Take a trip to the grand canyon and realize the portion of the Colorada River that exits sits higher then the place it enters. Proof of massive water erosion, i.e. the great flood.



If the earth was millions of years old we could walk across the gulf of mexico because it would be full of silt from the dumping of the mississipi.



If the earth was millions of years old then the niagra falls wouldnt exist since its erosion is very fast, something on the order of 14 miles from where it was first recoorded.