Ground water in the Fresno area, California

The Fresno area of California uses about 140,000 acre-feet of ground water a year for municipal and domestic purposes. An average of 2,000,000 acre-feet of water a year is pumped for irrigation. Major sources of recharge are deep penetration of irrigation water (80 percent) and seepage from canals, rivers, and streams (15 percent). Ground water occurs under unconfined and confined conditions; most water is pumped from the unconfined, alluvial aquifer. Ground-water quality is generally suitable for domestic and irrigation uses, although hardness and concentrations of nitrates and dissolved solids are of local concern. Water levels in the unconfined aquifer declined about 25 feet in the period 1947-1976. Levels in the confined aquifer declined about 100 feet in the period 1954-1976. Increased reliance on ground water for irrigation during the drought period will accelerate water-level declines.