Southwestern Water Muscle

Times are getting desperate:

This month, Texas asked the U.S. Supreme Court to hear its complaint that New Mexico has been diverting water it is obligated to send downstream under the 75-year-old Rio Grande Compact.

By allowing its residents to sink nearby wells and pump water from the river, "New Mexico has changed the conditions that existed in 1938 when the compact was executed," the Texas complaint charges.

The dispute centers on the Rio Grande Project, a system of dams and canals that impounds water at the Elephant Butte and Caballo reservoirs in New Mexico and delivers it to farmers in southern New Mexico and West Texas. The compact among Colorado, New Mexico and Texas settled years of litigation by establishing a formula for allocating the river's water to various users.

"All we're trying to do is protect the project and its users," says Pat Gordon, Texas' representative on the Rio Grande Compact Commission. "There's been a lot of tension for a lot of years. It seems that it's gotten progressively worse."

For one thing, he says, more than 2,500 wells have been drilled below Elephant Butte since the compact was signed. The wells cause water to flow from the river into the adjoining underground aquifer, he says, reducing the amount of water available for the irrigation network.

...Sarah Bond, an assistant New Mexico attorney general, denied that her state had changed its interpretation of the accounting and delivery of water under the compact.

"We are in compact compliance," Bond said in emailed comments. Referring to Texas' request pending before the high court, she added, "We would not speculate on any 'true motives' for the Supreme Court action. It would appear they want more water delivered to them than their compact entitlement."

...Charles DuMars, a prominent water law specialist and former University of New Mexico law professor, says the dispute "has been brewing for a long time." For years, New Mexico did not regulate groundwater pumping below Elephant Butte and only stopped issuing new well permits in 1980, he says.

...Water issues are taking on added urgency as hotter, drier conditions afflict Western states with their burgeoning urban populations. The Supreme Court agreed this month to hear another lawsuit from Texas over water — by a water district against Oklahoma. At issue is whether the Tarrant Regional Water District in northeastern Texas can use water supplies in Oklahoma.

In New Mexico, years of drought have left Elephant Butte water levels perilously low, and the mountains in northern New Mexico and southern Colorado are seeing lower-than-normal snowpack. Flow in the Rio Grande near Santa Fe this spring is projected to be just 47% of the 1981-2010 average.