The Effectiveness of Fault Zone Regulations in California

In 1990 a study was completed for the California Division of Mines and Geology on the effectiveness of California's fault zone regulations (the Alquist-Priolo Special Studies Zones Act and associated policies and activities). The Act, passed in 1972, instituted the following elements of a statewide mandatory approach to dealing with the hazard of surface fault rupture: state mapping of fault zones (Special Study Zones) where active faults are suspected; local government imposition of the requirement of a geologic study on new building projects within these Zones (with some single family dwellings and low-occupancy structures exempt); review procedures for the studies submitted by an applicant's geologist; prohibition of the siting of projects on active faults; notification of real estate purchasers that a property is located within a Zone. This paper presents the results of that evaluation and comments more broadly on applying the Alquist-Priolo model to other regions and to other geologic hazards.