Ground-water conditions in and near the Gila River Indian Reservation, south-central Arizona

In the early 1900 's when ground-water pumping began in the vicinity of the Gila River Indian Reservation, depths to water below the land surface ranged from less than 10 feet to about 130 feet and the general direction of ground-water flow was toward the northwest. In 1983, depths to water ranged from less than 50 feet to more than 700 feet. Water level decline since 1900 was more than 550 feet near Stanfield, 500 feet near Chandler Heights, and 350 feet east of Mesa and southeast of Eloy; about 100 feet near Sacaton; and less than 50 feet near Gila Crossing. In 1983, the ground water flowed westward toward the center of cones of depression east of Mesa; near Chandler Heights, Eloy, and Arizona City; and in the Maricopa-Stanfield area. An increase in the specific conductance of ground water has accompanied the lowering of water levels in many areas.