According to Reible, who heads UT’s Center for Research in Water Resources, 41 percent of the state’s water withdrawals are for power plants. Utilities return much of the water they withdraw; still, they use plenty of it to cool down their plants.

That turns into a real challenge during times of severe drought. Electric companies get 77 percent of their water from lakes, rivers and other forms of surface water.

Of course, lakes and river flows are often the first to get hammered in a drought. Evaporation can kill them, as North Texans witnessed in spectacular fashion when Lavon Lake started drying up in 2011.