San Joaquin River

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 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

Thousands of domestic and public supply wells face failure despite groundwater sustainability reform in California’s Central Valley

Nature Portfolio (Springer Nature) | September 8th, 2023

Time Limits for Western Water Rights

Natural Resources and Environment (SSRN) | November 1st, 2022

Time-lagged impacts of extreme, multi-year drought on tidal salt marsh plant invasion

Ecological Society of America (ESA) | June 11th, 2020

Climate change is projected to increase the frequency of extreme drought events, which can have dramatic consequences for ecosystems. Extreme drought may interact with o

Climate change is projected to increase the frequency of extreme drought events, which can have dramatic consequences for ecosystems. Extreme drought may interact with other stressors such as invasion by non-native species, yet little research has explored these dynamics. Here, we examine the physical mechanisms and temporal scale underlying a dieback of an invasive non-native plant, Lepidium latifolium, in tidal salt marshes of the San Francisco Bay, California, USA, during an extreme, multi-year drought occurring from 2012 to 2015. Using generalized additive mixed models (GAMMs), we explored the relationship between eight years of estuarine salinity data and five years of L. latifolium density data from three marshes spanning a gradient of salinity across the San Francisco Bay. We found a significant time-lagged (3 yr) effect of estuarine salinity on L. latifolium density, with high salinities preceding reductions in L. latifolium densities and low salinities preceding increases. The most dramatic change in stem density, a 54% reduction in 2015, was preceded by a salinity increase of 43% from 2011 to 2012. We found the L. latifolium decline was driven by impacts on mature, rather than young, plants. Additionally, we tested the importance of local precipitation in driving L. latifolium densities in a one-season rain exclusion experiment. We found 100% exclusion of precipitation during one rainy season (January–mid-May) did not have a significant impact on densities of mature stands of L. latifolium. Our finding that estuarine salinity was a key driver of L. latifolium invasion dynamics suggests sea level rise, like extreme drought, may hinder L. latifolium invasion, as it will also raise estuarine salinities. Further, our study highlights the importance of temporal lags in understanding climate change impacts on biological invasions, which has received very little study to date.

To Stop Desert Encroachment

Scientific American | November 1st, 1938

When Spanish vaqueros first entered the interior valley of California they saw only a vast expanse of desert, broken infrequently by patches of green vegetation a

When Spanish vaqueros first entered the interior valley of California they saw only a vast expanse of desert, broken infrequently by patches of green vegetation along the water courses. Little did they dream that in a span of two generations the region would become one of the world's garden spots, the home of thousands of prosperous families, and the source of millions of tons of food products known around the world. They did not envision the romance and adventure that marked the development of this great inland empire-now a two billion dollar agricultural wonderland built by irrigation and wholly dependent upon a single natural resource-water.

Total Water Management Study for the Central Valley Basin, California, Central Valley Project Intermittent Surface Water Supply, Working Document No. 6

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