Aspen’s recent storm and avalanche cycle damaged a house, caused an unknown amount of destruction to U.S. Forest Service facilities, threatened to cut off Aspen’s water supply and required use of an extraordinary amount of explosives at the ski areas.
“Up there in Highland Bowl, we’ve already thrown 400 shots since March 1,” Aspen Highlands Ski Patrol Director Mac Smith said Saturday. If not a record for use in a short period, it ranks right up there, he said.
Highland Bowl received about 85 inches of snow between Feb. 28 and March 10, according to records posted by aspenweather.net, a local micro-forecaster. That included dumps of 22 inches of March 6 and another 15.5 inches two days later.
Smith said the wet, heavy snow and rain at lower elevations created challenges for the ski patrol.
“The rain that happened down below gave us a snowpack that’s very unusual for us,” Smith said.
That required special attention because of the heavy, unstable load. Up top, where the snow was lighter, avalanche mitigation was of the type the patrol is used to — there was just more of it.
Smith has been director of the Aspen Highlands Ski Patrol since 1978-79 and worked as a patrolman and assistant director for a handful of seasons prior to that, so he’s got a long track record with Aspen storms.
He said he and longtime colleague O.J. Melahn, a member of the Highlands ski patrol’s snow safety team, were putting this storm into perspective during a conversation late last week.
“We’re in the top three storms of our careers,” Smith said.
There were storm cycles between the mid-1980s and mid-1990s that ranked right up there for snowfall and avalanche danger, he said.
Large avalanches have reached the floors of Maroon and Castle creek valleys over the past week. They temporarily decreased the stream flows and captured the attention of Aspen’s utilities staff.
“Castle and Maroon Creeks are our surface water source for the city of Aspen,” said Tyler Christoff, the city’s deputy director of utilities.
On three distinct episodes, the flow of water was severely decreased on Maroon Creek as the result of avalanches, he said.
The gauge operated by the U.S. Geological Survey shows that the stream flow fell from 22 cubic feet per second to less than 5 cfs at about midnight March 6. There were similar, drastic decreases again March 7-8 and 10.
In all cases, the creek found away to burrow through the packed snow and water flows climbed again after brief blockage.
The city’s water intake infrastructure is about 1 mile downstream from where the slides occurred, so none of the system was damaged, Christoff said. The bigger concern was whether a slide would completely block the creek and reduce the city’s water supply. Officials were particularly nervous when a slide affected Castle Creek and closed the road Saturday.
Christoff said Aspen doesn’t have a large water supply system.
“We’re kind of right out of the rivers and into the system,” Christoff said.
Once it was evident that the storm cycle was going to create historic-sized slides, the water department made sure its tanks and a small reservoir at the water plant were full. The demand currently isn’t high due to lack of lawn watering, he said, but if supply was reduced it might have required conservation.
Records and anecdotal information indicates the city hasn’t been forced to deal with avalanche threats to the water supply since winter 1993-94, Christoff said.
The Aspen-Sopris Ranger District of the U.S. Forest Service also is facing bigger issues than usual in most winters. An avalanche last weekend off Highlands Ridge into Conundrum Creek Valley buried the trailhead under an unknown amount of snow. The Colorado Avalanche Information Center labeled the slide “historic-sized and landscape-changing.”
White River National Forest Supervisor Scott Fitzwilliams said it will likely take months to assess the damage.
“We don’t know what’s underneath there,” he said. “We don’t know if we’ll have a trailhead.”
One thing is for certain, it will be a different experience out of the parking area. It used to be lined with trees. It’s now barren. The melting of the snow could cause further damage not only to infrastructure but the trail itself, Fitzwilliams said.
It is too soon to say if use of the trail will be affected during summer months, he said.
Foresters also have warned that piles of downed spruce trees could be “breeding grounds” for beetles, Fitzwilliams said. A spruce beetle epidemic has generally stayed south of Aspen. This event could invite them into the Roaring Fork watershed. Hundreds of trees were leveled by the Conundrum slide.
Forest Service facilities in Maroon Valley haven’t been checked because of the avalanche danger and thick blanket of snow.
Conundrum is the first high-use area that the Forest Service is aware of that took a big hit from an avalanche, according to Fitzwilliams.
The same slide, which barreled down the Five Fingers and K Chutes, damaged the house farther up Conundrum Creek Valley, at the end of the road by the trailhead. The amount of damage is unclear, but an avalanche retaining wall called a splitting wedge diverted debris and spared the structure from completion destruction.
The Conundrum Valley has several chutes above it that regularly slide. On Feb. 15, 1995, an avalanche killed Doug Hamilton, a 26-year-old man living in a tepee on the property of Martz Steinmetz, a longtime local who has since died. Steinmetz’s house was just downstream — closer to Castle Creek Valley — from the one damaged last week.