Light snowpack in Cascades not raising drought worries

  • Sun Apr 4th, 2010 9:52pm
  • News

By Oscar Halpert Herald Writer

Warm temperatures are behind a lower than typical snowpack in the Cascades this year.

The limited snowpack means less water from melting snow will flow into area rivers and streams in the coming months.

Officials who monitor snowpack say they’re not worried about a drought.

“I don’t see it as being a critical situation,” said Bruce Meaker, senior manager for water resources and regulatory affairs for the Snohomish County Public Utility District “Having said that, we would certainly recommend that people use their water resources wisely.”

Once a year, the PUD flies by helicopter into designated areas to measure the snowpack and water content.

There was 55.5 inches of snow on the ground Thursday — a little under 5 feet — at Stickney Ridge, 3,600 feet up in the Cascades above Spada Lake.

That’s a sharp drop from last year, when the snowpack reached 139.6 inches — or just under 12 feet — according to the PUD. It’s also well below the 97-inch average.

What’s the cause? El Nino, an ocean weather pattern that leads to warmer winters in the Pacific Northwest and greater-than-normal snowfall in the Southwest, experts say.

January’s average temperatures were a record 5.3 percent warmer than normal, said Brent Bower, a hydrologist with the National Weather Service in Seattle. Warmer than usual temperatures have been a clear pattern since early winter, he said.

The annual snowpack measurement is a key indicator of how much water will be available the rest of the year.

Meaker said the snowpack goes up and down in a five- to seven-year cycle. The latest snowpack total is higher than the 19.5 inches measured in 2005, he said. The record low was in 1992 when there was no snowpack; the PUD has been measuring since 1986.

Experts measure more than the snowpack’s depth when determining how much water will be available — they also measure how much of that snowpack contains water. Powdery, dusty snow has less water content than compact or slushy snow.

“That’s really what matters — how much of that water is held in the snow and what happens to that water? Does it come out slowly or is there a quick runoff?” said Mike Strobel, director of the National Water and Climate Center in Portland, Ore.

The latest measurement shows that 34 percent of the snowpack has water. That’s below the 43 percent average, Meaker said.

“We’re showing that the snowpack is less and the amount of water is less,” he said.

The Sultan Basin supplies water for roughly 80 percent of the county’s population. The PUD produces about 5 percent of its power from the Jackson Hydroelectric Project, which is downstream from the dam on the Sultan River. It gets most of the rest of its power from the Bonneville Power Administration.

Oscar Halpert: 425-339-3429, ohalpert@heraldnet.com.

Snowpack

Here are the snowpack measurements, in inches, at Stickney Ridge in the Cascades since 2005:

2005 — 19.5

2006 — 103.5

2007 — 95.7

2008 — 197.8

2009 — 139.6

2010 — 55.5

Source: Snohomish County PUD