From The Pueblo Chieftain (Chris Woodka):
The problem is, there have not been many good studies quantifying how much water will be needed for agriculture in the Arkansas River basin in the future. “A city can reliably tell you what their demand is every year, but we don’t even have an idea of what we currently need for agriculture,” said Mike Bartolo, director of the Colorado State University Agricultural Research Center at Rocky Ford. “Agriculture is way behind the curve.”
Statewide water supply studies by the Colorado Water Conservation Board have mostly concentrated on the Colorado River Basin with the twin goals of compact compliance and urban supply. Hardly any work has been done on assessing what a study of the supply for growing food should look like…
The irrigation system of the Arkansas Valley is a complex network of more than 12,000 water rights, return flows and variable weather conditions every month, much less year-to-year. There are also interactions between thousands of wells in the alluvial aquifer and surface flows that would take years to assess.
Even if the amount of water available could be predicted, it would be hard to estimate consumptive use. The state in the last five years has installed a weighing lysimeter at the Rocky Ford Research Center to look at consumptive use of alfalfa, the valley’s most common crop. Actually weighing the water used in this area is thought to be the most accurate way to estimate consumptive use for all crops. “Some days, I’ll look at the lysimeter readings and say, ‘Wow, did it use that much?’ ” Bartolo said.
More Arkansas Basin coverage here.