Drought conditions have slipped back into southwestern Colorado, with abnormally dry conditions extending into the Upper Arkansas River Basin, and the National Weather Service three-month outlook projects above-normal temperatures through November and equal chances of normal precipitation for Colorado.
The CoCoRaHS (Community Collaborative Rain, Hail and Snow) Network reports the following precipitation amounts, in inches, for the month of July in the Arkansas River Basin in Colorado:
The Bureau of Reclamation reports that Pueblo Reservoir water levels dropped from 228,345 acre-feet at the end of July to 222,043 acre-feet (68.8% full) at the end of August. The Turquoise Lake water level dropped from 114,100 acre-feet to 94,100.5 acre-feet (72.7% full) in August. Twin Lakes Reservoir levels decreased in August, from 129,492 to 117,611acre-feet (83.4% full). The water level in John Martin Reservoir has dropped from 85,623 acre-feet at the end of July to a current level of 29,377 acre-feet.
Over the past month, the Arkansas River flow near Leadville has dropped from 86.4 cfs to 21.9 cfs. Downstream, the gauge below Granite reads 376 cfs, and the Wellsville gauge near Salida currently reports 548 cfs.
The flow at Cañon City is currently 565 cfs, and the flow Pueblo Reservoir is currently 244 cfs. The gauge near Avondale reports a flow of 372 cfs, and the gauge at Rocky Ford reads 379 cfs. The current reading below John Martin Reservoir is 519 cfs, and the flow at Lamar has dropped to 25.4 cfs.
Calling Water Rights
As mentioned in the River Report for July, Division 2 (Arkansas Basin) Engineer Rachel Zancanella reaching out to water stakeholders across the basin in an effort to determine how best to address a change in water rights administration requested by the Colorado Attorney General's Office.
In the meantime, water-rights holders who could surrender priority under the potential change will be listed as "authorized diversions" instead of "calls." Under this interim water-rights administration policy, the Arkansas Basin currently has 16 calling water rights and nine authorized diversions.
The most senior calling right is the 1860 Hardscrabble Ditch on the Hardscrabble Creek, followed by the 1863 John W. Brown Ditch right on Huerfano River and the 1865 Cañon Heights Ditch right Fourmile Creek.
Four 1866 water rights are also calling for water: the Walsenburg Ditch on the Cucharas River, the Hayden Supply Ditch on Greenhorn Creek, the Model Ditch on the Purgatoire River, and the Gonzales Ditch on the Apishapa River.
The Cottonwood and Maxwell Ditch is calling for Cottonwood Creek water under its 1874 right, and the DeWeese Dye Ditch is calling for Grape Creek water under its 1877 right.
The water rights next in seniority are the 1880 Waggoner Ditch on Stout Creek, the 1881 Briscoe Ditch (Tenassee Ditch) on the South Arkansas River, the 1881 Dotson Ditch No. 1 on the Saint Charles River, and the 1884 Fort Lyon Canal on the Arkansas River mainstem.
Rounding out the current active calls are the 1887 Hyde Ditch, the 1889 X-Y Irrigating Ditch, and the 1949 Arkansas River Compact, all on the Arkansas River mainstem.
The nine authorized diversions now in priority are: