LCI served as the lead geologic consulting firm supporting the California Department of Water Resources (DWR) in their response to the Oroville Dam spillway emergency, and subsequent spillway recovery work, providing a team of over 30 geologists to support the project. LCI geologists performed a wide range of services, including rock mass characterization, excavation monitoring, and slope stability assessments. To support the evaluation and design of potential spillway restoration options, LCI geologists collaborated with geologists from DWR, the U.S. Bureau of Reclamation, and the U.S. Army Corps of Engineers to design and conduct an extensive field exploration and laboratory testing program to characterize site conditions. This program included drilling over 150 boreholes, seismic refraction profiles, and installing dozens of piezometers and inclinometers. LCI also assisted DWR and the Independent Forensic Team investigating the causes of the spillway failure by coring and excavating through the damaged spillway and characterizing materials in the old spillway foundation.
To support the construction of the restored spillways, LCI staff worked closely with DWR to develop contract specifications for cleaning deleterious materials from the foundations of new structures and approving foundations. LCI geologists subsequently mapped the foundation of the new flood control outlet (FCO) chute and emergency spillway structures. This involved developing drone-based orthophoto basemaps showing the freshly-cleaned foundation rock, and mapping nearly 22 acres of geology at a scale of 1:60 (one inch equals 5 feet), and over 29 acres at a scale of 1:120 (one inch equals 10 feet). All work was performed under the supervision of regulators from the Federal Energy Regulatory Commission (FERC), and the California Division of Safety of Dams (DSOD)