Aspen Journalism is compiling a data dashboard highlighting metrics of local public interest, updated weekly.
Roaring Fork basin snowpack remains above average
Snowpack in the Roaring Fork basin reached 147% of average for Nov. 13 with 2.8 inches of snow-water equivalent, according to NOAA.
SNOTEL sites that monitor snowfall throughout the winter measured the snowpack at Independence Pass at 91.9% of average on Nov. 13, with a “snow water equivalent” (SWE) of 2.2 inches, up from 2.09 inches on Nov. 6. Last year on Nov. 13, the SNOTEL station up the pass (located at elevation 10,600 feet) recorded an SWE of 2.4 inches, or 100% of average.
The monitoring station at McClure Pass located at elevation 9,500 feet recorded a SWE of 3.31 inches on Nov. 13, or 220% of average. That’s up from a SWE of 2.99 inches on Nov. 6. Last year, on Nov. 13, the station also measured a snowpack holding 0.91 inches of water.
On the northeast side of the Roaring Fork Basin, snowpack at Ivanhoe, which sits at an elevation of 10,400 feet, reached 2.99 inches on Nov. 13, or 142.5% of average.
Snowpack at Schofield Pass reached 4.29 inches on Nov. 13, which represents 110% of average. Schofield Pass sits at an elevation of 10,700 feet between Marble and Crested Butte.
Snow water equivalent — the metric used to track snowpack — is the amount of water contained within the snowpack, which will become our future water supply running in local rivers and streams.
The Roaring Fork is still running close to average below Maroon Creek but at less than 50% of average at Stillwater
The Roaring Fork River below Maroon Creek flowed at 104 cfs on Nov. 13, or 95.4% of average, according to the USGS gauge. That’s down from Nov. 6, when the river was flowing at 118 cfs, or 97.5% of average.
At Stillwater, located upstream of Aspen, the Fork on Nov. 13 ran at 15.3 cfs or 47.8% of average, down from 18.8 cfs and from 55.3% of average on Nov. 6.
The upper Fork’s flow is impacted by the Independence Pass transbasin diversion system that sends Roaring Fork headwaters to Front Range cities. Water flowing through the tunnel under the Continental Divide between Grizzly Reservoir on Lincoln Creek and the South Fork of Lake Creek measured 15.2 cfs on Nov. 13.
The Roaring Fork at Emma, below the confluence with the dam-controlled Fryingpan, saw and Nov. 13 streamflow of 256 cfs, or about 83.4% of average. That’s down from 302 cfs, or 93.5% of average, on Nov. 6.
Meanwhile, the Crystal River above Avalanche Creek, which is not impacted by dams or transbasin diversions, flowed at 75 cfs, or 102.5% of average, on Nov. 13. Last week, the river ran at 83 cfs, or 107.8% of average.
Lake Powell’s elevation is around four feet above critical level
Lake Powell‘s storage remains at one of its lowest levels recorded since it began filling in the 1960s. On Nov. 13, the reservoir was 23.83% full (with a total capacity based on a 1986 sedimentation survey) or 24.86% full (based on updated 2017-18 sedimentation data). That’s down from Nov. 6, when the nation’s second-largest reservoir was at 23.93% of capacity (1986 data) or 24.96% (based on 2017-18 data).
On July 1, the Bureau of Reclamation revised its data on the amount of water stored in Lake Powell, with a new, lower tally taking into account a 4% drop in the reservoir’s total available capacity between 1986 and 2018 due to sedimentation. Aspen Journalism in July published a story explaining the that drop in storage due to sedimentation.
The reservoir’s capacity has fallen since last year, when on Nov. 13, 2021, it was 29.28% full (based on 1986 data).
On Nov. 13, Lake Powell’s elevation reached 3,529.3 feet, or 170.7 feet from full pool, down from 3,529.7 feet on Nov. 6. The reservoir’s water level on Nov. 13 was about 4.3 feet above the target elevation of 3,525. Powell’s surface elevation this year peaked at 3,539.84 feet on July 3, after it dipped to its lowest level since filling of 3,522.24 on April 22. Last year, on Nov. 13, the reservoir reached 3,543.39 feet in elevation, or 156.61 feet from full pool.
The “minimum power pool” for turbines generating hydropower at the Glen Canyon Dam is 3,490 feet, and 3,525 feet has been set as a buffer to ensure that the reservoir and the turbines can continue to function properly.
Swinging air temperatures as winter approaches
High air temperatures at the Aspen airport increased from 33°F on Oct. 27 to 56°F on Nov. 2 before dropping to 30°F on Nov. 4, which is about 16 degrees below normal. Maximum air temperatures then rose to 60°F on Nov. 7-8 before going down to 33°F on Nov. 10, which is about 11 degrees below normal. Meanwhile, low temperatures dropped as low as 10°F on Oct. 28 before going up to 35°F on Nov. 8. Minimum temperatures went down again to 13°F on Nov. 10.
Clean air recorded in Aspen last week
The air quality in Aspen was “good” last week with an AQI index for ozone ranging from 35 on Nov. 10-11 to 43 on Nov. 9.
- Colorado’s Division of Water Resources
- Bureau of Reclamation
- Aspen Consolidated Sanitation District
- Aspen Global Change Institute