The Southern Nevada Water Authority’s board voted unanimously Thursday to keep pursuing a controversial project to pipe rural groundwater about 250 miles to Las Vegas. The vote came less than a month after Nevada’s top water regulator, in a complicated 111-page ruling, denied permits to the water authority to pump water out of four basins in Eastern Nevada.

Facing declining flows in the Colorado River — the source of Las Vegas’s water supply — and future growth, the water authority has long argued that it will one day need more water. For nearly three decades, it has looked for that water in Eastern Nevada near the Utah border.

The board vote to authorize litigation to appeal the state engineer’s ruling was unanimous and included Democratic gubernatorial Steve Sisolak, who recently came out against the project.

Before casting his vote, Sisolak clarified that the board members were “not voting today on our opinion of the pipeline.” A lawyer confirmed they were voting on whether to appeal the state engineer’s ruling. An agenda item for the meeting, however, said the board was being asked to weigh “appellate proceedings related to the Authority’s Groundwater Development Project.”

The Groundwater Development Project is the official name for the pipeline project.

“I thought it was an ill-conceived plan in the beginning and it’s an ill-conceived plan today,” Sisolak, chair of the Clark County Commission told The Nevada Independent on Saturday.

Even with renewed litigation, it’s unclear if and when the pipeline will ever be built.

“I believe that it is prudent to keep this project within our portfolio even though I don’t believe our community will have to have a serious discussion about whether or not to build the project for decades to come,” John Entsminger, the water authority’s general manager, said Wednesday.

The pipeline was first proposed in 1989 when the water authority filed for permission with the state engineer, Nevada’s top water regulator, to pump billions of gallons of water captured in underground rock. But the project to import rural water near Ely became a flashpoint, a divisive issue that split rural and urban interests. For decades, the project has been mired in litigation from the Great Basin Water Network, a coalition of ranchers, politicians and environmentalists.

In 2015, opponents of the pipeline successfully convinced a District Court judge in White Pine County to order the state engineer to reconsider granting pumping rights to the water authority. In August, the state engineer issued his ruling, pursuant to the judge’s order, and denied several rights to the water authority, something that opponents cheered as effectively killing the project.

But it didn’t. The state engineer argued, in a complicated ruling, that the district court erred in its decision, forcing to use a hydrologic methodology that had not previously been used in Nevada water law. As a result, the state engineer said he would appeal his own ruling to deny the rights.

The water authority’s board voted today to appeal that same ruling.

“For myself, I’m all about the policy,” said Clark County Commissioner Marilyn Kirkpatrick, who chairs the water authority board. “I like to make sure that the policy is right. I’ve worked with the state engineer so when the state engineer appeals a decision of his own, I feel that it’s our duty for the residents to ensure that we’re at that table, in that conversation going forward.”

In nearly thirty years since the pipeline was first proposed no ground has ever been broken for the project. The extra water that would be carried through the roughly 250-mile pipe has not been needed, even amid a record-setting ongoing drought in the Colorado River Basin.

Las Vegas has turned to conservation, pushing programs to incentivize the removal of grass, and returning reclaimed water to Lake Mead, the shrinking reservoir impounded by Hoover Dam. Before the vote and in a recent interview with The Nevada Independent, Entsminger said that the water authority’s goal is to continue pushing conservation and explore desalination.

“First second and third options are additional conservation,” he said.

But Entsminger has also argued to keep the pipeline in the water authority’s long-term resource plan. He defended the project, in the recent interview, as a way to ensure Las Vegas will have water decades into the future as flows on the Colorado continue to decline and the city grows.

“I wish that the water business was an ‘all the people happy all the time’ kind of business. But it’s not,” he said. “The simple fact of the matter is under the Nevada Constitution, all the water in the state of Nevada belongs to all of the people in the state of Nevada. Clark County as a whole uses less than five percent of all the water available within the state of Nevada. And if the day comes when 70 percent of the state’s population needs to take our water usage from five percent to six percent, I think that’s a valid public policy discussion to be had.”

The Colorado River, which supplies Southern Nevada with 90 percent of its water and water to about 40 million people in the Southwest, is stressed from drought, increased temperatures and overuse. States are likely to start taking voluntary cutbacks to their supplies next year to prevent water levels at Lake Mead, a critical reservoir for Nevada, Arizona and California, to drop lower.

Opponents of the pipeline criticized the vote on Thursday.

“We are disappointed but we aren’t surprised,” Patrick Donnelly, state director at the Center for Biological Diversity, said in a statement. “The Southern Nevada Water Authority has been pursuing the water grab for 29 years, and there was little reason to think they would stop today. But don’t mistake the rhetoric we heard in the meeting: today’s vote was a vote in favor of pursuing the pipeline.”

Disclosure: Steve Sisolak and Patrick Donnelly have donated to The Nevada Independent. You can see a full list of donors here.