In 1941, folk singer Woody Guthrie wrote a paean to the Columbia River's Grand Coulee Dam, enthusing that power generated by the New Deal monument "is turning our darkness to dawn."
But this summer, the Pacific Northwest's mightiest river could leave California in the dark. A stubborn drought has reduced water levels behind the Columbia's network of power-producing dams by a third, leaving less electricity available for export to the south.
And that prospect is making California's power grid operators nervous.
The Golden State historically has relied on Northwest hydropower to help keep the lights on and air conditioners humming during periods of peak summer demand, and this year will be no exception. California expects to import as much as 6,000 megawatts of Northwest power on the hottest summer days -- enough to serve about 4.5 million typical homes.
For now, power officials in the Northwest, whose massive hydroelectric dams can produce more than 15,000 megawatts of electricity when running full bore, say they should be able to meet that need, even if they can spare the extra power for only a few hours at a time.
But if California is hit by a severe late-summer heat wave -- statistically a 1-in-10 possibility -- the state would have to seek emergency supplies of Northwest hydropower to avoid forcing utilities to cut service to some large customers, according to a forecast released last month by the California Energy Commission.
And if sweltering weather grips Southern California for an extended period, the Columbia Basin's parched watershed might not be up to the task.
"We've got a lot of turbines on the river, and we can probably run them for three hours without depleting much of the water behind the dams," said John Fazio, a systems analyst with the Northwest Power and Conservation Council, which coordinates electricity supplies in Oregon, Washington, Idaho and Montana. "But we can't keep it up for a week."
Even normal weather conditions could severely tax California's electricity grid this summer, according to a recent forecast by the California Independent System Operator, which runs a 25,000-mile transmission grid that covers most of the state -- although major service areas such as the cities of Los Angeles and Sacramento are outside its jurisdiction.
