From The Pueblo Chieftain (Chris Woodka):
Colorado’s credit for water deliveries at the Kansas state line stands at more than 58,700 acre-feet under a rolling 10-year average. The annual accounting of deliveries, related to a 24-year U.S. Supreme Court case over the Arkansas River Compact, was given to the compact administration Wednesday.
In 2012, marked by statewide drought, there was a net depletion of 5,500 acre-feet to the Arkansas River. That was combined with other flows since 2003 to calculate the 10-year average.
While the final decision in the court case was issued in 2009, Colorado and Kansas continue to work through issues related to water deliveries.
Bill Tyner, assistant engineer for Colorado Division 2, reported that 1,160 acre-feet of replacement water was made available by the Lower Arkansas Valley Water Conservancy District to compensate for on-farm sprinkler improvements on more than 14,500 acres covering 100 farms.
Tyner reported a pond study is showing about 18 percent seepage, which is nearly twice the assumed rate in a “conservative” computer model. The pond study will be complete next year, but results from individual measurements already are being applied as credits for about 20 individual farmers.
“We’ll report next year on any changes we make in the model,” Tyner said.
Kansas accepted Colorado’s evaluation of the presumptive depletion for well pumping at 36.5 percent next year, said Kelly Thompson of the Colorado Division of Water Resources.
Kansas still has issues with a Colorado water court decree for the Lower Arkansas Water Management Association, said Eve McDonald, of the Colorado attorney general’s office.
For the second consecutive year, Kansas took no water from its account in John Martin Reservoir because of the low volume of water, dry conditions and the timing of flows, which arrived past the point when they could be used in Kansas.
“We lose less through evaporation than by running it down the river,” said Kevin Salter of the Kansas Division of Water Resources.
More Arkansas River Basin coverage here.