Aspen Journalism is compiling a data dashboard highlighting metrics of local public interest, updated at least weekly by mid-day Tuesday.

Crystal River streamflow tripled over the weekend

The USGS gauge on the Roaring Fork River near Aspen at Stillwater, located upstream of town, measured streamflow at 144 cfs on May 8, which is 122% of average. That’s up from last week, when the river was flowing at 58.9 cfs. On May 8, 2021, the river ran at 108 cfs.

The ACES gauge, located near the Mill Street Bridge in central Aspen, measured the Roaring Fork River flowing at 128.6 on May 8, because the Wheeler and Salvation diversion ditches are again operating for the season.

The Crystal River above Avalanche Creek, near Redstone, flowed at 906 cfs, or about 170.9% of average, on May 8. The warmer temperatures of last week increased the streamflow of the river as the Crystal jumped from 375 cfs on May 5. The Crystal River at the CPW Fish Hatchery bridge ran at 1,300 cfs on May 8, up from 391 cfs on May 5.

Local snowpack is at about 70% of average

Snowpack in the Roaring Fork Basin was at 73% of average, according to NOAA on May 8. It’s been below average since April 20, reaching that designation for the first time this season, the Roaring Fork Conservancy wrote on April 21.

SNOTEL sites that monitor snowfall throughout the winter measured the snowpack at Independence Pass at 52.6% of average on May 8, with a “snow water equivalent” (SWE) of 6.89 inches. The size of the snowpack relative to the 30-year average is down from last week’s 73.9%. Snowpack dropped from over 10 inches on May 4 to about less than 7 inches on May 8 due to warmer temperatures. Last year on May 8, the SNOTEL station up the pass recorded an SWE of 6.69 inches.

The monitoring station at the lower-elevation McClure Pass recorded a SWE of 0.31 inches, or 4.6% of average, on May 8. A week before, the station reported 3.11 inches of water contained in the snowpack, or 31.4% of average. Last year, on May 8, the station measured a snowpack holding 0 inches of water.

On the northeast side of the Roaring Fork Basin, snowpack at Ivanhoe contains higher water levels than the 1991-2020 average, with 15.12 inches on May 8, which is 105.7% of the average of 14.3 inches. It dropped from 17.01 inches of SWE on May 1. It’s up from last year’s 13.58 inches of SWE.

Snowpack at Schofield Pass reached 28.82 inches on May 8, which represents 90.3% of average. Schofield Pass’ snowpack has been below average for about two weeks. 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.

Lake Powell’s elevation increased 4.8 inches

Lake Powell‘s storage remains at one of its lowest levels recorded since it began filling in the 1960s. However, the amount of water stored in the reservoir increased over the past two weeks, as the annual runoff boosted river flows.

On May 8, the reservoir was 23.88% full. Last week, on May 1, it was 23.79% full. The reservoir’s capacity has fallen since last year, when on May 8, 2021, the reservoir was 34.65% of full.

The surface elevation of Lake Powell dipped below the target elevation of 3,525 feet on March 15, but it gained 4.8 inches between May 1 and May 8. On May 8, Lake Powell’s elevation reached 3,523.1 feet, or 176.9 feet from full pool, up from 3,522.7 feet on May 1. Last year, on May 8, the reservoir reached 3,561.37 feet, or 138.63 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 quality in Aspen improved last week

The air quality in Aspen was “good” this past week besides May 3 when air quality was moderate and the AQI index for ozone reached 63. This decline in air quality was probably caused by wildfires burning in New Mexico and Arizona and the prescribed burned across Colorado. Jannette Whitcomb, Aspen senior environmental health specialist, wrote in an email that it is commonplace to see moderate AQI for ozone in Aspen in the spring.

For the remainder of the week, the AQI index for ozone ranged from 45 on May 2 to 58 on May 4 and 7.

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,...