Seventy years after the completion of Hoover Dam, plans are in the works on a new round of massive public projects aimed at supplying water for growth in Nevada, Arizona and Utah. Within decades, the region could see a groundwater pipeline network stretching north from Las Vegas, and long pipelines from Lake Powell into Southern Utah and north central Arizona. Photo by John Locher. Click image for enlargement. Graphic by Mike Johnson. White Pine County rancher and pipeline opponent Dean Baker gives an aerial tour of Snake Valley in eastern Nevada, one of several rural watersheds targeted for groundwater development. Photo by John Locher.

When drawn on a map, the Southern Nevada Water Authority's proposed pipeline network across Eastern Nevada resembles a weed growing north from the parched soil of Las Vegas.

A wider view reveals other weeds set to sprout from the garden.

Over the next 20 years, as many as three massive pipelines could be built in Nevada, Utah and Arizona. Those projects would cost hundreds of millions of dollars and stretch across hundreds of miles of remote terrain to deliver water to growing communities barely within reach of the Colorado River.

"I guess somewhere we decided as humans it's better to take the water to the people instead of the people to the water. I guess we'll keep doing that," said Dennis J. Strong, director of the Utah Division of Water Resources.

Southern Nevada's pipeline network is merely the largest and costliest of the proposed projects. It is also the only one that seeks to tap groundwater in one watershed and move it to another.

The pipelines under consideration in Utah and Arizona would carry Colorado River water to burgeoning population centers in those states, far from the river's banks.

The Utah pipeline is expected to deliver almost 70,000 acre-feet of water a year to feed growth in St. George and along the Interstate 15 corridor in the southwest corner of the Beehive State. It also would supply 10,000 acre-feet to Kanab and 20,000 acre-feet to Cedar City.

But that will require no small feat of engineering.

First the water will need to be lifted some 2,600 feet from Lake Powell, near Glen Canyon Dam, to a high spot in the layer cake of sedimentary rock known as the Grand Staircase. From there, the water will fall some 3,000 feet to the Sand Hollow Reservoir northeast of St. George, possibly generating electricity on its downhill run to offset some of the project's overall power costs.

By the first of the year, the state expects to hire a consultant to analyze the energy aspects of the project, Strong said.

It will be six to 18 months before project officials are ready to file a right of way application for the pipeline, a move that will kick off a federal environmental review of the project.

"We are very early in the process," Strong said.

Some officials predict that without new water sources, shortages could hit in some areas of Southern Utah by as early as 2012.

The Lake Powell pipeline, preliminarily priced at about $500 million, might not be in place until 2020.

Arizona's pipeline project is even further out than that, "if it ever happens at all," said Thomas Whitmer, manager of regional water planning for the Arizona Department of Water Resources.

A study released by the department in August concluded that the north central part of the state will face "some serious unmet demands in the next 40 to 50 years," Whitmer said.

The area in question includes the Grand Canyon, the Navajo and Hopi reservations, and the communities of Flagstaff, Williams, Sedona and Page.

The study outlined about a dozen possible water solutions, including a 250-mile pipeline from Lake Mead to Flagstaff. Another, more likely scenario involves a shorter pipeline from Lake Powell to several communities in north central Arizona.

The various solutions range in cost from $400 million to $600 million, estimates Whitmer described as rough "appraisal-level numbers" that are daunting nonetheless.

"These are some very big dollars, especially for small communities," he said. "And you can build a pipeline, but the question is, what are you going to fill it with?"

Virtually all of Arizona's share of the Colorado River, 2.8 million acre-feet a year, is already spoken for. Much of it is diverted into the Central Arizona Project canal that feeds Phoenix and Tucson, and the rest is used by farming interests on or near the river.

Plans to supply north central Arizona with water from Lake Powell could be further complicated by a political distinction that divides the Colorado River into two basins, upper and lower.

Arizona is in the lower basin, but Powell is considered part of the upper basin, so any pipeline that taps the reservoir would require a potentially contentious water transfer between the two basins.

Unlike Arizona, Utah has more than enough Colorado River water to spare for a pipeline.

Utah's annual share of the river is 1.7 million acre-feet, of which roughly 1 million acre-feet are put to use each year, Strong said.

By comparison, Nevada uses, and reuses, nearly all of its allotment of 300,000 acre-feet, the smallest share by far among the seven Western states that draw water from the river.

One acre-foot of water is almost enough to supply two Las Vegas homes for one year.

"Just like Nevada intends to use all of its (Colorado River) allocation, Utah intends to use all of its allocation," Strong said. That could occur by 2030 or 2035, though he said "those are guesses."

"We can go wild with speculation about all the things that might happen," Strong said.

With an estimated cost of at least $2 billion, the Southern Nevada Water Authority's 285-mile pipeline project has moved well beyond speculation.

Sometime next year, Nevada's chief water regulator is expected rule on the authority's request to export almost 30 billion gallons of groundwater a year from White Pine County's Spring Valley, 250 miles north of Las Vegas.

Of the approximately 170,000 acre-feet of rural groundwater the authority ultimately hopes to deliver to Las Vegas, fully half of it would come from Spring Valley.

Authority officials insist there is enough unused water trapped beneath the rock in Clark, Lincoln and White Pine counties to satisfy Southern Nevada's growing thirst and its need for drought protection without harming the environment.

Water authority Deputy General Manager Kay Brothers said projects like the ones now being discussed in Nevada, Arizona and Utah are not so different, at least philosophically, than the Roman aqueducts built 2,000 years ago.

"It's nothing new," Brothers said. "It is what has allowed the West to grow. It's how it's been and how it will be."

But what some view as the march of human progress others see as a direct threat to their homes and their livelihoods.

Dean Baker and his family have been ranching for more than 50 years in one of the area's targeted by the SNWA. Their Snake Valley spread straddling the Nevada-Utah border is so large that Baker sometimes uses a small aircraft to check on cattle and range conditions.

He also gives the occasional tour, flying interested guests over old cattle ponds and spring-fed marshes that have been dried up by nearby agricultural pumping.

Baker points to these things as proof that his valley has no water to spare, let alone billions of gallons for some faraway city.

"I don't believe anyone experienced in underground water withdrawal in an area such as this thinks such a withdrawal can happen without significant negative impact," he said. "It just won't work."