America's biggest water taker gives almost all of it back — the biggest water keeper is the farm

"Largest consumer" has two answers. By withdrawals — water taken from rivers, lakes, and aquifers — thermoelectric power leads. By consumptive use — water that evaporates, transpires, or leaves in products and never returns — irrigation dominates. Eight USGS water-use categories, 2015 estimates (published 2018), 322 billion gallons per day of total U.S. withdrawals.

withdrawn, then returned to the source consumed — not returned consumption not estimated by USGS for 2015

Thermoelectric power withdraws 133 Bgal/d — 41.3% of the nation's total — but consumes only 4.31 Bgal/d, just 3% of what it takes; nearly all cooling water goes back. pubs.usgs.gov

Irrigation withdraws less (118 Bgal/d, 36.6%) but consumes 73.2 Bgal/d — 62% of its withdrawal and roughly 17 times the water thermoelectric power actually keeps. pubs.usgs.gov

The top three categories — thermoelectric, irrigation, and public supply (39 Bgal/d, 12.1%) — account for about 90% of all U.S. withdrawals. pubs.usgs.gov

The remaining five categories — industrial, aquaculture, mining, self-supplied domestic, and livestock — together stay below 10% of withdrawals, each under 5% on its own. pubs.usgs.gov

All eight categories, 2015

Category	Withdrawals (Bgal/d)	Share of all withdrawals	Consumptive use (Bgal/d)	% of withdrawal consumed	Source

Data: USGS Circular 1441, "Estimated use of water in the United States in 2015" (published 2018), the latest comprehensive nationwide category estimate. 8 rows, one per water-use category. Withdrawal is water taken from a source; consumptive use is the portion not immediately returned because it evaporates, is transpired, or is incorporated into products. Units are billion gallons per day; shares are calculated against the USGS total of 322 Bgal/d and may not sum exactly due to rounded source amounts and omitted tiny residual categories. USGS published 2015 consumptive-use estimates only for thermoelectric power and irrigation; other categories are shown without one.