Maps showing ground-water conditions in the upper San Pedro basin area, Pima, Santa Cruz, and Cochise Counties, Arizona; 1978

The upper San Pedro basin area includes about 1,800 square miles in southeastern Arizona. The main use of groundwater is for irrigation. During 1966-77, about 481,000 acre-feet of groundwater was withdrawn. Except near Sierra Vista and Fort Huachuca, the groundwater withdrawals have had little effect on water levels. Information shown on the maps includes altitude of the water level, depth to water, depth of well, hydrographs of the water level in selected wells, irrigated area, and specific conductance and fluoride concentration in the water. A table of pumpage also is included. (USGS)