The point is the water table closest to the surface in valleys.
In areas of topographic relief, the water table generally follows the surface but tends to approach it in valleys and intersect the surface with streams and lakes. Closest to the surface is the vented zone where the interstices between the soil are filled with both air and water. Below this layer is a saturation zone where the gaps are filled with water.
The water table is the subsurface boundary between the soil surface and the area where groundwater saturates the space between sediment and rock fissures. At this boundary, water pressure equals atmospheric pressure. The top surface of the groundwater is the groundwater table. Beneath this surface, all pore spaces and cracks in sediments and rocks are completely filled and saturated with water. Groundwater occurs in these saturated layers known as saturation zones or water vapor zones.
