What term describes the area around a pumped well where the groundwater is lowered due to pumping?

• A. Cone of depression
• B. Zone of saturation
• C. Radius of influence
• D. Water table

Answer: (A)

When you pump from a well, the groundwater level drops most near the well and gradually rises back toward its original level with distance, creating a cone-shaped dip in the water surface around the well. This localized lowering is called a cone of depression. It reflects how pumping draws water inward, producing a downward-sloping surface that looks like a cone centered on the well. The size and shape of this cone depend on how much water is pumped and the properties of the aquifer, such as permeability and thickness.

The other terms describe related ideas but not the specific phenomenon. The zone of saturation is simply the part of the aquifer below the water table where pores are filled with water, not the pumped region itself. The radius of influence refers to how far the pumping effect is detectable, which is about extent rather than the distinctive cone-shaped lowering. The water table is the upper surface of groundwater, not the lowered area around a pumped well.