One year after fire, Roaring Fork Valley dealing with flood risk, avalanche debris | AspenTimes.com

One year after fire, Roaring Fork Valley dealing with flood risk, avalanche debris

Last year on this date, all hell broke loose with the Lake Christine Fire and kept Roaring Fork Fire Rescue scrambling over a chaotic 36-hour period.

This year, instead of drought, the first responders are plucking river runners out of the engorged Roaring Fork on a regular basis and are on the alert for flash flooding and debris flows.

Last year, White River National Forest Supervisor Scott Fitzwilliams and his staff had already dealt with the Buffalo Mountain Fire in Summit County and were about to get engulfed in duties surrounding the Lake Christine Fire.

This year, U.S. Forest Service crews are dealing with the aftermath of one of the biggest avalanche seasons on record. They’ve cleared trailheads of downed timber, plowed roads of debris and fixed smashed facilities.

“It’s definitely a change from last year — a different kind of emergency to respond to.” — Scott Fitzwilliams, forest supervisor

“We find ourselves saying, ‘What a difference a year makes,’” Fitzwilliams said. “People that have been around here a long time say they’ve never seen avalanches and debris like this year.”

The drought that had the valley in its grips in 2018 gave way to abundant snowfall, an intense avalanche cycle during the first week of March and now a wet spring and summer. The stubborn snowpack is finally melting out of the high elevations and swelling rivers and streams longer than usual (see fact box).

Peak runoff was delayed when cool weather preserved the high snowpack longer into the spring and now summer.

“In a way, the public thought it peaked, it’s over, we’re done,” said Pitkin County Emergency Manager Valerie MacDonald. First responders knew there was a lot more runoff to come.

The Colorado Avalanche Information Center said there were 397 recorded avalanches in the Aspen zone, which includes the Marble area, in winter 2018-19. That compares with 357 slides during 2017-18, when snowfall was below average, and 385 the prior winter, when snowfall was about average.

“So, the total number is not astounding, but we had many more very large to historic-sized avalanches this season,” said Brian Lazar, deputy director of the avalanche information center and forecaster for the Aspen zone.

He said there were 26 slides that fell into the very large to historic category.

The Aspen-Sopris Ranger District of the U.S. Forest Service is dealing with the aftermath of those big slides. Travelers in Maroon Valley, Castle Valley, Conundrum Valley, Lincoln Creek and the east and west approaches of Independence Pass will witness the destructive force of the avalanches for years to come. Aspen trees trunks are strewn like matchsticks. The trunks of large conifers lay in a pulverized jumble.

There were landscape-altering slides that widened old avalanche chutes and took out trees that used to be on the fringes, or they ran longer than before and wiped out trees immune to avalanches for decades or even hundreds of years before.

In Lincoln Creek Valley, slides from the north and south sides of the road converged over the creek at a point that wasn’t very narrow.

Fitzwilliams said the White River staff is still assessing damage to national forest and facilities from the slides. Some of the destruction is tangible — bridges in East Maroon Valley and on the far end of Maroon Lake were swept away. Trunks litter the ground in numerous avalanche run-outs visible from roads.

“We know we’re going to have to deal with that deadfall,” Fitzwilliams said.

He has two big concerns with all the timber felled by the avalanches. First, tree trunks and limbs spilled into numerous streams in the forest. Once they get flushed out — whether it’s through the remaining runoff this year or in the future — they pose danger of clogging culverts, getting caught on bridge pilings or forming natural dams that result in flooding.

In addition, downed spruce lights up a neon sign that says “Spruce Beetles Welcome in Pitkin County.”

The spruce beetles have decimated forests to the south of Pitkin County. Now, all the deadfall will likely be an attractant to Aspen and a breeding ground.

“The beetles aren’t that far away,” he said.

Some of the deadfall will be chipped, Fitzwilliams said. Some areas also will be opened to firewood gathering.

“Most of it is going to stay where it is,” Fitzwilliams said.

The Ten Mile Range in Summit County was hit as hard by avalanches as the Elk Mountains around Aspen.

A special, national fund was available to respond to the Lake Christine Fire. The Rocky Mountain Region of the Forest Service made $150,000 available this spring to the White River National Forest for avalanche mitigation efforts. About $100,000 was spent in Summit County to clear a popular recreational path that was hit by 29 slides and for other clearing. Additional funds were spent in Pitkin County to expand existing agreements with the public works department on opening roads and trailheads.

“It’s definitely a change from last year — a different kind of emergency to respond to,” Fitzwilliams said.

RIVERS EXPECTED TO SURGE

The National Weather Service has a flood advisory for the Roaring Fork River near Aspen until further notice. The river is expected to rise to near 4.6 feet by early Friday. Flood stage is 5.0 feet.

A surge in the volume of water flowing in the Roaring and Fryingpan rivers is expected when reservoirs fill and diversions taper.

Twin Lakes Reservoir and Canal Co. informed Pitkin County that it will release more water in the Upper Roaring Fork basin likely starting on Thursday, according to Pitkin County Emergency Manager Valerie MacDonald. The company diverts water from the west side of the Continental Divide by tunnel and releases it on the Front Range. Its allocated space in Twin Lakes will fill on July 4, so the 550 cubic feet per second that it diverts will be released into Lincoln Creek and the Roaring Fork River.

“With no diversions through the Twin Lakes system, the (Roaring Fork River) could reach 1,400 cubic feet per second on Friday,” said a news release from Pitkin County.

MacDonald said there is flooding concern for some cabins east of Aspen but the biggest threat is to recreational users of the river.

“What we’re most concerned about is the unsuspecting angler or boater,” she said. MacDonald urged people thinking of entering the water to carefully consider the conditions and assess if they should wait.

Ruedi Reservoir is also nearing capacity so its releases have gone up and will stay up for the immediate future, according to the U.S. Bureau of Reclamation.

Hydrologist Tim Miller said the release from Ruedi Reservoir would increase to 850 cfs Wednesday. That release along with Rocky Fork Creek creates a flow of about 930 cfs on the Lower Fryingpan River.

Miller estimated on Tuesday that Ruedi Reservoir would fill to capacity in six days.

The inflow to Ruedi Reservoir spiked to about 1,600 cfs on Tuesday. The Colorado Basin River Forecast Center envisions the inflow hovering around 1,250 cfs for the next three days, then receding.

Increased releases from Lincoln Creek and Ruedi Reservoir will swell the Roaring Fork River to peak levels below the confluence.

Elsewhere in Pitkin County, the National Weather Service has issued a flood advisory for the Crystal River near Redstone. The water level is at 4.9 feet. Flood stage is 5.0.

scondon@aspentimes.com


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