Answer:
Zero
Explanation:
Hole is defined as a gap or aperture or cavity at a given surface, the surface could be any defined plane. Depth of a whole is given by distance between surface and end point of the hole.
Now in the given situation the place is ground level and the depth of hole is to be measured at ground level.
Hence the depth of a hole at ground level would be zero as the end point of hole is at the surface.