San Joaquin River

Agricultural Damages and Losses from ARkStorm Scenario Flooding in California

American Society of Civil Engineers (ASCE) | November 17th, 2016

Scientists designed the ARkStorm scenario to challenge the preparedness of California communities for widespread flooding with a historical precedence and increased l

Scientists designed the ARkStorm scenario to challenge the preparedness of California communities for widespread flooding with a historical precedence and increased likelihood under climate change. California is an important provider of vegetables, fruits, nuts, and other agricultural products to the nation. This study analyzes the agricultural damages and losses pertaining to annual crops, perennial crops, and livestock in California exposed to ARkStorm flooding. Statewide, flood damage is incurred on approximately 23% of annual crop acreage, 5% of perennial crop acreage, and 5% of livestock, e.g., dairy, feedlot, and poultry, acreage. The sum of field repair costs, forgone income, and product replacement costs span $3.7 and $7.1 billion (2009) for a range of inundation durations. Perennial crop loss estimates dominate, and the vulnerability of orchards and vineyards has likely increased with recent expansion. Crop reestablishment delays from levee repair and dewatering more than double annual crop losses in the delta islands, assuming the fragile system does not remain permanently flooded. The exposure of almost 200,000 dairy cows to ARkStorm flooding poses livestock evacuation challenges.

Agricultural Irrigation in This Drought: Where is the Water and Where Is It Going?

University of California Giannini Foundation of Agricultural Economics | May 14th, 2015

In the midst of its fourth year of drought, California now faces an estimated reduction in surface-water availability of 8.8 million acre-feet (maf) out of 29 maf in agri

In the midst of its fourth year of drought, California now faces an estimated reduction in surface-water availability of 8.8 million acre-feet (maf) out of 29 maf in agricultural applied water statewide. However, groundwater, the buffer water supply during drought, is replacing about 6.2 maf of surface water via additional pumping. This increased groundwater pumping is in addition to the 1.5 maf of annual average groundwater overdraft in the Central Valley. The net reduction of 2.6 maf in the total supply in 2015 may result in about 564,000 acres fallowed statewide, or about 120,000 more acres than last year's fallowing estimates.

Agricultural Land Use in California

Public Policy Institute of California (PPIC) | June 25th, 2024

Agricultural risks from changing snowmelt

Nature Portfolio (Springer Nature) | April 20th, 2020

Snowpack stores cold-season precipitation to meet warm-season water demand. Climate change threatens to disturb this balance by altering the fraction of precipita

Snowpack stores cold-season precipitation to meet warm-season water demand. Climate change threatens to disturb this balance by altering the fraction of precipitation falling as snow and the timing of snowmelt, which may have profound effects on food production in basins where irrigated agriculture relies heavily on snowmelt runoff. Here, we analyse global patterns of snowmelt and agricultural water uses to identify regions and crops that are most dependent on snowmelt water resources. We find hotspots primarily in high-mountain Asia (the Tibetan Plateau), Central Asia, western Russia, western US and the southern Andes. Using projections of sub-annual runoff under warming scenarios, we identify the basins most at risk from changing snowmelt patterns, where up to 40% of irrigation demand must be met by new alternative water supplies under a 4 °C warming scenario. Our results highlight basins and crops where adaptation of water management and agricultural systems may be especially critical in a changing climate.

Aliso Water District Groundwater Sustainability Plan

Aliso Water District Groundwater Sustainability Agency | January 17th, 2020

Aliso Water District Groundwater Sustainability Plan (Amended)

Aliso Water District Groundwater Sustainability Agency | July 7th, 2022

The January 2020 AWD GSA GSP, along with the other GSPs of the Delta-Mendota Subbasin, was deemed incomplete by DWR January 21, 2022 (Appendix H). The incomplete determin

The January 2020 AWD GSA GSP, along with the other GSPs of the Delta-Mendota Subbasin, was deemed incomplete by DWR January 21, 2022 (Appendix H). The incomplete determination provided 180 days to respond to the deficiencies identified by DWR. Subsequently, multiple consultations with DWR and meetings of the Delta-Mendota GSP groups were held to develop a coordinated response. This GSP, including the Common Chapter (Appendix B), addresses the concerns of DWR’s January 2022 Determination Letter. Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5

