San Joaquin River

Information Needs for Water Markets: Fair and Effective Water Markets Require Adequate Measurement and Reporting of Diversion and Use

University of California, Berkeley (UC Berkeley) | November 14th, 2024

Initial Alternatives Information Report for the North/Central Delta Improvement Study (Delta Cross Channel, Franks Tract, and Through- Delta Facility Evaluation)

U.S. Bureau of Reclamation (USBR) | March 17th, 2010

The U.S. Department of the Interior (Interior) Bureau of Reclamation (Reclamation) and the California Department of Water Resources (DWR) are evaluating the feasibility o

The U.S. Department of the Interior (Interior) Bureau of Reclamation (Reclamation) and the California Department of Water Resources (DWR) are evaluating the feasibility of using conveyance and operations actions in the north and central region of the Sacramento–San Joaquin River Delta (Delta) to improve water quality and fish conditions. Specifically, Reclamation is evaluating the feasibility of these actions in the North/Central Delta Improvement Study (NoCDIS or Study). The Initial Alternatives Information Report (IAIR) identifies, discusses, and screens measures to address the problems and opportunities. These measures are used to develop initial alternatives. Initial alternatives from the IAIR will be incorporated into and refined in the subsequent Plan Formulation Report (PFR). Subject to continued appropriations and a determination of federal interest, the Study should culminate in an Environmental Impact Statement/Environmental Impact Report (EIS/EIR) and a Feasibility Report. Reclamation is the federal lead agency for National Environmental Policy Act (NEPA) compliance, and DWR is the state lead agency for California Environmental Quality Act (CEQA) compliance.

Innovation in Monitoring: The U.S. Geological Survey Sacramento–San Joaquin River Delta, California, Flow-Station Network

U.S. Geological Survey (USGS) | January 1st, 2016

The U.S. Geological Survey (USGS) installed the first gage to measure the flow of water into California’s Sacramento–San Joaquin River Delta from the Sacramento River

The U.S. Geological Survey (USGS) installed the first gage to measure the flow of water into California’s Sacramento–San Joaquin River Delta from the Sacramento River in the late 1800s. Today, a network of 35 hydro-acoustic meters measure flow throughout the delta. This region is a critical part of California’s freshwater supply and conveyance system. With the data provided by this flow-station network—sampled every 15 minutes and updated to the web every hour—state and federal water managers make daily decisions about how much freshwater can be pumped for human use, at which locations, and when. Fish and wildlife scientists, working with water managers, also use this information to protect fish species affected by pumping and loss of habitat. The data are also used to help determine the success or failure of efforts to restore ecosystem processes in what has been called the “most managed and highly altered” watershed in the country.

Institutions and the Economic Efficiency of Managed Aquifer Recharge as a Mitigation Strategy Against Drought Impacts on Irrigated Agriculture in California

American Geophysical Union (AGU) | May 28th, 2022

Managed aquifer recharge (or intentional recharge) is a purposeful human intervention designed to supplement natural enrichment processes of groundwater aquifers by vario

Managed aquifer recharge (or intentional recharge) is a purposeful human intervention designed to supplement natural enrichment processes of groundwater aquifers by various methods. It holds the potential to mitigate the impact of climate uncertainty on irrigated agriculture by restoring storage levels in depleted aquifers, the economic value of which increases during droughts. We use a high-resolution dynamic regional hydroeconomic framework that endogenizes farming decisions in response to water quantity-quality changes, as well as complex hydrogeological principles to analyze several institutional designs and climate scenarios applied to the Kings Groundwater Basin in California. Our analysis demonstrates that intentional recharge is of high benefit to the region, potentially increasing average groundwater levels in the region by 20% over a 20 year horizon. Additionally, we show how this practice could become the subject of second-best arrangements among water users in the region in view of property rights to groundwater derived from recent legislation in California, thus increasing its materialization potential. However, we also find that the quantity recharged is sensitive to climate conditions and hydrological properties.

Instream Flow Studies for the Protection of Public Trust Resources: A Prioritized Schedule and Estimate of Costs

California State Water Resources Control Board (SWRCB) | February 18th, 2011

Chapter 5 of the 2009-10 Seventh Extraordinary Session (SB X7 1, Simitian) directs the State Water Resources Control Board (State Water Board) to submit to the Legislatur

Chapter 5 of the 2009-10 Seventh Extraordinary Session (SB X7 1, Simitian) directs the State Water Resources Control Board (State Water Board) to submit to the Legislature, by December 31, 2010, a prioritized schedule and estimate of costs to complete instream flow studies for two categories of rivers and streams, by two specific deadlines: 1) high priority rivers and streams in the Delta watershed that were not covered in the Board’s “Final Report on Development of Flow Criteria for the Sacramento-San Joaquin Delta Ecosystem” by 2012; and 2) all major rivers and streams outside the Sacramento River watershed by 2018. The definition of the two stream categories is ambiguous. There are a number of tributaries that are both in the Delta watershed and outside the Sacramento River watershed, including the San Joaquin, Calaveras, Cosumnes, and Mokelumne Rivers. The State Water Board interprets the first category to mean all Delta and Sacramento River tributaries not covered under the Board’s “Final Report on Development of Flow Criteria for the Sacramento-San Joaquin Delta Ecosystem.” Two additional schedules are prioritized for “all major rivers and streams outside the Sacramento River watershed.” This report identifies 138 rivers and streams for instream flow studies. The total estimated cost to conduct scientific instream flow studies for the high priority rivers and streams tributary to the Delta is $32.46 million. The total estimated cost to conduct scientific instream flow studies for the high priority rivers and streams outside the Delta watershed is $107.25 million. The detailed schedules and costs are preceded with a few short discussions on the timelines given in the directive, the organization of schedules, the cost estimates for instream flow studies, and cost estimates for the next logical step: setting instream flow objectives.

