The Water Districts of California

Association of California Water Agencies (ACWA) | April 1st, 1979

The Water Footprint of California’s Energy System, 1990–2012

Pacific Institute | February 1st, 2015

A new article by Julian Fulton and  Heather Cooley  evaluates the amount of water consumed in meeting California’s energy needs – also referred to as the water foot

A new article by Julian Fulton and  Heather Cooley  evaluates the amount of water consumed in meeting California’s energy needs – also referred to as the water footprint of energy. The article, published in Environmental Science and Technology, examines how the water footprint of energy changed between 1990 and 2012 – finding that the amount of water consumed substantially increased over recent decades without utilizing more of the state’s water resources, but rather by relying more heavily on water resources from outside the state. Much of that increase is attributable to the production of bioethanol, which recent energy policies have promoted to meet state greenhouse gas targets. Fulton and Cooley demonstrate that while efforts to mitigate climate change in California have been successful in reducing greenhouse gases, these policies may have shifted burdens from energy to water, rather than alleviate them. They conclude that more integrated analysis and planning of water and energy systems are needed to ensure that climate adaptation and mitigation strategies do not work at cross purposes. Abstract: California’s energy and water systems are interconnected and have evolved in recent decades in response to changing conditions and policy goals. For this analysis, we use a water footprint methodology to examine water requirements of energy products consumed in California between 1990 and 2012. We combine energy production, trade, and consumption data with estimates of the blue and green water footprints of energy products. We find that while California’s total annual energy consumption increased by just 2.6% during the analysis period, the amount of water required to produce that energy grew by 260%. Nearly all of the increase in California’s energy-related water footprint was associated with water use in locations outside of California, where energy products that the state consumes were, and continue to be, produced. We discuss these trends and the implications for California’s future energy system as it relates to climate change and expected water management challenges inside and outside the state. Our analysis shows that while California’s energy policies have supported climate mitigation efforts, they have increased vulnerability to climate impacts, especially greater hydrologic uncertainty. More integrated analysis and planning are needed to ensure that climate adaptation and mitigation strategies do not work at cross purposes.

The water footprint of water conservation using shade balls in California

Nature Portfolio (Springer Nature) | July 16th, 2018

The interest in quick technologic fixes to complex water problems increases during extreme hydroclimatic events. However, past evidence shows that such fixes might be ass

The interest in quick technologic fixes to complex water problems increases during extreme hydroclimatic events. However, past evidence shows that such fixes might be associated with unintended consequences. We revisit the idea of using shade balls in the Los Angeles reservoir to reduce evaporation during the recent drought in California, and question its sustainability by revealing the water footprint of this technologic water conservation solution.

The Water Quality Control Plan (Basin Plan) for the Sacramento River and San Joaquin River Basins Fifth Edition

Central Valley Regional Water Quality Control Board (CVRWQCB) | May 31st, 2018

The preparation and adoption of water quality control plans (Basin Plans) is required by the California Water Code (Section 13240) and supported by the Federal Clean Wat

