ARWC releases weekly River Report

Wetter weather patterns have tempered drought conditions in the upper Arkansas Basin and boosted snowpack, but the latest U.S. Drought Monitor report shows Extreme to Exceptional drought (the two highest intensity levels) across Baca, Bent and Prowers counties in the southeast corner of Colorado.

As the National Resources Conservation Service (NRCS) map shows, Arkansas Basin snowpack was at 101% of median as of May 29. The Fremont Pass SNOTEL site is reporting 90% of median.

Reservoir Storage
May 29 reservoir data from the U.S. Bureau of Reclamation showed 205,838​ acre-feet of water stored in Pueblo Reservoir and 63.7%  full. Twin Lakes Reservoir is 76.8% full at 108,219 acre-feet. Turquoise Lake is currently 58.1% full with 75,227 acre-feet in storage. 

U.S. Army Corps of Engineers data show 30,014 acre-feet of water currently stored in John Martin Reservoir. In spite of low water levels, the Colorado Parks and Wildlife website shows the east boat ramp at John Martin State Park is still open.

River Flows
Arkansas River flows are 202 cfs near Leadville, 690 cfs at Granite, 1,380 cfs at Wellsville and 1,570 cfs at Cañon City. Below Pueblo Dam and near Avondale, flows are 1,090 cfs and 1,390 cfs, respectively.

The Rocky Ford gauge is reporting 495 cfs. Below John Martin Reservoir flows are 610 cfs, and at Lamar, 58.8  cfs. 

Voluntary Flow Management Program
Flow management targets to support recreational boating are slated to begin July 1 after spring runoff. 

River Calls
Currently, the Arkansas Basin has 14 calling water rights, including four on the mainstem – the Fort Lyon Canal (1887 priority), the Hyde Ditch (1887), the X-Y Irrigating Ditch (1889) and the Arkansas River Compact for flows at the Colorado-Kansas state line.

The most senior calling right is the Model Ditch with an 1865 priority date on the Purgatoire River. The 1866 Gonzales Ditch right continues to call for Apishapa River water.

Other tributary calls include the RB Willis Ditch on Wahatoya Creek, a Cucharas River tributary, the Reservoir and the Pedro Gomez ditches on the Huerfano River and the Tremayne Ditch No.1 on Fourmile Creek.

The most junior calling water right on Arkansas River tributaries is the Waggoner Ditch on Stout Creek with an 1880 priority date.

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.

Joe Stone