Out West, it's said that water flows uphill toward money. That's more than bluster along the Colorado River, where rich, thirsty cities in Nevada and perhaps California are poised to use cash, Congress and even Colorado's own quirky laws to secure more water.

As growth takes off across the seven states covered in the Colorado River Compact that spells out water allocations, urban areas - especially Las Vegas - are investigating strategies that could make the desert bloom at other states' expense.

One such strategy could take advantage of the state of Colorado's longtime definition of water as "private property" that can be bought or sold. Water law is more restrictive in neighboring states, so Colorado would be the most vulnerable if Nevada maneuvered aggressively to buy up water from individual owners.

At least a half-dozen would-be water sellers in Colorado envision healthy profits, and they would prefer a hands-off approach by the state government. Colorado Gov. Roy Romer has other ideas.

"I don't have much control over Nevada. (But) I have been trying to send a message to the lower basin: "You're not gonna do this while I'm governor,"' Romer said.

Romer and others are worried that sales could upset the complex chessboard of water law. Ultimately, this could affect water rights that now are keeping taps flowing on Colorado's Front Range.

"If there were an interstate market on the river, Las Vegas could simply come into Colorado and buy up the Grand Valley and then transfer those agricultural water rights down to Las Vegas," said Jim Lochhead, executive director of the Colorado Department of Natural Resources.

In negotiations with the other states, Lochhead's department has been quietly reasserting Colorado's rights to 3.8 million acre-feet of water per year from the Colorado River system. As one of four "upper basin" states in the compact, Colorado has yet to use all the water allocated to it under the 1922 river treaty. That has allowed California and other "lower basin" states to keep taps and irrigation sprinklers flowing.

Meantime, several Colorado-based entities, such as oil companies, are interested in selling or leasing their water rights on the river or its tributaries. The Colorado Department of Natural Resources is fighting those attempts.

Nevada is pushing the limits of its allocation of 300,000 acre-feet a year. The amount was established when the river pact was signed 72 years ago. California has exceeded its limits for years but has started programs - at Romer's insistence - to eventually halt that.

Colorado's definition of water rights as private property is a concept so popular it may be politically impossible to change. But, if a bidding war erupted, that would leave Colorado in a more precarious position than neighboring water-rich states.

In Wyoming, water is a state-owned resource available to users by permit. Utah defines water as a salable property right, but it bars out-of-state sales.

Essentially, if one holder of Colorado water rights sells them privately to a buyer in another state, the interstate commerce clause of the U.S. Constitution could kick in. That could require equal treatment of other sellers and create an open market for water up and down the river system. Protections built into the compact for Colorado cities and farms could be destroyed.

"The state," Lochhead said, "would lose control of its water resources."

One proposal - the Roan Creek project - has been the focus of most recent concern. Nevada water officials last week toured the site.

The Roan Creek plan calls for a dam to be built on the Colorado River near De Beque, between Glenwood Springs and Grand Junction. The dam would be financed by money out of Nevada. Then that state would lease up to 175,000 acre-feet of water, using rights now held by Chevron Oil and Getty Oil, companies that originally bought the rights to produce oil from shale.

One acre-foot is about 326,000 gallons, or enough to meet the needs of a family of four for a year.

"Roan Creek is not a final solution for Nevada, but it certainly can be part of the solution. And we're willing to investigate that," said Janet Rogers, chairwoman of the Colorado River Commission of Nevada.

Roan Creek is not the only private-sale offer on the table. A total of 1.7 million acre-feet of water could be sold by Colorado holders to Nevada. These include:

• The Dominguez proposal on the Gunnison River, which would offer 1 million acre-feet.
• The Paradise proposal on the Colorado, 140,000 acre-feet.
• The NaTec proposal on the Colorado, 145,000 acre-feet.
• The Oak Creek Power Co. proposal on the Colorado, 200,000 acre-feet.
• The Rocky Mountain Power proposal on the White River, 60,000 acre-feet.

Without such individual sales, states could go to Congress in an attempt to reopen the compact. Many observers say a breakup of the compact by Congress isn't likely, even though the water-needy lower basin states have 66 votes in Congress, compared with 21 votes in the upper-basin states.

Like most states involved, California has internal squabbles over water that could keep it from assembling a bloc of votes in Congress.

None of that eases anxiety.

"Each state, while generally supportive of other states developing their apportionment, is fairly suspicious of activities in other states," says Sen. Ben Nighthorse Campbell, D-Colo.

