For over 20 years the vision of a nearly 300-mile long pipeline that would pump groundwater from rural valleys in eastern Nevada to the city of Las Vegas has floated, mirage-like, over the arid state. For the Southern Nevada Water Authority and its powerful general manager, Pat Mulroy, the project is a way to moisturize Las Vegas when the Colorado River is unable to slake the city’s thirst. For opponents -- environmentalists, ranchers, Native American tribes, and others -- it is a specter, an unnecessary development that could usher in irreversible environmental changes.

Last week, the Bureau of Land Management brought the pipeline a step closer to reality. In a 5,000-page Final Environmental Impact Statement the agency recommended allowing development of the underground pipeline across federal lands. The pipeline would transport groundwater from four valleys in the Great Basin region in eastern Nevada. The SNWA had already gained the water rights for up to 84,000 acre-feet of underground water from the Spring, Cave, Dry Lake and Delamar Valleys from Nevada’s state engineer but it needed BLM's approval to build its pipeline on the federal land.

The BLM’s recommendation excludes one controversial locale: Snake Valley, which is on the Utah-Nevada border and is another Great Basin area Mulroy wants to tap. The Authority does not have rights to water in Snake Valley yet, due to a pending agreement with Utah. Back in 2009, as Matt Jenkins reported for HCN, Nevada and Utah banged out a deal to share the groundwater in the aquifer there, but this has not been finalized because Utah has not signed the agreement yet. Mulroy has accused Utah of “bad-faith bargaining” and said the issue could end up at the Supreme Court if it is not resolved. Another reason the SNWA has not secured water rights in Snake Valley is that Nevada’s state engineer put a ten-year moratorium on deciding when to make a decision about the city's application for water rights from there.

The BLM’s preferred alternative is not quite the final word. There is a 60-day comment period before the Department of the Interior makes a final decision. Opponents of the project have filed a legal appeal in Nevada’s courts in response to the granting of the water rights for the four valleys. The Southern Nevada Water Authority anticipates more legal challenges too, according to spokesperson J.C. Davis. “It’s hard to order lunch without somebody filing a legal action against you,” he quipped in a telephone interview.

Over the years, opposition to the pipeline has been strong. And with the release of the BLM’s assessment there is criticism from many quarters. Susan Lynn, who is on the board of directors for opposition group the Great Basin Water Network, maintains that the state engineer did not properly consider the irreversible environmental impacts of permitting SNWA to take groundwater from the four valleys. She contends that the project will draw down the groundwater system throughout the valleys and, since groundwater is connected, impact Snake Valley anyway, ultimately having ill effects on rural counties that depend on tourism and public and private land grazing.

Advocacy group the Center for Biological Diversity warns that sucking up groundwater could desiccate the region’s springs and wetlands, compromising the survival of the Great Basin springsnail, a type of freshwater mollusk that plays a key role in breaking algae and decaying matter into food for fish, birds, turtles and other creatures. The National Parks Conservation Association and the Coalition of National Park Service Retirees have also voiced concerns, particularly with regards to “potential dust bowl conditions” created by sucking water from the watersheds. Leaders from the Confederated Tribes of the Goshute Reservation, located in Nevada’s White Pine County and in Utah’s Juab and Tooele counties, have also panned the proposal, accusing the BLM of allowing Las Vegas to “steal” the tribes’ water.

The project is unnecessary because Las Vegas’ population is not poised to grow at the rate that it did in the past, contends the Great Basin Water Network's Lynn. Conserving water in Las Vegas should be the priority, she says. Lynn also raised concerns about the cost of the project, which could run as high as $15 billion, and the SNWA’s ability to finance it. The Authority is already up to $3.3 billion in debt and has asked for federal assistance to pay for another water project known as the “third straw” – an intake pipe that will allow water managers to draw water from Lake Mead at 1,000 feet above sea level, a move that could be necessary under future water scarce conditions.

Despite opposition, the SNWA maintains that the pipeline is a crucial “safety net” for a water scarce future, explains Davis. He also noted that over the past decade the SNWA has waged an aggressive water conservation campaign, which in 2011 helped Southern Nevada use 36 billion gallons less water from the Colorado River than it did in 2002.

Judging by the legacy of opposition to the pipeline, as well as the hail of criticism fired at the BLM’s recent proposal, challenges and lawsuits will continue to dog the project. And with a hefty price tag sitting on top of these challenges it could be a long time 'til the pipeline actually materializes.

Brendon Bosworth is a High Country News intern.

Image: Snake Valley courtesy Wikimedia Commons.