Under what condition is the top of the water table a smooth surface?

Answer 1

When it is a natural lake.

Groundwater does not have a surface, it has a level when it is contained within an aquifer. Where the water table intersects the ground surface, a stream, river, or lake are the surface expression of a water table.

You must have lots of homework, so many questions. Look in your book. I'm sure all the answers are there.

Answer 2

I don't know what the questions is getting at but, the top level of water in a well would have a flat smooth surface. That water in that spot is at the top of the water table.