Colorado saw the return of monsoon weather patterns this past week, bringing welcome precipitation to the Arkansas Basin. Drought conditions have moderated but continue almost across the entire state.

Precipitation
As reported through the Community Collaborative Rain, Hail and Snow Network, also known as CoCoRaHS, here are the precipitation totals for the past week:

  • Leadville – 0.47 inch.
  • Buena Vista – 0.48-0.83 inch.
  • Salida – 0.32 inch.
  • ​Westcliffe – 0.18-0.55 inch.
  • Cañon City – 0.48-0.64 inch.
  • ​Walsenburg – 0.47-0.72 inch.
  • Trinidad – 1.07-1.72 inches.
  • Pueblo – 0.05-0.16 inch.
  • Colorado Springs – 0.29-1.47 inches.
  • Rocky Ford – 0.14 inch.​
  • Springfield – 0.58 inch.
  • Lamar – 0.25-0.33 inch.

Reservoir Storage
Current reservoir data from the U.S. Bureau of Reclamation shows the water level little changed in Pueblo Reservoir at 61.4% full with 198,335 acre-feet of water in storage. Turquoise Lake water storage increased to 107,416 acre-feet or 83% full. Twin Lakes Reservoir water storage increased slightly to 118,467 acre-feet, 84% full, in spite of increases in outflow as reported by the Bureau of Reclamation. U.S. Army Corps of Engineers data show 21,500 acre-feet of water currently stored in John Martin Reservoir.

River Flows
Arkansas River flows dropped to 131 cfs near Leadville and 624 cfs below Granite. Flows at the Wellsville gauge declined during the week but increased today to match last week’s flow of 1,140 cfs, including 5 cfs of Fry-Ark Project water. The Cañon City gauge currently reports 1,000 cfs. Flows below Pueblo Dam have increased to 888 cfs and to 1,260 cfs near Avondale. Near Rocky Ford, flows are 347 cfs  and below John Martin Reservoir, 413 cfs. The gauge at Lamar reports 110 cfs.

River Calls
Currently, the Arkansas Basin has 13 active calls and two authorized diversions – the Welton and Jose Maria ditches on the Huerfano River. The three calls on the mainstem remain unchanged from a week ago – the Amity Canal (1887 priority), the X-Y Irrigating Ditch (1889) and the 1949 Arkansas River Compact at the Kansas state line. The most senior calling right is the Titsworth Ditch with an 1863 priority date on Fourmile Creek, followed by the Model Ditch on the Purgatoire River (1865 priority). The Hayden Supply Ditch (1866) continues to call for water on Greenhorn Creek, as does the Gonzales Ditch (1866) on the Apishapa River, and the Garcia Ditch No. 2 (1867) and Welton Ditch (1889) on the Huerfano River. New calling water rights are the Fernandez Ditch (1868) on Turkey Creek and the Dotson Ditch No. 1 (1881) on the Saint Charles River.

The Arkansas River Report is provided by the Arkansas River Watershed Collaborative. ARWC is the nonprofit organization for the Arkansas Basin Roundtable, a group of water managers and stakeholders working with state agencies to find solutions to water-related issues in the basin. Roundtable members serve as the ARWC Board of Directors