Enhancing Water Supply through Invasive Plant Removal: A Literature Review of Evapotranspiration Studies on Arundo Donax

Nature Conservancy | February 11th, 2019

Removal of the invasive, non-native plant Arundo donax (Arundo, giant reed) along riparian corridors is being considered by groundwater sustainability agencies

Removal of the invasive, non-native plant Arundo donax (Arundo, giant reed) along riparian corridors is being considered by groundwater sustainability agencies as a potential water savings strategy that could provide co-benefits for groundwater sustainability as well as native ecosystem restoration. Arundo is a fast growing, densely vegetated reed that has purportedly high-water consumption (i.e., transpiration). This paper is intended to help agencies develop estimates of the water supply benefits that could be realized from Arundo removal.

Ensuring the Public Trust

University of California, Davis (UC Davis) | July 1st, 2012

The California Supreme Court's recognition of the public trust doctrine as an integral part of California's water rights system was one of the momentous events in the h

The California Supreme Court's recognition of the public trust doctrine as an integral part of California's water rights system was one of the momentous events in the history of California (if not United States) environmental policy.' The court looked back to the foundational purposes of the public trust to hold that there are limits to the sovereign power to privatize the rights to use the waters of the state, and it looked forward to conclude that prudent development and sustainable use of California's water resources require the state to retain authority to protect the public trust for the benefit of all Californians. The court also defined the public trust as an environmental baseline that both protects the traditional interests of navigation, commerce, and fisheries and embodies the contemporary scientific and popular understanding that there are ecological limits to the diversion and use of water for consumptive purposes. The lessons of National Audubon Society v. Superior Court2 are now a commonplace of water rights law, appearing not just in administrative orders and judicial opinions, but also in standard water rights terms, policy studies, and legislation.

Environmental Baseline Biological Resources - Fauna, Total Water Management Study for the Central Valley, California

U.S. Bureau of Reclamation (USBR) | January 1st, 1975

Environmental Characteristics of Select Managed Ponds in the Sacramento–San Joaquin Delta: Implications for Native Fish Conservation and Research

U.S. Geological Survey (USGS) | July 23rd, 2025

The use of wetlands to support native fish research and conservation efforts in the Sacramento–San Joaquin Delta (Delta) of California is a growing priority. The purpos

The use of wetlands to support native fish research and conservation efforts in the Sacramento–San Joaquin Delta (Delta) of California is a growing priority. The purpose of our study was to examine the physiochemical and biological characteristics of select managed ponds in the Delta to determine if they would be suitable habitats for research involving the conservation of delta smelt (Hypomesus transpacificus). We studied 10 managed ponds distributed across the central part of the Delta situated on Bacon Island and Bouldin Island in San Joaquin County, and Holland Tract and Webb Tract islands in Contra Costa County. The managed ponds had a diversity of physical habitat configurations and were not directly connected to waterways surrounding the islands and, therefore, not affected by tides. We studied the managed ponds from approximately November 2021 to December 2023 to assess water quality, zooplankton, fish, and pesticide metrics. Water levels in the managed ponds were managed to varying degrees and were mostly independent of climate-driven wet-dry seasonality. Water quality conditions varied among ponds and were independent of geographic location. Overall, mean monthly chlorophyll a concentration ranged from 15 to 57 (mean=30) micrograms per liter (μg/L), dissolved oxygen concentration ranged from 4 to 9 (mean=7) milligrams per liter (mg/L), pH was 8, salinity was 1 practical salinity units (PSU), specific conductance ranged from 1,202 to 1,839 (mean=1,471) microsiemens per centimeter (μS/cm), and turbidity ranged from 13 to 24 (mean=19) Formazin Nephelometric Units (FNU). Water temperature thresholds that contribute to stress (21 degrees Celsius [°C]) and mortality (28 °C) of delta smelt were often exceeded during summer and fall, though vertical stratification contributed to lower bottom temperatures in the deepest managed ponds, which could potentially provide thermal refugia for delta smelt so long as dissolved oxygen concentrations are suitable. Zooplankton populations were broadly similar among managed ponds and included calanoid and cyclopoid copepods that would be suitable prey for delta smelt. Overall average total zooplankton biomass, as measured with a Schindler-Patalas trap, was 0.6 μg/L (min=0, max=63.6) and peaked during spring at more than 4 μg/L. Fish populations highly varied among the managed ponds with potential predators of delta smelt such as largemouth bass (Micropterus salmoides) and black crappie (Pomoxis nigromaculatus) present in several of the managed ponds; predator distribution among ponds seemed to have been driven primarily by deliberate stocking to facilitate local fisheries. Measured pesticide concentrations were below U.S. Environmental Protection Agency Aquatic Life Benchmarks except for exceedances of three compounds (diuron [herbicide], clothianidin [insecticide], and deltamethrin [pyrethroid insecticide]) in samples collected from ponds on Bouldin Island and Webb Tract. Overall, most managed ponds seemed suitable to support delta smelt, though physical control of potential predators and summer temperature might be needed. The results provide guidance on how to engineer and manage new managed ponds to support research and conservation efforts for delta smelt and other native fishes.

