SANTA FE, N.M. -- By the time the Rio Grande reaches the New Mexico-Texas state line, it's more puddle than river.
Texas blames groundwater pumping in New Mexico for the Rio Grande's sorry condition and has asked the U.S. Supreme Court to intervene and force New Mexico to send more water downstream.
The Lone Star State says its neighbor is taking more water than it's allowed under the Rio Grande Compact, which divides water among Colorado, New Mexico and Texas. The Supreme Court will decide whether it will hear Texas' case in the coming weeks.
New Mexico farmers say that if the court takes the case and rules in Texas' favor, their fields could wither, and with them, New Mexico's agricultural economy. Farmers on both sides of the state line are dealing with one of the worst droughts in history.
"A number of farmers depend on pumping water from the Rio Grande, not only near El Paso but all the way down the river," which eventually forms part of the U.S.-Mexico border before flowing into the Gulf of Mexico, said Regan Beck, assistant general counsel for public policy for the Texas Farm Bureau. "Their operations are certainly in jeopardy, since they can't pump water."
Historically, under the Rio Grande Compact, 57 percent of the water supply below Elephant Butte Reservoir in southern New Mexico has been delivered to New Mexicans and 43 percent has been delivered to Texas.
But because of the drought, the federal Bureau of Reclamation, which manages Elephant Butte Reservoir and stores water to meet compact obligations, has decided against releasing water for farmers in southern New Mexico, leaving them dependent on groundwater.
"Texas winning the lawsuit in its entirely as is would be a death knell for agriculture in southern New Mexico," said Matt Rush of the New Mexico Farm and Livestock Bureau in Las Cruces. "We're amidst one of the greatest droughts that we've ever had, and we're without any water from the river."
The only thing keeping southern New Mexico's pecan plantations alive is groundwater pumping, he said, and if farmers are told to shut off their pumps so New Mexico can send more water to Texas, they will be left with no water at all.
"When you're dealing with pecan trees, which are a permanent, year-round crop, if you go without water for a significant amount of time, they're going to die," he said.
New Mexico is the second-largest producer of pecans in the United States, he added.
Just how much groundwater pumping in the lower Rio Grande has affected the river's flows is unknown, however. Texas didn't specify in its lawsuit how much water New Mexico is withholding but said it was enough to irrigate thousands of acres of farmland. The water supply for the city of El Paso, half of which comes from the Rio Grande, is also at risk, according to the suit.
One thing is clear: Farmers in New Mexico have increased groundwater pumping in recent years. New Mexico State Engineer Scott Verhines warned last year that groundwater use had drastically increased as Rio Grande flows shrank.
This isn't the first time the two states have tussled over the Rio Grande.
Under a 2008 agreement between Reclamation and irrigation districts in both states, New Mexico agreed to send more Rio Grande water to Texas to compensate for groundwater pumping. But New Mexico Attorney General Gary King (D) didn't like the deal, and in 2011 the state filed suit over it in federal court, saying Texas was getting too much water under the agreement and that it would hurt New Mexico agriculture to the tune of $183 million.
Texas saw that move as an attempt to circumvent the compact and decided to lob its own complaint "to protect its rights to the water legally apportioned to it," according to a statement from the Texas Commission on Environmental Quality.
King shot back, saying in a statement that Texas is "trying to rustle New Mexico's water and using a lawsuit to extort an agreement that would only benefit Texas while destroying water resources for hundreds of thousands of New Mexicans."
Some say the Texas suit is retaliation for New Mexico's recent legal action.
"In my opinion, I think this is a political issue more than anything else," Rush said, adding he doesn't think groundwater pumping in southern New Mexico is affecting Texas water deliveries.
Water disputes between the two states go back almost a century. A similar fracas over the Pecos River in eastern New Mexico and west Texas ended with the Lone Star State receiving more water. Water managers bought up water rights from farmers to comply with a court decision in favor of Texas and send more water downstream.
Farming interests in New Mexico are fearful that the same thing will happen in the Rio Grande Basin, with dire consequences for agriculture there.
"In these compact disputes, the lower state always has the upper hand," Rush said.
But regardless of how the legal battle turns out, the larger issue of how to find enough water to sustain some of the most valuable farmland in the country likely will remain elusive.
The Texas-New Mexico water war could be a harbinger of things to come, not only in the Southwest but throughout the West, as water managers struggle to keep irrigation canals full and taps flowing amid a changing climate and more frequent droughts.
"We haven't had this kind of a drought ever before," Rush said. "We thought the year before last was the worst we ever had, but this one is worse. And by all accounts, next year will be just as bad."