Maps showing ground-water conditions in the western part of the Salt River Valley area, Maricopa County, Arizona, 1977

In 1976 about 1.68 million acre-feet of ground water was pumped in the Salt River Valley. Since 1923, more than 73 million acre-feet has been withdrawn, which has resulted in a general decline in water levels. Water levels in the western part of the Salt River Valley area have declined as much as 350 feet. Information on the maps includes altitude of the water level, depth to water, change in water level (1923-77), and irrigated area. Long-term hydrographs of the water level in selected wells, a table of historical pumpage, and a brief discussion of the chemical quality of the ground water are included also.