Warmer than normal temperatures are melting away Washington’s mediocre snowpack – and with it, almost all hope for average stream flows this summer.

According to the latest Basin Outlook Report compiled by USDA’s Natural Resources Conservation Service (NRCS), statewide March 1 snowpack conditions have receded to 70 percent of average – down from 74 percent a month ago. The Green and Tolt river basins continue to report the lowest readings in the state at 32 percent of average.
“Record high elevation temperatures, combined with an obvious lack of precipitation, have dwindled snowpack averages in all areas of the state,” said Scott Pattee, water supply specialist with the NRCS in Mt. Vernon.
Those below-average snowpack conditions are translating directly to lower stream flow forecasts. “Predicted spring and summer stream flows have also dropped by several percentage points,” Pattee said.

NRCS measures the depth and water content of snow at more than 100 locations around the state. The data is used to estimate how much water will flow down rivers and streams and into reservoirs as the snow melts.

“High elevation snowpack is our state’s ‘water in the bank,’” Pattee said. “But this year’s warmer temperatures haven’t let us bank as much as we’d like. And as we approach, April 1, the snowpack saving clock is winding down,” he said.

April 1 is considered the most important date for determining spring and summer stream flows because after that date, snowpack accumulations typically begin shedding their moisture in the form of stream flow runoff.

Reflecting the state’s overall declining snowpack, most river basin averages remain below average:
• Lewis-Cowlitz – 70 percent of average
• North Puget Sound – 69 percent of average
• Central Puget – 41 percent of average
• Yakima area – 74 percent of average
• Wenatchee area – 81 percent of average
• Walla Walla – 68 percent of average
• Spokane – 52 percent of average

Only the Conconully basin reported above-average snowpack conditions, at 106 percent of average.

Pattee said these latest figures will come as no surprise to water managers who have been closely monitoring conditions throughout the winter. “Still,” he said, “the declining snowpack will complicate the daunting task of providing enough water to fill reservoirs and supply irrigation and municipal systems through the summer.”

And what are the odds of a miracle comeback?

“It is March, and we’ve had strong snowpack rebounds before,” Pattee said, “but with each passing day, the odds become more difficult to overcome. We’re certainly not out of the game yet,” he said, “but we’re in the late innings and running out of at-bats.”

© Copyright 2006 by North Cascades Broadcasting, Inc

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