(AP) Agricultural interests and residential subdivisions across the arid West are vying for control of water supplies that have emerged as one of the region's most coveted natural resources.

In one of the latest skirmishes, five Montana ranch owners filed a petition this week asking the Department of Natural Resources and Conservation to stop giving away water use rights for tens of thousands of new homes being built in areas once dominated by agriculture.

The ranchers' petition charges that the state's water rules are stacked against them. The rules allow small wells used by each house within larger subdivisions to qualify for exemptions from state water laws. Those laws otherwise give precedence to the "senior" rights of farms and ranches.

That means dozens or even hundreds of homes can be built in the same general area without any water permits and regardless of the strain that added demand might put on underground aquifers.

Rancher Polly Rex characterized the exemption as a loophole that ultimately could rob her of the means to grow hay and water her livestock. Rex said a subdivision of more than 60 homes going up next to her Absarokee ranch could eventually draw down the natural springs she uses on an adjacent 1,250-acre field.

"I just really don't think I should change how I do our business because of somebody else," said Rex, whose water rights date to the late 1800s. "We simply cannot hand out water rights in thin air. It's a dumb way to do business."

DNRC spokesman John Grassy said agency attorneys were reviewing the ranchers' petition, which would require the state to revisit its water regulations. "The petition raises issues of statewide significance," he said.

Montana is not the only state facing confrontations over water access. California officials expect to release a record-low amount of water to 25 million residents next year if the drought in that state continues, a grim outlook for local farmers and urban dwellers already struggling after three years of persistent dry weather.

Lester Snow, who directs the state Department of Water Resources, said this week the agency anticipates delivering just 5 percent of what was requested by its contractors — the lowest projection in history.

While water deliveries could increase if more rain and snow falls over the winter months — a likely possibility if El Nino weather patterns hit California — Snow said the state had to assume it would be faced with a fourth year of drought.

"We're putting people on notice to get on with conservation," Snow said. "We'll need to take measures because what if there is not only a fourth year of drought, but a fifth and sixth year?"

Last year, the state predicted it would deliver 15 percent of requested water but boosted that number to 40 percent by May.

State Water Project supplies feed most Southern California cities and help irrigate 750,000 farm acres scattered throughout the southern San Joaquin Valley, San Diego and Orange counties.

Source: Associated Press