The claim, as related in this article in the Guardian today, that the world's great rivers face "catastrophic collapse" seems at first like rank hyperbole. But upon reflection, one of the United States' great rivers -- the Colorado -- no longer pours into the sea. Dammed at more than 30 points, it dies as a salty trickle in the Sonoran Desert before it can reach the Gulf of California. If that can happen in the most powerful country in the world, well... (Come to think of it, the Colorado meets its end in Mexico, so maybe that explains our lack of concern). Anyway, the Colorado isn't even on the WWF's list of the world's ten great threatened rivers.