Snowfall in December and January significantly improved snowpack in the upper Arkansas River Basin, but the U.S. Drought Monitor shows extreme drought persisting across the southern extent of the lower Basin in Colorado.
At the January meeting of the Governor’s Water Availability Task Force, Brian Domonkos, a snow survey supervisor with the Natural Resources Conservation Service (NRCS), reported reservoir storage in the Arkansas Basin at 69% of average and 23% of capacity. By the end of January, the NRCS website was reporting reservoir storage at 92% of median.
While recent precipitation has improved the outlook for Ark Basin water supplies, the increased frequency of drought in recent years has produced dryer soils, a topic of discussion at the Task Force meeting. Soil aridification means that, as the snowpack melts, more water will be absorbed into the ground, thereby reducing runoff, lessening stream flows and changing the historical correlation between snowpack and streamflow.
The NOAA three-month temperature outlook predicts higher than normal temperatures across all of Colorado through April. The three-month outlook also predicts lower than normal precipitation for the entire state.
During the Water Availability Task Force meeting, Domonkos, reported that January snowpack in Colorado “is well above what we were seeing last year at this time. It’s awesome.” (Snowpack was around 70% of average in January 2021.)
The latest NRCS Snowpack Telemetry (SNOTEL) report shows basin-wide snowpack at 85% of median for snow-water equivalent (SWE). The highest readings are currently at Porphyry Creek (118%) and Saint Elmo (116%). The Fremont Pass SNOTEL station is reporting 102% of median while the Hayden Pass station sits at 40%.
As of Feb. 2, Arkansas River flows were 408 cfs at the Wellsville gauge near Salida – below the confluence with the South Arkansas River. Gauges upstream from Wellsville were not reporting flow data. At Cañon City the river was flowing at 375 cfs, compared to 63.4 cfs below Pueblo Dam, 286 cfs near Avondale and 151 cfs near Rocky Ford. The flow was 1.16 cfs below John Martin Reservoir and 15.2 cfs at Lamar.
The Boustead Tunnel into Turquoise Lake is seeing a discharge rate of 1.95 cfs. We'll pay closer attention to the Boustead once spring runoff begins. Since Colorado River Compact obligations take priority over the Fryingpan-Arkansas Project, transmountain diversions could again be limited in 2022.
The Arkansas River Basin had 12 active calls as of Feb. 2. The calling water right on the Arkansas mainstem is the Fort Lyon Storage Canal with a March 1, 1910, priority date. On the Cucharas River, calling structures are the Francisco Daigre Mill with a June 30, 1864, priority date and the Ballejos Ditch with an April 1, 1868, priority date. Calls on the Huerfano River are for the Upper Huerfano No. 2 and Welton Ditch with priority dates of March 15, 1869, and June 12, 1889, respectively. The Model Ditch (March 20, 1862) has a call on the Purgatoire River, and the Tenassee Ditch (April 30, 1880) has a call on the South Arkansas River. Remaining calls are on Currant Creek, Fourmile Creek, Greenhorn Creek, Hardscrabble Creek and Stout Creek.