The presence of saline water on land, whether ground water or intruding sea water, can be very destructive to natural and agricultural plant life. The high conductivity of such water makes it an excellent target for EM detection.

Fresh water for consumption is a scarce commodity in many parts of the world, and locating new supplies is a major concern. Airborne electromagnetic surveys can be used to detect freshwater-filled fractures in rock, or sandy paleochannels in the overburden. Water-filled fractures are generally more conductive than the surrounding rock.

As well as locating existing ground water, airborne electromagnetic surveys can be used to monitor the changing conditions and the rate at which the ground water is being recharged by rainfall. Conductivity maps are used to estimate water permeability (which is governed in part by clay content), and the permeability is related to the rate of downward flow of recharge water by test measurements on the ground.