The arid desert home for a tiny fish may now play a much bigger role in whether the Southern Nevada Water Authority will some day be allowed to pump vast amounts of water from beneath the Utah/Nevada border for piping to an increasingly thirsty Las Vegas.

The U.S. Fish and Wildlife Service said Wednesday that it plans to take the next 12 months to examine a petition by the Center for Biological Diversity to protect the least chub with federal listing as an endangered species.

The agency agreed with the petitioners' findings that taking all that water — between 25,000 and 50,000 acre-feet per year — may hurt the least chub population in three specific areas within the Snake Valley in Utah.

But even if the least chub does get federal protection as an endangered species, Water Authority spokesman J.C. Davis doesn't think it will be a deal-killer for his group's proposal.

"Everybody's goal, and we support that goal, is that the habitat is protected," he said.

On Oct. 1, the Center for Biological Diversity and two other groups filed a notice of intent to sue Interior Secretary Dirk Kempthorne for what they said was a failure to respond to a petition to federally list the least chub as threatened or endangered.

The center's biodiversity program director Noah Greenwald said he doesn't anticipate his group will need to follow through on the lawsuit because of the Fish and Wildlife Service's finding.

At the end of the agency's 12-month review, a decision will be made on whether to list the fish as threatened or endangered.

The least chub has been around for 15,000 years and grows to be less than three inches long. Recorded declines in its numbers began in the 1940s and 1950s. Three of the six remaining populations of least chub make their home in the Leland Harris Spring complex, Gandy Salt Marsh and Bishop Spring in the Snake Valley region of Utah's west desert.

Critics of the Southern Nevada Water Authority's proposal to take water from aquifers in the Snake Valley along the border say it would dry up the habitat for three populations of the least chub and possibly create a dust-bowl environment, prompting fears it could lead to air-quality problems all the way east to the Wasatch Front.

The federal agency's decision Wednesday "highlights the disastrous consequences on people and wildlife of pumping groundwater to feed Las Vegas' insatiable growth," Greenwald said in a statement.

A battle that includes multiple state and local agencies from both sides of the border is ongoing in the courts and before the Nevada state engineer.