Even before Utah became a state, territorial lawmakers concluded that water rights might be subverted if rivers and streams dried up.

If such scarcity came to pass, says an 1880 law, farmers' water could be set aside for domestic use. It was a common-sense statute that deemed drinking water more important than crop irrigation in sparse times.

But what once was common sense increasingly has become a point of contention -- and would be stripped from the law under a bill the Senate approved Friday.

Rep. Kerry Gibson, R-Ogden, a dairy farmer and the sponsor of HB241, indicated during an interview at the Capitol that his measure was a response -- if not a pushback -- to a bill passed last year that loosened the "first in time, first in right" doctrine that underlies all of Western water law.

To Gibson and other critics, including Mike Styler, executive director of the state Department of Natural Resources, last year's bill, sponsored by Rep. Patrick Painter, R-Nephi, tipped the balance in favor of cities over farmers and ranchers by neutralizing the threat of losing the rights if the state engineer found cities had been derelict in their legal duties. At the time, Styler said this threat of forfeiture "encourages a healthy fear in everyone's mind."

HB241 turns the advantage back to farmers and ranchers who hold the oldest water rights by removing the provision that granted exceptions to those rights in times of scarcity -- a condition that never has been clarified in the law.

Gibson said he could imagine such scarcity arising from an emergency, such as an earthquake or the collapse of a city well. But even then, he said, nothing should disrupt the seniority system. People should just figure out how to buy and sell water to meet everyone's needs.

"It should be a straight market response," Gibson said. "There is no basic principle in water rights more important than first in time, first in right."

The League of Cities and Towns opposed the bill and managed to persuade lawmakers to delay implementation until after the 2010 Legislature to allow for further study of potential consequences.

Jodi Hoffman, the league official who has been following the bill, said the measure could be clarified to define some of the fundamentals of water law, such as the requirement that water be put to beneficial use -- and what is beneficial, anyway, in an urbanized state where agriculture makes up only a small part of the overall economy?

The law, Hoffman said, should rank the importance of all uses, define scarcity and pinpoint which public uses -- like, say, watering golf courses -- would have to halt when water dwindles.

But the league opposes the notion that the market should have the ultimate say, as do other experts who argue water shouldn't be considered a commodity like oil or soybeans, because it is basic to human survival.

"We continue to lose sight of that," said water attorney Steven Clyde, who testified against Gibson's bill. "It was a lot easier when there was still water to appropriate."