Aspen Journalism is compiling a data dashboard highlighting metrics of local public interest, updated at least every Tuesday. Check back for updates as we add more features.

Roaring Fork and Crystal river streamflows down from last week but remain near last year’s levels

The USGS gauge on the Roaring Fork near Aspen at Stillwater, located upstream of town, measured streamflow at 16.5 cfs on Nov. 14, which represents 50% of average. A week before, the river was flowing at 20.5 cfs. On Nov. 14, 2020, the river ran at 17.1 cfs.

The ACES gauge, located near the Mill Street Bridge in central Aspen, measured the Roaring Fork at an average of 20.34 cfs on Nov. 14, down from 23.26 cfs on Nov. 7. The river ran at 20.39 cfs on that day last year.

Roaring Fork streamflow levels remain below the minimum instream flow of 32 cfs established by a 1976 water rights decree but are close to last year’s averages.

The Crystal River above Avalanche Creek, near Redstone, flowed at 75 cfs, or 102.1% of average on Nov. 14, which is down from 84 cfs on Nov. 7. That’s up 50% from the streamflow last year, when the river ran at 49 cfs on Nov. 14, 2020. The Crystal River at the CPW Fish Hatchery bridge ran at 88.8 cfs on Nov. 14. That puts the river near the minimum instream flow set at 100 cfs set by the 1979 water rights decree.

Maximum air temperature keeps swinging from day to day

Aspen experienced a wide temperature swing, from a high of 64°F on Nov. 6, which is 17.6 degrees above normal, to a high on Nov. 10 of 40°F, which is 4.2 degrees below normal. Minimum temperature was averaging at around 28°F, from 25 °F to 31°F.

Clean air reported in Aspen

The air quality in Aspen was “good” this past week. The AQI index for ozone ranged from 30 on Nov. 13 and 3 to 42 on Nov. 9.

Lake Powell keeps drying up

Lake Powell could potentially fall below minimum power pool in 2022, which is an elevation of 3,490 feet, according to the U.S Bureau of Reclamation. “Should extremely dry hydrology continue into next year, Lake Powell could reach elevation 3,490 feet as early as July 2022,” the press release noted.

Lake Powell‘s storage kept getting lower this past week, reaching its lowest level recorded since it began filling in the 1960s and ’70s on Nov. 14, when the reservoir was 29.27% of full.

Last week, on Oct. 31, the reservoir was 29.41% of full. The reservoir’s capacity has fallen since last year, when on Nov. 14, 2020, the reservoir was 44.44% of full.

The surface elevation of Lake Powell is also in decline and hit a record low on Nov. 14, 2021, when the reservoir’s elevation dropped to 3,543.3 feet, or 156.7 feet from full pool. The reservoir has lost five inches since Nov. 7, when the elevation was at 156.2 feet from full pool. Last year, on Nov. 14, the reservoir reached 3,589.88 feet or 110.12 feet from full pool.

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,...