Through what mechanism?
What is the volume of water required to cover the Earth 2 miles deep?
About 4.36EE19 Gallons.
Are you assuming a topography similar to what we have today,
or perhaps you have left open the possibility that the land masses were a lot more “level” - no big deeps, no high plains or mountains...
Actually, if the earth were “level” today, it would be totally covered with the water that is currently on the surface.