Aspen Journalism is compiling a data dashboard highlighting metrics of local public interest, updated weekly.
Local rivers are running below average
At Stillwater, located upstream of Aspen, the Roaring Fork River ran at 73.8 cfs on May 5, or 71.7% of average, up from last week when the river ran at 62 cfs but down from 88.6% of average.
Water through the tunnel that sends Roaring Fork flows east of the Continental Divide ran at 37.7 cfs on May 5, down from 47.7 on April 28.
The USGS sensor below Maroon Creek recorded the Fork running at 229 cfs on May 5, or 85.8% of average, up from 225 cfs but down from 109.8% of average, on April 28.
At Emma, below the confluence with the dam-controlled Fryingpan, the May 5 streamflow of 554 cfs represented about 94.06% of average. That’s down from 630 cfs on April 28 and from 127.3% of average.
Meanwhile, the Crystal River above Avalanche Creek, which is not impacted by dams or transbasin diversions, flowed at 311 cfs or 67.2% of average. Last week, the river ran at 298 cfs, or 96.1% of average.
The Colorado River ran at 4,720 cfs at Glenwood Springs, or 107.5% of average, on May 5, down from 4,910 cfs last week, while the Colorado flowed at 6,380 cfs near the Colorado-Utah stateline, or 67.7% of average.
Snowpack at McClure Pass is almost gone
Snowpack in the Roaring Fork basin is dropping as temperatures are going up. Snowpack went from 11.9 inches of snow-water equivalent per site on April 28 to 10 inches on May 5, or 88% of median, according to NRCS.
SNOTEL sites that monitor snowfall throughout the winter measured the snowpack at Independence Pass at 86.8% of median on May 5 with a “snow water equivalent” (SWE) of 12.5 inches, down from 14.3 inches and from 87.2% of normal on April 28. Last year on May 5, the SNOTEL station up the pass (located at elevation 10,600 feet) recorded an SWE of 12.8 inches.
The monitoring station at McClure Pass, located at elevation 8,770 feet, recorded a SWE of 0.3 inches on May 5 or 5% of median. That’s down from last week’s SWE of 3.8 inches. Last year, on May 5, the station measured a snowpack holding 17.4 inches of water.
On the northeast side of the Roaring Fork Basin, snowpack at Ivanhoe, which sits at an elevation of 10,400 feet, reached 20.4 inches of SWE on May 5, or 141.7% of median.
Snowpack at North Lost Trail, which sits at an elevation of 9,219 feet, has reached 4.1 inches of SWE on May 5, which is down from 7.9 inches on April 28.
Snowpack at Schofield Pass reached 24.8 inches on May 5, which represents 79% of median. That’s down from 25.6 inches on April 28. 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 has gained 1.5 feet of water since last week
Lake Powell‘s water levels are up. On May 5, the reservoir was 33.69% full (based on updated 2017-18 sedimentation data). That’s up from April 28 when the nation’s second-largest reservoir was at 33.22%.
On July 1, 2022, 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 2022 published a story explaining the that drop in storage due to sedimentation. We will be now using the 2017-18 sedimentation data only.
On May 5, 2023, the reservoir was 24.63% full.
On May 5, Lake Powell’s elevation reached 3,560.9 feet, or 139.1 feet from full pool, which is up from 3,559.4 feet on April 28. Last year, on May 5 the reservoir reached 3,528.4 feet in elevation, or 171.6 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.
Swinging air temperatures recorded in April at ASE
High air temperatures at the Aspen airport varied quite a lot in April but increased overall. They went from 32°F on April 6 to 66°F on April 14 before dropping to 51°F on April 16. On April 23, they reached 68°F before dipping again to 40°F on April 27. At the end of the month, high air temperatures reached 58.8°F, or 0.2 degrees below normal. Meanwhile, low temperatures ranged from 15°F on April 7 to 42°F on April 23. On May 2, low temperatures were down to 25°F.
