LAS CRUCES — Southern New Mexico's water supply is ample for the next two to three decades, and could remain steady for 70 years or more if conservation continues and water recycling technology is implemented, experts say.

"Planning is the key," said Ed Archuleta, manager of the El Paso (Texas) Water Utilities Public Service Board. "I can't emphasize enough planning and collaborating between communities, counties, the states of Texas and New Mexico and the U.S. and Mexico. I don't see any problems in this region for a long time, 20 to 30 years at least."

Desalination plants could significantly increase the water supply, said Archuleta, who was among panelists participating in a conference, "Transboundary Water Crises: Learning from Our Neighbors in the Rio Grande and Jordan River Watersheds." The conference wrapped up over the weekend.

One desalination plant already operates in El Paso. Another is planned in Otero County in Southern New Mexico.

"Desalination is going to be a major force going forward," Archuleta said.

And he said it can be affordable. The high cost of building desalination plants should be considered in the light that the return on investment, substantial water supplies, ultimately will be far greater than the price tag, Archuleta said.

"It's a misnomer that it's unaffordable," he said. "Ocean desalination can be 1 1/2 to two times more (expensive) than inland desalination."

The director of the Water Resources Research Institute at New Mexico State University, Karl Wood, said the impact of desalination plants will be dramatic because three-fourths of New Mexico's water is brackish.

An estimated billions of acre-feet of brackish water lie in the Tularosa Bolson east of the Organ Mountains, he said.

"With desalination, there's a potential to provide our region with water for thousands of years," Wood said. "To put the amount of brackish water in the Tularosa Bolson that could be treated into potable (drinking) water into some kind of perspective, the city of Las Cruces uses something like 20,000 acre-feet of water a year."

An acre-foot, equal to 325,821 gallons, can meet the annual water needs of two U.S. households.

A study is under way on the Mesilla Bolson, which has the greatest potential for providing water to Doña Ana County, to determine the amount of brackish water that could be treated. Wood said the bolson has not been extensively studied, so the information will offer valuable insight for conservation, reclamation and diversification programs to maintain a sufficient water supply.

Archuleta said efforts to recycle water must be expanded. Technologies are being developed that could enable reclaimed water to be mixed with pure water, providing a stable supply and reducing depletion of bolsons and aquifers, he said.