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

Twin Lakes Tunnel started diverted again

Transbasin diversion resumed around Oct. 28.

At Stillwater, located upstream of Aspen, the Roaring Fork River ran at 21.4 cfs on Oct. 29, or 59.4% of average, up from last week when the river ran at 20.3 cfs and 53.4% of average.

Water through the tunnel that sends Roaring Fork flows east of the Continental Divide went from 1.6 cfs on Oct. 22 to 15.2 cfs on Oct. 29.

The USGS sensor below Maroon Creek recorded the Fork running at 135 cfs on Oct. 29, or 106.3% of average. On Oct. 22, the river was also running at 135 cfs.

At Emma, below the confluence with the dam-controlled Fryingpan, the Oct. 29 streamflow of 353 cfs represented about 106.6% of average. That’s up from 336 cfs on Oct. 22 and from 96.8% of average.

Meanwhile, the Crystal River above Avalanche Creek, which is not impacted by dams or transbasin diversions, flowed at 75 cfs or 88.2% of average. Last week, the river ran at 65 cfs, or 70.3% of average.

The Colorado River ran at 2,340 cfs at Glenwood Springs, or 114.7% of average, on Oct. 29, up from 2,270 cfs last week, while the Colorado flowed at 4,370 cfs near the Colorado-Utah stateline, or 105.8% 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 keep going down

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. 29, the reservoir was 37.44% full (based on updated 2017-18 sedimentation data). That’s down from Oct. 22, when the nation’s second-largest reservoir was at 37.49%.

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. 29, 2022, the reservoir was 25.02% full.

On Oct. 29, Lake Powell’s elevation reached 3,572.8 feet, or 127.2 feet from full pool, which is down from 3,572.9 feet on Oct. 22. Last year, on Oct. 29 the reservoir reached 3,529.92 feet in elevation, or 170.08 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.

Air temperatures dropped at ASE

High air temperatures at the Aspen airport went from 71°F on Oct. 21 to 59°F on Oct. 26, which is about seven degrees above average. Meanwhile, low temperatures went from 35°F on Oct. 23 to 27°F on Oct. 25.

Clean air in Aspen

The air quality in Aspen was “good.” The air quality index for ozone ranged from 26 and Oct. 28 to 44 on Oct. 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,...