But there really is no "surplus."

Every drop that's siphoned off to slake the growing thirst of Las Vegas already sustains a form of life, said Deacon, the lead author of a newly published research piece in BioScience magazine.

The article in the September issue examines the consequences of depleting Nevada's groundwater reserves. It's a practice Deacon said poses a serious threat to both Nevada agriculture and 20 species of already endangered wildlife, from the Devil's Hole pupfish to the Southwestern Willow flycatcher.

"The only way we're going to avoid environmental disaster and disaster to rural livelihoods is to combine growth stabilization policies with creative, cutting-edge technology," Deacon said, echoing the points he presented to readers of the national publication on biology research.

That means pushing conservation over consumption, using technology to improve water reclamation, and finding a way to slow growth.

Deacon acknowledged that turning away from growth and allowing the demand for water to flatten out flies in the face of the developer-friendly policies maintained by local governments. He hopes to shift public support away from growth agendas and refocus it on keeping Las Vegas livable.

"This is the most policy-directed piece of science writing I've ever done," Deacon said of the peer-reviewed article crafted over four years. "We must recognize the cost we're imposing, not only on our neighbors, but also on the environment."

The impetus for Deacon's scholarly activism is the water authority's plan to divert water from a rural aquifer that extends across the central and southern state for use in Las Vegas.

In April, the state engineer gave the water authority permission to take up to 40,000 acre-feet of water annually from Spring Valley, the White Pine County aquifer due west of Snake Valley. The water authority is seeking permission to tap into other eastern Nevada water resources.

Kay Brothers, deputy general manager of the water authority, has read part of Deacon's article and been briefed on the rest of it by staff members. She said she respects Deacon and his position but said he fails to consider the safeguards that will prevent the worst-case scenario from happening.

"You can manage the groundwater system," Brothers said Thursday. "There's also a body of law in place to protect the groundwater system and monitor the impact on sensitive resources."

And no one can deny the need for more water, which Brothers said is not rooted solely in growth. Drawing off water from the rural groundwater reserves also is a form of drought protection at a time when Colorado River resources are diminishing.

"If we can't utilize the groundwater resources in this state, what are we going to do?" Brothers asked.

The water authority already encourages conservation and issues rebates for replacing grass with desert-friendly landscaping, Brothers said. The water authority also has negotiated for a larger share of the Colorado River.

But controlling growth, as Deacon suggests, is something Brothers said she cannot even begin to address.

"I don't know how to do that," Brothers said. "How do you tell people not to move here?"

Deacon examined the laws that govern water use and the protection of sensitive resources and found them lacking.

The laws were written at a time when no one envisioned the type of expansion now taking place, he said. One of the results is that the potential claims on rural water reserves are now greater than the expected annual input.

Deacon found that existing groundwater permits for the 78 basins examined in the article appropriate 102 percent of the basins' cumulative perennial yield. That gap could widen drastically should the state engineer approve additional requests from other entities for water allocations from the rural reserves.

History shows the consequences of that course of action, Deacon said.

In the 1950s, overzealous groundwater pumping led to the failure of major Las Vegas Valley springs, leading to the extinction of more than one native fish, including the Las Vegas dace.

"Providing for the water needs of a growing Las Vegas Valley by relying on historical practices is a recipe for ecological disaster," Deacon said in the article.

"New technologies can help increase water availability and efficiency of use, but in the long run they are futile unless combined with reduced growth of human populations."