LINTON - Falling levels on Lake Oahe are forcing many area farmers to let their irrigation systems sit idle and switch their cornfields to wheat, barley and sunflowers.

Larry Umber ran 1,400 feet of pipe to reach the Missouri River water last year, using a portable, diesel-powered pump to keep his four center-pivot sprinklers going. He was able to pump for a while until it no longer became workable.

"I've got half a million dollars of irrigation equipment that I'm paying for that's sitting idle," he said.

Umber said he feels like a casualty of a political battle between upstream and downstream interests along the Missouri.

Upstream states with reservoirs want more water kept in the lakes for recreation and domestic water supplies, while downstream states want a steady flow for navigation, to cool power plants and for their municipal water systems.

Without irrigation, Umber and his neighboring farmers have had to resort to dry-land farming, growing mostly small grains which have a lower return.

Tom Scherer, a North Dakota State University agricultural engineer, estimates that idle irrigated fields in Emmons County translate into a direct loss of $1.5 million and a total economic loss of $4.95 million.

That's a big hit for the rural county of 3,913 residents, which lost 10 percent of its population during the 1990s.

Most North Dakota farmers who irrigate use groundwater, but the Missouri is the source for 16 percent of the state's irrigated acres.

On average, an irrigated acre in North Dakota produces gross yields four to five times that of a dry-land acre, excluding payments from farm subsidies, Scherer said.

That amounts to a financial loss of about $300 an acre, he added, excluding any subsidies. Irrigation also helps to ensure reliable yields.

Umber, a third-generation farmer, owns 1,600 acres of land and rents another 2,000 acres from neighbors. He also runs 800 cows on 800 acres of pasture.

Last year he grew some barley, but dry conditions and cold weather stunted the crop.

Altogether, 15 farmers in Emmons County have been forced to idle 3,630 acres of irrigated land, according to figures from the North Dakota Irrigation Association. That's more than half of the 6,500 acres developed for irrigation in the county.

Across the river in Sioux County, the Standing Rock tribe also has been forced to idle some of its irrigated fields.