Aspen officials preparing for onslaught of avalanche debris during runoff
City of Aspen officials are preparing in the coming weeks for massive amounts of debris to come down from Maroon and Castle creeks after historic avalanches this winter.
Tyler Christoff, the city’s deputy public works director, told City Council last month that with hardly any debris coming down the streams because of drought conditions last year and avalanche debris this year, the head gates on Castle and Maroon creeks could get clogged.
“We are anticipating a double whammy coming down stream once we start seeing that melt off,” he said at the March 26 council meeting.
At that same meeting, Margaret Medellin, the city’s utilities portfolio manager, said the city’s drinking water could be at risk if the head gates are obstructed.
“We are going to be monitoring conditions at our head gate,” she said. “We expect avalanche debris will reach our head gates and it’s going to take a considerable effort to keep those clear.”
Dave Hornbacher, the city’s director of utilities, told The Aspen Times last week that when one of the avalanches occurred in the Maroon Creek Valley in March, the USGS monitor on the head gate showed that almost no water came through for a couple of hours.
He said crews are checking the head gates twice a day, as well as going higher into the watershed to assess the situation.
City officials also are ensuring that heavy equipment can make it to the head gates in case large amounts of debris need to be hauled out, Hornbacher said.
Medellin told council that the area was seeing average snowpack conditions until March when it dramatically changed with record amounts of snowfall.
The entire state saw increased snowpack that month, which is unprecedented, she said.
And in the continental U.S., it was the wettest year in history, Medellin noted.
Last fall, Pitkin County and most of the state were dealing with severe drought conditions, but by February there was some relief in sight, she told council.
A big snowpack typically translates into a big runoff year but hydrologists and other observers say that might not happen this spring because a very thirsty ground will absorb the water.
“The state continues to warn water providers that as the region recovers from the extreme dry conditions of 2018, soil moisture deficits are likely to result in lower runoff than would normally be expected for current snowpack conditions,” Medellin wrote in a memo to council.
Much of the state remains in drought status, including Pitkin County, according to Medellin.
City Council in March agreed with staff’s recommendation to be cautiously optimistic in its approach to drought declarations as the irrigation season begins, and the city will stay in step with what the state does.
The state drought task force recommended April 1 to the governor’s office that it remain in a holding pattern and refrain from altering the drought status.
The city will wait until that task force meets again May 6 to decide whether to change its drought status.
Medellin and Hornbacher plan to update council at its meeting May 20.
“We are going to be very attentive and paying attention to what’s going on,” Hornbacher said, adding conditions can change quickly in the high country. “We are still being very cautionary.”
Many of the restrictions under a stage 2 water shortage are common sense practices that may be extended, city officials noted.
Stage 2 comes with mandatory restrictions for all Aspen water customers, including no watering lawns more than three days a week and no more than 30 minutes per sprinkler zone per day.
Restrictions also include no watering native areas more than two days a week and no watering lawns between 10 a.m. and 6 p.m., and at any time when it is raining.
And there cannot be any watering of lawns, landscaping or amenity resulting in ponding or the flowing of water onto paved surfaces. There also is no washing of sidewalks, driveways, patios, tennis courts and parking areas.
“Our community really responded to the situation we were in and I think they learned that they can use a lot less water,” Medellin told council. “So we don’t want to open the flood gates, so to speak, and say, ‘Use all the water you want,’ because that’s never going to be true.”
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