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

Streams keep flowing faster and well above 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.

At Stillwater, located upstream of Aspen, the Roaring Fork River ran at 337 cfs, or 105% of average on May 29. That’s up from 276 cfs but down from 113.1% of average on May 21.

The USGS sensor below Maroon Creek recorded the Fork running at 1,160 cfs on May 29, or 186.2% of average. That’s up from 816 cfs on May 21.

At Emma, below the confluence with the dam-controlled Fryingpan, the May 29 streamflow of 1,830 cfs represented about 124.5% of average. That’s up from 1,390 cfs, but down from 125.2% of average, on May 21.

The transbasin diversion that sends Roaring Fork basin headwaters east of the Continental Divide was flowing at 402 cfs on May 29, up from 336 cfs on May 21.

Meanwhile, the Crystal River above Avalanche Creek, which is not impacted by dams or transbasin diversions, flowed at 1,730 cfs, or 153.1% of average, on May 29. Last week, the river ran at 1,490 cfs, or 156.7% of average.

The Colorado River ran at 11,500 cfs at Glenwood Springs, or 137.9% of average on May 29, up from 11,300 cfs last week, while the Colorado flowed at 28,700 cfs near the Colorado-Utah stateline, or 163.1% of average.

Snowpack below high alpine nearly gone

Snowpack in the Roaring Fork basin has dropped from last week, reaching an average of 4 inches of snow-water equivalent per site on May 29, or about double the median, according to NRCS.

The monitoring station near Independence Pass, located at elevation 10,600 feet, has been recording a SWE of zero inches since May 28.

The SNOTEL stations at McClure Pass (elevation 8,770), Ivanhoe (10,400) and North Lost Trail (9,219) recorded a snowpack holding less than half an inch of water, from 0.2 inches on May 29 for McClure Pass to 0.3 inches for that day for Ivanhoe and North Lost Trail.

Meanwhile, snowpack at Schofield Pass reached 27.1 inches on May 29, which represents 169.4% of median. That’s down from 36.7 inches on May 21. 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 keeps filling

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. On May 29, the reservoir was 31.65% full (with a total capacity based on a 1986 sedimentation survey) or 33.02% full (based on updated 2017-18 sedimentation data). That’s up from May 21, when the nation’s second-largest reservoir was at 28.49% of capacity (1986 data) or 29.72% (based on 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. Aspen Journalism in July published a story explaining the that drop in storage due to sedimentation.

The reservoir’s capacity has fallen since last year, when on May 29, 2022, it was 25.94% full (based on 1986 data).

On May 29, Lake Powell’s elevation reached 3,558.7 feet, or 141.3 feet from full pool, up from 3,547.4 feet on May 21. The reservoir’s water level on May 29 was 33 feet above the target elevation of 3,525. Last year, on May 29, the reservoir reached 3,531.12 feet in elevation, or 168.88 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 close to normal

High air temperatures at the Aspen airport are close to normal as they went up to 69°F on May 23, or about four degrees above normal. Meanwhile, low temperatures were between 34°F and 39°F.

‘Good’ air quality reported last week but two ‘moderate’ air quality days

The air quality in Aspen was “good” last week except on May 23 and 27 when the AQI index reached 57 for PM2.5 and 54 for ozone, respectively. For the remainder of the week, the AQI index ranged from 43 on May 24 to 50 for ozone on May 29.

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,...