High winds continued to plague Colorado and the Arkansas River Basin this week, contributing to several wildfires. The U.S. Drought Monitor shows little change across Colorado with moderate to severe drought conditions across most of the basin, but the drought map has not been updated to reflect Sunday's snowstorm, which improved snowpack. The NOAA three-month temperature and precipitation outlook was recently updated, projecting above-normal temperatures and below-normal precipitation for all of Colorado through July.

Snowpack
According to the National Resources Conservation Service (NRCS), basin snowpack dropped to 63% of median, measured as snow-water equivalent, as of April 24. Ark Basin SNOTEL data from April 25 show Porphyry Creek at 89% of median, Saint Elmo at 81%, Fremont Pass at 88% and Hayden Pass at 32%. The Apishapa SNOTEL station reads 150% of median, but that reading has been flagged as likely not valid.

Reservoir Storage
Current reservoir data from the U.S. Bureau of Reclamation shows Pueblo Reservoir is 68.8 % full with 222,249 acre-feet
of water in storage. Twin Lakes Reservoir is 68% full with 95,873.7 acre-feet in storage. Turquoise Lake currently stores 47,501.5 acre-feet of water and is 36.7% full. U.S. Army Corps of Engineers data shows 44,444 acre-feet of water currently stored in John Martin Reservoir, well below its capacity of 348,599 acre-feet.

River Flows
Arkansas River flows have increased since last week, with gauges reading 318 cfs below Granite, 346 cfs at Wellsville and 352 cfs at Cañon City. Below Pueblo Dam, flows are 324 cfs, 745 cfs near Avondale and 162 cfs near Rocky Ford. Below John Martin Reservoir flows have ramped up to 75.4 cfs. At Lamar flows are currently 47.5 cfs. 

Voluntary Flow Management Program
Flows at Wellsville are on target for the Voluntary Flow Management Program for April 1 to May 15. 

River Calls
Calling water rights in the Arkansas Basin increased from 11 to 18 active calls this week. Seven calls are on the mainstem, including the 1875 Lamar Canal water right, the 1884 Fort Lyon Canal right and Las Animas Consolidated water right. The most senior calling water right is the Chilili Ditch with an 1862 priority date on the Huerfano River. Other tributary calls include Bray Ditch on North Cottonwood Creek with an 1867 priority date, the Bannister Sump Well on Fountain Creek with an 1866 priority date, the Titsworth Ditch on Fourmile Creek with an 1865 priority date, and the Gonzales Ditch on the Apishapa River with an 1866 right.

High winds and dry conditions continued across much of the Arkansas River Basin this past week, prompting Red Flag warnings and burn bans. Nonetheless, wildfires broke out in Bent, Otero and Custer counties as well as at Fort Carson. Moderate to severe drought conditions dominate most of the basin with extreme to exceptional drought persisting in the southeast corner of the state.

Snowpack
National Resources Conservation Service data show that the past week’s dry, windy conditions in the Arkansas Basin dropped snowpack from 97% to 88% of median (based on snow-water equivalent). Despite the basin-wide trend, snowpack increased at some NRCS SNOTEL sites, including Porphyry Creek, which currently reports 115% of median, up from 98%. Saint Elmo snowpack is back up to 111% after dropping to 100% the previous week. Fremont Pass rebounded to 93%, up 8 percentage points. Snowpack at Apishapa and Hayden Pass dropped to 91% and 82%, respectively.

Reservoir Storage
Current data from the U.S. Bureau of Reclamation shows Pueblo Reservoir at 69.7% of capacity with 225,051 acre-feet of water in storage. Other Reclamation reservoirs, like Twin Lakes and Turquoise Lake, are not currently reporting these numbers.

The Army Corps of Engineers report for April 15 shows 45,188 acre-feet of water currently stored in John Martin Reservoir, which has a capacity of 348,599 acre-feet.

River Flows
The Colorado Division of Water Resources reports Arkansas River flows are currently 114 cfs at Granite and 205 cfs at the Wellsville gauge near the Fremont-Chaffee County line, below the Voluntary Flow Management target of 250 cfs. In Cañon City, Arkansas River flows are 232 cfs. Below Pueblo Dam, flows are 108 cfs, 305 cfs near Avondale and 183 cfs near Rocky Ford. Below John Martin Reservoir flows have crept up to 0.46 cfs. At Lamar flows are 6.82 cfs, the same as a week ago.

River Calls
Active calls for water in the Arkansas Basin are at 11, with six calls on the mainstem, unchanged from a week ago. Calling water rights continue to include the Lamar Canal with an 1875 priority date, the Fort Lyon Canal with an 1884 priority date and the Buffalo Canal with an 1885 priority date. Tributary calls include the Model Ditch with an 1862 priority date on the Purgatoire River, the Titsworth Ditch with an 1865 priority date on Fourmile Creek, the Gonzales Ditch with an 1866 priority date on the Apishapa River, the May Ditch with an 1869 priority date on the Huerfano River, and the Hardscrabble Ditch with an 1871 priority date on Hardscrabble Creek.

