Over the last 25 years, it's almost as if a giant hand has reached out to gradually tighten the irrigation faucet on Shad Stamm's farm near Benkelman.

In 1980, the water allocation to his western Nebraska farm from the Upper Republican Natural Resources District was 22 inches per year. It dropped to 16 inches per center pivot in 1983, then to 15, and to 14.5 for 2003 and 2004.

The outlook for the next three years, Stamm told the audience for a panel discussion on "The Value of Water" in Lincoln on Tuesday, is 13.5 inches.

Given the possibility of another drought-plagued growing season, "I think we're only seeing the tip of the iceberg on scrutiny of our water use," Stamm said.

Grain and livestock producer Stamm was one of six participants in a dialogue offered as part of a 2005 Husker Feed Grains and Soybean Conferences at The Cornhusker hotel. It was sponsored by six grower and commodity checkoff groups.

Farmers and agricultural officials who attended didn't need to be reminded about depleted reservoirs, well-drilling moratoriums, increased state regulation and other signs of crisis in the nation's second-most irrigated state.

Stamm thinks the day is coming when the moratorium on new irrigation wells, now concentrated in central and western counties, will stretch across the state.

Some of the farmers paying as much as $220,000 a quarter section for irrigated land in his area, even as they continue to battle drought, may not be around to see it, he said.

"I honestly think we're going to have to have a decline in property or rental values or none of us are going to survive down there."

The two-day conference in Lincoln began just four days after the Nebraska Supreme Court made a pivotal irrigation ruling in a case filed by the Spear T Ranch at Bridgeport in 2002.

The court said the ranch could sue for damages under circumstances in which more than 100 high-capacity wells have cut the surface flows in Pumpkin Creek, a Platte River tributary, that its management used to water crops.

Mike Jess, another panelist who is a member of the University of Nebraska-Lincoln faculty and the former director of the Nebraska Department of Water Resources, said some of the liability could pass to the public.

That's possible because a judge could rule that the Legislature had failed to act to resolve the effects of groundwater pumping on surface water rights.

In any case, Jess said, "They should have the right to go back to Bridgeport and have a trial. And I suspect that's what's going to happen."

On a brighter note, panelist and UNL ag economist Ray Supalla said farmers facing shortages of irrigation water may find they can cut water usage as much as 20 percent without seriously hurting their corn and soybean results.

"The last units of water you're applying are not adding very much to grain yields," Supalla said.

He said that conservation approach, as opposed to taking land out of irrigation altogether, would have "quite modest" effects on local economies.

Reach Art Hovey at 523-4949 or at ahovey@alltel.net.