Elephant Butte was near capacity in the 1990s; it’s now at 3.5 percent
Copyright © 2013 Albuquerque Journal
With a month of sometimes impressive rains around New Mexico, the calls have been coming in to the National Weather Service office in Albuquerque: “Is the drought over?”
The answer, repeatedly, is “no.”
Elephant Butte Reservoir is still nearly empty, the state’s rangeland is still mostly bereft of grass and the state’s mountain watersheds are still largely parched. Just a little less so.
“It’s taken many years to develop,” Weather Service meteorologist Chuck Jones said during a meeting Tuesday of the state’s Drought Monitoring Working Group. “It’s going to take time to get rid of it.”
But as bountiful summer thunderstorms trigger flash floods, fill some irrigation ditches, raise some reservoir levels and leave scattered ponds around New Mexico, current conditions are a reminder that drought depends on where you are and how you use water.
“There are all sorts of definitions of drought out there,” said New Mexico State University professor Phil King, who serves as technical adviser to the Elephant Butte Irrigation District, southern New Mexico’s largest farm water agency.
First of all, there’s the question of the rain itself. Overall, New Mexico’s July rains are above average, but for the “water year” to date (since Oct. 1), Albuquerque’s rainfall is still just 77 percent of average.
And summer thunderstorms are a hit-and-miss affair. Albuquerque, for example, had received 2.77 inches of rain at the airport through Monday, nearly double the average for the first 29 days of July. But across the Albuquerque metro area, reported rainfall totals range from as little as 1.4 to a high of more than 5 inches.
Across New Mexico, points as distant as Chama in the north and Carlsbad in the south are above average for the month. But if you’re in Farmington in the northwest or Raton in the northeast, you’re in the below average category.
The strangest case of summer rain haves vs. have nots may be the area around Silver City, in southwest New Mexico, where July rainfall totals range from 1.66 to 9.49 inches, according to Jones, depending on whose rain gauge got hit by the summer thunderstorms and who missed out.
If you’re a farmer depending on irrigation water, the rains have either bailed you out or helped very little, depending on where you are. In the Middle Rio Grande Conservancy District, many ditches have been running full but the rain means farmers don’t need the water, according to Raymond Abeyta of the U.S. Bureau of Reclamation. For some farmers, the rain has been too much, wetting alfalfa when it should be drying in the summer sun before shipment to customers.
For Rio Grande farmers in southern New Mexico, the rain is largely irrelevant, King said. They depend on a big winter snowpack to fill Elephant Butte Reservoir. Elephant Butte was last full in the 1990s, and a combination of shrinking winter snowpacks and continued irrigation use downstream has drained it in the years since.
This year, it dropped to its lowest levels since the early 1970s. That resulted in the shortest, driest irrigation season on record for the lower Rio Grande’s chile and pecan farmers, according to King. With the irrigation season now over, Elephant Butte has begun to rise, but barely, up from 3 percent of capacity to 3.5 percent. “The best drought indicator we have is Elephant Butte, and 3.5 percent sure sounds like a drought to me,” King said Tuesday.
If you’re a rancher, the condition of the state’s open range is the critical drought indicator. On that score, the rains are helping, according to Les Owen with the New Mexico Department of Agriculture. Sort of.
On a recent drive through the state, Owen saw a little new grass growth between Las Cruces and Albuquerque, and some improved conditions northwest of Albuquerque. But once he crossed the continental divide into the San Juan Basin of northwest New Mexico, “it starts turning brown again,” he told the drought group members Tuesday. “It’s kind of spotty,” Owen said. Overall, according to a report from Owen, 82 percent of the state’s rangeland is in “poor” or “very poor” condition, meaning the rain has not been enough to help much.
After an abysmal winter and spring, the state’s mountain watersheds have averaged 50 to 90 percent above average rainfall in July, according to Wayne Sleep of the Natural Resources Conservation Service. In the long run, conditions in mountain watersheds matter a great deal in the process of alleviating drought. The drier they are going into the winter season, the worse the runoff next spring will be.
On that score, Sleep says a network of sensors recently installed is showing increased moisture near the surface, but it is still not soaking in very deeply.
Winter snow on those mountains is what will begin to refill Elephant Butte next year and thereby alleviate drought for southern New Mexico farmers, or not, King said. The drier the soil to start with in the fall, the worse the resulting runoff will be next spring, King said. So he’s watching the mountain soil moisture with interest.