San Joaquin River

The Implications of Agricultural Water for the Central Valley

Westlands Water District | September 6th, 2017

This report is the companion report to last summer’s publication The Economic Impact of the Westlands Water District on the Local and Regional Economy. That study had m

This report is the companion report to last summer’s publication The Economic Impact of the Westlands Water District on the Local and Regional Economy. That study had many important findings, including: Westlands Water District (WWD) directly accounts for nearly 29,000 jobs and $3.6 billion of economic activity. The state’s continued failure to provide the contracted water levels has resulted in an 18 percent loss of economic output within the district; Economic pressures coupled with the prolonged shortfall in water availability have driven growers to shift to less labor-intensive crops; Westlands growers provide significant shares of the national supplies of many key fresh fruit, produce, and nuts; and Sustaining domestic production of fresh fruit, produce and nuts serve critical national priorities, including National security, environmental protection, worker protection, providing workers with reasonable wages, and using scarce water resources efficiently. In this analysis, the research focuses on the implications to the local economy and communities of the agriculture-driven jobs that Westlands and other water districts in the region foster. Among its most important findings are: Consistent and ongoing provision of the full allocation of water to WWD would result in a 19.9 percent increase in employment and more than a 17 percent increase in economic output from WWD alone. Providing none of the allocation to the growers in the WWD (through either policy choices or a long-term drought) would result in an 80 to 86 percent decrease in both employment and economic output in the district. This would represent 25,000 to 27,000 jobs and more than $3.0 billion of economic output in the local economy. In the presence of a long-term water crisis in the region, the economic impacts for Fresno and Kings Counties would be major. Agriculture directly contributes to (conservatively) one in six jobs in Fresno County and one in five jobs in Kings County. It accounts for at least one-sixth of the economic output of Fresno County and nearly one-fourth of the economy in Kings County. For solar construction to replace this level of employment in the county, more than $6.24 billion dollars a year would have to be invested in new solar projects within the county’s boundaries. Agriculture provides employment, income and opportunity to a wide range of workers in the region with extremely limited education and training. More than half of agricultural workers have less than a high school education and 95 percent have no college. Agriculture does provide a path for social mobility with opportunities to advance and earn significantly higher wages, even for these low skilled workers. Almost 90 percent of the workers who would be displaced by disruptions to the agricultural sector in the Central Valley are Hispanic. Communities that show success in attracting manufacturing have much better educated labor pools. The disappearance or significant reduction of agriculture as a major employer in the region, could have severe consequences for the local economy, including: o The loss of billions in public revenues; o Major migration from the region could turn local communities into ghost towns; o For those that remain behind, they would change from being net contributors to the local economy to recipients of public resources through the social safety net. In its final section, the study identifies four action items needed to ensure that the region experiences more of the benefits that can be reaped from a vibrant agricultural sector in the region and to avoid the major challenges that would arise if it shrank significantly. These recommendations include: Devise a statewide plan for water and water policy in California; Expand storage capacities significantly and improve the state’s ability to move water between systems and projects; Reprioritize the use of available water resources toward agriculture; and Expand the water resources available in the state through conservation, desalinization, and recycling. Agricultural production is a national security asset—especially in today’s uncertain global trade climate, it is essential to have a reliable and accessible domestic food supply. There are a limited number of places where the climate, soil and space overlap as they do in the California Central Valley to produce an ideal climate for agriculture. Not surprisingly, California’s irrigation technologies are increasingly among the best in the world. Add to that the state’s stringent environmental regulations on the use of pesticides, worker protections, and food handling regulations, and the state’s food supply is among the safest in the world. Once the land that supports this critical national asset is dedicated to other purposes, and once the industrial infrastructure that supports the processing and distribution of these crops are gone, they are almost impossible to rebuild. All it takes is enough water to make it work—a problem that humans have been solving since the first patch of crops were planted in prehistoric times. With the technologies available, we should be able to solve it today.

The Influence of Zooplankton Availability on Delta Smelt Condition and Foraging Across Habitat Contexts

Publisher not available | December 19th, 2025

Strategies for endangered species conservation may have different outcomes depending on the habitat context in which they are implemented. Understanding these context-dep

Strategies for endangered species conservation may have different outcomes depending on the habitat context in which they are implemented. Understanding these context-dependent effects can help optimize and target management efforts. In this analysis, we investigate how environmental and food-web conditions interactively affect condition and foraging of Delta Smelt (Hypomesus transpacificus), an endangered fish endemic to the San Francisco Estuary (the estuary). Food limitation, in terms of pelagic zooplankton availability, is considered a main factor that contributes to the decline in Delta Smelt abundance. Our overarching objective was to examine whether the effect of zooplankton on Delta Smelt depended on habitat context. Specifically, we hypothesized that zooplankton would less positively effect Delta Smelt condition—as measured by hepatosomatic index (HSI)—and foraging success in areas with nearby tidal wetlands, because these adjacent habitats may provide access to prey items from the epibenthos and fringing vegetation. In contrast, in regions with limited proximity to wetlands, we hypothesized that Delta Smelt would rely more on pelagic prey, which would manifest as a more positive effect of zooplankton on body condition and foraging success for Delta Smelt. Using models that accounted for habitat in multiple ways, we found little evidence that zooplankton and habitat interactively influenced Delta Smelt condition or gut fullness. Rather, the influence of zooplankton on HSI and gut fullness was generally positive across habitat contexts. Given the well-documented food limitation in the estuary, promoting the availability of pelagic zooplankton is a rational, albeit complex, management aim. Furthermore, our results suggest that efforts to increase zooplankton would broadly benefit Delta Smelt across a wide range of habitat contexts.

