Study: Idahoans using more water

BOISE (AP) - Americans are using less water, though people in the Northwest individually use more than the national average and Idahoans use more than people in any other state.

A study by local, state and federal officials tracking everything from collective sips at the public fountain to irrigating crops to water used to cool nuclear power plants has found that water usage has dropped to levels of at least 40 years ago.

"This is the first time we've seen this large a decline nationally," said Molly Maupin, a Boise-based hydrologist with the U.S. Geological Survey and lead author of "Estimated Use of Water in the United States in 2010."

"The magnitude of the overall decline was a little surprising to us," she said.

The 56-page report released earlier this month is a snapshot taken at five-year intervals with the most recently compiled information covering 2010. The report was somewhat delayed, Maupin noted, because of the government shutdown and sequestration.

Officials found that in 2010 the U.S. used an average of 355 billion gallons of water per day. That's 13 percent less than 2005, and the lowest amount since before 1970. The five-year snapshots that started in 1950 track water removed from the system, meaning water that is used and then returned to the system can be counted again.

Idaho is listed as leading the nation, with residents using 168 gallons of water per person per day (the national average is 88 gallons per day). But other western states are close, the report said, as residents try to keep yards from going brown in desert climates. "People in some areas have neighbors who get mad at them if they don't have green yards," Maupin said.

In Washington, the per capita daily usage was 111 gallons, Oregon was 113 gallons. People in Arizona used 147 gallons daily, the report said, compared with 144 gallons daily in Wyoming and Hawaii and 134 gallons per day in Nevada.

Officials say the main reason for the drop in 2010 on a national level is water-saving advances in cooling technology at thermoelectric power plants, which produce power with stream-driven turbine generators using everything from coal to natural gas to nuclear fission.

Of the 13 percent decline in national water usage, the report found, 75 percent of that came from conservation efforts among power plant operators. The elimination of many "once through" plants that were replaced with plants that recirculate water is one of the main reasons for the water savings, Maupin said.

Possibilities for the power plant makeovers vary, ranging from environmental regulations to power plant operators potentially being concerned about a changing climate.