Water use in the United States is categorized based on how water is handled. Water is withdrawn when it is taken from a source, such as a river or aquifer. Water is consumed when it is evaporated, incorporated into a product, or otherwise removed from the local water cycle and not immediately returned. The three largest categories of water use in the U.S. are thermoelectric power generation, agricultural irrigation, and public supply. These categories account for the vast majority of freshwater utilized daily across the nation.
The Dominant Water Use: Thermoelectric Power
Thermoelectric power generation (including facilities powered by coal, natural gas, and nuclear energy) is the largest single user of water withdrawal in the United States. This sector accounts for approximately 40 to 50% of the total freshwater withdrawn nationwide. This immense volume of water is primarily used for cooling purposes to condense the steam that drives the turbines.
The vast majority of this withdrawn water is non-consumptive, meaning it is returned to the original source, such as a river or lake, after circulating through the cooling system. This process is especially true for older power plants that utilize “once-through” cooling technology. This high-withdrawal use is concentrated predominantly in the eastern half of the country, particularly the Southeast, Northeast, and Midwest regions. While the water is returned, it is often done at a warmer temperature, which can still impact the local aquatic ecosystem.
The Highest Consumptive Use: Agricultural Irrigation
Agricultural irrigation represents the highest consumptive use of freshwater in the nation, accounting for approximately 80% of the country’s total consumption. Consumption is high because the water applied to fields is not returned to the source but is lost to the local watershed through evapotranspiration.
Irrigation is also a highly withdrawal-intensive activity, accounting for roughly 47% of total freshwater withdrawals between 2010 and 2020. This practice is concentrated in the arid and semi-arid Western U.S., including the High Plains region. Although only a fraction of the nation’s cropland is irrigated, this land is responsible for a large percentage of the total value of U.S. crop sales.
The necessity of irrigation allows for the production of high-yield crops in regions otherwise unsuitable for agriculture. This practice sustains the domestic food supply and a significant portion of the agricultural export economy. Consequently, this high rate of water consumption places considerable stress on water sources, particularly where irrigation is most prevalent.
Water for Everyday Life: Public and Domestic Supply
The public supply category provides water to households, businesses, and institutions for domestic, commercial, and industrial uses. This is the most visible form of water use for the average citizen, delivered directly to their homes for daily activities. Quantitatively, however, the public supply is significantly smaller than the withdrawals for thermoelectric power or the consumption by irrigation.
The average person uses between 80 and 100 gallons of water per day for indoor household activities. The largest indoor uses include toilet flushing, showering and bathing, and laundry. Outdoor uses, such as landscape watering, can substantially increase this total, especially in warmer climates.
Sources and Regional Stress
Water used across all sectors is drawn from two primary sources: surface water (rivers, lakes, reservoirs) and groundwater (aquifers). Historically, surface water has been the larger source, accounting for about 74% of freshwater withdrawals, with groundwater making up the remaining 26%. The dependence on each source varies greatly by region and the specific water-use sector.
The long-term sustainability of water use is threatened by regional water stress, where consumption patterns exceed natural replenishment. A prominent example is the High Plains Aquifer, which supports nearly a third of the nation’s irrigated cropland. Extensive pumping, primarily for irrigation, has caused water levels to drop significantly, with declines exceeding 150 feet in parts of Texas and Kansas.
In many areas of the High Plains, the rate of water extraction substantially surpasses the aquifer’s natural recharge rate, leading to net depletion. This over-extraction highlights the challenge of balancing high consumptive demand, such as agriculture, with the finite availability of water sources.