Ground-water resources of Lanfair and Fenner Valleys and vicinity, San Bernardino County, California

Lanfair and Fenner Valleys and vicinity cover about 1,300 square miles in eastern San Bernardino County, California. Average annual precipitation ranges from 3 to 10 inches over the area. Ground water is utilized primarily for stock and domestic purposes, and occurs in the unconsolidated deposits as well as in the highly fractured consolidated rock. Ground-water levels in wells range from 5 to 600 feet below land surface, and well yields range from 3 to 1,200 gallons per minute throughout the study area. Records indicate that water levels are at or near their predevelopment levels. Springs occur along faults and formational contacts and generally discharge less than 5 gallons per minute. Measured ground-water outflow from Lanfair Valley at Piute Spring ranged from 100 to 630 acre-feet per year. Most of the water is of good quality for domestic and stock use. However , water from two wells indicates a concentration of sulfate that is above the recommended limit for drinking water. Water supplies are adequate for present needs. However, large-scale pumping would result in the lowering of the water table and a reduction of the ground water in storage. (USGS)