(Manmade) snow is for fighting over

Sipapu Ski and Summer Resort is tucked into a narrow valley above the northern New Mexico village of Peñasco. As ski areas go, it's minuscule, with less than 5 percent of the skiable acreage of Vail. Yet Sipapu has built a reputation by consistently being the first resort in New Mexico to open for the season in mid-November.

Nature, however, doesn't always cooperate by delivering snow in time, so Sipapu depends on manmade snow. "The pressure is to get it open, and snowmaking is our insurance," says John Paul Bradley, Sipapu's manager, who sports a scruffy beard and spends nearly every waking moment during the early season tending to snow guns. The guns blast a mixture of compressed air and water over the slopes, and the droplets freeze when the temperature's low enough and humidity's right. This fall, the resort spent $80,000 -- a substantial investment for such a small ski area -- installing new equipment to make its snowmaking more productive. But more snowmaking requires more water, which requires finding and buying rights to that water.

Sipapu currently can divert some 5.9 million gallons each year from the Rio Pueblo, a tributary to the Rio Grande. That's barely enough to get the mountain ready for Christmas during snowless winters, says Bradley. So, like many Western ski areas, Sipapu is now hunting vigorously for more. Last September, the resort filed an application with the state asking for 350 acre-feet, or about 114 million gallons, of additional water rights on the Rio Pueblo.

Sipapu plans to offset the added diversion with water bought at auction from the Jicarilla Apache Tribe. But there's a catch: That water originates in the San Juan River Basin, is diverted through a tunnel under the Continental Divide and put into the Chama River where it finally enters the Rio Grande. That means the transfer would result in a net loss for the Rio Pueblo for 25 miles, from the ski area to the river's confluence with the Rio Grande.

Robert Templeton is a commissioner on an acequia (irrigation ditch) downstream from Sipapu. Templeton acknowledges the ski resort's local economic benefits, but he also doesn't want to see the environment sacrificed for more ticket sales. While the manmade snow eventually melts back into the watershed, Templeton says additional runoff in the spring does nothing to make up for diversions done in late fall when the river is at its lowest.

In the last 40 years, Templeton has seen the watershed struggle with an increasingly arid climate: Irrigators have to ration longer into the growing season, domestic wells have gone dry, and many are worried about the overall ecological health of a river that sometimes shrinks to a trickle. During dry years -- like the last two -- a big diversion by Sipapu could force a showdown between water-rights holders up and down the river. "We're looking at a dwindling resource, and there are going to have to be difficult questions asked," Templeton says. "I think we're coming to a time where push is coming to shove."

Region-wide water stockpiling of this sort has raised questions about whether ski areas are assuming too much clout in an ever-drying region –– especially as it becomes obvious that increased snowmaking is only a temporary solution in a warming climate.

In December, the ski industry won a major fight against the U.S. Forest Service when a judge struck down a provision that would have taken water rights away from resorts that operate on national forests and given them to the federal government. The Forest Service, which wants to keep water tied to public lands, fears that ski areas may start selling off their water rights if that becomes more profitable than the ski business itself.

It's not a far-fetched scenario. "We're getting kind of to the edge," says Glenn Porzak, a Boulder, Colo., attorney who supported the ski areas against the Forest Service. Porzak says that most competing water users have so far been able to compromise, but it's getting harder. Water rights are an increasingly scarce and valuable commodity, and interstate water allocations are stretched to their limits.

Some resorts are trying novel methods to solve the problem. Heavenly Ski Resort in California has computerized its snowmaking operations, making them more efficient by allowing crews to remotely turn on snow guns instantly, and only when conditions are optimal. Loveland Ski Area in Colorado captures manmade snow as it melts and stores it in an offsite reservoir to be reused in future snowmaking.

Other methods have been more controversial. This season, Arizona Snowbowl near Flagstaff began using treated effluent from the city's wastewater plant for snowmaking on a mountain considered sacred by several Native American tribes. The resort calls the approach an "environmentally and economically responsible decision," but it prompted fierce protests and lawsuits from environmentalists and tribes.

If the ominous predictions of climate change prove accurate, ski towns will likely see more of this kind of friction. It may come down to a painful choice: Keep the snow on the ski slopes, or have water in your faucets and irrigation ditches.

• Climate Change