New SNOTEL to help Aspen’s water planning
Castle Peak site collects weather, snowpack data
Heather Sackett/Aspen Journalism
Water managers at the city of Aspen have a new tool to help them better understand and plan for the city’s water supply.
Last week, after four years of planning and permitting, crews from the National Resources Conservation Service installed a new snow telemetry (SNOTEL) site in the headwaters of Castle Creek. Named Castle Peak, the new SNOTEL site is one of the highest in the state at 11,500 feet.
The SNOTEL network is a collection of over 900 automated remote sensing sites in high-elevation, mountainous watersheds across the West. The stations collect data about snowpack depth and water content, air temperature, wind, solar radiation, humidity, precipitation and soil moisture.
This publicly available data provides a real-time snapshot of conditions in Colorado’s high country. It can help avalanche forecast centers know how much new snow is in the backcountry after a storm; soil moisture data can help wildland firefighters know when forests are dangerously dry.
Perhaps most importantly, SNOTEL data helps scientists understand climate change impacts to water supply and predict how much water will be available come spring.
Support Local Journalism
“In the western United States, about 80% of the annual water used in many basins comes from mountain snow,” said Brian Domonkos, NRCS Colorado snow survey supervisor. “That means it’s a resource we can monitor and get an idea of how much water we have in the snowpack and anticipate how much will be melting in the spring for use throughout the summer.”
The city of Aspen staff requested the site just below treeline off of Pearl Pass Road because the city gets the majority of its water from Castle Creek. NRCS agreed it would be a good spot to enhance their network of SNOTEL sites. Aspen paid the $45,000 cost of setting up the site, while NRCS will be responsible for maintaining it going forward.
“Most folks are pretty psyched that we have another piece of data and something that will be more representative of the basin than what we’ve had in the past,” said Steve Hunter, utilities resource manager with the city of Aspen.
Site fills a data gap
Aspen water managers previously have used SNOTEL sites on Independence Pass, Schofield Pass, North Lost Trail, Upper Taylor in the Gunnison River basin and sites in the Fryingpan River basin to estimate how much water was in the Castle Creek drainage.
“There was really this big hole, a missing gap in this area,” Hunter said.
In many cases, SNOTEL data can help officials manage their reservoirs, releasing more water to make room for a big spring runoff or holding more back in years with a sparse snowpack. Aspen does not have a big storage bucket; the Leonard Thomas Reservoir it uses to store municipal water only holds about 10 acre-feet. Hunter said Aspen will use the SNOTEL data to make decisions about water conservation and when to enact outdoor watering restrictions.
“It gives us a way to quickly adapt, depending on what we’re seeing up there as far as snowpack,” he said. “I think that’s going to be super helpful.”
Aspen received several letters of support for the project when it was applying for a grant from the U.S. Bureau of Reclamation in 2020, including from Pitkin County, Colorado Water Conservation Board, Roaring Fork Conservancy and Aspen Global Change Institute. While the grant wasn’t funded, it demonstrated strong support for the new SNOTEL site.
“Since all data from these proposed stations will be public, these monitoring sites would benefit both the city of Aspen and other mountain towns and municipalities seeking to better understand potential climate change impacts on water supplies,” reads the letter from AGCI.
The Castle Peak SNOTEL is just one piece of Aspen’s effort to better understand its water supply availability. Its 2020 Municipal Drought Mitigation and Response Plan says the city would benefit from a stream gauge on Castle Creek above its diversion point to improve monitoring and make drought declaration decisions. The city is still working on the Castle Creek stream gauge.
Along with other governments across the state, Aspen has also funded Airborne Snow Observatories, a company that measures snowpack from the air using LiDAR, a laser technology that can sense snowpack depth across a wide area. Aspen contributed $50,000 to ASO flights in the Roaring Fork watershed this year.
Real-time data from the new SNOTEL site can be found on the NRCS website. The site does not yet have “percent of normal” values since this is its first year of operation.
This story is provided by Aspen Journalism, a nonprofit, investigative news organization covering water, environment, social justice and more. Visit http://aspenjournalism.org.
