Predicted Columbia River runoff in 2007 portends adequate supply and average prices for electricity

January 18, 2007

The water supply in the Columbia River Basin is near average, and that means the supply of hydroelectricity should be normal through the spring and summer months, according to an analysis (740k PDF) by the Northwest Power and Conservation Council.

The Council based its analysis on a forecast of the January-July Columbia River runoff volume issued by the Northwest River Forecast Center in Portland on January 8. The forecast, based on measurements of snowpack and assuming normal precipitation through the end of July, predicts a runoff volume during the seven-month period that totals 105 million acre-feet at The Dalles Dam, which is 98 percent of the 30-year historical average. The forecasted runoff volume in other areas of the basin are both lower — 82 percent of average at Idaho Power Company’s Brownlee Dam on the Snake River, for example — and higher — 126 percent of normal for the Yakima River, and 100 percent of normal at Grand Coulee Dam.

“The regional surplus of electricity, combined with the predicted average runoff, is good news for Northwest electricity consumers because it means high prices are unlikely,” Council Chairman Tom Karier of Spokane said.

Currently, the Northwest has an electricity surplus of about 3,900 average megawatts (based on the Council's recently adopted resource adequacy energy standard), or more than enough power for two cities the size of Seattle. This assumes that power generated by independent power producers, about 2,700 megawatts, would be available in the Northwest. Even if that power were sold outside the Northwest, however, the surplus still be would on the order of 1,200 megawatts, according to the Council.

For planning purposes, the Council uses the lowest-ever recorded runoff as the base — called “critical water” — against which to measure the forecasted amount. The nearly normal forecasted runoff means that hydropower dams in the Columbia River Basin will produce nearly 4,000 megawatts more electricity than would be produced under “critical water” conditions. This means that low-cost hydropower will be available to displace electricity from higher-cost power plants fired by coal and natural gas. In short, average runoff means lower power electricity prices than would be the case if the runoff were below average, according to the Council.

The supply and price of electricity should remain at average levels through the spring and summer even if the U.S. District Court in Portland orders an increase in water spills at Snake and Columbia river dams to aid passage of juvenile salmon and steelhead, according to the Council. The region’s electricity surplus is large enough that an increase in spills, which would reduce hydropower generation, would not eliminate the surplus.

Contacts:

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