Aspen Journalism is compiling a data dashboard highlighting metrics of local public interest, updated weekly.

Snowpack remains above average in the Roaring Fork Basin

Snowpack in the Roaring Fork basin reached 109.7% of average for Dec. 25 with 6.8 inches of snow-water equivalent, according to NOAA.

SNOTEL sites that monitor snowfall throughout the winter measured the snowpack at Independence Pass at 93.9% of average on Dec. 25, with a “snow water equivalent” (SWE) of 6.1 inches, up from 5.31 inches on Dec. 19. Last year on Dec. 25, the SNOTEL station up the pass (located at elevation 10,600 feet) recorded an SWE of 6.5 inches, or 99.9% of average.

The monitoring station at McClure Pass located at elevation 9,500 feet recorded a SWE of 6.81 inches on Dec. 25, or 117.4% of average. That’s up from a SWE of 6.5 inches on Dec. 19. Last year, on Dec. 25, the station also measured a snowpack holding 5.2 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 6.81 inches on Dec. 25, or 117.4% of average.

Snowpack at Schofield Pass reached 11.81 inches on Dec. 25, which represents 99.3% 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.

Ice jam blocks the Fork’s streamflow below Maroon Creek

The Roaring Fork River below Maroon Creek didn’t record any streamflow data on Dec. 25 due to ice blocking the river’s flow since Dec. 16, according to the USGS gauge.

At Stillwater, located upstream of Aspen, the Fork on Dec. 25 ran at 14.2 cfs or 52.6% of average, up from 13.3 cfs and from 49.3% of average on Dec. 19.

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 6.9 cfs on Dec. 25.

The Roaring Fork at Emma, below the confluence with the dam-controlled Fryingpan, saw on Dec. 25 streamflow of 269 cfs, or about 101.1% of average. That’s down from 274 cfs, or 103.4% of average, on Dec. 19.

Meanwhile, the Crystal River above Avalanche Creek, which is not impacted by dams or transbasin diversions, flowed at 59 cfs, or 111.5% of average, on Dec. 25. Last week, the river ran at 52 cfs, or 93.6% of average.

Lake Powell’s elevation is about two inches above critical level

Lake Powell‘s storage remains at one of its lowest levels recorded since it began filling in the 1960s. On Dec. 25, the reservoir was 22.85% full (with a total capacity based on a 1986 sedimentation survey) or 23.84% full (based on updated 2017-18 sedimentation data). That’s down from Dec. 19, when the nation’s second-largest reservoir was at 23.09% of capacity (1986 data) or 24.08% (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 Dec. 25, 2021, it was 27.81% full (based on 1986 data).

On Dec. 25, Lake Powell’s elevation reached 3,525.2 feet, or 174.8 feet from full pool, down from 3,526.2 feet on Dec. 19. The reservoir’s water level on Dec. 25 was 2.4 inches 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 Dec. 25, the reservoir reached 3,538.08 feet in elevation, or 161.92 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.

‘Clean’ air in Aspen

The air quality in Aspen was “good” last week with an AQI index for ozone ranging from 33 on Dec. 25 to 43 on Dec. 22-23.

Laurine Lassalle is Aspen Journalism’s data desk editor, where she works to catalogue and analyze local public data. She also heads our our “Tracking the Curve” project, documenting COVID-19 in Pitkin,...