The pendulum swings from dry to wet
Colorado and Utah
Colorado is sloshing through its wettest spring in more than a decade. Heavy rain and snowstorms continued throughout April and May, resulting in above-average reservoir storage-levels. The statewide snowpack level in mid-May was 199 percent of average.
Near Boulder, where the ground was 80 percent saturated, residents faced perhaps the worst flooding in 101 years. The weather was responsible for at least one death when yet another storm hit the state on May 17. After getting stuck in mud and water on Interstate 25, a woman abandoned her car only to be killed by another passing vehicle. During the same storm, a Burger King parking lot collapsed in Golden, Colo., and dozens of rockslides were reported, closing many roads.
But according to the Natural Resources Conservation Service, the greatest flood risks continued in western Colorado, in the Gunnison, Arkansas and San Juan river basins.
There was an up side: Arapahoe Basin, a ski area just west of Denver, remained open through April with a snow base of 100 inches; then 11 inches of new snow fell during the first week of May. The resort hopes to remain open for the Fourth of July holiday.
Rafters at Dvorak Expeditions, which runs trips on 10 rivers through seven Western states, said they were hoping for a gradual release of water from the high country. "If it's a nice, calm, easy spring ... and it just sort of spreads itself over the whole summer, that's wonderful, that's ideal," says Jaci Dvorak.
In Utah, a warm February was followed by a stormy March, adding to snowpack levels, and residents compare conditions this year with those of 1983, when a sharp rise in spring temperatures melted a huge snowpack and brought on heavy flooding.
The statewide snowpack level hit 233 percent of average in mid-May and precipitation levels were also above average. The result: Rivers such as the Green near Jensen in the northeast and Little Cotton Creek in the southeast were rising and could be at risk of flooding.
Brian McInerney, a hydrologist with the National Weather Service, says snow was still adding to the snowpack in late April.
"The longer we keep this period going where it's cold and we keep adding to the snowpack, the window gets narrower for all that water to come down," he says. "It isn't a big deal right now, but it's something we're acutely watching because it could get scary. If it just dumps a ton of rain on this snow, we'll have problems real fast."
The Willamette River in northwestern Oregon swelled this spring to its highest level in eight years, and Idaho boasted its best snowpack since the mid-1980s, which was good news for young salmon migrating to the Pacific Ocean (see story on page 6). Idaho's Wood and Lost River basins held the best snowpack in the state this year, more than 130 percent of average, and forecasters predicted they could reach as much as 150 percent. Last year those basins were hardest hit by drought.
Washington is struggling through its wettest year since 1991. Steady winter rains have been filling reservoirs and rivers, and the statewide snowpack level was 126 percent of average.
Scott Pattee, a water supply specialist with Washington state's Natural Resources Conservation Service, says flooding isn't a concern because balmy March temperatures melted the mid-level snowpack.
"We should be pretty safe at this point," says Pattee. "There's no guarantee, of course ... If we get great big torrential rains or something, that would make a difference."
Twenty-five-year-old precipitation records were swept away in January, and torrential rains in February caused flooding on the Skokomish River in western Washington. Pattee says no areas in Washington are dry right now - a stark contrast to last year's widespread drought conditions which resulted in water rationing for some farmers.
Farmers in Montana feared the worst when low precipitation levels for the first half of the winter seemed to match last year's, which figured in months of summer drought. Midwinter balmy weather had the snowpack melting as early as February, with Miles City, in eastern Montana, recording a high of 72 degrees on Feb. 24 - 11 degrees higher than the previous record set 99 years earlier. By that time, snowpack levels were 12 percent below average and the state's Drought Advisory Committee warned of the potential for a dry summer.
But April brought wet, cool weather that boosted snowpack levels to slightly above normal. In all of the Western states, southwest and central Montana enjoyed some of the highest gains in snowpack. Farmers in the east and southeast may still have cause for concern, though; in some of these areas the year's precipitation level remained below average.
"At this point it looks a lot better than it did but it can change really fast as far as the irrigators go," says Jim Steinveisser, of the drought committee. "The ones that are irrigating out of some of these rivers that have very little snowpack are going to be in serious shape down the road."
Dry patches held on in the southwest as well, though most of Arizona, New Mexico and Nevada aren't nearly as dry as last year. The snowpack was already melting in Arizona and New Mexico in May, and little snow existed below 8,000 feet. Reservoir storage in most areas registered average to above average.
Parts of northern Nevada, however, stayed dry and some streamflows remained below average, although many reservoirs across the rest of the state showed their highest levels in five years. The Sierra Nevadas were hammered by early spring storms that added to snowpacks, and the Lake Tahoe basin showed the highest snowpack level - 252 percent - that was 14 times last year's. Seven of Nevada's basins held snowpack at or near 200 percent of average.
* Karen McDonald, HCN intern