Some encouraging words came from Mexican President Vicente Fox the other day. Encouraging, that is, if you want South Texas producers to have enough water to grow the melons and onions that end up on grocery shelves here in North Texas. President Fox told a group of Texas newspaper executives in Austin last week that water conservation could chip away at Mexico's water debt to the United States. That's an important concession. The backlog now stands at about 1.4 million acre-feet of water, or equal to four times Mexico's annual obligation to the U.S. The debt never seems to get better, and the fact Mr. Fox proposed constructive specifics deserves notice.

Water conservation alone will not solve the problem. Mexico actually could wipe off a large chunk of it through transferring water the country has on storage behind Falcon and Amistad dams along the Rio Grande. But no one involved in this ongoing discussion should sniff at the Fox suggestion. Farmers in both South Texas and Northern Mexico rely on irrigation to grow their fruits and vegetables. And good irrigation techniques can make a huge -- huge -- difference in saving water. To cite two examples, Northern Mexico farmers waste water through allowing irrigation water to evaporate in canals. And they still flood fields, instead of using more efficient drip irrigation systems. South Texas has similar problems. JoJo White of a Hidalgo water district says old systems plague South Texas farmers as well.

The North American Development Bank recently gave money to both sides of the Rio Grande to improve water systems. Here's a place President Fox can make good on his conservation emphasis. His administration should ensure the bank's investment actually yields water savings, which in turn go to reduce Mexico's water debt. We've said all along that Mexico and the U.S. do not need to become bitter enemies over this water issue. Still, Mexico needs to take its obligation seriously. Better water management can make sure Mexico has enough for itself -- and to repay its neighbor.