A federal report finds that South Dakota uses an average of 500 million gallons of water daily.
The report from the U.S. Geological Survey says 54 percent of the water comes from ground water and 46 percent from surface water.
About 58 percent of the water used annually is for irrigation.
The next highest use is 20 percent that goes to domestic, commercial and industrial users.
The report found that water use in South Dakota declined by about 175 million gallons per day from 1985 to 2005, largely because of less irrigation.