Environmental Impact Report/Environmental Impact Statement (EIR/EIS) for the Cadiz Groundwater Storage Dry-Year Supply Program

Bureau of Land Management (BLM) | September 13th, 2001

In February 1999, Metropolitan issued a Notice of Preparation of an EIR for the Cadiz Project which would be constructed and operated by Metropolitan in the Cadiz and Fe

In February 1999, Metropolitan issued a Notice of Preparation of an EIR for the Cadiz Project which would be constructed and operated by Metropolitan in the Cadiz and Fenner Valleys of the eastern Mojave Desert, San Bernardino County, California. The BLM determined that an EIS would be required as the proposed action includes an amendment of the CDCA Plan for an exception to the utility corridor requirements and grant(s) of right-of-way across federal lands. The BLM issued a Notice of Intent to Prepare an EIS for the proposed action in March 1999. In May 1999, the BLM issued a Notice of Public Meeting and extension of the scoping comment period. The Draft EIR/EIS was published in November 1999 with a 104-day public review period that ended in March 2000. Because numerous comments raised questions regarding groundwater management issues, a Supplement to the Draft EIR/EIS was prepared to provide additional information and to present the Groundwater Monitoring and Management Plan (Management Plan) that has been incorporated into the proposed project. The Management Plan will govern the water storage and extraction operations in the affected groundwater basins to ensure that project operations will not result in any unacceptable adverse impacts to groundwater resources or air quality. The Supplement to the Draft EIR/EIS was circulated for an 80-day public review period that ended in January 2001. The Cadiz Project is proposed by Metropolitan who is acting in partnership with the private company Cadiz Inc. The project will involve construction and operation of a 35-mile pipeline for conveying water between the Iron Mountain Pumping Plant on the Colorado River Aqueduct and the Cadiz/Fenner area, a Cadiz Pumping Plant at Metropolitan.s existing Iron Mountain Pumping Plant facility, 390 acres of spreading basins for percolation of Colorado River water into the groundwater basin in the Cadiz/Fenner area, a wellfield for extracting stored Colorado River water and indigenous groundwater, and associated power poles and line along the conveyance pipeline and in the wellfield. This Final EIR/EIS contains comments received on the Draft EIR/EIS and the Supplement to the Draft EIR/EIS, detailed responses to those comments, and integrates the information contained in the Draft EIR/EIS and Supplement to the Draft EIR/EIS with revisions as appropriate in response to comments.

