CAP: Water savings from fallow program fall below estimate

The 1,500-acre pilot land fallowing program within the Yuma Mesa Irrigation and Drainage District did conserve water during its three-year run, but not as much as expected, Central Arizona Project representatives said Thursday.

They spoke at a quarterly Colorado River Citizens Forum meeting held in Yuma, where a panel of residents with varying levels of knowledge about the area’s chief source of water bring in experts to talk to them and the public about issues affecting the river.

The fallowing program ran from 2013 to 2016, during which farmers who agreed to participate by not taking water deliveries to parts of their district were paid $750 per year per acre as compensation for not putting the land in production.

In 2014 the water savings per acre in the program was 4.9 acre feet, in 2015 5.1 acre feet per acre, and in 2016 it was 5.36 acre feet, for an annual water savings of 6,800 to 7,500 acre-feet, said Perri Benemellis, manager of the CAP’s Central Arizona Groundwater Replenishment District’s water supply program.

The study’s initial estimate was there would be a savings of about 6 acre feet, which she said was a “conservative” number based off the estimate of 7 acre feet, taken from a Bureau of Reclamation fallowing program from 2008-10 which never came up with a way to calculate actual water savings from not having land in production.

“The problem here is you’re trying to measure something that isn’t happening,” Benemellis said.

CAP worked with a land mapping firm for a couple of years leading up to the study to analyze crops then growing on the acres that would be fallowed for the study. The data they used included accepted consumptive uses for the crops involved, adjusted by the amount of water vapor produced by those plants, as measured by a nearby weather station.

Benemellis said the estimates taken from the research done just before the fallowing started were a savings of 4.8 to 5.2 acrefeet per fallowed acre, in line with the actual results. Those water savings were measured on the ground and correlated with the amount of water that wasn’t released from Lake Mead to YMIDD during those years.

Because the water not used stayed in Lake Mead, Benemellis said, it became part of the efforts in recent years to keep enough water in the reservoir to keep it from going below an elevation of 1,070 feet, which would trigger a water shortage declaration from the BOR which would affect Arizona first.

Citizens’ Forum chairwoman Bobbi McDermott was skeptical of the methodology the study used.

“How do you measure a vacant field, when you don’t have crops growing on it, transpiring, being irrigated, all of this . ... I still don’t see how this gives me the answers I’m looking for, or the answers you’re looking for,” she said.

She also took issue with the district not getting any money or credits for water saved, or ability to use the water in future years, although the farmers were compensated. “So the district gets absolutely nothing out of this, other than a lot of headaches and paperwork?”

Benemellis responded the same thing happens whenever any district doesn’t use its full allocation of Colorado River water. “It’s all beneficial use, all of our water rights are for beneficial use in that year. It’s law of the River, that’s how it operates.”

YMIDD Manager Pat Morgan acknowledged the district didn’t get any direct benefit from the program, aside from some money for a demonstration and for lost revenues for excess water. “Everybody who participated in the program liked how it ran,” he said.

“Of course, they got paid $750 an acre,” McDermott interjected.

“Yes, but it also helped the land,” Morgan said. “We’ve probably got about 2000 lemon trees that weren’t as productive as they used to be, and I know a lot of lemon farmers feel kind of trapped by them. One of them actually walked into the office one day and said, ‘this is great, we’ve got 3,000 acres of lemon trees that need to come back out, because I don’t get as much out of them as I put into them.

He added, “It’s difficult, especially for lemon farmers, to decide when to take their trees out because it’s so expensive. So he has the revenue to be able to go in and pull out those trees. We had a lot of young trees planted this year because of it. There are other reasons, the price of lemons is up.”

He said he doesn’t see much of a downside to continuing limited fallowing within the district, “so long as you don’t let it get too big or too long.”

The practice of paying farmers not to irrigate their land as a water conservation measure is controversial in Yuma and other agricultural areas, due of fears that taking too much land out of production would eliminate a large number of jobs throughout the production chain and damaging the local economy.

Yuma County is not part of the CAP, whose farmers would likely be the first users to be affected by any declared water shortage. Benemellis said the study is intended to provide answers about if and how shorter-term fallowing programs would work.

“We want to find out, was there a way to craft a program to do rotational fallowing, a voluntary program, pay an appropriate sum for the folks who were interested in participating in the program, do a defensible water savings quantification, and do it in a way that was not damaging to the economy of the area,” she said.

She said so far CAP has been pleased with the results, and the final report will be completed for distribution within the next couple of months.