The factory farming system relies on immense amounts of feed crops that are processed and delivered to confined animals. That system has claimed about half of the nation’s agricultural resources, including cropland and water. About 80% of the water consumption in the U.S. is attributable to agriculture, mostly for irrigation. And, broadly estimated, about half of agriculture’s usage is due to animal ag.[1]
See the following questions for references, and Water Usage by Feed Crops.
Of the 8 water use categories tracked by the U.S. Geological Survey (USGS), agriculture withdraws more freshwater than any other, accounting for ~42% of all freshwater withdrawals. Almost all of agriculture’s withdrawals are for irrigation.[1]
Dieter, C.A. et al., (2018) Estimated Use of Water in the United States in 2015, U.S. Geological Survey, Table 2A, p. 10. [Although the USGS tracks saline water usage, mostly in the service of thermonuclear plants, saline amounts are not included (only freshwater). Agriculture includes Irrigation (118 billion gallons per day – Bgal/day), Livestock & poultry (2 billion), and Aquaculture (7.55 billion). All other uses include Public supply (39 billion), Domestic use (3.26 billion), Industrial (14 billion), and Mining (1.88)]
Water withdrawal refers to the amounts of water removed from surface or groundwater sources.[1,2]
Water consumption refers to the amounts of water withdrawn that are “evaporated, transpired, incorporated into products or crops, consumed by humans or livestock, or otherwise removed from the immediate water environment.”[3,4]
Dieter, C.A. et al., (2018) Estimated Use of Water in the United States in 2015, U.S. Geological Survey, p. 61.
Paul Reig (2013) What’s the Difference Between Water Use and Water Consumption? World Resources Institute. https://www.wri.org/insights/whats-difference-between-water-use-and-water-consumption#
Dieter, C.A. et al., (2018), p. 59.
Water Footprint Calculator (2022) Water Use, Withdrawal and Consumption. https://www.watercalculator.org/footprint/water-use-withdrawal-consumption/
Water that is withdrawn may or may not be consumed. If it is consumed, it is not returned to its original source and is not available for reuse.[1]
Thermoelectric power plants and agricultural irrigation consistently withdraw the largest amounts of freshwater, but they use it in different ways. Thermoelectric plants withdraw water for cooling purposes, yet most of the heated water is released back into the environment and not consumed.
Agricultural irrigation, on the other hand, consumes most of the water it withdraws.[2] Water that is consumed and thus permanently lost, affects the available amount of the water supply.
Water Footprint Calculator (2022) Water Use, Withdrawal and Consumption. https://www.watercalculator.org/footprint/water-use-withdrawal-consumption/
Dieter, C.A. et al., (2018) Estimated Use of Water in the United States in 2015, U.S. Geological Survey, Table 7, p. 27. [Consumption of 73.2 billion gallons per day (Bgal/d) /118 Bgal/d withdrawal = 62%. Note that water used for thermonuclear power, though not consumed, can be very damaging to fish due to excess heat added to their ecosystems.]
Agriculture consumes far more freshwater than any other water use category. And consumption – not withdrawal – is the critical factor in understanding allocations of water resources. About 80% of total U.S. consumptive water use is allocated to agriculture.[1-4]
Moreover, about half of the withdrawals for irrigation are from groundwater (as opposed to surface water).[5] Groundwater is not easily replenishable and is being depleted at rates that are unsustainable.[6,7] Surface waters, including streams, rivers, and lakes, can also be depleted by irrigation.
Glenn Schaible & Marcel Aillery (2012) Water Conservation in Irrigated Agriculture: Trends and Challenges in the Face of Emerging Demands, USDA Economic Research Service, EIB 99, Abstract [“U.S. agriculture accounts for 80-90 percent of the Nation’s consumptive water use (water lost to the environment by evaporation, crop transpiration, or incorporation into products).”]
Rehkamp, S., & Canning, P. (2018). Measuring embodied blue water in American diets: an EIO supply chain approach. Ecological Economics, 147, 179-188, p. 179. [“…about 80% of the consumptive water use in the United States can be attributed to agriculture.”]
