On July 9, State Engineer Tracy Taylor issued a ruling that clears the way for the authority to pump more than 6 billion gallons of groundwater a year from three watersheds in Lincoln County. When stretched through reuse, the water from Cave, Delamar and Dry Lake valleys could supply almost 64,000 Las Vegas homes.

But in a petition filed Friday in Ely, opponents argue that Taylor dramatically overestimated how much water could be safely withdrawn from the mostly empty valleys and underestimated how much water should be held in reserve to supply future development there.

Speaking on behalf of the petitioners, Bob Fulkerson said the decision was made to seek a judicial review because "the issues on these valleys were so stark and cried out for relief."

"We've pledged to fight this with every tool at our disposal," said Fulkerson, who is executive director of the Progressive Leadership Alliance of Nevada and a member of the Great Basin Water Network, two groups that oppose the water grab.

A similar petition, filed Thursday in Pioche on behalf of a ranching operation in Lincoln County, specifically challenges the portion of Taylor's ruling concerning Cave Valley.

Susan Joseph-Taylor, chief hearing officer for the Nevada Division of Water Resources, said the court "might try to consolidate" the separate review requests so they can be heard at the same time.

Water authority spokesman J.C. Davis said agency officials couldn't comment on the petitions Friday afternoon because they had yet to see them.

Under state law, anyone directly impacted by a water transfer can petition to have a ruling by the state engineer reviewed by a district judge. Joseph-Taylor said "whoever is unhappy" with the outcome of the review can appeal it to the Nevada Supreme Court.

"The state engineer is very often upheld, because the standard is the court can't reweigh the evidence of record from the hearing," Joseph-Taylor said.

In other words, no new arguments about the pipeline project will be heard during the judicial review. If the engineer's decision is supported by the evidence already on record, the court will most likely back his ruling, Joseph-Taylor said.

The petitions filed this week represent the first judicial reviews requested in connection with the authority's pipeline project. Last year, Taylor granted the authority access to 13 billion gallons of groundwater a year in White Pine County's Spring Valley, but that ruling drew no such legal challenge.

"In Spring Valley, the issues were not so bold," Fulkerson explained. "We take these court actions very seriously, and we don't want to file lawsuits every chance we get."

By as early as 2013, the authority hopes to start pumping groundwater south through a pipeline that could stretch more than 250 miles and cost between $2 billion and $3.5 billion.

Authority officials see the project as a way to supply water for growth in the Las Vegas Valley and insulate the community from drought on the Colorado River, which provides 90 percent of the community's drinking water.

Critics argue that large-scale groundwater pumping in the arid valleys of eastern Nevada threatens wildlife and the livelihoods of ranchers and farmers.

The state engineer's next major hearing on the project is tentatively slated for this fall, when he will consider the authority's applications for groundwater in Snake Valley, an aquifer that straddles the Nevada-Utah border in White Pine County.

On Tuesday, two Utah counties and several American Indian tribes filed suit in Ely to be included as "interested parties" in the Snake Valley hearing. Taylor previously rejected a request from those groups for interested party status.

Contact reporter Henry Brean at hbrean@reviewjournal.com or 702-383-0350.