The U.S. Geological Survey, in cooperation with the Santa Barbara County Water Agency, continued the study of the ground-water resources of Santa Barbara County (fig. 1) in 1963. As part of the study, the Geological Survey made monthly water-level measurements in 247 wells; 17 of which were equipped with automatic water-level recorders. These measurements and measurements made by the Santa Maria Valley Water Conservation District are included in this report— In addition, the U.S. Bureau of Reclamation measured the water levels in wells along the Santa Ynez River between Cachuma Dam and Rucker Crossing, but the measurements have not been included herein.

In addition to the observation-well program, the Geological Survey is preparing interpretive reports on the ground-water conditions in the Ellwood-Gaviota area, the Lompoc and Santa Ynez upland areas of the Santa Ynez River basin, the Santa Barbara-Summerland area, and the Santa Maria Valley. The basic data from which these reports are being prepared can be consulted at the Santa Barbara office of the Geological Survey.

This report was prepared by the Geological Survey, Water Resources Division, under the general supervision of Fred Kunkel, district geologist in charge of ground-water investigations In California, and under the immediate supervision of C. P. Zones, geologist in charge of the Santa Barbara subdistrict office.

Measurements for the period 1941-55 were published in U.S. Geological Survey water-supply papers; measurements for the period 1956-62 were released locally in duplicated form.' A report by G. A. LaRocque, Jr., and others (1950) contains descriptions of 2,246 wells in the ground-water basins of the county in 1942. It also contains many water-level measurements made before 1942 by the city of Santa Barbara, the Santa Maria Valley Water Conservation District, the San Joaquin Power Division of the Pacific Gas and Electric Co., the Union Sugar Co., the Union Oil Co., and other organizations and individuals.

Comprehensive reports on the geology and ground-water resources of the Santa Ynez River basin (Upson, Thomasson, and others, 1951; Wilson, 1959), the south-coast basins (Upson and others, 1951), the Santa Maria Valley area (Worts, 1951), the Cuyama Valley (Upson and Worts, 1951) and the San Antonio Creek valley (Muir; 1964) were published as Geological Survey water-supply papers. A report on stream runoff and ground-water storage capacity of the Santa Ynez River valley (Troxell and Wilson, 1952) was released to the open file in October 1952. A complete bibliography of reports of investigations made by the Water Resources Division, U.S. Geological Survey, in Santa Barbara County since 1940 is included in this report.