Then you are ignorant of geology, soil mechanics, and hydrology. In numerous ways the Grand Canyon looks exactly like what it is, the result of the Colorado River winding across a desert for millions of years as the Kaibab uplift slowly rises (this tectonic uplift is ongoing and measurable). Clue for the clueless: Dambursts and ocean floods don't cause meanders. Nor do they cause 1000ft sheer drops in tough limestone.
No, I can appreciate erosion and other geological processes. However, you failed to answer the question as to how much water, as in cubic measurements would it take to carve out the Grand Canyon?