Making electricity takes massive amounts of water.
"About one to three trillion gallons of water per year in the Catawba river alone" which is many times what people in the region use for drinking, bathing and watering lawns, says Peter Frumhoff, with the Union of Concerned Scientists.
The Union of Concerned Scientists has released a new report about power plants and the nation's water supply.
Power plant-related stress on the Catawba River is primarily linked to water temperature. Duke Energy draws on the river to power steam turbines and cool off systems at several coal and nuclear plants. Nearly all of the cooling water goes back into the river, but it's warmer by then. That stresses the river's wildlife, says David Merryman of the Catawba Riverkeeper.
"In Lake Wylie, we're seeing mussels die nearly every year near the hot-hole of Allen Steam Station," says Merryman. "In Lake Norman, we're experiencing annual deaths of our striped bass that we pay to stock in that lake because of the impacts of McGuire Nuclear Station."
Speaking on Charlotte Talks Tuesday morning, Duke Energy energy and environmental policy director Eric Myers would only say that water going back into river is "less than 10 degrees" hotter than when it came out.
The Union of Concerned Scientists is calling for power companies to adopt less water-intensive technologies for cooling their plants. But Duke's Myers says those technologies need more fuel, so the power plants become less efficient.
"The emissions associated with producing electricity could go up as we try to manage the water stress issues - and this report points that trade out," says Myers. "It's a delicate balance and it's something that we want all of our stakeholders to be engaged in so we make those choices together."
Duke Energy leads a large group of stake holders working to extend the life of the Catawba River. By 2048, the group projects the river won't be able to meet the region's water demands.