LAS VEGAS - Nevada's water pipeline proposal is being called the most important water case the state has ever heard, and only days remain for public comment. The plan is to pipe 42 billion gallons of water per year from rural Nevada and Utah to southern Nevada.

Brian Fadie, technology director for the organization ProgressNow Nevada, opposes the project, both for environmental concerns and because of its massive cost.

"It's going to cost at least $15 billion, and those costs are going to be passed onto Nevada ratepayers, when the state is facing astronomical unemployment, astronomical foreclosure rates. It's just not something the state needs right now."

The Southern Nevada Water Authority says the pipeline is needed to ensure a safe and reliable water supply for 70 percent of the state's population. Opponents counter that the pipeline is unnecessary, expensive and environmentally catastrophic.

Launce Rake, a board member of the Great Basin Water Network, says local tribes are among those who face both human and environmental costs from losing that much water.

"Exporting this volume of water will cause deserts to expand in an area the size of Vermont. That's going to have a devastating impact on habitat and, in fact, on the human inhabitants, the Native Americans and rural inhabitants of the Great Basin."

Pipeline backers have pledged to be on the lookout for any signs the project is causing environmental damage, but Brian Fadie warns Nevadans not to count on that.

"I think that once this thing gets built, it's going to have a massive amount of inertia behind it. So, even if we do notice ecological impacts, it's going to be very, very difficult to mitigate those impacts."

A news conference by opponents of the project is set for 2 p.m. today at the Nevada Conservation League office, where Launce Rake says more than one thousand statements opposing the project will be presented.