Gone in a Generation

Laura Harper farms the 34 acres of pecan trees in the Mesilla Valley of southern New Mexico that her late mother, Sally, established as one of the region’s first organic orchards. She has depended on the Rio Grande to irrigate. But decades of drought have made the river an unreliable source of water. For much of the year, says Harper, 45, the river is “cut off” — dammed up at a reservoir called Elephant Butte to manage its flows.

One day in March, the river was almost entirely dry near Harper’s orchard. One day in September, it was running full, swelled by the release of water from the reservoir upstream. The levels ebb and flow each year; what has been steady is the persistence of overall drought.

In a warming climate, Harper worries that this valley may not be able to sustain the thirsty orchards that produce a healthy and lucrative pecan crop. She and her fellow farmers have been pumping more water from underground.

There’s stark evidence of the problem near the town of Truth or Consequences, about 100 miles north of the Mexican border. The century-old Elephant Butte Dam was constructed along the Rio Grande to provide power and irrigation to south-central New Mexico and West Texas, and the resulting reservoir spans 60 square miles.

The gap between the reservoir’s current water level and the high-water mark on surrounding ridges is clearly visible. One March day this spring, the gap measured 88 feet. And although rains and melting snow since then have raised the reservoir’s water level, Elephant Butte is at only 22 percent of its capacity.

The region has suffered through long, dry spells before. Many folks in the valley talk about the intense drought of the 1950s, when New Mexico farmers first began installing pumps to extract groundwater to irrigate their pecan orchards and fields of chiles and alfalfa.

But something is different about the drought this time, many climate scientists suspect.

The mountain snowpack in the southern Rockies and parts of northern New Mexico that feeds the Rio Grande’s headwaters has declined about 25 percent since the late 1950s, said David Gutzler, a climate scientist at the University of New Mexico. As for temperature: New Mexico certainly saw some warm days in the 1930s, at the time of the Dust Bowl. But the state has had an extraordinary warming streak since about 1970, seeing the average annual temperature rise by more than 3 degrees Fahrenheit in just under 50 years.

So there’s less snow and ice in the mountains, and, scientists theorize, the water that does run off is evaporating faster, because of those higher temperatures, and before the river reaches the southern farms.

Not everyone agrees with this theory, or with Laura Hill’s concerns that climate change may threaten pecan farming in the valley.

Jay Hill, 34, is using technology to test new farming methods in the region. He manages his irrigation systems from his phone and posts gorgeous Instagram photos of his fields.

And he’s highly successful. He grows pecans and over a dozen other crops over thousands of acres he acquired over 19 years, starting in high school. That’s when Jay’s father, who himself farmed as a hobby, pushed him to create a business plan so he could get his first bank loan to grow a crop.

With precious little water coming from the depleted reservoir in recent years, many of the farmers along the Rio Grande have had to rely so heavily on groundwater that Texas in 2013 sued New Mexico over the practice. The lawsuit, which is before the Supreme Court, alleges that the wells near the Rio Grande are siphoning off groundwater that is hydrologically connected to the river — in violation of the 1939 Rio Grande Compact, which governs water resources between the states.

There’s great fear in southern New Mexico that the court’s ruling could result in reduced water allocations. There’s also a tacit acknowledgement that the epic legal battle proves how harsh the drought is. It’s unlikely that the states would be battling over this in times of plenty.

The ultimate solution, Hill insists, is to keep finding smart ways to use less water.

There’s plenty of innovation underway throughout the valley and in pecan production, which has boomed in New Mexico, bringing in a record harvest of 92 million pounds and sales of $220 million in 2017. In addition to experimentation with drip irrigation, farmers use lasers to finely slope the ground in their orchards. That allows water to be distributed evenly, without waste.

Meanwhile, the Elephant Butte Irrigation District is trying to capture as much stormwater as possible during intense rainstorms and channel it into the river system.

Will that be enough, however, as the desert Southwest keeps getting hotter?

“They’re talking about getting by with less water, and ignoring the fact that it’s less and less and less as long as it gets warmer and warmer and warmer,” said Jonathan Overpeck, a climate scientist at the University of Michigan who specializes in drought and water. “That’s the political twist that frustrates climate scientists.”