Healthy snowpack to fill streams, lakes
The National Weather Service has some good news for the Inland Northwest: Streams and lakes will be full this summer thanks to a deep snowpack in the mountains.
A water supply outlook issued this week calls for stream flows to be near 100 percent of normal from April through September.
That will benefit farmers who irrigate, along with migrating steelhead and salmon, electrical utilities and recreational users. A substantial snowpack, particularly at lower elevations this year, also should delay the beginning of wildfire season in the mountains, experts said.
“Right now, the snowpack is looking excellent,” said Scott Pattee, water supply specialist for the U.S. Natural Resource Conservation Service.
The healthy snowpack should also fill the region’s smaller lakes, many of which are fed by mountain runoff. For example, Newman Lake in Spokane County has a snowpack that is 106 percent of normal, Pattee said.
He said storms in late February boosted the northeast Washington snowpack to 98 percent of normal from earlier readings of about 84 percent. Snowpacks often build in the mountains through the end of March.
As of Friday, Chewelah Peak had 15 feet of snow at the summit while Schweitzer Peak reported 11 feet of snow on top.
Similarly healthy snowpacks in the Cascades will boost stream flows above 100 percent on the upper Yakima, Okanogan, Similkameen, Wenatchee, Chelan and Methow rivers. Farmers use those streams to feed high-value crops such as cherries, alfalfa hay, apples, corn, wine grapes and potatoes.
“The Yakima is looking great this year,” Pattee said. It is forecast to flow at 116 percent of normal in its upper stretches and 102 percent of normal on the lower portions.
Britt Dudek, first vice president for the Washington Farm Bureau, said irrigation is critical for farm production. His region in Douglas County gets only 9 inches of precipitation on average annually, while it takes 36 inches to grow fruit. “Water is very, very important to us,” he said. “Without it, we’re a desert.”
Water supplies coming out of British Columbia are above normal as well, the weather service said in its forecast, issued Thursday.
Debbie Simock, spokeswoman for Avista Utilities, said the strong stream flows will allow Avista to run its hydropower generators at full capacity during the spring. Its waste wood and natural gas thermal plants can then be taken off line for routine maintenance.
The healthy water supply also ensures that Lake Coeur d’Alene will be filled to its normal summer level, she said. On Friday, the Spokane River was flowing at about 7,900 cubic feet per second.
Out-migrating runs of salmon and steelhead should get plenty of water for an easy ride to the ocean, while returning adults will be able to find their spawning beds covered with water, Pattee said.
Weather forecasters said a continuation of wet weather this month could help boost water supplies even more.
This comes on the heels of an El Niño warming of the Pacific Ocean that had threatened to bring dry weather to the Inland Northwest this winter.
El Niño is now giving way to a possible La Niña cooling of the Pacific, which is known for increasing precipitation levels.
Jeff Cote, forecaster for the weather service in Spokane, said this year’s El Niño was not as strong as past El Niño episodes and consequently had little effect on the region’s winter weather.