From The Pueblo Chieftain (Chris Woodka):
Flows in the Arkansas River below Pueblo Dam increased slightly with the end of winter water storage this week, but not significantly. The reason is that water continues to be released for the Pueblo flow management program and much of the winter water was stored in downstream reservoirs, including on the Colorado Canal, the Fort Lyon and in John Martin Reservoir.
“The movement of the agricultural water is a side benefit to the Arkansas River flows through Pueblo,” said Steve Witte, Water Division 2 engineer.
Winter water stored about 101,000 acrefeet this year, but only about 27,000 acre-feet were stored in Lake Pueblo. An acre-foot is 325,851 gallons.
Flows in the Arkansas River at Avondale were about 320 cubic feet per second this week, about the same as during the two weeks preceding the end of the winter water program. One cubic foot of water is about the same volume as a basketball.
Meanwhile, flows above Lake Pueblo in the Arkansas River have increased in recent weeks because the Bureau of Reclamation is making room in Turquoise and Twin Lakes for Fryingpan-Arkansas Project water. The March 1 forecast predicts about 73,000 acre-feet will be moved across the Continental Divide this year. But that can increase or decrease, depending on snowpack, said Roy Vaughan, Fry-Ark manager for the Bureau of Reclamation.
Repairs have been completed on the Mt. Elbert hydropower plant, allowing for full operation of Fry-Ark systems.
Releases from the upper reservoirs are adding about 270 cfs to the Arkansas River above Pueblo, which is running at twice the rate it was three weeks ago.
From The Pueblo Chieftain (Chris Woodka):
Flows into John Martin Reservoir have not been reduced by the winter water storage program on the Arkansas River, according to an analysis by the Colorado Division of Water Resources. The issue is of concern because of questions raised by Kansas during court cases against Colorado over the Arkansas River Compact. John Martin Reservoir, completed in 1948, regulates flows between the two states under the compact.
“We’ve never showed them evidence that they’ll buy into about the winter water program, but we keep trying,” division engineer Steve Witte told the Southeastern Colorado Water Conservancy District board Thursday.
The winter water storage program allows irrigation flows to be stored from Nov. 15 to March 15, and ended last week. This year, about 101,000 acre-feet were stored at various locations and will be divided among ditch companies east of Pueblo.
The analysis looked at diversions by ditches in Colorado from 1950-1975 and from 1976-2013. Winter water began as a voluntary program in 1976 and was later formalized in a water court decree.
“There hasn’t been any significant change as a result of winter water,” Witte said.
Diversions above John Martin totaled 72 percent to 77 percent in the 1950-1975 period, and were about 75 percent in the 1976-2013 period. Past analysis of the water levels in John Martin showed little difference in pre-winter water and post-winter water years. But those types of studies don’t explain changes because of operational changes or drought. The new study also looked at potential differences in wet, dry and average years, but found none, Witte said.
More Arkansas River Basin coverage here.