I think I get what you're trying to say. If all the land on Earth was made flat and the land above sea level was put in the oceans, how far would the water level rise.
But anyways, here goes my shot at it (disregarding the absurdity of the idea):
The average height of land above sea level for the earth is 5449 inches. (Source not reputable)
I hate the Imperial system, so 5449 inches = 138.4046 metres.
~30% of the Earth is land.
So the surface area of Earth times 30% times the average height of land above sea level = volume of land above sea level.
Note: For simplicity of calculation, I'm assuming land BELOW sea level is negligable. The effect of neglecting this part of the calculation will make the final answer slightly higher than what it actually is.
The surface area of Earth is 5.1 × 10^8 km² (from Wikipedia). This equals 5.1 x 10^14 m² (1 km² = 10^6 m²)
So the volume of land above sea level is approximately 2.12 x 10^16 cubic metres.
The volume of the Earth's oceans is 1.35 x 10^24 mL (from one of my previous posts). This is equal to 1.35 x 10^18 cubic metres of water.
The combined volume of land above sea level and water is therefore: 1.37 x 10^18 m^3.
The ratio of the two volumes (Combined volume of land above sea level and oceans to volume of the oceans) = 1.015%
The mean radius of Earth is 6,371.0 km (according to Wikipedia and assuming the radius goes to sea level).
(For the ease of calculation, I'm going to assume it is uniform - that Earth is a perfect sphere)
The ratio times the radius of Earth gives 6466.6 km.
6466.6km - 6371.0 km = 95.6 kilometres
But keep in mind we've made a LOT of assumptions and got information from a few unreputable sources. This number isn't accurate, but gives a good ballpark figure.
A sea level rise 95.6km would put the water near the Karman Line in the thermosphere (at about the altitude where the aurora takes place). At this altitude, Noah would have a lot more to worry about than flooding. Noah and the cute little animals would have to worry about lack of oxygen and food, a temperature of 1500 degrees Celsius, among very many other things.
Sorry. This theory too is not plausible. To be fair, I said originally that this calculation would be slightly high. In reality, the actual height is probably somewhere between 85 and 90 kilometres (good educated guess). But the problems are still there.
This theory has been debunked.