There are two questions that are frequently asked regarding the Flood. The first one is, “If there really was a global flood, where did all that water go? The second is, “How could there be a worldwide flood? We do not have enough water to cover the whole earth above the tallest mountains.
These arguments sound good on the surface until one dives a bit deeper. The answer to this question is amazingly simple yet well-known (and even Christian) scholars have never thought of it. In fact, popular “progressive Creation” teacher, Hugh Ross says that he can’t believe in a global flood because of the first point.
Both objections can be answered together: What if the mountains were not as high before the flood as they are today? Psalm 104:8 (NASV) says, “The mountains rose; the valleys sank down. . .” This appears to be at the end of the Flood. So we might conclude the waters ran off as the mountains rose and the valleys and sea basins deepened. Indeed, there is ample evidence that the mountains have risen (in fact, it appears that some are still doing so). Also there is abundant evidence of catastrophic erosion – both in the form of “sheet” erosion resulting in broad, relatively flat plains or plateaus, and in the form of deep-cutting valley or canyon erosion.
Additionally, if you look carefully at a globe, you will find that nearly 75% of the earth is covered with water. Calculations show that if you could “flatten” all the mountains and make the earth smooth like a billiard ball, there would be enough water to cover the entire earth by 1 ½ to 2 miles of water.
So, was there enough water to cover the earth? Yes, indeed. Where is it now? Some of the floodwaters are probably still locked in the sediments of the earth, underground reservoirs, and glaciers but most of it is in the oceans. God’s Word and God’s world agree.