Environmental Law Foundation, et al. Plaintiffs and Respondents, v. State Water Resources Control Board, et al. Defendant, Cross-defendant and Respondent; County of Siskiyou, Defendant, Cross-complainant and Appellant

State of California | August 29th, 2018

Click here to read Brian Gray, Senior Fellow at the Public Policy Institute of California Water Policy Center and a Professor Emeritus at UC Hastings, on this ruling

Click here to read Brian Gray, Senior Fellow at the Public Policy Institute of California Water Policy Center and a Professor Emeritus at UC Hastings, on this ruling and the potential ramifications under the Sustainable Groundwater Management Act.

Environmental Water Transactions in the Colorado River Basin: A Closer Look

Stanford University | November 14th, 2018

Over the last 30 years, the voluntary transfer of water and water rights for environmental uses has become a recognized strategy for restoring streamflow in the Western

Over the last 30 years, the voluntary transfer of water and water rights for environmental uses has become a recognized strategy for restoring streamflow in the Western United States. Historically, taking water out of a stream was a legally required element of an appropriative water right. Water rights holders who left all or a portion of their right instream to enhance fish populations, riparian habitat or recreation, risked forfeiture or diminishment of their water right. Beginning in the 1980’s, state laws began to recognize both the appropriation of new water rights for instream use and to allow the transfer and amendment of existing appropriative rights for those uses. Click here for previous report.

Ephemeral floodplain habitats provide best growth conditions for juvenile Chinook salmon in a California river

Environmental Biology of Fishes (Springer) | June 6th, 2008

We reared juvenile Chinook salmon for two consecutive flood seasons within various habitats of the Cosumnes River and its floodplain to compare fish growth in river and

We reared juvenile Chinook salmon for two consecutive flood seasons within various habitats of the Cosumnes River and its floodplain to compare fish growth in river and floodplain habitats. Fish were placed in enclosures during times when wild salmon would naturally be rearing in floodplain habitats. We found significant differences in growth rates between salmon reared in floodplain and river enclosures. Salmon reared in seasonally inundated habitats with annual terrestrial vegetation experienced higher growth rates than those reared in a perennial pond on the floodplain. Growth of fish in the non-tidal river upstream of the floodplain varied with flow in the river. When flows were high, there was little growth and high mortality, but when the flows were low and clear, the fish grew rapidly. Fish displayed very poor growth in tidally influenced river habitat below the floodplain, a habitat type to which juveniles are commonly displaced during high flow events due to a lack of channel complexity in the main-stem river. Overall, ephemeral floodplain habitats supported higher growth rates for juvenile Chinook salmon than more permanent habitats in either the floodplain or river. Variable responses in both growth and mortality, however, indicate the importance of providing habitat complexity for juvenile salmon in floodplain reaches of streams, so fish can find optimal places for rearing under different flow conditions.

Establishing ecological thresholds and targets for groundwater management

Nature Portfolio (Springer Nature) | April 3rd, 2024

Groundwater is critical for many ecosystems, yet groundwater requirements for dependent ecosystems are rarely accounted for during water and conservation planning. Here w

Groundwater is critical for many ecosystems, yet groundwater requirements for dependent ecosystems are rarely accounted for during water and conservation planning. Here we compile 38 years of Landsat-derived normalized difference vegetation index (NDVI) to evaluate groundwater-dependent vegetation responses to changes in depth to groundwater (DTG) across California. To maximize applicability, we standardized raw NDVI and DTG values using Z scores to identify groundwater thresholds, groundwater targets and map potential drought refugia across a diversity of biomes and local conditions. Groundwater thresholds were analysed for vegetation impacts where ZNDVI dropped below −1. ZDTG thresholds and targets were then evaluated with respect to groundwater-dependent vegetation in different condition classes and rooting depths. ZNDVI scores were applied statewide to identify potential drought refugia supported by groundwater. Our approach provides a simple and robust methodology for water and conservation practitioners to support ecosystem water needs so biodiversity and sustainable water-management goals can be achieved.

Estimated Ground-Water Discharge by Evapotranspiration from Death Valley, California, 1997–2001

U.S. Geological Survey (USGS) | July 1st, 2003