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

Streamflows down from last week

At Stillwater, located upstream of Aspen, the Roaring Fork River ran at 32.2 cfs on Oct. 1, or 71.6% of average, down from last week when the river ran at 36.2 cfs and 75.4% of average.

Water through the tunnel that sends Roaring Fork flows east of the Continental Divide dropped from 14.2 cfs on Sept. 17 to 1.6 cfs on Oct. 1.

The USGS sensor below Maroon Creek recorded the Fork running at 118 cfs on Oct. 1, or 98.3% of average, down from 127 cfs and 106.7% of average, on Sept. 24.

At Emma, below the confluence with the dam-controlled Fryingpan, the Oct. 1 streamflow of 323 cfs represented about 76.9% of average. That’s down from 362 cfs on Sept. 24 and from 81.7% of average.

Meanwhile, the Crystal River above Avalanche Creek, which is not impacted by dams or transbasin diversions, flowed at 66 cfs or 61.3% of average. Last week, the river ran at 73 cfs, or 61.5% of average.

The Colorado River ran at 2,170 cfs at Glenwood Springs, or 101.4% of average, on Oct. 1, down from 2,260 cfs last week, while the Colorado flowed at 3,490 cfs near the Colorado-Utah stateline, or 90.2% of average.

Aspen Journalism is compiling real time streamflow data. You can find all the featured stations from the dashboard with their real-time streamflow on this webpage.

Lake Powell’s water levels remain unchanged

Lake Powell‘s water levels began their seasonal rise in mid-March as warming temperatures initiated snowmelt, after the reservoir in the winter dropped to its lowest level on record since filling. Water levels peaked in early July and are now slowing decreasing. On Oct. 1, the reservoir was 37.7% full (based on updated 2017-18 sedimentation data). That’s slightly down from Sept. 24, when the nation’s second-largest reservoir was at 37.72%.

Last year, on July 1, 2022, 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. We will be now using the 2017-18 sedimentation data only.

On Oct. 1, 2022, the reservoir was 25% full.

On Oct. 1, Lake Powell’s elevation reached 3,573.6 feet, or 126.5 feet from full pool, which is the same as Sept. 24. Last year, on Oct. 1, the reservoir reached 3,529.43 feet in elevation, or 170.57 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.

High air temperatures well above normal

High air temperatures at the Aspen airport went from 67°F on Sept. 23 to 77°F on Sept. 28, which is about 13 degrees above average. Meanwhile, low temperatures dropped from 43°F on Sept. 21 to 30°F on Sept. 24 before going up to 38°F on Sept. 27.

Air quality still ‘good’ in Aspen

The air quality in Aspen was “good.” The air quality index for ozone ranged from 36 on Sept. 30 and Oct. 1 to 44 on Sept. 25.

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,...