Water Quality Conditions in the Sacramento-San Joaquin Delta during 1995

California Department of Water Resources (DWR) | August 1st, 1999

Water year 1995 was a wet year, ending an eight-year period of predominantly dry and critically dry years.  After a relatively dry fall, January and March precipitation

Water year 1995 was a wet year, ending an eight-year period of predominantly dry and critically dry years.  After a relatively dry fall, January and March precipitation was heavy and produced flooding in the Central Valley.  By May 1, precipitation was 165% of average, snowpack water content was 215% af average, seasonal runoff was 170% of average, and reservoir storage was 110% of average. In 1995, the Net Delta Outflow Index (NDOI) was used to estimate Delta outflow, and the Sacramento and San Joaquin River Unimpaired Runoff indices were used to determine water year type for 1995.  Using these indices, water year 1995 was officially classified as wet on May 1, 1995.  All standards, including those in Water Right Decision 1485, as amended by the 1995 Water Quality Control Plan, were met in 1995. The entire 1995 calendar year was characterized by excess conditions, and both State Water Project and Central Valley Project water requirements were met as well as in-Delta consumptive uses.  Delta outflows were high throughout the year, and the calculated average monthly flows exceeded 80,000 cubic feet per second (CFS) during the peak outflow period (January through May), and 3,000 cfs during the minimum outflow period (July through November).

Water Reliability in the West - 2021 SECURE Water Act Report

U.S. Bureau of Reclamation (USBR) | January 4th, 2021

The Bureau of Reclamation (Reclamation) is the largest wholesaler of water in the country. Reclamation delivers water for municipal, agricultural, tribal, and environment

The Bureau of Reclamation (Reclamation) is the largest wholesaler of water in the country. Reclamation delivers water for municipal, agricultural, tribal, and environmental water uses, including providing one out of five farmers in the Western United States (West) with irrigation water for 10 million acres of farmland that produce 60 percent of the Nation’s vegetables and 25 percent of its fruits and nuts. The Omnibus Public Land Management Act of 2009 (Public Law 111-11), Subtitle F of Title IX of the Act (Science and Engineering to Comprehensively Understand and Responsibly Enhance [SECURE] Water Act) recognizes that changes to temperature, precipitation (rainfall and snowfall), and the timing and quantity of snowpack and runoff pose a significant challenge to the protection and use of water resources. Every 5 years, Reclamation submits a report to Congress under the SECURE Water Act that analyzes projected risks to water supplies in the West using the best available science and highlights collaborative efforts to mitigate those risks. This Water Reliability in the West - 2021 SECURE Water Act Report (2021 Report) provides a West-wide assessment of expected changes to water supplies, uses, and demands; highlights progress; and describes actions taken to increase water supply reliability since the 2016 SECURE Water Act Report. Reclamation has a broad range of programs and projects that help increase the reliability of water and power deliveries. Our activities include science and research, planning, infrastructure sustainability, efficient hydropower production, and on-the-ground actions to increase reliable water supplies to meet water demands. These activities are undertaken in collaboration with our customers, stakeholders, and partners. In the West, competing demands for water for farms, cities, Tribes, the environment, recreation, hydropower, and other uses can lead to conflict. Conflict escalates particularly during droughts, which are expected to be more frequent and severe with climate change. Fostering strong relationships is essential to carry out Reclamation’s everyday operations, conduct long-term planning efforts, and avoid unnecessary conflicts. Reclamation operators and planners rely on information about precipitation, snowpack, streamflow, temperatures, water demands, and groundwater to make informed decisions. Reclamation’s 2021 West-Wide Climate and Hydrology Assessment (2021 Assessment) builds on our 2011 and 2016 West-wide assessments of future temperature and precipitation change by using several complementary approaches, including analyses based in paleohydrology derived from tree rings (dendochronology) that help answer this question: “If droughts in the distant past were to occur today, how would water systems perform?” With our Federal, State, Tribal, and local partners, we address challenges resulting from climate change and shifting demographics. We use a multi-faceted approach to support reliable water and hydropower deliveries; to help maintain healthy ecosystems; to protect federally-listed fish, wildlife, and plants, as well as designated critical habitat; and to manage risks (e.g., droughts, floods, and fires). Implementing the SECURE Water Act has served as a catalyst for collaboration and innovation, improving our understanding of climate change impacts to water resources and our ability to address those impacts.

Water Resource Modeling of the Colorado River: Present and Future Strategies

Utah State University | August 21st, 2019

The CRSS is imprecisely configured to address water supply and environmental management issues within many large tributaries of the headwater branches, including the Colo

The CRSS is imprecisely configured to address water supply and environmental management issues within many large tributaries of the headwater branches, including the Colorado River upstream from Glenwood Springs, the Yampa River upstream from Maybell, the Little Snake River upstream from Lily, the Dolores River, the Duchesne River watershed, the White River upstream from Watson, the Animas River, the Little Colorado River watershed, the Virgin River watershed, and other tributaries in the Lower Basin. Today, river management programs, endangered fish recovery programs, and some Native American tribes are focusing on these tributaries. It is important for stakeholders to understand that the CRSS is most appropriate for addressing basin-wide issues but is not designed to address issues within these tributaries. Expanding the spatial resolution of the CRSS to do so will require significant effort.