Alternatives for Delta Water Transfers

California Department of Water Resources (DWR) | November 1st, 1983

Aluminum- and iron-based coagulation for in-situ removal of dissolved organic carbon, disinfection byproducts, mercury and other constituents from agricultural drain water

Journal of Geochemical Exploration (Elsevier) | May 9th, 2019

Agricultural production on wetland soils can be significant sources of dissolved organic carbon (DOC), disinfection byproduct precursors, mercury and nutrients to downst

Agricultural production on wetland soils can be significant sources of dissolved organic carbon (DOC), disinfection byproduct precursors, mercury and nutrients to downstream water bodies and accelerate land subsidence. Presented as a potential solution for in-situ water quality improvement and land subsidence mitigation, chemically enhanced treatment wetlands (CETWs) were used to leverage both coagulation and wetland processes. In this study, we evaluated the performance of coagulants ferric sulfate (Fe dosing) and polyaluminum chloride (Al dosing) to remove pollutants from agricultural drain water using the coagulation system designed for CETWs. Both coagulation treatments removed over 70% DOC from source waters, resulting in removal efficiencies (mg-DOC removed per mg-metal dosed) of 1 under Al dosing and 0.5 under Fe dosing. Coagulation by both treatments preferentially removed UV254 active compounds compared to the bulk DOC concentration, suggesting coagulation targeted aromatics more effectively. Phosphates and haloacetic acids were also removed more readily, whereas trihalomethanes, dissolved organic nitrogen and filtered mercury species were removed at similar or lower rates than DOC. Dissolved inorganic nitrogen was not amenable to coagulation and removal was not observed. Freundlich, Langmuir and Monod models explained 33% of the variance in DOC removal for Al dosing and 78–89% of the variance for Fe dosing. All three models indicated Al dosing had higher removal efficiency and affinity for DOC than Fe dosing under study conditions, but when used to predict maximum removal efficiency there was no cohesiveness between the three models due to different model assumptions. Consideration of fluorescence dissolved organic matter and UV254 as surrogates for DOC concentration showed both were equally suitable before coagulant application, but as surrogates after coagulant application, neither could be deemed more fit as a surrogate since both were shown suitable for different treatment scenarios.

American shad — the Delta’s most-abundant and least-considered anadromous fish

Center for California Water Resources Policy & Management | February 21st, 2022

American shad are the Chinook salmon of herring. Like Chinook salmon, adult American shad spend several years in the ocean before returning to rivers for spawning — the

American shad are the Chinook salmon of herring. Like Chinook salmon, adult American shad spend several years in the ocean before returning to rivers for spawning — they’re anadromous. Also, like salmon, anglers love shad because they’re fun to catch and good to eat. Well, okay, shad are not as good to eat as ocean caught salmon, but they are delicious when prepared well. American shad are native to the east coast of North American. They were introduced to the Sacramento River after repeated releases of shad fry — transported via the then newly completed transcontinental railroad — between 1871 and 1880. Shad quickly became abundant in the Sacramento River and proceeded to colonize many other rivers along the West Coast. In the Columbia River system, shad are now the most abundant anadromous fish species migrating upstream through impoundments on the lower Columbia River. At Bonneville Dam — 140 river miles upstream of the Columbia River mouth — an average of 2.2 million adult shad migrated upstream each year between 1992 and 2003. In contrast, an average of 940,000 adult salmonids migrated annually past Bonneville Dam during the same period.

Amoral Water Markets?

Georgetown University | June 15th, 2023

Severe water scarcity in the western United States is prompting legitimate questions about the best way to decide which places, people, industries, and species need it mo

Severe water scarcity in the western United States is prompting legitimate questions about the best way to decide which places, people, industries, and species need it most. Water markets, which allow for trading water like a commodity, are perennial proposals during times of scarcity. Water markets have an innate allure: promising to efficiently reallocate water to the highest value uses, minimize risk, and preserve the environment, while relying on the invisible hand to brush aside politically painful values-based questions. This view portrays markets as an amoral arbiter of the best use of water. But water markets are not amoral; they express the historic value judgments baked into the existing western water law system, and layering market approaches over the existing system will both exacerbate the negative impacts of those values and further entrench existing law. In this Article, we show that the West is not ready for water markets.