The early April weather pattern brought high winds and warmer weather to the Arkansas River Basin and did nothing to improve snowpack levels. The U.S. Drought Monitor shows moderate to severe drought conditions across the basin, little changed since last week. NOAA has not yet issued a new three-month temperature and precipitation outlook.

Snowpack
The latest snowpack data from the National Resources Conservation Service (NRCS) shows basin-wide snowpack at 97% of median, down from 98% a week ago. Snowpack at Porphyry Creek dropped from 121% to 98%, and at Saint Elmo, from 110% to 100%. The snowpack at Fremont Pass diminished from 92% to 85% during the past week. Snowpack at the Apishapa SNOTEL station reached 95% of median. Hayden Pass dropped slightly this week to 85%.

Reservoir Storage
The NRCS Reservoir Storage Report has not yet been updated for the Arkansas Basin's major reservoirs. Current reservoir data from the U.S. Bureau of Reclamation shows Pueblo Reservoir 70.1% full with plenty of capacity to accommodate the annual April 15 deadline for ensuring that that the reservoir has space available for flood control. Water stored in Pueblo Reservoir currently sits at 226,089 acre-feet.

River Flows
Arkansas River flows are currently 119 cfs at Granite, 247 cfs at the Wellsville gauge downstream from Salida and 326 cfs at Cañon City. Below Pueblo Dam, flows are 199 cfs, 500 cfs near Avondale and 93.8 cfs near Rocky Ford. Below John Martin Reservoir flows have dropped to 0.08 cfs. At Lamar flows are currently 6.82 cfs. 

Voluntary Flow Management Program
Flows at Wellsville are slightly below the target range of 250-400 cfs established by the Voluntary Flow Management Program for April 1 to May 15. 

River Calls
The Arkansas Basin currently has 11 active calls, six of which are on the mainstem, including the Lamar Canal with an 1875 priority date, the Fort Lyon Canal with an 1884 priority date and the Buffalo Canal with an 1885 priority date. Tributary calls include the Baca Irrigating Ditch with an 1862 priority date on the Purgatoire River, the Titsworth Ditch with an 1865 priority date on Fourmile Creek, the Gonzales Ditch with an 1866 priority date on the Apishapa River, and the May Ditch with an 1869 priority date on on the Huerfano River.

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.

​Snowpack
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.

Reservoir Storage
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: 

• Turquoise Lake, 113%.
• Twin Lakes Reservoir, 126%.
• Clear Creek Reservoir, 106%.
• Pueblo Reservoir, 126%.
• John Martin Reservoir, 80%.

River Flows
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).  

River Calls
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.

​Colorado's February precipitation failed to maintain Arkansas River Basin snowpack compared to the past 20 years. The U.S. Drought Monitor shows severe drought persisting in most areas in the basin with extreme drought in the southern edge of the lower Ark Basin in Colorado as well as the two western corners of Colorado (i.e., 9% of the state). The NOAA three-month temperature outlook projects higher than normal temperatures across all of Colorado through May. The three-month outlook also predicts lower than normal precipitation for the entire state.

Snowpack
The latest National Resources Conservation Service (NRCS) Snowpack Telemetry (SNOTEL) report shows basin-wide snowpack at 76% of median for snow-water equivalent (SWE) and precipitation at 83% of median. The highest snowpack readings continue to be recorded at Porphyry Creek (119%) and Saint Elmo (115%). Snowpack at Fremont Pass has dropped from 102% of median a month ago to a current reading of 90%. The Apishapa SNOTEL station reports 75% while the Hayden Pass station improved from 40% a month ago to 69% at present.

Reservoir Storage
Statewide reservoir storage was reported at 78% of average and 43% of total capacity during the February Governor's Water Availability Task Force meeting. This link accesses the latest NRCS reservoir report, which is unfortunately producing suspect and incomplete data for February. The issue should be resolved soon. 

River Flows
As of March 5, Arkansas River flows were 252 cfs at Granite, 393 cfs at the Wellsville gauge near Salida and 361 cfs at Cañon City. Below Pueblo Dam, flows were 64.9 cfs, increasing to 276 cfs near Avondale before dropping to 155 cfs near Rocky Ford. The flow was 1.64 cfs below John Martin Reservoir and 10.6 cfs at Lamar. Boustead Tunnel discharge rates were not available as of this writing.

River Calls
The Arkansas River Basin had eight active calls as of March 5. The Fort Lyon Storage Canal remains the calling water right on the Arkansas mainstem with a March 1, 1910, priority date. The Holitas Reservoir has a call on the Cucharas River with a March 20, 1901, priority date. The Upper Huerfano No. 2 is the calling structure on the Huerfano River with a priority date of March 15, 1869. The Model Ditch (March 20, 1862) continues its call on the Purgatoire River, as does the Tenassee Ditch (April 30, 1880) on the South Arkansas River. Additional calls are in place on Fourmile Creek and Greenhorn Creek. The Winter Water Storage Program ends March 14, which will likely impact calling water rights.

​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.

Snowpack
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%.

River Flows
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.
​
River Calls
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.