By SANDRA CHEREB
CARSON CITY, Nev. (AP) -- Could tiny snails found in isolated, high desert springs along the Nevada-Utah line scuttle plans to pump billions of gallons of water to Las Vegas?
That's the thrust of a lawsuit filed by an environmental group that claims four species of springsnails could perish if Southern Nevada Water Authority is allowed to build a massive pipeline and pump groundwater from rural areas to quench the thirst of Nevada's gambling metropolis.
"This pumping is like a very small moving cancer across the landscape," said Rob Mrowka, a Nevada advocate for the Center for Biological Diversity.
In its lawsuit filed Thursday in U.S. District Court in Washington, D.C., the center asks a federal judge to compel the Fish and Wildlife Service to issue its conclusions on whether the bifid duct, flag, hardy and Lake Valley pyrg -- all species of springsnails -- deserve protection under the Endangered Species Act.
The center and others petitioned the Fish and Wildlife Service in 2009 to list 42 Great Basin springsnail species, including the four noted in the lawsuit, for federal listing as threatened or endangered. In a preliminary finding last year, the service said the snails -- measuring from an about an eighth to a quarter-inch in size -- may warrant protection but further review was needed to make that determination.
"There's actually 25 species of springsnails that are imminently threatened by the pipeline project," said Rob Mrowka, a Nevada advocate for the Tucson, Ariz.-based environmental group. But under an agreement struck with the service in 2011 to limit litigation, the center's lawsuit focuses on only the four springsnails, he said.
The lawsuit doesn't target the pipeline or water pumping directly and SNWA is not named as a defendant. But springsnails, should they be given endangered species protection, would give critics more legal ammunition to fight the project in other court actions.
"Assuming the pipeline is approved and a right of way is granted, we want to be in the position of being able to stop it at least temporarily while the courts decide," Mrowka said.
Jason King, Nevada's state engineer, granted SNWA approval in March to pump up to 84,000 acre-feet of groundwater a year from four rural valleys to Las Vegas -- home to 2 million people and 40 million tourists a year. Several lawsuits have been filed in state courts challenging that decision, and the project itself is years, if not decades away from becoming reality.
Environmentalists and others argue water pumping would dramatically reduce ground water levels, threatening not only the springsnails but other wildlife, agriculture, ranching and rural lifestyles.
Last month, the U.S. Bureau of Land Management released its environmental study and recommended approval of its preferred alternative for SNWA to build a 280-mile long pipeline needed to carry water from the rural counties to Las Vegas. The price tag was initially estimated at $3 billion, but critics say the actual cost could reach $16 billion.
The BLM report is now in a 60-day review period, and a final record of decision is expected by the end of the year.
Also still pending is a biological review from the U.S. Fish and Wildlife Service on the consequences the water project would have on wildlife.
Ted Koch, Nevada superintendent for the service, said that review, requested by BLM and the water authority, should be completed next month.
"Of the four species they named in their suit, two of them -- the Lake Valley and flag pyrg -- are technical assistance species that we were concerned enough about that we did review the impacts," Koch said. He added that review is different than a detailed analysis on whether something should be listed as threatened or endangered, and the report will not address that question.
Mrowka said the snails date back to the ice age.
As the ice receded, "the springs and the streams became isolated ... and species have evolved particular to a certain spring," he said.
Lake Valley pyrg, for example, live in only one spring -- in Lake Valley.
"They are tied to unique spring water chemistry as well as spring flow physics," Mrowka said. "They live in a very narrow niche in the spring itself."
The snails serve a critical environmental role and their extinction could have a domino effect on other species such as frogs, toads, dragon and damsel flies, desert fish, birds and mammals, environmentalists argue.
"Freshwater invertebrates like springsnails influence water chemistry, nutrient cycling, rates of productivity and decomposition, and are vital links in the food web," the lawsuit said. "Great Basin spring systems tend to be hotspots of biodiversity, and by protecting springsnails, protection of spring water quality and quantity is guaranteed."
Copyright 2012 The Associated Press.