PHOENIX - The Arizona Supreme Court on Wednesday rebuffed efforts by the state to claim water rights tied to its 9.3 million acres of trust land.

The justices unanimously rejected arguments by attorneys for the state that when the federal government gave the land to Arizona in 1912 to hold in trust, it also provided "reserved" water rights for that property. Instead, the court said the state's rights are no different, and no better, than others.

Robert Glennon, a professor of law at the University of Arizona, said what makes the ruling significant is if the justices had accepted the state's arguments, it would have caused havoc.

"They want water, retroactively, for 9 million acres of land," he said. "Just think of how disruptive that would be, both to claims of some tribes and also to the existing cities and farms and mines that are using water."

And Glennon, author of several books including the 2009 "Unquenchable: America's Water Crisis and What to Do About It," said the implications of giving the state title to all that water would have put many other users at the back of the line.

"There wouldn't have been much left," he said. "It would have been a staggering amount of water."

The high court, in its ruling, also rejected claims by attorneys for the state that denying the water rights would somehow damage the whole purpose of the federal government giving all that land to the state: to support public schools and other government functions.

"The state has not argued that, without federal reserved water rights, the state trust lands will become worthless or incapable of producing a fund to support their designated beneficiaries," wrote Justice John Pelander for the court. "Indeed, state trust lands have been without such rights produced revenue for a century."

Vanessa Hickman, the deputy state land commissioner, conceded the point.

In the 2011 fiscal year, the most recent figures available, the state sold nearly 5,600 acres, generating $104 million, even in a depressed real estate market. By comparison, five years earlier, before the real estate bubble went bust, the state generated nearly $375 million in sales from the sale of just 3,426 acres.

But Hickman said there's much more money to be had, which is why the state is not giving up.

All those sales were of pure land, with no water rights. She figures that if the state's remaining property suddenly comes with water, it will bring far more at auction.

"We all know as more land is sold and more land is put into production, we all know how much more valuable access to water becomes," she said. And that, in turn, means far more cash for public schools and others who are beneficiaries of the trust.

Hickman said the state is looking at its options.

When Arizona became a state in 1912, the federal government gave it nearly 11 million acres to be leased or sold to benefit mainly public education, but also everything from prisons to universities. About 9.3 million acres remain.

Attorneys for the state argued that when the federal government gave Arizona the land, it also gave the state "reserved" water rights associated with all that acreage.

But Pelander said Congress apparently intended to transfer only the land, and was aware the property was worth less without water rights. He wrote that federal lawmakers addressed that by doubling the amount of trust land provided, "not by reserving federal water rights for those lands," Pelander wrote.

Hickman agreed the state never pursued its claims before, suggesting it wasn't a priority until now.

"Perhaps 100 years ago people weren't focused on water as much as they are today," she said.