CARLSBAD, N.M. — Just after the local water board announced this month that its farmers would get only one-tenth of their normal water allotment this year, Ronnie Walterscheid, 53, stood up and called on his elected representatives to declare a water war on their upstream neighbors.

“It’s always been about us giving up,” Mr. Walterscheid said, to nods. “I say we push back hard right now.”

The drought-fueled anger of southeastern New Mexico’s farmers and ranchers is boiling, and there is nowhere near enough water in the desiccated Pecos River to cool it down. Roswell, about 75 miles to the north, has somewhat more water available and so is the focus of intense resentment here. Mr. Walterscheid and others believe that Roswell’s artesian wells reduce Carlsbad’s surface water.

For decades, the regional status quo meant the northerners pumped groundwater and the southerners piped surface water. Now, amid the worst drought on record, some in Carlsbad say they must upend the status quo to survive. They want to make what is known as a priority call on the Pecos River.