The Big Tujunga Dam is located at the base of the San Gabriel Mountains and was constructed in the early 1930’s to control floods and to conserve water. In 2004, the California Division of Safety of Dams imposed a seismic restriction on the dam, that reduced the long-term storage to 1,484 acre-feet from the current 5,960 acre-feet. Shimmick improved the safety of the dam by cleaning the foundation, placing mass concrete, modifying the spillway, removing and replacing the dam crest and appurtenant structures, stabilizing the canyon walls with consolidation drilling, grouting, and rock bolts, and establishing a new dam control system.
Shimmick self-performed the majority of the work on the project including the foundation excavation, batching and placing of 90,000 cubic yards of mass concrete with post cooling, construction of valve house and control house, installation of large diameter outlet pipes and valves from 24 to 72 inches, and the electrical power and control.
