Whereas a lot of the Higher Arkansas River Basin stays drought-free, extreme drought has returned to components of the decrease basin with the southeastern nook of Colorado now experiencing excessive drought, in accordance with the most recent U.S. Drought Monitor report. 

Snowpack

Regardless of latest snowfall within the higher basin, early season snowpack is trending beneath common with NRCS Snowpack Telemetry (SNOTEL) information exhibiting basin-wide snowpack at 76 % of median for snow-water equal (SWE). The best studying is at the moment at Saint Elmo, the place the SNOTEL station reveals SWE at 4.5 inches, 118 % of median. Extra correct than SNOTEL information, aerial snow survey information is predicted to be carried out in Colorado this winter by Airborne Snow Observatories, however that information is just not but out there.

Water Availability

The Governor’s Water Availability Activity Drive report for November summarizes information for Water Yr 2022, noting it was “the sixth warmest and thirty fifth driest on report going again to 1896” with February being the coldest month of the yr. Colorado skilled a “moist July” and benefited from “monsoonal moisture within the central and southern components of the state.”

As Water Yr 2023 begins, “Colorado has a number of the finest antecedent soil moisture in years,” the report states, “however on the japanese aspect of the Divide, (soil) situations are loads drier than regular. Precipitation is close to regular at 95 % of median. … La Nina appears prone to proceed by way of early winter and presumably past. On common, the Northern Rockies are wetter throughout La Nina and with colder temperatures that may end up in good snowpack situations. Drier situations could influence the southern a part of the state.”

Winter Water Storage Program

The Winter Water Storage Program (WWSP) within the Arkansas River Basin runs from Nov. 15 to March 14 yearly. This system was devised throughout the early planning phases of the Fryingpan-Arkansas Mission and shops water that might in any other case be diverted by irrigators downstream from Pueblo Reservoir throughout the winter months. This saved water is then launched throughout the next irrigation season.

The WWSP has been refined to reach at “an equitable technique of apportioning the saved water among the many WWSP members and avoiding harm to non-participants.” Negotiations finally produced a consensus amongst members and objectors, producing an preliminary decree authorized by Water Court docket Choose Tracey in 1987. In 1990, Tracey entered an order making the decree ultimate.  

The members within the WWSP primarily retailer their WWSP water in Pueblo Reservoir but additionally use Henry, Meredith, Holbrook, Dye, Adobe, Horse Creek, Nice Plains and John Martin reservoirs. When house is proscribed, precedence for storage of WWSP water in Pueblo Reservoir goes to entities that do not have entry to off-channel reservoir storage. When energetic, the WWSP impacts reservoir storage, river flows and calling water rights within the Arkansas Basin.

Reservoir Storage

Water storage in Pueblo Reservoir elevated throughout November, from 177, 342 acre-feet to 184,866 acre-feet or 57.2 % full. Water storage in Turquoise Lake fell from 85,368.5 acre-feet a month in the past to 84,452.2 acre-feet or 65.3 % full. At Twin Lakes storage ranges additionally decreased in November, from 120,899 acre-feet to 114,014 acre-feet or 80.9 % full. The U.S. Military Corps of Engineers experiences water storage in John Martin Reservoir elevated from 11,442 acre-feet to fifteen,921 acre-feet in November.

River Flows

With Fyingpan Arkansas challenge water releases at the moment suspended and the WWSP in impact, Arkansas River flows have typically decreased in Colorado. The Leadville gauge hasn’t reported any new information for the previous week, and the gauge at Granite at the moment reads 119 cfs. River move at Wellsville is 315 cfs, and at Canon Metropolis, 380 cfs. The move beneath Pueblo Reservoir has dropped 69.9 cfs, a mirrored image of the WWSP. The gauge close to Avondale at the moment reads 289 cfs, whereas the move at Rocky Ford has dropped to 68.8 cfs. Circulate beneath John Martin Reservoir has dropped to 1.16 cfs however has elevated to 16.3 cfs close to Lamar.

Calling Water Rights

With the WWSP in impact, solely eight water rights are at the moment calling for water within the Arkansas Basin. Probably the most senior calling proper is the Lewellyn McCormick proper with an 1864 precedence date on the Purgatoire River. The 1866 Gonzales Ditch proper on the Apishapa River is subsequent in precedence, adopted by the 1867 Coleman Ditch proper on Hardscrabble Creek.

The Fernandez Ditch (1868 precedence) has a name on Turkey Creek, the Higher Huerfano No. 2 (1869) has a name on the Huerfano River, and the Doris Ditch (1870) has a name on Fourmile Creek. On the Arkansas River mainstem, the 1910 Fort Lyon Storage Canal proper has a name, and as all the time, the Arkansas River Compact has a name on the Kansas state line to make sure that Colorado sends water to Kansas.