The Arkansas River Basin benefited from increased snowfall across the southern half of Colorado in March. Snowpack levels have improved, and the U.S. Drought Monitor shows drought conditions lessening from severe to moderate across much of the basin in Colorado, with extreme drought persisting only in the southeastern plains. The NOAA three-month temperature outlook continues to project above-normal temperatures across all of Colorado as well as lower than normal precipitation.
Colorado Snowpack Map for April 2
The latest snowpack data from the National Resources Conservation Service (NRCS) shows basin-wide snowpack at 98% of median, up from 76% at the end of February. The Porphyry Creek and Saint Elmo SNOTEL sites continue to record the highest snowpack levels: 121% and 110%, respectively. Snowpack at Fremont Pass is 92%, little changed in the past month. Snowpack increased to 94% at Apishapa. Hayden Pass also improved from 69% to 86% over the past month.
The NRCS Reservoir Storage Report shows statewide water storage dropping from 75% of median a month ago to 62% as of April 1. Arkansas Basin storage is at 90% of median, and basin reservoir levels are:
As of April 2, Arkansas River flows were 145 cfs at Granite, 295 cfs at the Wellsville gauge downstream from Salida and 366 cfs at Cañon City. Below Pueblo Dam, flows were 174 cfs, increasing to 516 cfs near Avondale before dropping to 108 cfs near Rocky Ford. The flow was 0.23 cfs below John Martin Reservoir and 7.59 cfs at Lamar.
Voluntary Flow Management Program
Flows at Wellsville are within the target range (250-400 cfs) established by the Voluntary Flow Management Program (VFMP). Under the VFMP, water managers limit releases from upper basin reservoirs from April 1 to May 15 to maintain optimum conditions for trout fry emergence. The VFMP established a framework for owners of senior water rights to manage their water so that it provides additional benefits through non-consumptive water uses, e.g., for whitewater rafting and fishery health. Through May 15, water managers use upstream reservoirs to limit flows to the optimal range for trout fry emergence, supporting healthy young trout strong enough to survive the high flows of spring runoff. During summer months, the VFMP supplements river flows by releasing water from upstream reservoirs, supporting the the local recreation economy. The water is then retained in Pueblo Reservoir where rights owners can use it for its decreed "beneficial uses" (like irrigation and municipal water service).
The Winter Water Storage Program (WWSP) ended March 14, signaling more dynamic river administration. The Basin had 11 active calls as of April 3; six of those were on the river, including the flow requirement at the Kansas state line under the Arkansas River Compact. Tributary calls include the Gonzales Ditch, an 1866 water right on the Apishapa River, and the Kittridge Ditch No. 2, an 1870 right on West Fourmile Creek.