Driving through the Wyoming sagebrush west of Cheyenne, the clouds of dust rising from the road give way to giant plumes of steam shooting into the warming sky.
This is the Jim Bridger power plant, one of the largest coal-fired power sources in the nation and an enormous emitter of carbon dioxide pollution. At the plant's edge there's a reservoir, lined with rocks and clumps of drying grass. The plant sucks up about 16 million gallons of water each day, using it to power more than million homes across six western states, all the way to Oregon.
But there's a problem that looms for the coal plant operator and the customers that rely on it for electricity. This water is piped here from the Green River, a tributary of the rapidly shrinking Colorado River. Now, amidst a decades-long drought and a shortage of water downstream across the Southwest, future conservation in the basin could mean industrial users like Jim Bridger see their water shut off, says Wyoming State Engineer Brandon Gebhart.
"They would be likely the first one shut off. Unless they were able to find a different source of water, we would have to just shut off their water and not allow them to divert," Gebhart says.
The western U.S. hasn't been this dry for more than 1,200 years, but 30 western coal plants continue to suck up 156 million gallons a day of the region's scarce water, according to the Energy Information Administration. Now the very plants whose emissions help drive climate change are at risk of shutdowns, because the water they need to operate has fallen to unprecedented levels.
Some utilities are already sending warnings, telling federal regulators that the drought could threaten coal plant operations. But there's uncertainty at the state level over which officials are responsible for managing drought risk to power plants and the threat of brownouts and blackouts.
Old coal plants like Jim Bridger have for decades been critical to the grid, says David Eskelsen, spokesman for Rocky Mountain Power, a division of PacifiCorp, which operates the Wyoming plant. "With all the concerns about the use of fossil fuels, climate change, and the use of water in this way," Eskelsen says, "that has to be balanced against the role that these particular power plants play in the stability of the regional transmission system."
But rising water scarcity in the West means the stability of coal plants like Jim Bridger is no longer a sure thing, says Joe Smyth, research manager at the Energy and Policy Institute, a utility watchdog group.
"If you don't have water to cool it, you can't run it, right? Like it's not a minor risk. It is a very disruptive event," he says, "If you're not aware of those risks, then you are not really operating your power plants responsibly."