Integrated Management of Delta Stressors: Institutional and Legal Options

Public Policy Institute of California (PPIC) | April 22nd, 2013

Despite some recent progress, the current institutional landscape for regulation and management of stressors in the in the Sacramento–San Joaquin Delta is highly fragme

Despite some recent progress, the current institutional landscape for regulation and management of stressors in the in the Sacramento–San Joaquin Delta is highly fragmented. A modest but powerful set of institutional changes can help produce better environmental outcomes while containing management costs—which are likely to exceed several hundred million dollars annually. This report lays out proposals for institutional reform.

Integrated simulation of consumptive use and land subsidence in the Central Valley, California, for the past and for a future subject to urbanization and climate change

U.S. Geological Survey (USGS) | October 17th, 2010

Competition for water resources is growing throughout California, particularly in the Central Valley where about 20% of all groundwater used in the United States of Ameri

Competition for water resources is growing throughout California, particularly in the Central Valley where about 20% of all groundwater used in the United States of America is consumed for agriculture and urban water supply. Continued agricultural use coupled with urban growth and potential climate change would result in continued depletion of groundwater storage and associated land subsidence throughout the Central Valley. For 1962–2003, an estimated 1230 hectametres (hm3) of water was withdrawn from fine-grained beds, resulting in more than three metres (m) of additional land subsidence locally. Linked physically-based, supply-constrained and demand-driven hydrological models were used to simulate future hydrologic conditions under the A2 climate projection scenario that assumes continued “business as usual” greenhouse gas emissions. Results indicate an increased subsidence in the second half of the twenty-first century. Potential simulated land subsidence extends into urban areas and the eastern side of the valley where future surface-water deliveries may be depleted.

Integrated Water Operations in California: Hydropower, Overdraft, and Climate Change

University of California, Davis (UC Davis) | July 16th, 2015

Several management and climate cases are evaluated with the updated CALVIN, a hydro-economic optimization model of California’s inter-tied water supply infrastructure.

Several management and climate cases are evaluated with the updated CALVIN, a hydro-economic optimization model of California’s inter-tied water supply infrastructure. Updates to the CALVIN model include new projected 2050 agricultural target demands and scarcity penalties, improvements to network-flow representation, especially agricultural, urban, and wildlife refuge demands, and extended surface and ground water hydrology, now covering an 82-year historical inflow hydrology. A new energy price scheme is applied to CALVIN, which incorporates hourly energy price variations into monthly CALVIN operations. Using one constant average price for a month underestimates hydropower revenue and overestimates pumping costs. Hourly-varying moving average prices improved representation of hydropower revenue without creating significant scarcities to agricultural and urban water users. Effects of ending long-term groundwater overdraft in the Central Valley are evaluated with several management cases using CALVIN. The cases include effects of Delta outflow and Delta exports from a “no overdraft” policy. The least cost overdraft that minimizes groundwater pumping and scarcity costs is calculated for the 82-year period. Prohibiting Delta exports result in severe water scarcities south of the Delta. Water operations are more economical when overdraft is ended with adaptations, such as more Delta exports, increased groundwater banking, and water trades, than historical operations with overdraft. Finally, climate change effects under a warmer and drier climate scenario are studied and results are compared to historical hydrology. A drier and warmer climate shifts the timing and magnitude of stream flows. Spring snowmelt decreases and winter flows increase. Modelled reduction in rim inflows averages about 28%. This warmer-drier climate increases water scarcities, but adverse effects can be diminished with water sales, higher Delta exports, more conjunctive use, and wastewater recycling. 

Intensification of hydrological drought in California by human water management

American Geophysical Union (AGU) | January 25th, 2017

Inter-population differences in salinity tolerance of adult wild Sacramento splittail: osmoregulatory and metabolic responses to salinity

Conservation Physiology (Society of Experimental Biology) | December 10th, 2020

The Sacramento splittail (Pogonichthys macrolepidotus) is composed of two genetically distinct populations endemic to the San Francisco Estuary (SFE). The allop

The Sacramento splittail (Pogonichthys macrolepidotus) is composed of two genetically distinct populations endemic to the San Francisco Estuary (SFE). The allopatric upstream spawning habitat of the Central Valley (CV) population connects with the sympatric rearing grounds via relatively low salinity waters, whereas the San Pablo (SP) population must pass through the relatively high-salinity Upper SFE to reach its allopatric downstream spawning habitat. We hypothesize that if migration through SFE salinities to SP spawning grounds is more challenging for adult CV than SP splittail, then salinity tolerance, osmoregulatory capacity, and metabolic responses to salinity will differ between populations. Osmoregulatory disturbances, assessed by measuring plasma osmolality and ions, muscle moisture and Na+-K+-ATPase activity after 168 to 336 h at 11 salinity, showed evidence for a more robust osmoregulatory capacity in adult SP relative to CV splittail. While both resting and maximum metabolic rates were elevated in SP splittail in response to increased salinity, CV splittail metabolic rates were unaffected by salinity. Further, the calculated difference between resting and maximum metabolic values, aerobic scope, did not differ significantly between populations. Therefore, improved osmoregulation came at a metabolic cost for SP splittail but was not associated with negative impacts on scope for aerobic metabolism. These results suggest that SP splittail may be physiologically adjusted to allow for migration through higher-salinity waters. The trends in interpopulation variation in osmoregulatory and metabolic responses to salinity exposures support our hypothesis of greater salinity-related challenges to adult CV than SP splittail migration and are consistent with our previous findings for juvenile splittail populations, further supporting our recommendation of population-specific management.