FLAGSTAFF, Ariz. (AP) -- A shortage in Arizona's allocation of water from the Colorado River would fall onto farmers in the central and southern parts of the state, and limit the amount of water that can be stored underground, officials said in response to new federal projections on the supply.
The U.S. Bureau of Reclamation released the projections Friday that show a 2 percent chance of Lake Mead in Nevada reaching the trigger point in 2015 for a shortage declaration and a 50 percent chance in 2016. Arizona would see its 2.8 million acre-foot allocation reduced by 11.4 percent, or 320,000 acre feet that is sold to non-American Indian agricultural users and stored underground.
The cuts would force farmers to rely partly on wells to pump water for their fields but aren't deep enough to require Arizona to pull from its water savings bank.
"If we think about this in terms of a paycheck, our paycheck is reduced so that we can't contribute to our 401K," said Chuck Cullom, Colorado River program manager for the Central Arizona Project. "We can still make our mortgage, our car payment, but we're not saving for the future. And that's a significant impact as we look at the impacts of climate change."
Cities like Phoenix and Tucson, which have water delivered through a series of canals managed by CAP, as well as American Indian tribes, would be spared from any losses.
Sidney Smith, general manager at the Hohokam Irrigation District in Coolidge, said she's been telling farmers for the past year to start fixing up their wells in case they have to revert to pumping groundwater. Not all of the farmers have wells, and wells on some land that farmers lease from municipalities are in bad shape, she said.
"Coolidge is very, very small. It's a farming community," she said. "Basically if farming stops here, it's going to hurt the whole community."
Wells already have been running within the Maricopa-Stanfield Irrigation and Drainage District near Casa Grande in anticipation of a river water shortage in 2016 and planned reductions in the CAP supply. The district's general manager, Brian Betcher, said it is assessing how many of the available 300 wells need to be brought online. The district built out a canal system in the late 1980s to deliver the Colorado River water to farmers growing cotton, alfalfa, wheat, barley, fruit and vegetables, and to dairies, and tied the wells into it.
"The agricultural community does not relish the idea of going back to groundwater reliance, but it's a reality they've understood," he said. "That it's not a matter of if, it's a matter of when, and then it's a matter of how much and how fast."
Cullom said farmers already were expecting reductions as American Indian tribes that settled water claims to the Colorado River build the infrastructure to put it to use. The 400,000 acre-feet that now is delivered to more than a handful of irrigation districts will drop to 300,000 acre feet in 2017 and will be reduced periodically until 2030, when CAP no longer commits excess water to the non-Indian agricultural pool.
"They have to make an economic decision, the cost of increasing their groundwater capacity versus the value of the commodity," he said. "I don't want to underplay the difficult decisions they will face. From a water management perspective, the idea, the theory was that we would deliver renewable Colorado River water to replace groundwater."
But with the back-to-back driest years in a century on the Colorado River, Arizona and Nevada may need to supplement the river water supply.
Arizona has invested millions of dollars to store water underground in locations along the CAP canal system and pushed conservation efforts so that tribes and the state's major metropolitan areas won't suffer. Water managers estimate that there's more than a 50-year supply of water underground.
"While the possibility of a shortage declaration is significant, Arizona has been planning and preparing for just such a condition for decades," said Sandra Fabritz Whitney, director of the Arizona Department of Water Resources and chairwoman of the Arizona Water Banking Authority.
Prices for water also could go up as CAP sells less water and its revenues drop. Cullom said the CAP board could consider dipping into a rate stabilization fund, making changes to tax collections or raising rates to address the increase.