Trickle can be attributed to drought-like conditions
The Animas River has been setting records this week, but not the kind of records you want to see for the waterway that cuts through the heart of Durango.
According to a U.S. Geological Survey gauge station that has 107 years of water level data, there have been record-low flows almost daily.
The previous record low for March 6 was set in 1990 when the Animas River was flowing at 121 cubic feet per second. On Tuesday, the Animas River was flowing at 104 cfs. And on Wednesday, the previous record low of 118 cfs in the 1990s was shattered when the Animas River averaged 107 cfs.
These numbers are provisional and must be confirmed by the USGS. They are based on the daily average discharge levels recorded at a gauge station near the Powerhouse Science Center, 1333 Camino del Rio.
The dismally low flows can be tied to drought-like conditions that have plagued Southwest Colorado this winter, said Jeff Derry, executive director of the Center for Snow & Avalanche Studies.
The Animas River typically flows to a near trickle in fall and winter as snowpack builds up in the higher elevations before eventually melting into peak flows during spring and early summer. But this winter is abnormal.
For context, the mean flow for the Animas River on March 8 is 240 cfs. But a gauge reading at 9:30 a.m. Thursday showed the river flowed at less than half that – about 114 cfs – a record low.
Derry said extremely dry conditions in the fall created these historically low flows, and the dryness continued most of the winter. That, in part, has caused the water table to remain low.
Even worse, terrain at lower elevations is bone dry.
SNOTEL stations (weather-monitoring sites operated by National Resource Conservation Service) are mainly located above 10,000 feet in elevation, and even there, snowpack is at only 50 percent of normal, based on about 40 years of records. Low elevations aren’t tracked as closely.
A SNOTEL station at Cascade Creek at 8,800 feet, near Purgatory Resort, measured the snowpack at 34 percent of normal Thursday.
Jerry Archuleta, with the National Resource Conservation Service in Pagosa Springs, said the latest stream flow forecasts show the Animas River’s spring runoff is likely to be less than 50 percent of normal averages.
NRCS data show water storage in Southwest Colorado reservoirs is about 105 percent, compared with 114 percent at this time last year.
Carryover storage from last year’s heavy snow totals will help with this year’s coming drought, but it could hurt irrigators next year, said Bruce Whitehead, executive director of Southwestern Water Conservation District.
Whitehead said this year mirrors another notably dry and dangerous year: 2002, the year of the Missionary Ridge Fire. Right now, the region is above 2002’s snowpack levels, but that could rise or fall depending on the weather.
The United States Drought Monitor’s data indicates this year is actually worse than 2002.
“It doesn’t look good,” Whitehead said. “Hopefully we get some more moisture. In the past, we’ve had late spring storms come in and bring snowpack up considerably.”
Jim White, an aquatic biologist with Colorado Parks and Wildlife, said fish populations in the Animas River are safe – for now; the water is still cold and fish are too inactive to detect problems.
Once water temperatures begin to rise, though, fish and aquatic bugs will become more active but will have less room to move around because of low water. This can cause overcrowding and lead to deadly diseases.
“Then we could also have sediment and algae issues, so yeah, we’re concerned for the long term,” White said. “The outlook is not looking good for these fish and the river.”
Right now, there are no signs that it is going to change.
Andrew Lyons, a meteorologist with the National Weather Service in Grand Junction, said the La Niña weather pattern that cuts Southwest Colorado off from any meaningful moisture is expected to persist until at least May.
That means for the next three months, below-average precipitation and above-average temperatures will continue in Durango.
For the record, it appears the lowest the USGS gauge station has ever recorded the Animas River flowing was about 100 cfs.
Interesting this winter season of 2017-18 is about 50% of average (SNOTEL 30 yr. average) but not a record low for the Rio Grande Basin, San Miguel, Dolores, Animas and San Juan River Basins (see information below). 1976-77 set the gold standard for record low Snow/Water Equivalent ~ ‘SWE’ for the last 42 years. Next in line for low SWE were 1980-81, 1990-91 and then 2001-02. I’d like to understand how/why the Animas River can be at a record low in 107 yrs of history knowing that this years low, but not record low snow pack doesn’t line up with the empirical evidence of the Animas flow ?? … rōbert