The water table is:
the surface of ground water
only found underground
usually very shallow
all of the above

Ground Water

Explanation:

The surface of this ground water is called the water table. In lakes and swamps, the water table is above the surface of the ground. In other areas the water table may be a few meters or even hundreds of meters beneath the surface.

explanation:

on disadvantage of hydroelectric power is the cost. another disadvantage of using hydroelectric power is finding a water source powerful enough to harvest hydroelectric power.