Water bank could be short by May
Unless Mother Nature surprises New Mexico with a couple of good snow storms, irrigators, depending on the water bank this season, may get cut off as early as May.
Middle Rio Grande Conservancy hydrologist David Gensler reported the news at the MRGCD special water bank board meeting in Albuquerquelast week. But at least water bank irrigators won't have to worry about a hike in their lease fees this season.
The MRGCD water bank is a way for farmers to irrigate lands in the district from which water rights have been severed, either because of disuse, transfer or sale.
These farmers lease irrigation water made available because other land in the district is now incapable of being irrigated, usually because of incompatible uses, such as buildings or roadways.
The water bank curtailments do not affect farmers irrigating lands in the district from which the water rights have not been sold nor transferred.
Last year, the MRGCD board, responding to irrigation shortages caused by drought conditions in 2012, voted to implement a new water bank policy that took effect this January.
Under the new policy, water bank users will face curtailment — irrigation cut off — if the amount of water in storage and flowing in the Rio Grande drops below certain monthly parameters already posted on the district's website.
Other irrigators will not be subject to the water bank curtailments.
The new policy is designed to create more flexibility in the system so irrigators can benefit from quickly changing flow situations.
The district hydrologists or local division managers can reinstate irrigation to water bank users when local conditions in their area increase flow in the river, even if the system-wide supply is still below the cut-off parameters for that month. Run-off from summer thunderstorms often fill ditches in the vicinity of the storms, and that's when the water bank curtailments would be lifted for irrigators served by those ditches.
When the Rio Puerco starts running, water bank irrigators will have their curtailments lifted immediately.
Gensler wasn't comfortable foretelling New Mexico's spring and summer water situation this early in the season, but he bowed to farmers and wildlife managers who need a heads-up.
"This year looks to be a bad one," he said. "We have greatly depleted reservoirs. We need to have a significantly above-average year just to get back to normal."
He said late winter and spring storms could save the season, but long-term climate predictions indicate a warm and dry winter with "no noticeable run-off."
Low to zero run-off affects not only irrigators but also species dependent on river flows, such as the endangered silvery minnow, which spawns when the river runs high in late May.
Late spring runoff is estimated to be 1,000 cubic feet per second at the Central Avenue bridge gage in Albuquerque, below the 2,500 to 3,000 cfs amount minnow experts think is the lower limit for a good spawn, Gensler said.
He said the district will try to provide the most beneficial spawning conditions for the minnow with the amount of water it has to work with, perhaps by moving water the state is required by treaty to deliver to Texas and Mexico to Elephant Butte in May.
"The U.S. Corps of Engineers could store some water early in the season at Cochiti Reservoir, and then release it as a pulse to coax about 5,000 to 10,000 acre feet into the system," he said.
An acre foot is enough water to cover an acre with a one-foot layer of water, about 325,851 gallons.
If a natural spring run-off doesn't materialize, the MRGCD will have to use water stored behind upstream dams to augment natural river flow to supply irrigators, but there is little water to work with right now.
"We don't have any stored water this year," Gensler said. "There's 20,000 acre feet in storage right now."
He said the district will try to capture 20,000 more acre feet in upstream reservoirs this spring, but the district will have far less at the beginning of this year's irrigation season than it did last year when 103,000-acre feet stood behind dams.
Spring growing conditions put extra demands on supply, he said. Last year, district irrigators consumed 40,000 acre feet in 34 days as farmers watered plants growing fast in warm and windy weather,
The district then supplements river flow with stored water to meet demand.
"We will have to use stored water even earlier than last year, maybe as early as mid May," he said. "We will likely have enough natural flow in March, April, May and maybe June. After that, it's unlikely we will meet the natural flow requirement and curtailment of water bank users will likely happen. We don't know how long the curtailment will last."
Gensler said water shortages will mean hardship for regular irrigators up and down the system as well.
"There will be a strict scheduled rotation," he said. "Some ditches will be turned off for significant lengths of time. This year we are not going to turn on the ditches and everybody gets water when they want it. We are going to get strict with everybody."
Socorro farmer and MRGCD board member Chris Sichler delivered the Water Bank Committee Report to the board, emphasizing the need to help small-scale water bank irrigators faced with an uncertain season.
"The board's goal is to get the administrative fee down," Sichler said.
After some discussion, the board agreed to keep the one-time lease administration fee at the 2012 rate of $100. Water bank leases will be good for up to five consecutive years, unless the lease terms change, in which case the $100 fee will be charged for the new lease. The yearly $78 per acre water bank charge will not increase in 2013.