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

Above-average June precipitation recorded at ASE

Precipitation measured at Aspen airport was slightly above average in June 2022, with a total of 0.94 inches compared with the 1991-2020 average of 0.91 inches, according to NOAA. In May, precipitation was 88% of average, with a total of 1.34 inches of rain and snow. As of July 14, 0.38 inches of rain had fallen on Aspen for the month, which has an average total of 1.64 inches.

Roaring Fork streamflow at Maroon Creek down to 50% of average

The USGS gauge located on the Roaring Fork River below Maroon Creek measured streamflow at 50.8% of average, or 312 cfs, on July 17, down from 402 cfs, or 61.4% of average, on July 10.

Near Emma, the Roaring Fork was flowing at 511 cfs on July 17, or 57.4% of average. That’s down from 665 cfs on July 10, but up from 56.4% of average.

The Crystal River above Avalanche Creek, near Redstone, flowed at 235 cfs, or about 44.3% of average, on July 17. That’s down from July 10 when the river was flowing at 344 cfs, or 46.7% of average.

Downstream, the Crystal River at the CPW Fish Hatchery bridge ran at 191 cfs on July 17, down from 321 cfs on July 10.

Lake Powell’s elevation has lost one foot since last week

Lake Powell‘s storage remains at one of its lowest levels recorded since it began filling in the 1960s. While the amount of water stored in the reservoir began increasing in April due to seasonal runoff, both the storage and surface elevation values reported at the reservoir have been on the decline the over the last two weeks.

On July 17, the reservoir was 26.06% full (with a total capacity based on a 1986 sedimentation survey) or 27.21% full (based on 2017-18 sedimentation data), down from July 10, when it was 26.37% full (1986 data) or 27.5% (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.

“After inputting the new data on July 1, 2022, storage values at the current elevation were updated, resulting in a decrease of 443,000 acre-feet,“ bureau officials wrote in an email. 

Aspen Journalism published a story explaining the recent drop in storage due to sedimentation.

The reservoir’s capacity has fallen since last year, when on July 17, 2021, it was 33.13% full (1986 data).

On July 17, Lake Powell’s elevation reached 3,538.3 feet, or 161.7 feet from full pool, down from 3,539.5 feet on July 10. Last year, on July 17, the reservoir reached 3,556.46 feet, or 143.54 feet from full pool. The surface elevation of Lake Powell came back up above the target elevation of 3,525 feet on May 16, after dipping below it on March 15.

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.

Above-normal air temperatures reported since July 9 in Aspen

Max air temperatures at the Aspen airport have been above normal since July 9, from 73°F on July 5, or six degrees below normal, to 88°F on July 9, which is about eight degrees above normal. On July 14, high air temperature reached 86°F, or six degrees above normal. Meanwhile, the minimum increased from 45°F on July 7 to 51°F on July 10, or about five degrees above normal.

‘Good’ air quality recorded last week in Aspen

The air quality in Aspen was “good” this past week. The AQI index for ozone ranged from 39 July 15 to 46 on July 11.

Laurine Lassalle

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,...