PORTLAND — When parched Southwest states recently considered ways they might bring more water to the overtaxed Colorado River, they imagined snaking a fiberglass straw up the Pacific coast and sipping from the Columbia River.

That’s probably a pipe dream, but it’s also a recurring vision the drenched Northwest might not want to laugh off forever.

When desert cities — enduring record drought — reach the breaking point, water will have to come from somewhere. And water in the West is largely a zero-sum game: For someone to get it, someone else will have to give it up.

Although the Northwest appears to be swimming in water, rapid growth and salmon demands mean most of it is spoken for in summer. But if some is up for grabs at other times, what should be done with it?

Is water the new oil, and could Oregon become the new Texas? Could the Northwest sell some of its wealth of water the way Alaska sells oil from its pipeline?

At least one Oregon lawmaker says so, seeing water sales as a way to fund public services without raising taxes. But a veteran of Northwest salmon fights warns the region to resolve its internecine bickering over fish and water so it can mount a united defense if the Southwest comes knocking.

Because, in a drier future, the choices are few: Either people move to the water, migrating northwest as the Southwest runs dry. Or water moves to the people, through a new generation of long-distance pipelines and canals.

“There will be nothing done with water in the West without there being winners and losers,” says Patrick O’Toole, a Wyoming rancher and president of the Family Farm Alliance. Cities may expect to buy water from farms, but that’s not a good solution as global food shortages make farming a crucial national need, he says.

So they may have to look elsewhere.

Oregon laws probably would not allow the sale of water outside the state, but Alaska changed its law years ago so it could pipe water to Los Angeles if the opportunity arose. Asked how much California would have to pay for Alaskan water, former Alaska Gov. Walter “Wally” Hickel said, “Depends how thirsty they are.”

Colorado River states’ recent study of ideas for supplementing the dwindling river mentions an undersea aqueduct from the Columbia River, which flows between Oregon and Washington. The report doesn’t recommend the far-out option, and nobody expects a proposal any time soon.

But it does hint at just how precious water may become.

“That may be a choice Oregon may be faced with or presented with by some states from the Southwest: `We’d like to buy your water,”’ says Michael E. Campana, director of Oregon State University’s Institute for Water and Watersheds. “That seems preposterous now, but in 30 or 40 years, who knows? I’m not willing to say that’s not going to happen.”

It’s not a new idea.

Campana went to graduate school in Arizona and remembers students asking what would happen when the booming Southwest ran out of water. A professor answered, “Don’t worry, we’ll just pump it out of the Columbia.”

In the 1960s, Southern California water leaders quietly discussed routing Columbia River water to Lake Mead, the reservoir that supplies Las Vegas and Los Angeles. But powerful U.S. Sen. Henry “Scoop” Jackson of Washington killed the idea with a provision prohibiting federal engineers from studying it.

That provision has expired, but the idea is still roundly dismissed as politically impractical, environmentally troublesome and financially prohibitive.

The Colorado, with less than a tenth the flow of the Columbia, supports nearly 30 million people, three times the population of Oregon and Washington combined. But its water was divvied up when the river was unusually full and now cannot meet rising demands. An eight-year drought, for instance, has left Lake Mead half empty.

The states — Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming — reached a hard-fought agreement last year on how to spread the pain of water shortages. Their deal promoted water conservation, but also committed to study options for bringing extra water into the Colorado system.

They considered more than 10 possibilities: desalinating ocean and brackish drainage water, capturing and reusing stormwater runoff, seeding clouds to generate more rain — even towing in icebergs wrapped in plastic.

Two involve the Northwest: rerouting water from rivers outside the Colorado drainage, such as the upper Snake, into the Colorado system, and the undersea aqueduct from the Columbia, possibly to Southern California.

The idea builds on studies looking at undersea pipelines from Alaska or Northern California. They found the concept feasible but extremely expensive. The new study discusses a high-strength fiberglass pipeline collecting water near the mouth of the Columbia, below hydroelectric dams, and snaking south offshore.

Pumping stations might be required along the way. The study suggests the cost could top $150 billion — some 20 times Oregon’s annual general fund budget. Feasibility studies alone could be more complex than the $450 million worth of analysis for the trans-Alaska oil pipeline.

The study adds flatly that “considerable opposition from the states of Washington and Oregon and from environmental groups should be expected if this option were proposed.”

Richard Golb, a water consultant who represents irrigation districts in Oregon and is the former executive director of a California water association, says there is no Columbia surplus to give away. Oregon needs its water. And, he says, “the Columbia River is a big part of what makes Oregon Oregon.”

Southwest leaders emphasize they’re not coming after Northwest water. The pipeline and other options are not recommendations, says Bill Rinne, director of surface water resources for the Southern Nevada Water Authority in Las Vegas, which led the study. They’re just concepts to ponder as the West grows and develops.

“You must keep some of these things on the table,” he says. “They may stimulate other ideas.”