Konar, M., & Marston, L. (2020). The Water Footprint of the United States. Water (Basel), 12(11), 3286. [“Between 74–93% … of all blue water consumed in the US is for irrigated agriculture and livestock production.” at p. 3. “Blue water is water from a source, such as a reservoir, river, lake, or aquifer.” at p. 2.]
Richter, B. D., et al., (2020). Water scarcity and fish imperilment driven by beef production. Nature Sustainability, 3(4), 319–328, Table 1, p. 321. [Crop irrigation = 75% + Livestock Watering = 2%.]
Dieter, C.A. et al., (2018) Estimated Use of Water in the United States in 2015, U.S. Geological Survey Table 4A, p. 16. [Total groundwater withdrawals for irrigation = 57.2 billion gallons per day (Bgal/d) / 118 (Bgal/d) total agricultural use]
Lopez, J. R., et al., (2022). Sustainable use of groundwater may dramatically reduce irrigated production of maize, soybean, and wheat. Earth’s Future, 10(1), e2021EF002018.
Rojanasakul, Mira, et al., (August 28, 2023) America Is Using Up Its Groundwater Like There’s No Tomorrow. New York Times. https://www.nytimes.com/interactive/2023/08/28/climate/groundwater-drying-climate-change.html
The largest irrigated crops by acreage – corn, soybeans, alfalfa/hay, and pasture/rangeland – are primarily used as feed crops for factory farmed animals. They account for ~61% of all irrigated crops.[1]
USDA NASS (2024) Census of Agriculture, 2023 Irrigation and Water Management Survey, Vol 3, AC-22-SS-1, Table 38. [Note that “If two or more crops were harvested from the same land during the year (double cropping), the acres were counted for each crop. Therefore, the total acres of all crops harvested could exceed the acres of cropland harvested.” Appendix B definition “Acres and quantity harvested.”] [Corn includes corn for grain + corn silage; Alfalfa/Hay includes alfalfa haylage and other hay & haylage. For calculations, see, https://docs.google.com/spreadsheets/d/1D3nnEa6Uj_xFPCop10hfaLVRuhEPkEcoyWvpOmiBWSI/edit?gid=0#gid=0]
Factory farms withdraw large amounts of freshwater – for drinking water, manure management, cleaning, etc. Although livestock water usage on farms is less than 1% of all freshwater withdrawals, it is large enough to be one of the eight water use categories tracked by the USGS.[1]
Aquaculture (fish farming) is a significant user of freshwater, withdrawing almost 4 times as much as livestock.[2]
Slaughter and processing plants are also large users of freshwater relative to the total usage of their local communities. These plants generate wastewater with high levels of contaminants.[3]
Dieter, C.A. et al., (2018) Estimated Use of Water in the United States in 2015, U.S. Geological Survey, Table 8, p. 32. [The USGS defines [The USGS defines livestock to include dairy cows, beef cattle, sheep and lambs, goats, hogs, horses, and poultry.]
Dieter, C.A. et al., (2018), Table 9, p. 34.
USDA FSIS (2022) Use of Water in Animal Production, Slaughter, and Processing, Journal of Food Protection, Vol. 85, No. 12, 1756–1778 (Adopted 2021, Washington DC, National Advisory Committee on Microbiological Criteria for Foods), p. 1764. [“Water used in establishments processing animal protein contains high amounts of organic matter, pathogenic and nonpathogenic microorganisms, and residual chemicals from cleaning and sanitizing activities.”]
Most federal agencies and many researchers view all crops as being of equal value; they are treated as the essential products of American farmers “feeding the world.” Rarely acknowledged is the fact that our top 3 crops are almost entirely used for either animal feed (here and in relatively wealthy foreign countries), biofuels, corn fructose, or cheap cooking oil. That we choose to grow these crops in water-stressed areas is often viewed as an unfortunate necessity.
Factory farming’s contribution to the steady depletion of a critical common resource is another under-explored negative externality of this industry.