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

Air quality and fire season

The Colorado Department of Health and Environment issued an air quality advisory warning on July 12 at 7 am in effect until 9 am on July 13. Fires in the Northwest aided by winds are bringing smoke to Colorado. Within the past 24 hours, the air quality in Aspen has been declared as “unhealthy for sensitive groups.”

June 2021 wastewater flow rates catching up

Wastewater flow rates reported by the Aspen Consolidated Sanitation District, located near the Aspen-Pitkin County Airport, provide a benchmark that correlates with the volume of people in town at a certain point in time.

According to ACSD data, the volume of wastewater coming through the treatment plant in June 2021 nearly caught up with June 2019 levels. The average daily flow in June 2021 of 1.36 million gallons was 0.8% lower than in June 2019.

However, during the Independence Day weekend, the volume of wastewater was lower than in 2019 but higher than last year. On July 4, 2021, 1.6 million gallons of wastewater flowed through the facility, while 1.8 million gallons were treated in 2019 — a 11% decrease.

Air temperature is back up

Since July 1, the air temperature is increasing again, up to 88°F on July 4 for the maximum temperature, which is 8.5°F above normal, and up to 51°F on July 5 for the minimum temperature, which is 5.5°F above normal.

Water levels remain low

Local rivers in the Roaring Fork Valley and beyond keep seeing low stream flows. The Colorado River below Glenwood Springs ran at 2,270 cfs on July 7, which is 34.76% of average for the day. On the same day, the USGS station located just upstream of Aspen measured the Roaring Fork River flowing at 89.7 cfs, which is 38.7% of average.

Lake Powell‘s storage has been very low during this first week of July. On July 7, 2021 the reservoir was 33.8% of full, compared to July 7, 2020 when the reservoir was 52.3% of full.

The surface elevation of Lake Powell was also lower than usual. On July 7, 2021, the reservoir’s elevation was at 3,558.9 feet or 141.1 feet from full pool. Last year, on that same day, the reservoir reached 3,609.9 feet or 90 feet from full pool.

If the surface elevation of the reservoir on the Utah-Arizona state line, which stores Colorado River water, drops below 3.525.5 feet, it would trigger a host of consequences, including impacts to the operation of Glen Canyon Dam affecting hydropower production, releases from upstream reservoirs to prop up Lake Powell, and potential litigation between the seven states that share water under the 1922 Colorado River Compact.

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,...