The preparation and adoption of water quality control plans (Basin Plans) is required by the California Water Code (Section 13240) and supported by the Federal Clean Water Act. Section 303 of the Clean Water Act requires states to adopt water quality standards which "consist of the designated uses of the navigable waters involved and the water quality criteria for such waters based upon such uses." According to Section 13050 of the California Water Code, Basin Plans consist of a designation or establishment for the waters within a specified area of beneficial uses to be protected, water quality objectives to protect those uses, and a program of implementation needed for achieving the objectives. State law also requires that Basin Plans conform to the policies set forth in the Water Code beginning with Section 13000 and any state policy for water quality control. Since beneficial uses, together with their corresponding water quality objectives, can be defined per federal regulations as water quality standards, the Basin Plans are regulatory references for meeting the state and federal requirements for water quality control (40 CFR 131.20). One significant difference between the state and federal programs is that California's basin plans establish standards for ground waters in addition to surface waters. Basin Plans are adopted and amended by Regional Water Boards under a structured process involving full public participation and state environmental review. Basin Plans and amendments thereto, do not become effective until approved by the State Water Resources Control Board (State Water Board). Regulatory provisions must be approved by the Office of Administrative Law. Adoption or revision of surface water standards are subject to the approval of the U.S. Environmental Protection Agency. Basin Plans complement water quality control plans adopted by the State Water Board, such as the Water Quality Control Plans for Temperature Control and Ocean Waters. It is the intent of the State and Regional Water Boards to maintain the Basin Plans in an updated and readily available edition that reflects the current water quality control program. This Basin Plan covers the entire Sacramento and San Joaquin River Basins. A separate Basin Plan covers the Tulare Lake Basin. The Basin Plan was first adopted in 1975. In 1989, a second edition was published. The second edition incorporated all the amendments which were adopted and approved since 1975, updated the Basin Plan to include new state policies and programs, restructured and edited the Basin Plan for clarity, and incorporated the results of triennial reviews conducted in 1984 and 1987. The Third Edition - 1994 incorporated all amendments approved between 1989 and 1994, included new state policies and programs, edited and restructured the Basin Plan to make it consistent with other regional and state plans, and substantively amended sections dealing with beneficial uses, objectives, and implementation programs. The current edition (Fourth Edition - 1998) incorporates two new amendments approved since 1994. One amendment deals with compliance schedules in permits and the other addresses agricultural subsurface drainage discharges. In this Basin Plan, "Regional Water Board" refers to the Central Valley Regional Water Quality Control Board and "State Water Board" refers to the State Water Resources Control Board. Appendix Updates and amendments  are at the State Water Board "Basin Plan" page

The Water Rights Process

California State Water Resources Control Board (SWRCB) | June 1st, 2002

A water right is a legal entitlement authorizing water to be diverted from a specified source and put to beneficial, nonwasteful use. Water rights are property rights, bu

A water right is a legal entitlement authorizing water to be diverted from a specified source and put to beneficial, nonwasteful use. Water rights are property rights, but their holders do not own the water itself – they possess the right to use it. Some water rights require a permit or license from the State Water Resources Control Board, whose objective is to ensure that the state’s waters are put to the best possible use and that the public interest is served. In making decisions, the Board must keep three goals in mind: • Developing water resources in an orderly manner. • Preventing waste and unreasonable use of water. • Protecting the environment. The State Board’s duties are not limited to permits and licenses. It may be called upon to adjudicate water for entire systems or to act as a “referee” or fact-finder in court cases involving water rights.

The Well Fixer's Warning

The Atlantic | August 17th, 2021

The well fixer and I were standing at the edge of an almond orchard in the exhausted middle of California. It was late July, and so many wells on the farms of Madera Co

The well fixer and I were standing at the edge of an almond orchard in the exhausted middle of California. It was late July, and so many wells on the farms of Madera County were coming up dry that he was running out of parts to fix them. In this latest round of western drought, desperate voices were calling him at six in the morning and again at midnight. They were puzzled why their pumps were coughing up sand, the water’s flow to their orchards now a trickle.

The West Wide Drought Tracker: Drought Monitoring at Fine Spatial Scales

American Meteorological Society (AMS) | September 1st, 2017

 The western United States has seen increases in population and water use over the past century. Total water use has remained relatively unchanged over the past several

 The western United States has seen increases in population and water use over the past century. Total water use has remained relatively unchanged over the past several decades due to water conservation efforts. However, water scarcity has become more acute across much of this semiarid region during recent decades due to long-term declines in water storage juxtaposed with the region’s notable hydroclimatic variability. Observed declines in mountain snowpack and increases in atmospheric demands tied to long-term warming trends have further exacerbated water scarcity and increased the importance of monitoring efforts given the array of social, economic, and ecosystem sectors dependent upon the already stressed water supply. The recent severe drought in California and protracted drought across much of the southwestern United States over the past couple decades have prompted demand for accessible drought decision-making information at appropriate spatial scales across the western United States. 

