Even the driest of winters would not test the "adequacy" of the Northwest's supply of electricity despite the region's heavy reliance on hydro power, according to recent analysis produced by the Northwest Power and Conservation Council's Power Division staff.

"It almost really doesn't matter," senior system analyst John Fazio told the Council Wednesday. Since 1999 when the region had a 4,000 average megawatt deficit, the region has lost about 10 percent of its demand and gained about 15 percent in generation.

The result is about a 6,400 average megawatt swing to a 2,400 surplus supply. By way of comparison, the surplus is about twice as much electricity as the city of Seattle consumes in a year.

The current energy adequacy standard adopted last year by the Council requires the region to maintain at least a balance between resources and loads on an annual basis. The standard includes a 1,500 megawatt planning adjustment. So the new adequacy analysis shows the region with a 3,900 average megawatt surplus in relation to the standards.

The NPCC staff power outlook is based on critical hydro conditions, the driest winter on record -- 1936-37. Most of the moisture that pours through hydroelectric dams over the course of the year comes from snowpack that builds over the winter.

At this point in time, hydro provides about 75 percent of the electricity consumed in the region on average with gas fired plants and other sources providing the remainder. Even in a critical water year hydro could still provide slightly more than half of the region's power.

"We could keep the lights on but it would cost more," Fazio of the switch to other resources.

He stressed that the analysis is of power supply only. It doesn't take into account potential problems transmitting that power to all the corners of the region, or unexpected instances of hydropower sources going offline for mechanical failures or other reasons.

"The bottom line is that we don't expect a problem," Fazio told the Council.

Power demand decreased because some large industries, particularly aluminum plants, have reduced production. Also, the regional economy still has not fully recovered from the energy crisis of 2000 and 2001, when a short supply -- in part caused by a drought in the hydropower-dominated Northwest -- combined with regulatory problems in California to drive up prices significantly, according to a Council press release.

According to the Council's analysis, the power supply now is 41 percent above average during the winter demand period, and 28 percent above average summer demand.

With the winter snow collection period past the halfway mark, the Northwest River Forecast predicts spring-summer runoff will be near average. That means the supply of hydroelectricity should be normal through the spring and summer months, according to Council analysis.

The Council based its analysis on a forecast of the January-July Columbia River runoff volume issued Jan. 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 volume at the lower Columbia dam represents runoff from a large share of the Columbia Basin .

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 forecast is for 94 percent of normal runoff at the lower Snake River 's Lower Granite Dam. Tributaries such as the Clearwater , Salmon, Imnaha and Grand Ronde flow into the Snake between Hells Canyon and Lower Granite.

"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.

An average runoff year means that meeting flow targets desired for salmon and steelhead migrations are dicey.

Based on average flows over the years, a slightly subpar water year gives "probably a 50-50 chance that we are going to meet that target in the spring" at Lower Granite on the lower Snake River and McNary on the Columbia , Fazio said. With average flows, summer targets are rarely met.

"We just don't meet it that often with the reservoirs we've got," Fazio said. Those reservoirs are only capable of storing at any given time about 15 percent of the annual runoff

The supply adequacy analysis 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.

A 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.

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.