We Canadians can be a prickly sort. So I for one wasn’t particularly surprised to see that large majorities of us are opposed to selling water to the U.S. (This is the same country that’s gotten extremely wealthy — and abandoned its Kyoto commitment — by selling the U.S. as much tar sand oil as we can make.) Still, Jim Margolis’ recent article at The American Prospect has some interesting bits.

Now looms a U.S. invasion Canadians take more seriously. This one is real, and its target is more tangible — their water. They think we’re coming after it. They’re right.

It isn’t that the water wars are the talk of the nation; they were rarely mentioned in the recent federal election campaign. But the dispute bobs beneath the surface, a regular topic of conversation among the political elites. From the left, the Council of Canadians calls for a national water policy that would prevent “bulk water exports and diversions.” From the right, former Alberta Premier Peter Lougheed predicted that, “the United States will be coming after our fresh water aggressively within three to five years.”

One newsmagazine here, Macleans, had a cover article last year about the American desire for Canadian water. And you can get an idea of the coming talking points from the right by the tone of the article:

But Canada, the most water-rich nation on the planet, wants no part of this new world. And that puts our priorities on a collision course with the needs of our biggest trading partner and most essential ally. Already the White House has mused about the need to open the Canada-U.S. border to water exports, and dozens of communities are lining up to reform a 96-year-old treaty that limits the amount drawn from the Great Lakes. This country is in a position to provide a solution that would yield enormous economic and humanitarian benefits for the entire continent, even the world.

Wow! Sign me up! After all, we’re talking about feeding the hungry, feeding the poor, right?

Not so fast. A few paragraphs earlier, Macleans tells us what this is actually about:

Lake Mead is the principal source of drinking water for the Las Vegas valley — the fastest growing urban area in the United States. In all, more than three trillion gallons of water have disappeared due to drought, evaporation and overuse in five years, raising profound questions about the sustainability of growth in the U.S. southwest. The Colorado River, which not only feeds Lake Mead but also drives the turbines of the Hoover Dam, is a critical source of drinking water and power for much of southern California and Arizona. And between 2000 and early 2005, its flow dropped by almost half.

Las Vegas — despite pursuing aggressive water conservation — is having to reconsider its development plans, and this is a humanitarian crisis? Gee, how about we don’t move so many people in to the desert? How’s that for a solution? Never mind the fact that this entire idea is based on a flawed premise: Canada’s water resources don’t just belong to Canadian people. Surely we have gotten to the point where we can ask about the justice in destroying animal habitats, too?

That said, the problem of global water-poverty is a real one, even if the American case is about as unsympathetic as you could find. Countries with far fewer resources — and far poorer populations — face real water shortages. Aside from the social-justice angle, there’s the geopolitical one: countries like Turkey or China (which control the sources of water for Iraq and Indochina, respectively) have a huge incentive to stiff their neighbors down the river. What happens when China builds the next Three Gorges and turns off the tap to Vietnam?

One usual answer is seawater desalination. And desalination costs have come down as the price of tapping new sources of water has gone up. But the scale is truly daunting: the U.S. uses 137 billion gallons of water a day for agriculture alone. The “plus” side is that U.S. irrigation is so inefficient that there’s plenty of savings to be had. Only 4.2 million acres use micro-irrigation, for example. It gets better, actually — micro-irrigation systems also allow farmers to dramatically reduce pesticide and fertilizer use, so we get a trifecta, ecologically speaking: Less water, less fertilizer, less pesticide.

So there’s the choice: Either the U.S. can start using water more efficiently or start importing water from Canada. Given that mass water exports could ruin sensitive Canadian ecosystems, I know where I stand.

Just so long as we don’t see “Operation: Thirsty Eagle,” complete with an armored assault on Toronto, anytime soon.