Arrow-right Camera
The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

Low snowpack presents picture, problems for Spokane area

Climate scientists are eager to study our unusual winter. By 2050, it could be the Northwest’s new normal.

Average amounts of moisture fell over most of Washington, Idaho and Oregon this winter, but warmer temperatures meant most of the precipitation fell as rain instead of snow.

The snow deficit in the mountains isn’t a direct result of climate change, scientists say. They attribute the lack of snowfall to warmer ocean temperatures off the Washington coast and a persistent high-pressure ridge. Both phenomena fall within the range of normal climate variations, but they raised average temperatures 4 to 10 degrees in March.

“Even though we can’t blame our super-warm winter on global warming, this year is really interesting, because it’s what our global climate models are forecasting for the future,” said Karin Bumbaco, Washington’s assistant state climatologist.

By midcentury, “we would expect that we’d get a winter like this, with a whole lot of rain and not so much snow,” she said.

Bumbaco and other Northwest climate scientists are meeting in Boise next week with farmers, fish biologists, wildland fire managers and utilities to talk about how the low snowpack will affect the region this summer. NOAA’s National Drought Information System is hosting the meeting.

“We want to document what we’re seeing,” Bumbaco said. “In Washington, we know that we’re moving away from snow-dominated basins. … This serves as a lesson for what we need to be prepared for.”

Local river flows diminish

Drought on the heels of normal precipitation underscores the Northwest’s dependence on mountain snowpack, which acts as a natural reservoir. Melting snow recharges rivers during the dry summer months, providing water for crops, fish migration, power generation and recreation.

The Yakima River basin, which is critical to the state’s agriculture industry, has five water storage reservoirs, but growers often refer to snowpack as the “sixth reservoir.” With this year’s snowpack at 21 percent of normal in the lower Yakima basin, the water available for irrigation will decline sharply by late summer.

For Bryan Alford, a Pasco farmer, that means hard choices about this year’s apple crop. If there’s not enough water to irrigate late-ripening varieties, such as Pink Ladys and Fujis, his workers will strip the immature fruit from the trees to preserve the orchards.

Water availability dictates “whether we harvest the crop, or whether we protect the trees for the long term,” Alford said.

About 40 percent of Washington’s watersheds are in a drought situation, with the low snowpack expected to create hardships for water users later this summer.

Across the Inland Northwest, the picture is more complex. Rivers with headwaters in the higher mountain ranges of Western Montana and Canada have fared better in terms of summer flow forecasts.

“Those higher elevations stayed cold enough to build a snowpack and hold on to their snow,” said Kevin Berghoff, a senior hydrologist at the Northwest River Forecast Center.

Avista Utilities’ two largest dams are on the Clark Fork River, which originates in Montana. The Clark Fork’s flows are forecast at 75 percent of normal through September. As a result, the utility isn’t expecting a significant impact on this year’s power production, said Patrick Maher, Avista’s senior hydro operating engineer.

The Upper Columbia River is in a similar situation. At Grand Coulee Dam, flows in the Columbia are projected at 83 percent of normal, thanks to a strong Canadian snowpack. By late August, however, Lake Roosevelt – the reservoir behind the dam – could be drawn down nearly two feet to provide water for migrating salmon and steelhead, said Lynne Brougher, a Bureau of Reclamation spokeswoman.

In the Spokane-Coeur d’Alene basin, the outlook is grimmer. Flows for the Spokane and Coeur d’Alene rivers through September are forecast at less than half of normal, which would be the third worst conditions since 1970.

“We pretty much melted out in March,” said Katherine Rowden, hydrologist for the National Weather Service’s Spokane office.

Tough summer for fish

Water availability won’t be a problem for most residents. Winter rains replenished soil moisture for the region’s dryland wheat farmers, Rowden said. And the greater Spokane area draws its water from the Spokane Valley-Rathdrum Prairie Aquifer, a vast underground reservoir with 10 trillion gallons of water.

“It’s such a massive resource that it’s not really affected,” Rowden said. But, a hotter, drier summer, with heavy pumping from the aquifer, will further diminish flows in the Spokane River, she said.

For redband trout, the Spokane River’s signature native fish, it’s shaping up as a tough summer.

Adult redbands can seek out areas of deeper, colder water in the river. But young redbands aren’t strong swimmers yet, preferring to stay in the shallows. If they’re forced into deeper water to find cooler temperatures, they’ll be fighting currents and predators, said Randy Osborne, a Washington Department of Fish and Wildlife biologist.

Earlier this year, the state Department of Ecology adopted flow rules for the Spokane River, partly to keep water in the river for fish. However, the agency doesn’t have the ability to regulate aquifer withdrawals under pre-existing water rights, said Brook Beeler, a department spokeswoman. Any water conservation would have to be a voluntary effort, she said.

The Little Spokane River is a different story. The agency expects to restrict withdrawals by 140 junior water rights holders in late summer to protect fish habitat. The restrictions occur every few years, based on flow conditions. The people affected have the option of buying replacement water from the Whitworth Water District, Beeler said.

Late rains in May and June could help blunt the impact of the low snowpack, said Rowden. At this point, the outlook is for warmer-than-normal temperatures, but the precipitation forecast could go either way, she said.

Longer, smokier fire season

Rain or not, wildland firefighters are gearing up for a longer, smokier fire season in the Inland Northwest.

The Colville National Forest’s high ridges get hundreds of lightning strikes during summer thunderstorms. But only about 50 lightning-caused fires start on the forest each year because the ridges are usually snow-covered through June, said Tim Sampson, the forest’s fire manager.

Earlier snowmelt speeds up the drying of ignition sources, such as grasses and other small fuels.

“We’re concerned about the fuels being available for a longer duration,” Sampson said. “Even if we get rains in June, we’re going to have a quicker rebound to drier conditions.”