Romer, Lochhead and other upper-basin officials have urged that the lower-basin states work out water trades among themselves to help cover droughts and handle growth. Such efforts have begun informally in California and Arizona, though it will take years for them to reach a scale that might make the lower basin self-sufficient.

Under new proposed regulations from the U.S. Bureau of Reclamation, which oversees the lower-basin through dam management, enough water should be available for 10 to 20 years, says Elizabeth Rieke, assistant interior secretary.

Beyond that, well-planned shifts from farming to city use may keep lower-basin cities alive over the next century, she said.

"The needs of urban users over the next 100 years are less than 20 percent of the current deliveries to agriculture in the lower basin. So it should be possible to meet the urban needs from existing uses," Rieke said.

But Nevada is so close to using its full allotment that its officials are demanding a "flexible" reading of the compact and court opinions interpreting it.

"If the states are unable to accommodate each other, the Congress will have to become involved," said U.S. Sen. Harry Reid, D-Nevada.

As the West fills up, federal officials say they can pinpoint shifts that have changed water needs in the seven decades since the compact was signed.

"Agriculture, mining and timber are no longer the dominant economic enterprises," said reclamation commissioner Dan Beard, who oversees southwestern water projects for the Interior Department.

Fears that the upper-basin allotment will be drained by changes are unfounded, he said.

"Interstate transfers are only going to take place when the states agree that is what's going to take place," Beard said.

But with urban water demand surging, "The reality is, the world has changed."

Others believe what ought to be changing is growth policies.

"At the end of World War II, the West had about 16 million people; right now we're closing in on 60 million," says Charles Wilkinson, a University of Colorado law professor who specializes in regional issues. "If you read the letters to the editor in papers all across the West, in Reno or Boise or Jackson or Denver or Phoenix, you see a level of attention to growth that we've never had before.

"We're going to have to start reining in growth. Because if we don't, we're not going to have a West anymore; we're going to lose the distinctive qualities that brought people here to begin with."

COLORADO RIVER COMPACT FACTS

• Signed in 1922, it establishes set amounts of water for Colorado, Wyoming, Utah, New Mexico, Nevada, Arizona and California. These limits vary sharply from state to state, and were based on initial estimates of likely future demand by each state.

• Colorado, Wyoming, Utah and New Mexico also abide by a separate treaty among those "upper basin" states. Squabbles among the other three "lower basin" states prevented such an agreement for them. As a result, the federal Bureau of Reclamation plays a stronger role in the lower basin in brokering disputes. The bureau also controls federal dam use in both basins.

• In 1944, the United States also agreed to deliver 1.5 million acre-feet of Colorado River water to Mexico each year.

• Explosive growth in California has caused the state to exceed its limits on the compact many years. In 1991, during a drought, California officials asked for the right to take 400,000 acre-feet more than the state's allotment; Colorado Gov. Roy Romer agreed on condition that interstate talks begin to meet individual needs but still uphold the compact.

• Though innovative steps are helping with California's problems, it may face drought as soon as next year; and booming Las Vegas has become a new sticking point in river relations.

Ten Tribes May Affect Water Flow

Ten American Indian tribes that hold rights along the Colorado River or its tributaries also could affect how water is apportioned.

They could open up a market for water sales from one state to another, and some tribes have expressed interest in doing just that.

Colorado's two tribes, the Southern Utes and the Ute Mountain Utes, agreed in 1988 to be treated like other Colorado water users in a law approved by Congress. It states that those tribes can't sell their water unless other private users in Colorado - such as owners of the Roan Creek rights in western Colorado - start up a market first.

Leonard Burch, chairman of the Southern Utes, says that's not a fair restriction, especially with delays in construction of the Animas-LaPlata water project. The $653 million project is supposed to supply long-promised water to Colorado reservations in the Four Corners area.

Animas-LaPlata has been approved by Congress, but is hung up over environmental concerns. It also may be scaled back. An Interior Department inspector general's report in July called it "economically infeasible" as originally planned. The report suggested cash payments to the tribes instead of the project being built at full scale.

If Animas-LaPlata isn't built soon, Burch said, the tribes may want to reassert their right to sell water rights to bring in some money to finance economic development.

"Our patience is wearing pretty thin now," he said. "We thought we complied with all the necessary requirements" for environmental issues in Animas-LaPlata. "Each time we finish with that, there's another roadblock."

If the Southern Utes did sell water rights, Burch said, the money would go toward "developing our natural resources on the land we own."