Water Right Decision 1485: Sacramento-San Joaquin Delta and Suisun Marsh

California State Water Resources Control Board (SWRCB) | August 16th, 1978

Water storage decisions will determine the distribution and persistence of imperiled river fishes

Ecological Society of America (Wiley) | December 17th, 2020

Managing the world’s freshwater supply to meet societal and environmental needs in a changing climate is one of the biggest challenges for the 21st century. Dams provid

Managing the world’s freshwater supply to meet societal and environmental needs in a changing climate is one of the biggest challenges for the 21st century. Dams provide water security; however, the allocation of dwindling water supply among reservoirs could exacerbate or ameliorate the effects of climate change on aquatic communities. Here, we show that the relative sensitivity of river thermal regimes to direct impacts of climate change and societal decisions concerning water storage vary substantially throughout a river basin. In the absence of interspecific interactions, future Colorado River temperatures would appear to benefit both endemic and nonnative fish species. However, endemic species are already declining or extirpated in locations where their ranges overlap with warmwater nonnatives and changes in water storage may lead to warming in some of the coolest portions of the river basin, facilitating further nonnative expansion. Integrating environmental considerations into ongoing water storage negotiations may lead to better resource outcomes than mitigating nonnative species impacts after the fact.

Water Surplus and Drought Management Update - Conditions as of 11/29/2022

Metropolitan Water District of Southern California (MWD) | December 13th, 2022

Water Temperature Modeling Platform Mid-Term Review

Delta Stewardship Council (Delta Council) | October 21st, 2021

Water Wasted to the Sea?

University of California, Davis (UC Davis) | July 15th, 2017

West False River Drought Salinity Barrier Final EIR

California Department of Water Resources (DWR) | November 8th, 2024

With the proposed project, a temporary drought salinity barrier would be installed in West False River up to two times over 10 years, with each installation remaining in

With the proposed project, a temporary drought salinity barrier would be installed in West False River up to two times over 10 years, with each installation remaining in place for up to 20 months over two consecutive calendar years. The barrier would be installed if a drought were to occur during the 2026–2035 period and the drought conditions indicate that a barrier in West False River would be an effective tool to preserve upstream reservoir storage for health, safety, and regulatory releases, while preventing saltwater intrusion into the central and southern portions of the Sacramento–San Joaquin Delta (Delta). The drought salinity barrier would be constructed only if DWR, in cooperation with other State and federal agencies, determines that drought conditions have reduced water storage in Northern California reservoirs to critical levels, such that projected Delta outflow would be insufficient to control increased salinity intrusion into the Delta. 

Western and Traditional Ecological Knowledge in ecocultural restoration

University of California, Davis (UC Davis) | October 1st, 2018

 The Delta Plan (DSC 2013) calls for “protecting and enhancing the unique cultural values” of California’s Sacramento–San Joaquin Delta, a 2,800-km2 (1,100 mi2)

 The Delta Plan (DSC 2013) calls for “protecting and enhancing the unique cultural values” of California’s Sacramento–San Joaquin Delta, a 2,800-km2 (1,100 mi2) region that was occupied by indigenous peoples for ~5,000 years. The legacies of Native Californians need to be included in the Delta Plan, especially Traditional Ecological Knowledge (TEK) of ways to gather, hunt, and fish for food; build shelters; prepare medicines; and perform ceremonies — along with ways to make tools, clothing, baskets, and shelters. Plants were not just collected but also tended, which involved planned burning, digging, planting, weeding, harvesting, and seed dispersal. Populations of plants that have cultural significance and unique values should be enhanced under the Delta Plan. While Western Ecological Knowledge (WEK) offers a strong foundation for restoration of species assemblages and ecosystems, TEK adds culturally-significant species to restoration targets and traditional management practices to achieve ecological resilience. We compare 11 attributes of WEK and TEK that aid ecological restoration; all are complementary or shared by these two ways of knowing. Both WEK and TEK emphasize adaptive approaches for managing natural resources, as mandated in the Delta Plan. We suggest that WEK–TEK restoration sites throughout the Delta can be linked (virtually) to honor cultural integrity and nurture a “Sense of Place” for Native Californians and others. At the same time, such a network could foster ways to achieve sustainability through the TEK ethic of reciprocity, which WEK lacks. A network of WEK–TEK sites could enhance unique cultural values while supporting passive recreation and attracting ecotourists.