FLOYDADA — J. O. Dawdy, who has been a farmer for 36 years, is so worried about getting enough groundwater that he is considering a lawsuit to protect his right to it.

As sleet pounded his West Texas farmhouse one recent afternoon, Mr. Dawdy and three other farmers said that new regulations — which limit the amount of water they can withdraw from the Ogallala Aquifer and require that new wells have meters to measure use — could have crippling effects on their livelihoods.

“We view it as a real property-rights violation,” said Mr. Dawdy, who grows cotton. If the restrictions had been in place last year during the drought, he said, his land would not have produced a crop.

Water is a contentious issue across Texas, but tensions have been especially high in a 16-county groundwater conservation district stretching from south of Lubbock into the Panhandle, an area considered part of America’s “breadbasket.” There, farmers reliant on the slowly diminishing Ogallala are fighting to maintain their right to pump unrestricted amounts of water. The issue gained urgency last month when a landmark Texas Supreme Court opinion confirmed that landowners own the water beneath their property, in the same way they own the oil and gas.