Thermal performance in juvenile hatchery Oncorhynchus tshawytscha: aerobic scope tests over a range of environmental temperatures

U.S. Environmental Protection Agency (EPA) | March 15th, 2016

In heavily-altered ecosystems, anthropogenic factors coupled with global climate change have drastically changed available habitats for many native fishes (Cloe

In heavily-altered ecosystems, anthropogenic factors coupled with global climate change have drastically changed available habitats for many native fishes (Cloern and Jassby 2012, Moyle et al. 2013). Water projects such as large hydropower dams have altered flow and temperature regimes (Poff et al. 1997, Bunn and Arthington 2002, Marchetti and Moyle 2001), and reduced or degraded native spawning and rearing habitats (Sheer and Steel 2006, Pelicice and Agostinho 2008), while global climate change has resulted in warmer overall river temperatures (Cloern and Jassby, 2012). As ecologically relevant environmental variables like temperature have shifted, fish populations have subsequently declined (Cloern and Jassby, 2012; Hanak et al., 2015). Native California fishes have been disproportionately affected by these changes, and precipitous population declines have been observed for several species, some of which are listed under the Endangered Species Act (ESA) (Moyle et al. 2013). Despite documented correlations between fish declines and changes in environmental variables such as temperatur e (Moyle and Leidy, 1992; Moyle et al. 2010; Quiñones and Moyle 2014), there has been a profound lack of data available on the actual physiological and/or behavioral mechanisms driving fish population declines. Physiological performance data, such as information on aerobic scope, may help provide mechanistic explanations for both how and why fish population declines are occurring. Furthermore, as populations decline and management becomes more crucial for population persistence, thermal limits, optimal thermal ranges, and data on how key physiological processes, such as metabolic rate, change in response to environmental variables becomes more important. Therefore, the objectives of our study were to quantify the aerobic scope of juvenile Chinook salmon ( Oncorhynchus tshawytscha) acclimated to two different rearing temperatures (14 or 20 °C) and tested over a temperature range of 12-26°C.

Third Supplement To State Water Resources Board Bulletin No. 11, San Joaquin County Investigation, Basic Data, Calaveras Unit 1956-57

California Department of Water Resources (DWR) | January 21st, 1958

Thirstwaves: Prolonged Periods of Agricultural Exposure to Extreme Atmospheric Evaporative Demand for Water

American Geophysical Union (AGU) | March 20th, 2025

Global atmospheric evaporative demand has increased, impacting agricultural productivity and water use. Traditionally, trend assessments have been limited to total evapor

Global atmospheric evaporative demand has increased, impacting agricultural productivity and water use. Traditionally, trend assessments have been limited to total evaporative demand, overlooking shifts in daily extremes, which are meaningful for agrohydrological outcomes yet largely unknown. Here, using a fully physical metric of evaporative demand, that is, standardized short crop reference evapotranspiration, we introduce the concept of thirstwaves—prolonged periods of extremely high evaporative demand—and analyze their characteristics during 1981–2021 growing seasons for the conterminous US. Findings show that long-term mean spatial patterns demonstrated by thirstwave characteristics do not follow that of total or mean evaporative demand. Weighted for cropland area harvested, thirstwave intensity, duration, and frequency have increased by 0.06 mm d−1 decade−1, 0.10 days decade−1, and 0.39 events decade−1, respectively during 1981–2021. Statistically significant trends appear across 17%, 7%, and 23% of cropland area for intensity, frequency, and duration. Not only have thirstwaves increased in severity, but the likelihood of no thirstwaves occurring during the growing season has significantly decreased. Our work proposes a novel metric to describe periods of extremely elevated evaporative demand and presents a systematic analysis of such conditions historically for US croplands.