Flood risk increasing as spring snow piling up

Spring flooding still possible

The pristine snow in Red Lady Bowl, marked only by the fresh tracks of late season skiers, makes last year seem like a fuzzy memory—the mountain streaked in red and brown by mid-April, the cumulative effect of six major dust events. But while a snowpack at 143 percent of average, according to the latest SNOTEL data, seems to be holding this season’s dust takeover at bay, we’re not out of the woods yet for aggressive spring runoff or flooding.

“We’ve had a relatively uneventful dust season,” said Frank Kugel, general manager of the Upper Gunnison River Water Conservancy District. “Thus far there haven’t been any [dust events] with the significant impact on snowpack that we’ve had in recent years, so that’s the good news. The bad news is the snowpack is accumulating and it should be dropping at this time of the year. We are actually higher to date than we were in 2008, so flooding is now getting to be a concern.”
According to Chris Landry, dust-on-snow expert and director for the Center for Snow and Avalanche Studies in Silverton, Colo., the Gunnison Basin has actually seen the same number of dust events this year as last, but there seems to be less dust.
“The difference between this year and last is that the mass of dust contained [in the snowpack] is less. It appears that way, at least. Data samples are still being processed,” Landry said.
According to Landry, sampling has shown that there are fewer than six layers of dust in the snowpack—some have merged into thick or single layers. But there is what Landry calls a “non-trivial” dust buried in the snowpack.
“Dust does not disappear once it’s in the snowpack, and sooner or later—it’s entirely dependent on the weather—that dust will resurface. As the snow melts and dust accumulates at the surface of the snow, [the dust] will melt back down to maybe one or two more underlying layers and those will merge, and the albedo [or reflectivity of the snow] will be reduced a little more,” Landry said. When that happens, snowmelt accelerates and can lead to flooding. “There will be an effect and the weather will dictate the timing of that effect and the intensity and duration, how sustained the dust effect will be.”
Last season’s most significant dust event occurred May 22. If that happened again, according to Landry, it would land right on top of the snow pack and have an immediate effect. The concern that water officials are planning for now is accelerated runoff that could lead to flooding.
“Our district works in close cooperation with the district Bureau of Reclamation, so they will be increasing releases [from the Taylor Reservoir] to try to make more space available to try to absorb some of these stronger runoffs that may occur,” Kugel said. “The longer it stays cold, the higher potential there is for flooding to occur and the less warning we’ll have.”
“Ideally we like to see warm temperatures during the day, around 50 or 60 degrees, to get things melting pretty well in the daytime but still freezing at night. That way it slows [melting] down,” said Scott Morrill, Gunnison County emergency manager. “Our concern is that the forecast is showing late next week it heats up and then stays above freezing at night.”
 In anticipation of potential flooding, Morrill and Kugel are in communication with each other and the weather service on a regular basis, and Morrill has been running public service announcements encouraging property owners who live along creeks and rivers to consider flood insurance and consider having sand bags on hand to prepare properties. But the fact remains, Morrill said, that they’re dealing with Mother Nature. It’s a wait and see situation, and there’s a balance between preparation and concern.
“We’re not trying to downplay this, but we’re also not trying to create fear,” Morrill said. “There is [a flooding] potential this year and we’re not out of the woods yet. The sense I get from talking to people is that they think the runoff season isn’t going to be that big of a deal, and it might not be. But there is that potential.”
For more information on spring runoff and flood preparation, visit www.gunnisoncounty.org/emergency_management_flood.html or the town of Crested Butte web site.