floodplains managed to favor native fishes should have the following characteristics: (1) extensive early season flooding, (2) complete drainage by the end of the flooding season, (3) few areas with permanent water, (4) a mosaic of physical habitats, (5) regular annual flooding but with high variability in flood regime.

Paying for California's Water System

Public Policy Institute of California (PPIC) | May 31st, 2021

Paying it Forward: The Path Toward Climate-Safe Infrastructure in California

Climate-Safe Infrastructure Working Group | September 1st, 2018

Performance of Fire Danger Indices and Their Utility in Predicting Future Wildfire Danger Over the Conterminous United States

American Geophysical Union (AGU) | November 20th, 2023