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

Recent warmer temperatures boost local streamflow

The USGS gauge on the Roaring Fork River near Aspen at Stillwater, located upstream of town, measured streamflow at 203 cfs on Sunday, June 5, which is 52.9% of average. The Fork ran as high as 229 cfs on May 28 before dropping to 161 cfs on June 1 due to the cooler temperatures of the past holiday weekend. Streamflow has been increasing again as temperatures warm. On June 5, 2021, the river ran at 303 cfs.

The Crystal River above Avalanche Creek, near Redstone, flowed at 1,340 cfs, or about 103.1% of average, on June 5. The Crystal was down to 750 cfs on June 1. The Crystal River at the CPW Fish Hatchery bridge ran at 958 cfs on June 5. That’s up from 846 cfs on June 1 but down from 1,620 cfs on May 28.

Seasonal peak flows on most local rivers occurred around May 19, when the Fork at Stillwater ran at 319 cfs and the Crystal near Redstone ran at 2,030. Aspen Journalism recently published a story about river flows peaking early this year.

Snowpack is almost gone across much of the Roaring Fork Basin

Snowpack in the Roaring Fork Basin was at 4% of average on June 5, according to NOAA. It’s down from last week’s 26% of average due to recent warmer temperatures. 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 9.8% of average on June 5, with a “snow water equivalent” (SWE) of 0.12 inches. Last year on June 5, the SNOTEL station up the pass (located at elevation 10,600 feet) recorded an SWE of 0 inches.

The monitoring station at McClure Pass recorded a SWE of 0 inches on June 5. A week before, the station reported 0.2 inches of water contained in the snowpack, or 28% of average. Last year, on June 5, the station also measured a snowpack holding 0 inches of water.

On the northeast side of the Roaring Fork Basin, snowpack at Ivanhoe is now gone with 0 inches on June 5.

Snowpack at Schofield Pass reached 0.2 inches on June 5, which represents 1.6% of average. Schofield Pass’ snowpack has been below average for about a month. 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 is getting close to reaching 10 feet above target level

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 month, as the annual runoff boosted river flows.

On June 5, the reservoir was 26.7% full. Last week, on May 30, it was 26% full. The reservoir’s capacity has fallen since last year, when on June 5, 2021, the reservoir was 34.62% of full.

The surface elevation of Lake Powell exceeded the target elevation of 3,525 feet on May 16, after dipping below it on March 15. On June 5, Lake Powell’s elevation reached 3,534 feet or 166 feet from full pool, up from 3,531.3 feet on May 30. Last year, on June 5, the reservoir reached 3,561.27 feet, or 138.76 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.

Aspen recorded two days with ‘moderate’ air quality this past week

The air quality in Aspen was “good” this past week besides two days, June 1 and 2, when air quality was moderate and the AQI index for ozone reached 54 and 51, respectively. This decline in air quality was probably caused by wildfires burning in New Mexico and Arizona and prescribed burns 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 43 on June 5 to 50 on June 4.

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,...