Reevaluation and Reconstruction of California Dams

An adequate dam safety program must include reevaluation of existing dams as performance and hydrologic records accumulate and as the engineering profession advances in its knowledge and understanding of the true action of structures under load. The State of California has administered a dam safety law since 1929. Because dam hazards have increased nearly tenfold due to great population growth and increased numbers of dams, the State's dam safety program was intensified recently. Older dams are being reexamined for adequate spillway capacities and safe stress and stability factors. Presently, 90 of the nearly 1,100 dams in California have been identified as meriting a structural design reevaluation. Spillway capacity reevaluation has been found advisable for 80 dams. Plans and work for reconstruction are in various stages of progress for many of these dams and reevaluation is under way on the remainder. Sever case histories and the emergent corrective actions are briefly described.