HISTORY OF ENGINEERING GEOLOGY IN THE CALIFORNIA-DEPARTMENT-OF-WATER-RESOURCES

Engineering geology has played an essential role in the projects of th e California State Department of Water Resources (DWR), Numerous pione ering techniques by DWR geologists include a) the first active element analog/digital model of a groundwater basin, b) cost estimates for tu nneling, c) test plots evaluating shallow land subsidence (hydro-compa ction), d) a mobile rock mechanics laboratory, e) field and laboratory evaluations of specific yield, and f) determination of coastal aquife rs subject to sea-water intrusion, Eventual results of these technique s include a) digital ground-water basin models with increasing complex ity, b) and c) choice of the lowest cost route and geotechnical method s to bring water to southern California, d) rock properties available to engineers for preliminary design, e) values of storage capacity for 250 ground-water basins, and f) construction of fresh-water injection barriers to preserve ground-water basins. Geologists obtained and int erpreted for their engineer colleagues the essential geologic informat ion utilizing advanced geophysical and drilling techniques for both th e California Water Plan and the State Water Project, The former its a master plan for utilization of all the water resources of the state, T he latter, now essentially complete, included planning,design, and con struction of 14 dams, 21 pumping plants, an underground power plant, 1 1 power recovery stations, 6 tunnels, and 561 mi of aqueduct, bringing water to the San Francisco Bay area and from the central and northern parts of the State to the heavily populated south. A geothermal test well completed by DWR in the Imperial Valley encountered fluid of insu fficiently high temperature for economic development, DWR geologists h ave been active in the initial organization and the development of the Association of Engineering Geologists, and have also been active in t he Geological Society of America, particularly in the Engineering Geol ogy and Hydrogeology Divisions.