well we geologists (and i say WE because i am going to school for geology) sure as hell dont call it noah's flood. it wasnt a flood that made the grand canyon anyways. it was a river.
yes, water is a damn strong force, but only under certain circumstances. if you pressurize it, yes it can cut metal, but rivers dont flow at 500psi. the strongest force is something called cavitation which is basically air bubble bursting with tremedous force in waterfalls. this is what is acting on the bottom of the niagra falls. given time (time meaning many millenia at least because the geological time scale usually deals with millions of years) all this will cut a canyon, but a flood means nothing when you're dealing with large rivers. there are already huge amounts of water flowing though the grand canyon, and yet there are no visible changes from day to day. in fact its widely accepted that the grand canyon is about... 5 million years old based on the fossil records.
anyways this HAS kind of gotten away from what i was trying to say. i wasnt trying to turn this into a debate about religion or anything like that. i was trying to point out how stupid it is that the government is doing exactly what it is supposed to prevent in this case. i mean... the whole "accommodating creationists" argument aside, whats in the constitution? freedom of speech for one thing. at the very least this issue about the grand canyon is unconstitutional and im amazed that we havent seen a real **** storm about it yet.
<EDIT> you posted while i was typing, nil8. just so you know, ice can do some damage. ice is what formed the nice jagged mountains up here (like the rocky mountains). the only thing is that the grand canyon is sandstone so if a glacier came through there, everything would be wiped clean, no canyons.