The water-bearing potential of the geologic formations in the western part of Santa Cruz County, Calif., is evaluated. Most of the sedimentary formations in this area are fine-grained rocks of Tertiary age that have been folded and faulted. These rocks, in general, yield supplies of water sufficient only for individual domestic supplies. The Lompico and Santa Margarita Sandstones, however, are coarser grained and have the potential to yield moderate quantities of water (50-100 gallons per minute). Areas where the Lompico Sandstone might warrant explorations are (1) near and on the west side of the Ben Lomond fault, (2) near and south of the outcrop of the Lompico Sandstone between Ben Lomond and Felton, and (3) in the area near Bald Mountain School. The Santa Margarita Sandstone should be explored by test drilling in the area between Davenport and Bonnie Doon. The quality of ground water is generally good, although saline water occurs in the San Lorenzo Formation near Redwood Grove and Riverside Grove. (Woodard-USGS)
Additional publication details
USGS Numbered Series
Geology and ground-water in western Santa Cruz County, California, with particular emphasis on the Santa Margarita Sandstone
Water-Resources Investigations Report
U.S. Geological Survey,
1 map : col. ;on sheet 86 x 117 cm. fold. to 30 x 22 cm.