MOUNT VERNON, Wash. — Worries of Washington summer drought have evaporated with mountain snowpack estimated at 99 percent of normal by USDA’s Natural Resources Conservation Service.
The main concern now is that irrigation water for orchards from Ahtanum Creek near Union Gap and from Entiat and Methow rivers north of Wenatchee could run low by mid-summer if warmer-than-normal spring weather continues, said Scott Pattee, NRCS water supply specialist in Mount Vernon.
Accelerated warmth will cause the snowpack to “ripen” a few weeks ahead of normal which could be problematic along those rivers since they have no reservoirs, Pattee said.
“Orchards need water all the way through harvest, so we want to see a mild spring to keep the snowpack up there as long as possible,” he said.
But overall Washington’s water outlook on April 3 was much better than it was on Feb. 6 when low snowpack triggered the first meeting of the water availability committee of the governor’s drought task force in four years. Snows since then closed the gap.
The early April snowpack assessment is the main reading of the year because it is the basis for the NRCS April through September streamflow forecast that irrigators and farmers depend upon to make planting and other decisions, Pattee said.
Snow storms in the last weekend of March boosted the statewide snowpack to 99 percent of normal, up 5 percent from the prior week, he said. Most streams are forecast at 90 to 105 percent of normal, he said, with the Olympic Mountains as the exception where snowpack is the lowest in the state at 82 percent.
The Elwah and Dungeness rivers are forecast at 85 and 80 percent, respectively, which is still good enough that it won’t concern flower farmers and shellfish in the area, Pattee said.
Snowpack south of Mount Rainier, feeding the Lewis and Cowlitz rivers, is at 88 percent, but snowpack in most of the Cascade Mountains is 100 to 106 percent and 125 percent in the Walla Walla country, he said.
Streamflow of the Cedar River, the main source of Seattle city water, is forecast at 102 percent of normal, Pattee said. Others in that area: Skagit, 115 percent; White, 102 percent; and Green, 95 percent.
Upper Yakima reservoirs are 102 percent; Yakima River at Cle Elum is 100 percent; Yakima River at Parker is 100 percent; Naches, 102 percent; Ahtanum at Union Gap, 88 percent; Methow, 90 percent; Stehekin, 105 percent; Chelan, 98 percent; Entiat, 95 percent; Wenatchee, 98 percent; Icicle, 96 percent; Coeur d’Alene Lake inflow, 110 percent.