MOUNT VERNON, Wash. - Judging from the heavy snowpacks in the mountains and the amount of water in that snowpack, farmers in Western Washington could be in for a very wet spring and possibly more flooding, warn USDA Natural Resources Conservation Service officials.
"If warm rains start falling, the snow will come off the mountains fast," said Steve Nissley, NRCS district conservationist. "And though snow can act as a buffer and hold some of the water back, if it gets to a point that the snow starts melting at the same time that it's raining, things could get bad."
In the Cascades, there's almost twice as much snow as normal, according national forecasters. In the north part of the Olympics, there's about 20 percent more snow than normal.
To compound the problem, that snow contains a lot of water. In an average year, 35 percent of the snow in the Cascades is water, but this year, more than 40 percent of it is water. That means for every 10 inches of snow, for example, there's more than four inches of water, instead of the usual 3.5 inches. This extra water adds up in a big way, especially when looking at this year's total snowpack.
"Everyone's wondering what's going to happen," said Nissley. "The fields are very wet right now, and unless there's a change in the weather, planting could be delayed and that would impact yields. Potentially this could affect almost all the crops."
Nissley's co-worker, Scott Pattee, a water-supply specialist, pointed out that twice as much snow in the mountains adds up to twice as much water melting off the mountain slopes once the warmer weather begins. But the extra water in that snow adds another dimension to the picture.
"That's where our forecast of high probability of flooding problems is coming from," said Pattee, pointing out that even after much of the runoff is absorbed or evaporates, the rivers will continue to swell. This year, the snowpack in the Cascades begins at the 4,000-foot level, about 1,000 feet lower than normal, said Pattee. In the Olympics, the snowpack is at the 3,500-foot level, 500 feet lower than normal.
Meanwhile, the snow is soaking up the heavy rains and then refreezing. As a result, the snow is getting wetter and wetter.
Snowpack in the Central Cascades, which feeds the Cedar, Snoqualmie, Snohomish and Skykomish rivers, is running more than 184 percent of normal. Pattee said water flows in those rivers are expected to be about 122 percent of normal between April and September. Flows in the Green River in south King County are expected to be 128 percent of normal.
In the northern end of the Olympic range, the higher than usual snowpacks will lead to increased water flows in the Elwha River from April through September.
And though most of the recent floods in Western Washington have been the result of heavy rains, the snowpack is beginning to loosen up as a result of the rain and warmer temperatures.
In Mason County, where the Skokomish River flooded last week after a 9-inch rainfall that deluged the area in just 24 hours, the flood waters are now receding. But Joe Murray, director of the Mason County Department of Emergency Management, said things could get wetter yet.
"We have supersaturated soils that can't absorb any more water and the reservoirs and lakes are full," he said. "There are heavy snowpacks in the mountains, and if we get warm weather and rain, we could be in for a very wet spring."
Taking a look at the big picture, flooding in the Skokomish Valley is beneficial, said Murray, because it brings down the rich soils. But there's also a downside.
"If you're in a flood plain, you take the risk of delayed planting and lost crops," Murray said.
In the Skagit Valley, wet weather may delay planting of broccoli, peas, and seed crops such as mustard, spinach, beet, kale, turnip, radish and Swiss chard.
"We're probably going to be behind the eight ball in getting these crops started compared to when we usually do," said Dyvon Havens, horticultural extension agent in Skagit County.
Meanwhile, the recent deluge of rain has ruined some of the area's cabbage-seed fields, although Havens said she doesn't yet know the extent of that damage.
And the rains and excessively wet fields have also put a halt to the spring potato harvest.
"We had early fall rains last year," said Havens, "and they couldn't get into the fields to harvest all of the potatoes. Now they're having a hard time getting to them because of the rain."
Back to Storm and Flood Index