Minnesotans used 1.4 trillion gallons of water in 2007. The electrical power industry used 839 billion gallons, mostly for pass-through cooling. Public waterworks used 227 billion gallons. Industries – led by mines and paper producers — used 167 billion gallons. Farmers and other users pumped 167 billion gallons for irrigation. None of the totals includes many small – less than 10,000 gallons a day or 1 million gallons a year — private wells that are not required to report their water usage to the state. — Source: Minnesota Department of Natural Resources