I assume you mean, "using only water presently on the Earth". If we can import unlimited amounts of water, then of course the answer is "yes".
No one knows exactly how much water is underground, but estimates are that it's a very small amount compared to the amount in the oceans. I came across some numbers years ago, (quoting from my own book here, is that cheating?) 97% of the world's water is in the oceans, 2% in ice caps and glaciers, 1% underground, 0.02% in fresh water rivers and lakes.
So as others have said, melting the ice gaps and bringing up all the underground water wouldn't increase the level of the oceans very much, not enough to cover all the land.
On the other hand, I think the common theory among creationists today is that before Noah's Flood the Earth was more nearly spherical, i.e. the mountains weren't as high nor the ocean trenches as deep. If you think about it for a moment, if the Earth was a perfect sphere, it wouldn't take very much water at all to cover it (relatively, any way). Do the arithmetic and if the Earth was a perfect sphere, the amount of water in the oceans today would cover it to a depth of 1.7 miles.
So the (logically) easiest scenario to flood the Earth is: level the mountains and fill in the ocean trenches. If the highest mountains and the deepest trenches were about 1/4 what they are today, the entire world would be under water.