The Alquist-Priolo Earthquake Fault Zoning Act was passed in 1972 to mitigate the hazard of surface faulting to structures for human occupancy. This state law was a direct result of the 1971 San Fernando Earthquake, which was associated with extensive surface fault ruptures that damaged numerous homes, commercial buildings, and other structures.
Surface rupture is the most easily avoided seismic hazard.
The Alquist-Priolo Earthquake Fault Zoning Act's main purpose is to prevent the construction of buildings used for human occupancy on the surface trace of active faults. The Act only addresses the hazard of surface fault rupture and is not directed toward other earthquake hazards. The Seismic Hazards Mapping Act , passed in 1990, addresses non-surface fault rupture earthquake hazards, including liquefaction and seismically induced landslides. The maps are distributed to all affected cities, counties , and state agencies for their use in planning and controlling new or renewed construction. Local agencies must regulate most development projects within the zones.