A moment ago you were citing a website that claims that it was made during the Flood. Now you're saying it's due to a breaking dam. Which is it? And which dam, when?
That little River did not carve that great big canyon.
If you knew the most basic things about the Grand Canyon (i.e., enough to have an informed opinion about how it might have formed), you'd know that "that little river" is today a trickle of what it once was, because IT WAS DAMMED UPSTREAM in 1960-62 by the building of the Glen Canyon Dam.
Prior to that, the Colorado River could reach flow volumes of 200,000 cubic feet per second.