What is groundwater primarily found in?

Groundwater is primarily found in aquifers, which are underground layers of water-bearing rock or sediment that can store and transmit groundwater. Aquifers allow water to flow and can be tapped into through wells for various uses, including agriculture, drinking water, and industrial processes.

This is distinct from the other options listed, which refer to surface water. Rivers and lakes, streams, ponds, and surface reservoirs contain water above ground, whereas groundwater is located beneath the Earth's surface in porous geological formations. Understanding the role of aquifers is essential in Arizona, where groundwater management is crucial due to the arid climate and limited surface water resources.