The Magnitude of California's Water Challenges

UnIversity of California, Davis (UC Davis) | June 4th, 2024

California will see increasing water scarcity from climate change, the end of overdrafting groundwater and the Colorado River’s massive reservoirs, increased water dedi

California will see increasing water scarcity from climate change, the end of overdrafting groundwater and the Colorado River’s massive reservoirs, increased water dedications for environmental flows, and other factors, such as salination of aquifers and land subsidence reducing canal capacities. Total reduction in average water availability in the coming decades will likely range from 4.6 to 9 million acre-feet per year. For context, this is equivalent to the water use of 1 – 2.8 million acres of irrigated agriculture or most urban water use in California. Perhaps 20-30% of this loss will likely be addressed by ongoing water conservation and supply improvements, being planned and implemented, leaving a 3 – 7.2 million acre-feet/year likely net average difference between statewide water demands and availability.

The Metropolitan Water District of Southern California Annual Report for the Fiscal Year July 1, 2018 to June 30, 2019

Metropolitan Water District of Southern California (MWD) | December 1st, 2019

The Once and Future Delta: Mending the broken heart of California

Bay Nature | April 1st, 2010

On March 30, 1772, Spanish explorer Pedro Pages was traveling east along the south shore of Suisun Bay, looking for a land route around the seemingly endless chain of b

On March 30, 1772, Spanish explorer Pedro Pages was traveling east along the south shore of Suisun Bay, looking for a land route around the seemingly endless chain of bays extending inland from the Golden Gate. Mounting to Willow Pass, the rise of land between present-day Concord and Pittsburg, he found himself staring at a new obstacle: an enormous expanse of marshland, threaded with bright channels. He had "discovered" the Sacramento-San Joaquin River Delta.

The potential of collaborative solutions to improve management of California (United States) wildlands

Restoration Ecology, Society for Ecological Restoration (SER) | November 13th, 2024

The Pulse of the Bay 2022: 50 Years after the Clean Water Act

San Francisco Estuary Institute (SFEI) | October 13th, 2022

This August an algal bloom of historic proportions blanketed San Francisco Bay. The most concerning aspect of the bloom was the death of thousands of fish across wide are

This August an algal bloom of historic proportions blanketed San Francisco Bay. The most concerning aspect of the bloom was the death of thousands of fish across wide areas of the Bay, including 10,000 yellowfin goby, hundreds of striped bass and white sturgeon, and other species like green sturgeon, bat rays, and sharks. This is the most widespread and deadliest fish kill in the Bay in recent memory.

The Rainfall Intensity-Duration Control of Debris Flows After Wildfire

American Geophysical Union (AGU) | May 23rd, 2023

The Rebirth of California Fish & Game Code Section 5937: Water for Fish

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

Swarms of living creatures will live wherever the river flows. There will be large numbers of fish, because this water flows there and makes the salt water fresh; so wh

Swarms of living creatures will live wherever the river flows. There will be large numbers of fish, because this water flows there and makes the salt water fresh; so where the river flows everything will live. Fishermen will stand along the shore; from En Gedi to En Eglaim there will be places for spreading nets. In an average year, California receives inflows and imports of water totaling around 200 million acre-feet,2 enough water to cover the entire state twenty-three inches deep. But California is a state of spatial and temporal water extremes. Spatially, precipitation varies wildly: Death Valley in the Southeast averages less than three inches per year, yet the northwestern corner of the state averages over 140 inches per year. More than 70% of California’s stream flow originates north of Sacramento, but more than 80% of the water is used south of Sacramento. Temporally, precipitation varies both seasonally and annually. California’s wet season typically runs from October or November to April or May, with little or no precipitation during the growing season, from May to September.7 Annual rainfalls of 40% or more below average and 36% or more above average each typically occur once every six to seven years.  To balance these extremes, over 1,300 dams store water across the state, supplying water for urban, industrial, and agricultural uses. While these uses sustain a tremendous part of California’s economy, they also come at high, often unappreciated costs. Fish also need water, so dams that alter water flows for human benefits may also have marked negative impacts on fish.

The Relationship between California Rainfall and ENSO Events

American Meteorological Society (AMS) | November 1st, 1989

This paper examines the annual rainfall over California during 11 ENSO events within the period 1950 to 1982. During six of these, unusually wet conditions prevailed thro

This paper examines the annual rainfall over California during 11 ENSO events within the period 1950 to 1982. During six of these, unusually wet conditions prevailed throughout California; conditions were near normal during five events; and in one extreme drought occurred statewide. A comparison with the ENSO classification scheme of Fu et al, based on SST patterns in the Pacific, shows an excellent correspondence. Type 1 years, with large positive temperature anomalies east of the date line and lasting well into winter, are invariably events that enhance California rainfall. Normal years coincide with Type 2 ENSO events (moderate warming over a broad sector); the dry year is the sole Type 3 year, with weak anomalies confined to the eastern Pacific. This study also shows that the response to ENSO is regionally specific. Although throughout the state most years with extremely wet conditions are ENSO years, the tendency for an ENSO event to increase rainfall is greatest in Southern California, where 9 of 11 events produced above-normal rainfall and 8 of the 10 wettest years was an ENSO year. The pattern is more complex in central California; there ENSO years are almost invariably ones with highly abnormal rainfall, but they may be either wet or dry. The areas least influenced by ENSO are the Sierra Nevada and Northern California. The reasons for the geographical pattern of response become apparent when the seasonality and causes of rainfall in the various regions are evaluated.