Park Ranger Brandon Marsmaker steers his patrol boat Wednesday past the white "bathtub ring" that marks the effects of drought at Lake Mead. The Las Vegas Valley gets 90 percent of its water from the lake, but the community is outgrowing that supply. Photo by RUBEN D. LUEVANO/REVIEW-JOURNAL Sprinklers spray an alfalfa field in White Pine County's Spring Valley. Southern Nevada Water Authority chief Pat Mulroy says the Las Vegas Valley must get a steady water supply from Eastern Nevada. Photo by John Locher.

There is less than a month to go before a decisive state hearing on plans to pipe water to Las Vegas from White Pine County, and Southern Nevada Water Authority General Manager Pat Mulroy says she is finished being subtle.

For years, Mulroy and others have warned that without an additional source from somewhere, the Las Vegas Valley would one day outgrow its water supply.

Now she says that without a steady supply of water from White Pine County's Spring Valley and elsewhere, growth in Southern Nevada could grind to a halt within 10 years.

"This isn't because we have any particular interest in going up to White Pine County. It's because we don't have a choice," she said.

Her comments come as the water authority prepares for a three-week hearing, set to convene Sept. 11 in Carson City, on some 91,000 acre-feet of groundwater a year it hopes to pipe south from Spring Valley.

If stretched through reuse, 91,000 acre-feet could supply more than 80,000 Las Vegas Valley households.

It will be up to State Engineer Tracy Taylor, chief of the Nevada Division of Water Resources, to decide how much water, if any, can be pumped out of Spring Valley, 250 miles north of Las Vegas, without damaging existing water rights or the environment.

It could take months for Taylor to issue his decision following the hearing.

Right now, the Las Vegas Valley gets about 90 percent of its water from the Colorado River.

As recently as five years ago, officials in Southern Nevada were touting a series of interstate agreements that would allow the community to take and store enough surplus river water to supply itself for the next 50 years. Then came the worst drought on record, which shrank the river, erased any surplus and forced the authority to accelerate its pipeline plan.

Though the Las Vegas Valley could one day increase its water supply by desalting seawater or seeding clouds at the headwaters of the Colorado, those resource solutions are decades way, Mulroy said.

Without imported water from Spring Valley and elsewhere in Eastern Nevada, she said, the community could outgrow its share of the Colorado River sometime between 2013 and 2016. When that happens, Southern Nevada will have to tap the water it has managed to bank here and in Arizona in spite of the drought, but those reserves will only last so long.

"They're bridge resources," Mulroy said of the banks. "They've got to bridge to somewhere."

Mulroy said she decided to step up her warnings about the valley's water supply picture as a response to those now rallying against the pipeline project, namely environmentalists from outside White Pine County.

"I have no choice but to respond," she said. "I have to push back."

But as emotion builds in the run-up to next month's hearing, so too does the potential for blunders and misunderstandings.

Mulroy has spent the past few days explaining herself to state officials after a story in Wednesday's Las Vegas Sun suggested she would seek to have the state engineer replaced if he didn't rule in the water authority's favor.

The Sun quoted Mulroy saying that "the governor can remove the state engineer and appoint a new one."

Mulroy insists the comment was taken out of context and that what she said during her hourlong meeting with Sun staff members Tuesday "was never, ever, ever intended as a veiled threat."

"The quote is correct, but it's in answer to a completely different question," said water authority spokesman Scott Huntley. "It absolutely reads like a threat, and she did not do that."

Huntley said the authority asked the Sun to print a retraction, but the newspaper is standing behind the story.

"There's nothing to retract," said Sun Managing Editor Michael Kelley. "I think that they (water authority officials) are sorry she said it."

The day the story appeared, Mulroy called Taylor's boss, Allen Biaggi, to explain what happened. Mulroy said she planned to place a similar call to Taylor, as soon as he returns from field work in Spring Valley.

Mulroy also penned a letter to the editor to the Sun, which Kelley said the newspaper would publish today.

White Pine County rancher Dean Baker, a vocal opponent of the pipeline plan, said he doesn't know whether Mulroy really made the threat, but he has no trouble believing Las Vegas water officials would consider such a thing.

"I have felt all along that Southern Nevada Water Authority intended to do whatever it took to get the water," Baker said. "I have felt all along that we were dealing with desperate people."

Biaggi, who heads up the state Department of Conservation and Natural Resources, said all of the rhetoric would have no bearing on next month's water hearing. He said Taylor will weigh the interests of the public, the environment and the economy of the state and then render a decision based on sound science.

"My position is that the state engineer and my office will continue to follow the state law. We will follow our job and our mandate," Biaggi said.